Marine animals of the Sea of ​​Okhotsk. Plants of the Sea of ​​Okhotsk. temperature and salinity

The Sea of ​​Okhotsk is the sea of ​​the Pacific Ocean, separated from it by the Kamchatka Peninsula, the Kuril Islands and the island of Hokkaido.
The sea washes the shores of Russia and Japan.
The area is 1603 thousand km². The average depth is 1780 m, the maximum depth is 3916 m. The western part of the sea is located above the gentle continuation of the continent and has a shallow depth. In the center of the sea are the Deryugin depressions (in the south) and the TINRO depression. In the eastern part there is the Kuril basin, in which the depth is maximum.

Sea of ​​Okhotsk map of the Far East

In the chain of our Far Eastern seas, it occupies a middle position, protrudes quite deeply into the Asian continent, and is separated from the Pacific Ocean by the arc of the Kuril Islands. The Sea of ​​Okhotsk has natural boundaries almost everywhere, and only in the south-west from the Sea of ​​Japan is it separated by conditional lines: Cape Yuzhny - Cape Tyk and in the Laperouse Strait Cape Crillon - Cape Soya. The southeastern boundary of the sea runs from Cape Nosyappu (Hokkaido Island) through the Kuril Islands to Cape Lopatka (Kamchatka), while all passages between the island. Hokkaido and Kamchatka are included in the Sea of ​​Okhotsk. Within these limits, the expanse of the sea extends from north to south from 62°42′ to 43°43′ N. sh. and from west to east from 134°50′ to 164°45′ E. e. The sea is considerably elongated from the southwest to the northeast and expanded approximately in its central part.

GENERAL DATA, GEOGRAPHY, ISLANDS
The Sea of ​​Okhotsk is one of the largest and deepest seas in our country. Its area is 1603 thousand km2, volume 1318 thousand km3, average depth 821 m, maximum depth 3916 m. marginal type.

There are few islands in the Sea of ​​Okhotsk. The largest border island is Sakhalin. The Kuril ridge has about 30 large, many small islands and rocks. The Kuril Islands are located in the seismic activity belt, which includes more than 30 active and 70 extinct volcanoes. Seismic activity is manifested on the islands and under water. In the latter case, tsunami waves are formed. In addition to the named "marginal" islands in the sea, there are the islands of Shantarsky, Spafaryeva, Zavyalova, Yamsky and the small island of Iona - the only one of them remote from the coast.
With a large length, the coastline is indented relatively weakly. At the same time, it forms several large bays (Aniva, Patience, Sakhalin, Academies, Tugursky, Ayan, Shelikhov) and bays (Udskaya, Tauiskaya, Gizhiginskaya and Penzhinskaya).

Atsonopuri volcano, Iturup Island, Kuril Islands

October to May - June Northern part the sea is covered with ice. The southeastern part practically does not freeze.

The coast in the north is strongly indented; in the northeast of the Sea of ​​Okhotsk, its largest bay, Shelikhov Bay, is located. Of the smaller bays of the northern part, the most famous are the Eyriney Bay and the bays of Shelting, Zabiyaka, Babushkin, Kekurny.

In the east, the coastline of the Kamchatka Peninsula is practically devoid of bays. In the west, the coastline is heavily indented, forming the Sakhalin Bay and the Shantar Sea. In the south, the largest are Aniva and Patience bays, Odessa Bay on Iturup Island.

Fishing (salmon, herring, pollock, capelin, navaga, etc.), seafood (Kamchatka crab).

Extraction of hydrocarbon raw materials on the shelf of Sakhalin.

The rivers Amur, Okhota, Kukhtui flow into it.

Sea of ​​Okhotsk Cape Velikan, Sakhalin Island

Main ports:
on the mainland - Magadan, Ayan, Okhotsk (port point); on the island of Sakhalin - Korsakov, on the Kuril Islands - Severo-Kurilsk.
The sea is located on the Okhotsk subplate, which is part of the Eurasian plate. bark under for the most part Sea of ​​Okhotsk continental type.

The Sea of ​​Okhotsk is named after the Okhota River, which in turn comes from Evensk. okat - "river". Previously, it was called Lamsky (from the Evensk. lam - "sea"), as well as the Kamchatka Sea. The Japanese traditionally called this sea Hokkai (北海), literally "North Sea". But since this name now refers to the North Sea of ​​the Atlantic Ocean, they changed the name of the Sea of ​​​​Okhotsk to Ohotsuku-kai (オホーツク海), which is an adaptation of the Russian name to the norms of Japanese phonetics.

Cape Medyay Sea of ​​Okhotsk

Territorial regime
The water area of ​​the Sea of ​​Okhotsk is inland waters, the territorial sea and the exclusive economic zone of two coastal states - Russia and Japan. According to its international legal status, the Sea of ​​Okhotsk is closest to a semi-enclosed sea (Article 122 of the UN Convention on the Law of the Sea), since it is surrounded by two or more states and mainly consists of a territorial sea and an exclusive economic zone of two states, but it is not one, since connected to the rest of the world's oceans not by a single narrow passage, but by a series of passages.
In the central part of the sea, at a distance of 200 nautical miles from the baselines, there is an area elongated in the meridional direction, traditionally referred to in the English-language literature as Peanut Hole, which is not included in the exclusive economic zone and is an open sea outside the jurisdiction of Russia; in particular, any country in the world has the right to fish here and conduct other activities permitted by the UN Convention on the Law of the Sea, excluding activities on the shelf. Since this region is an important element for the reproduction of the population of some species of commercial fish, the governments of some countries expressly prohibit their vessels from fishing in this area of ​​the sea.

On November 13-14, 2013, the Subcommittee established within the framework of the UN Commission on the Limits of the Continental Shelf agreed with the arguments of the Russian delegation as part of the consideration of the application of the Russian Federation to recognize the bottom of the above section of the high seas as a continuation of the Russian continental shelf. On March 15, 2014, the 33rd session of the Commission in 2014 adopted a positive decision on the Russian application, first filed in 2001, and filed in a new edition in early 2013, and the central part of the Sea of ​​Okhotsk outside the exclusive economic zone of the Russian Federation was recognized Russian continental shelf.
Consequently, in the central part, other states are prohibited from extracting "sedentary" biological resources (for example, crab) and developing subsoil. Catching other biological resources, such as fish, is not subject to the restrictions of the continental shelf. Consideration of the application on the merits became possible due to the position of Japan, which, by an official note dated May 23, 2013, confirmed its consent for the Commission to consider the essence of the application without regard to resolving the issue of the Kuril Islands. Sea of ​​Okhotsk

temperature and salinity
In winter, the water temperature at the sea surface ranges from -1.8 to 2.0 °C, in summer the temperature rises to 10-18 °C.
Below the surface layer, at a depth of about 50-150 meters, there is an intermediate cold layer of water, the temperature of which does not change during the year and is about −1.7 °C.
The waters of the Pacific Ocean entering the sea through the Kuril Straits form deep water masses with a temperature of 2.5 - 2.7 ° C (at the very bottom - 1.5-1.8 ° C). In coastal areas with significant river runoff, the water temperature is around 0 °C in winter and 8-15 °C in summer.
The salinity of surface sea waters is 32.8-33.8 ppm. The salinity of the intermediate layer is 34.5‰. Deep waters have a salinity of 34.3 - 34.4 ‰. Coastal waters have a salinity of less than 30 ‰.

RESCUE OPERATION
Incident in December 2010 - January 2011
Icebreaker "Krasin" (year of construction 1976), analogue of the icebreaker "Admiral Makarov" (year of construction 1975)

From December 30, 2010 to January 31, 2011, a rescue operation was carried out in the Sea of ​​Okhotsk, which received extensive media coverage.
The operation itself was large-scale, according to the Deputy Minister of Transport Viktor Olersky and the head of the Federal Agency for Fishery Andrei Krayny, rescue operations on such a scale have not been carried out in Russia for 40 years.
The cost of the operation was in the range of 150-250 million rubles, 6,600 tons of diesel fuel were spent on it.
15 ships, on which there were about 700 people, were captured by ice.
The operation was carried out by the forces of the icebreaking flotilla: the icebreakers Admiral Makarov and Krasin, the icebreaker Magadan and the tanker Victoria worked as auxiliary vessels. The coordinating headquarters of the rescue operation was located in Yuzhno-Sakhalinsk, the work was carried out under the leadership of the Deputy Minister of Transport of the Russian Federation Viktor Olersky.

Most of the vessels got out on their own, the icebreakers rescued four vessels: the trawler Cape Elizabeth, the research vessel Professor Kizevetter (first half of January, Admiral Makarov), the refrigerator Coast of Hope and the mother ship Sodruzhestvo.
The first aid was provided to the seiner Cape Elizabeth, whose captain led his vessel after the introduction of a ban on entering the area.
As a result, Cape Elizabeth was frozen into ice in the area of ​​the Sakhalin Bay. Sea of ​​Okhotsk

The second liberated vessel was the Professor Kizevetter, whose captain, as a result of the investigation, was deprived of his diploma for six months.
In the area of ​​January 14, the icebreakers gathered together the remaining ships in distress, after which the icebreakers escorted both vessels of the caravan on a coupler.
After the “whiskers” of the “Commonwealth” broke off, it was decided to first drive a refrigerator through heavy ice.
The wiring was suspended in the region on January 20 due to weather conditions, but on January 24, the Coast of Hope refrigerator was brought to clean water.
On January 25, after bunkering, the Admiral Makarov returned to escort the mother ship.
On January 26, the towing "whiskers" broke again, we had to lose time for the delivery of new ones by helicopter.
On January 31, the floating base Sodruzhestvo was also taken out of ice captivity, the operation ended at 11:00 Vladivostok time.

Red Cape, Three Brothers Islands

SHELEKHOVA BAY
Shelikhov Bay is a bay of the Sea of ​​Okhotsk between the coast of Asia and the base of the Kamchatka Peninsula. The bay got its name in honor of G. I. Shelikhov.
Length - 650 km, width at the entrance - 130 km, maximum width - 300 km, depths up to 350 m.
In the northern part, the Taigonos Peninsula is divided into the Gizhiginskaya Bay and the Penzhina Bay. The rivers Gizhiga, Penzhina, Yama, Malkachan flow into the bay.
Covered with ice from December to May. The tides are irregular, semi-diurnal. In the Penzhina Bay, they reach the maximum value for the Pacific Ocean.
The bay is rich in fish resources. Fishing objects are herring, halibut, flounder, Far Eastern saffron cod.
In the southern part of the Shelikhov Bay there is a small archipelago of the Yamskiye Islands.
In Shelikhov Bay, tides reach 14 m.

Sakhalin Bay, swans have arrived Sea of ​​Okhotsk

SAKHALIN BAY
Sakhalin Bay is a bay of the Sea of ​​Okhotsk between the coast of Asia north of the mouth of the Amur and the northern tip of Sakhalin Island.
It is wide in the northern part, narrows to the south and passes into the Amur Estuary. Width up to 160 km Nevelskoy Strait connected with the Tatar Strait and Sea of ​​Japan.
From November to June it is covered with ice.
The tides are irregular daily, up to 2-3 m.
Industrial fishing (salmon, cod) is carried out in the waters of the bay.
On the shore of the bay is the port of Moskalvo.

Aniva Bay, Korsakov Port, Sakhalin Island

ANIVA BAY
Aniva is a bay of the Sea of ​​Okhotsk south coast Sakhalin Islands, between the peninsulas of Crillon and Tonino-Anivsky. From the south it is wide open to the La Perouse Strait.
The origin of the name of the bay is most likely connected with the Ainu words "an" and "willow". The first is usually translated as "available, located", and the second as "mountain range, rock, peak"; thus, "Aniva" can be translated as "having ridges" or "located among the ridges (mountains)".
Width 104 km, length 90 km, maximum depth 93 meters. The narrowed part of the bay is known as Salmon Bay. The warm current Soya affects the temperature regime and the dynamics of currents inside the bay, which is changeable.

Sakhalin (Japanese 樺太，Chinese 库页/庫頁) is an island off the east coast of Asia. Part of the Sakhalin region. The largest island in Russia. It is washed by the Sea of ​​Okhotsk and the Sea of ​​Japan. It is separated from mainland Asia by the Tatar Strait (in the narrowest part, the Nevelskoy Strait, it is 7.3 km wide and freezes in winter); from the Japanese island of Hokkaido - by the La Perouse Strait.

The island got its name from the Manchu name of the Amur River - "Sakhalyan-ulla", which means "Black River" - this name, printed on the map, was erroneously attributed to Sakhalin, and in further editions of the maps it was already printed as the name of the island.

The Japanese call Sakhalin Karafuto, this name goes back to the Ainu "kamuy-kara-puto-ya-mosir", which means "land of the god of the mouth." In 1805, a Russian ship under the command of I.F. Kruzenshtern explored most of the coast of Sakhalin and concluded that Sakhalin was a peninsula. In 1808, Japanese expeditions led by Matsuda Denjuro and Mamiya Rinzo proved that Sakhalin was an island. Most European cartographers were skeptical of the Japanese data. For a long time, on various maps, Sakhalin was designated either as an island or a peninsula. Only in 1849 did the expedition under the command of G. I. Nevelsky put an end to this issue, passing on the military transport ship Baikal between Sakhalin and the mainland. This strait was subsequently named after Nevelskoy.

The island is elongated meridionally from Cape Crillon in the south to Cape Elizabeth in the north. The length is 948 km, the width is from 26 km (the Poyasok isthmus) to 160 km (at the latitude of the village of Lesogorskoye), the area is 76.4 thousand km².

BAY OF PATIENCE
Gulf of Patience is a bay of the Sea of ​​Okhotsk off the southeastern coast of Sakhalin Island. In the eastern part it is partially bounded by the Patience Peninsula.
Bay opened in 1643 Dutch navigator M. G. De Vries and named by him the Gulf of Patience, since his expedition had to wait here long time thick fog, which made it impossible to continue sailing.
The bay is 65 km long, about 130 km wide, and up to 50 m deep. The Poronai River flows into the bay.
In winter, the bay freezes over.
The waters of the bay are rich in biological resources, including chum salmon and pink salmon.
The port of Poronaysk is located in Patience Bay. Sea of ​​Okhotsk

- a chain of islands between the Kamchatka Peninsula and the island of Hokkaido, separating the Sea of ​​Okhotsk from the Pacific Ocean in a slightly convex arc.
The length is about 1200 km. The total area is 10.5 thousand km². To the south of them is the state border of the Russian Federation with Japan.
The islands form two parallel ridges: the Greater Kuril and the Lesser Kuril. Includes 56 islands. They are of great military-strategic and economic importance. The Kuril Islands are part of Sakhalin region Russia. The southern islands of the archipelago - Iturup, Kunashir, Shikotan and the Habomai group - are disputed by Japan, which includes them in the Hokkaido prefecture.

Relate to the regions of the Far North
The climate on the islands is marine, rather severe, with cold and long winters, cool summers, and high humidity. The mainland monsoon climate undergoes significant changes here. In the southern part of the Kuril Islands, frosts in winter can reach -25 ° C, the average temperature in February is -8 ° C. In the northern part, the winter is milder, with frosts down to -16 ° C and -7 ° C in February.
In winter, the islands are affected by the Aleutian baric minimum, the effect of which weakens by June.
The average temperature in August in the southern part of the Kuril Islands is +17 °C, in the north - +10 °C.

List of islands with an area of ​​more than 1 km² in the direction from north to south.
Name, Area, km², height, Latitude, Longitude
Great Kuril Ridge
northern group
Atlasova 150 2339 50°52" 155°34"
Shumshu 388 189 50°45" 156°21"
Paramushir 2053 1816 50°23" 155°41"
Antsiferova 7 747 50°12" 154°59"
Macanrushi 49 1169 49°46" 154°26"
Onecotan 425 1324 49°27" 154°46"
Harimkotan 68 1157 49°07" 154°32"
Chirinkotan 6 724 48°59" 153°29"
Ekarma 30 1170 48°57" 153°57"
Shiashkotan 122 934 48°49" 154°06"

middle group
Raikoke 4.6 551 48°17" 153°15"
Matua 52 1446 48°05" 153°13"
Russhua 67 948 47°45" 153°01"
Ushishir Islands 5 388 — —
Ryponkicha 1.3 121 47°32" 152°50"
Yankich 3.7 388 47°31" 152°49"
Ketoi 73 1166 47°20" 152°31"
Simushir 353 1539 46°58" 152°00"
Broughton 7 800 46°43" 150°44"
Black Brothers Islands 37,749 — —
Chirpoy 21 691 46°30" 150°55"
Brat-Chirpoev 16 749 46°28" 150°50"

Southern group
Urup 1450 1426 45°54" 149°59"
Iturup 3318.8 1634 45°00" 147°53"
Kunashir 1495.24 1819 44°05" 145°59"

Small Kuril Ridge
Shikotan 264.13 412 43°48" 146°45"
Polonsky 11.57 16 43°38" 146°19"
Green 58.72 24 43°30" 146°08"
Tanfilyev 12.92 15 43°26" 145°55"
Yuri 10.32 44 43°25" 146°04"
Anuchina 2.35 33 43°22" 146°00"

Geological structure
The Kuril Islands are a typical ensimatic island arc at the edge of the Okhotsk plate. It sits above a subduction zone where the Pacific Plate is being swallowed up. Most of the islands are mountainous. The highest height is 2339 m - Atlasov Island, Alaid volcano. The Kuril Islands are located in the Pacific volcanic ring of fire in a zone of high seismic activity: out of 68 volcanoes, 36 are active, there are hot mineral springs. Large tsunamis are not uncommon. The most famous are the tsunami of November 5, 1952 in Paramushir and the Shikotan tsunami of October 5, 1994. The last major tsunami occurred on November 15, 2006 in Simushir.

DETAILED GEOGRAPHY OF THE SEA OF OKHOTSK, DESCRIPTION OF THE SEA
Basic physical and geographical features.
The straits connecting the Sea of ​​Okhotsk with the Pacific Ocean and the Sea of ​​Japan and their depths are of great importance, since they determine the possibility of water exchange. The Nevelskoy and La Perouse straits are comparatively narrow and shallow. The width of the Nevelskoy Strait (between Capes Lazarev and Pogibi) is only about 7 km. The width of the La Perouse Strait is somewhat larger - about 40 km, and the greatest depth is 53 m.

At the same time, the total width of the Kuril Straits is about 500 km, and the maximum depth of the deepest of them (Bussol Strait) exceeds 2300 m. Thus, the possibility of water exchange between the Sea of ​​Japan and the Sea of ​​Okhotsk is incomparably less than between the Sea of ​​Okhotsk and the Pacific Ocean. However, even the depth of the deepest of the Kuril Straits is much less than the maximum depth of the sea, therefore, r, which separates the sea basin from the ocean.
The most important for water exchange with the ocean are the straits of Bussol and Krusenstern, since they have largest area and depth. The depth of the Bussol Strait was indicated above, and the depth of the Kruzenshtern Strait is 1920 m. The Friza, Fourth Kuril, Rikord and Nadezhda straits are of less importance, the depths of which are more than 500 m. The depths of the remaining straits generally do not exceed 200 m, and the areas are insignificant.

The shores of the Sea of ​​Okhotsk, which are not identical in external forms and structure, in different regions belong to different geomorphological types. From fig. 38 shows that for the most part these are abrasion shores altered by the sea, only in the west of Kamchatka and in the east of Sakhalin there are accumulative shores. In general, the sea is surrounded by high and steep shores. In the north and northwest, rocky ledges descend directly to the sea. A less high, and then a low-lying mainland coast approaches the sea near the Sakhalin Bay. The southeastern coast of Sakhalin is low, and the northeastern coast is low. very abrupt. The northeastern coast of Hokkaido is predominantly low-lying. The coast of the southern part of western Kamchatka has the same character, but its northern part is distinguished by some elevation of the coast.

The bottom relief of the Sea of ​​Okhotsk is varied and uneven. In general, it is characterized by the following main features. The northern part of the sea is a continental shelf - an underwater continuation of the Asian mainland. The width of the continental shoal in the area of ​​the Ayano-Okhotsk coast is approximately 100 miles, in the area of ​​the Uda Bay - 140 miles. Between the meridians of Okhotsk and Magadan, its width increases to 200 miles. From the western edge of the basin of the sea is the island sandbar of Sakhalin, from the eastern edge - the continental shelf of Kamchatka. The shelf occupies about 22% of the bottom area. The rest, most (about 70%) of the sea is located within the continental slope (from 200 to 1500 m), on which separate underwater heights, depressions and trenches stand out.
The deepest southern part of the sea deeper than 2500 m, which is a section of the bed, occupies 8% of the total area. It is elongated as a strip along the Kuril Islands, gradually narrowing from 200 km against about. Iturup up to 80 km against the Krusenstern Strait. Great depths and significant slopes of the bottom distinguish the southwestern part of the sea from the northeastern part, which lies on the continental shelf.
Of the large elements of the relief of the bottom of the central part of the sea, two underwater hills stand out - the Academy of Sciences of the USSR and the Institute of Oceanology. Together with the protrusion of the continental slope, they determine the division of the sea basin into three basins: the northeastern TINRO basin, the northwestern Deryugin basin, and the southern deep-water Kuril basin. The depressions are connected by gutters: Makarov, P. Schmidt and Lebed. To the northeast of the TINRO depression, the Shelikhov Bay trough extends.

Kamchatka, race on the coast of the Sea of ​​Okhotsk, Berengia 2013

The least deep TINRO basin is located to the west of Kamchatka. Its bottom is a plain lying at a depth of about 850 m with a maximum depth of 990 m. The Deryugin Depression is located to the east of the underwater base of Sakhalin. Its bottom is a flat, elevated plain at the edges, lying on average at a depth of 1700 m, the maximum depth of the depression is 1744 m. The deepest is the Kuril basin. This is a huge flat plain, lying at a depth of about 3300 m. Its width in the western part is about 120 miles, its length in the northeast direction is about 600 miles.

The hill of the Institute of Oceanology has a rounded shape, it is extended in the latitudinal direction by almost 200 miles, and in the meridional direction by about 130 miles. The minimum depth above it is about 900 m. The upland of the USSR Academy of Sciences is indented by the peaks of underwater valleys. A remarkable feature of the relief of the hills is the presence of their flat tops, which occupy a large area.

CLIMATE OF THE SEA OF Okhotsk
By its location, the Sea of ​​Okhotsk is located in the monsoon climate zone of temperate latitudes, which is significantly influenced by the physical and geographical features of the sea. Thus, a significant part of it in the west deeply protrudes into the mainland and lies relatively close to the cold pole of the Asian land, so the main source of cold for the Sea of ​​Okhotsk is in the west, and not in the north. The relatively high ridges of Kamchatka make it difficult for warm Pacific air to penetrate. Only in the southeast and south is the sea open to the Pacific Ocean and the Sea of ​​Japan, from where a significant amount of heat enters it. However, the effect of cooling factors is stronger than warming factors, so the Sea of ​​Okhotsk is generally the coldest of the Far Eastern seas. At the same time, its large meridional extent causes significant spatial differences in the synoptic situation and meteorological indicators in each season. In the cold part of the year, from October to April, the Siberian anticyclone and the Aleutian low act on the sea. The influence of the latter extends mainly to the southeastern part of the sea. Such a distribution of large-scale baric systems determines the dominance of strong, stable northwestern and northern winds, often reaching storm strength. Low winds and calms are almost completely absent, especially in January and February. In winter, the wind speed is usually 10-11 m/s.

The dry and cold Asian winter monsoon significantly cools the air over the northern and northwestern regions of the sea. In the coldest month (January), the average air temperature in the northwest of the sea is −20–25°, in the central regions −10–15°, only in the southeastern part of the sea it is −5–6°, which is explained by the warming effect Pacific Ocean.

The autumn-winter time is characterized by the emergence of cyclones of predominantly continental origin. They entail intensification, winds, and sometimes a decrease in air temperature, but the weather remains clear and dry, as they bring in continental air from the chilled mainland of Asia. In March-April, large-scale baric fields are restructured. The Siberian anticyclone is collapsing and the Honolulu High is getting stronger. As a result, during the warm season (May to October), the Sea of ​​Okhotsk is under the influence of the Honolulu High and the area of ​​low pressure located over Eastern Siberia. In accordance with this distribution of the centers of action of the atmosphere, weak southeasterly winds prevail over the sea at this time. Their speed usually does not exceed 6-7 m/s. Most often, these winds are observed in June and July, although stronger northwesterly and northerly winds are sometimes observed in these months. In general, the Pacific (summer) monsoon is weaker than the Asian (winter) monsoon, since the horizontal pressure gradients are small in the warm season.

bay Nagaevo

In summer, the air warms up unevenly over the entire sea. The average monthly air temperature in August decreases from southwest to northeast from 18° in the south to 12–14° in the center and to 10–10.5° in the northeast of the Sea of ​​Okhotsk. During the warm season over southern part oceanic cyclones quite often pass through the seas, which are associated with an increase in wind to a storm, which can last up to 5-8 days. The predominance of southeasterly winds in the spring-summer season leads to significant cloudiness, precipitation, and fog. Monsoon winds and stronger winter cooling of the western part of the Sea of ​​Okhotsk compared to the eastern part are important climatic features of this sea.
Quite a few mostly small rivers flow into the Sea of ​​Okhotsk, therefore, with such a significant volume of its waters, the continental runoff is relatively small. It is equal to approximately 600 km3/year, while about 65% is provided by the Amur. Other relatively large rivers - Penzhina, Okhota, Uda, Bolshaya (in Kamchatka) - bring much less fresh water into the sea. It arrives mainly in spring and early summer. At this time, the influence of continental runoff is most noticeable, mainly in the coastal zone, near the mouth areas. major rivers.

Geographical position, large length along the meridian, monsoonal change of winds and good connection of the sea with the Pacific Ocean through the Kuril Straits are the main natural factors that most significantly affect the formation of the hydrological conditions of the Sea of ​​Okhotsk. The values ​​of heat input and output in the sea are determined mainly by radiative heating and cooling of the sea. The heat brought by the Pacific waters is of subordinate importance. However, for the water balance of the sea, the inflow and outflow of water through the Kuril Straits plays a decisive role. The details and quantitative indicators of water exchange through the Kuril Straits have not yet been studied enough, but the main ways of water exchange through the straits are known. The flow of surface Pacific waters into the Sea of ​​Okhotsk occurs mainly through the northern straits, in particular through the First Kuril. In the straits of the middle part of the ridge, both the inflow of Pacific waters and the outflow of Okhotsk waters are observed. Thus, in the surface layers of the Third and Fourth Kuril Straits, apparently, there is a runoff of water from the Sea of ​​Okhotsk, while in the bottom layers there is an inflow, and in the Bussol Strait, on the contrary: in the surface layers, an inflow, in the deep layers, a drain. In the southern part of the ridge, mainly through the straits of Ekaterina and Friza, there is mainly a runoff of water from the Sea of ​​Okhotsk. The intensity of water exchange through the straits can vary significantly. In general, in the upper layers of the southern part of the Kuril ridge, the runoff of the Sea of ​​Okhotsk waters predominates, and in the upper layers of the northern part of the ridge, Pacific waters enter. In the deep layers, the influx of Pacific waters generally prevails.
The inflow of Pacific waters largely affects the distribution of temperature, salinity, formation of the structure and general circulation of the waters of the Sea of ​​Okhotsk.

Cape Stolbchaty, Kunashir Island, Kuril Islands

Hydrological characteristic.
The sea surface temperature generally decreases from south to north. In winter, almost everywhere, the surface layers cool down to a freezing temperature of −1.5–1.8°. Only in the southeastern part of the sea does it remain around 0°, and near the northern Kuril Straits, the water temperature reaches 1–2° under the influence of the Pacific waters penetrating here.

Spring warming at the beginning of the season mainly goes to the melting of ice, only towards the end of it does the water temperature begin to rise. In summer, the distribution of water temperature on the sea surface is quite diverse (Fig. 39). In August, the warmest (up to 18-19 °) waters adjacent to the island. Hokkaido. In the central regions of the sea, the water temperature is 11-12°. The coldest surface waters are observed near about. Iona, near Cape Pyagin and near the Kruzenshtern Strait. In these areas, the water temperature is kept within 6-7 °. The formation of local centers of increased and decreased water temperature on the surface is mainly associated with the redistribution of heat by currents.

The vertical distribution of water temperature varies from season to season and from place to place. In the cold season, the change in temperature with depth is less complex and varied than in warm seasons. In winter, in the northern and central regions of the sea, water cooling extends to horizons of 100–200 m. rises to 1–2° in the southern part of the sea; near the Kuril Straits, the water temperature drops from 2.5–3.0° on the surface to 1.0–1.4° at 300–400 m horizons and then gradually rises to 1, 9-2.4° at the bottom.

In summer, surface waters are heated to a temperature of 10-12°C. In the subsurface layers, the water temperature is slightly lower than on the surface. A sharp decrease in temperature to values ​​of −1.0–1.2° is observed between horizons of 50–75 m; in horizons of 200-250 m it is 1.5-2.0°. From here, the temperature of the water almost does not change to the bottom. In the southern and southeastern parts of the sea, along the Kuril Islands, the water temperature drops from 10–14° at the surface to 3–8° at a 25 m horizon, then to 1.6–2.4° at a 100 m horizon and down to 1 .4—2.0° at the bottom. The vertical temperature distribution in summer is characterized by a cold intermediate layer, a remnant of the winter cooling of the sea (see Fig. 39). In the northern and central regions of the sea, the temperature in it is negative, and only near the Kuril Straits does it have positive values. In different areas of the sea, the depth of the cold intermediate layer is different and varies from year to year.

The distribution of salinity in the Sea of ​​Okhotsk varies relatively little with seasons and is characterized by its increase in the eastern part, which is under the influence of Pacific waters, and its decrease in the western part, desalinated by continental runoff (Fig. 40). In the western part, salinity on the surface is 28–31‰, and in the eastern part it is 31–32‰ or more (up to 33‰ near the Kuril ridge). In the northwestern part of the sea, due to desalination, the salinity on the surface is 25‰ or less, and the thickness of the desalinated layer is about 30–40 m.
Salinity increases with depth in the Sea of ​​Okhotsk. At the horizons of 300-400 m in the western part of the sea, the salinity is 33.5‰, and in the eastern part it is about 33.8‰. At the 100 m horizon, the salinity is 34.0‰, and further towards the bottom it increases insignificantly, by only 0.5–0.6‰. In individual bays and straits, salinity and its stratification may differ significantly from the open sea, depending on local hydrological conditions.

Temperature and salinity determine the values ​​and distribution of the density of the waters of the Sea of ​​Okhotsk. In accordance with this, denser waters are observed in winter in the northern and central ice-covered regions of the sea. Some less density in a relatively warm Kuril region. In summer, the water density decreases, its lowest values ​​are confined to the zones of influence of coastal runoff, and the highest values ​​are observed in the areas of distribution of Pacific waters. Density increases with depth. In winter, it rises relatively slightly from the surface to the bottom. In summer, its distribution in the upper layers depends on the temperature values, and on the middle and lower horizons on salinity. IN summer time a noticeable density stratification of the waters along the vertical is created, the density increases especially significantly at the horizons of 25-35-50 m, which is associated with the heating of waters in open areas and desalination near the coast.

Cape Nyuklya (Sleeping Dragon) near Magadan

The possibilities for the development of water mixing in the Sea of ​​Okhotsk are largely related to the peculiarities of the vertical distribution of oceanological characteristics. Wind mixing is carried out in the ice-free season. It flows most intensively in spring and autumn, when winds blow over the sea. strong winds, and the stratification of waters is not yet very pronounced. At this time, wind mixing extends to a horizon of 20–25 m from the surface. Strong cooling and powerful ice formation in the autumn-winter time contributes to the development of convection in the Sea of ​​Okhotsk. However, it proceeds differently in its different regions, which is explained by the features of the bottom topography, climatic differences, the inflow of Pacific waters, and other factors. Thermal convection in most of the sea penetrates up to 50-60 m, since the summer heating of surface waters, and in the zones of influence of coastal runoff and significant freshening, cause vertical stratification of waters, which is most pronounced on the indicated horizons. The increase in the density of surface waters due to cooling and the resulting convection are not able to overcome the stability maximum located at the aforementioned horizons. In the southeastern part of the sea, where Pacific waters mainly spread, relatively weak vertical stratification is observed; therefore, thermal convection propagates here to 150–200 m horizons, where it is limited by the density structure of the waters.
Intense ice formation over most of the sea excites an enhanced thermohaline winter vertical circulation. At depths of up to 250-300 m, it spreads to the bottom, and its penetration to greater depths is prevented by the maximum stability that exists here. In areas with a rugged bottom topography, the spread of density mixing into the lower horizons is facilitated by the sliding of water along the slopes. In general, the Sea of ​​Okhotsk is characterized by good mixing of its waters.

Features of the vertical distribution of oceanological characteristics, mainly water temperature, indicate that the Sea of ​​Okhotsk is characterized by a subarctic water structure, in which cold and warm intermediate layers are well pronounced in summer. A more detailed study of the subarctic structure in this sea has shown that the Sea of ​​Okhotsk, Pacific, and Kuril varieties of the subarctic water structure exist in it. With the same nature of the vertical structure, they have quantitative differences in the characteristics of water masses.

Based on the analysis of T, S-curves in combination with a consideration of the vertical distribution of oceanological characteristics in the Sea of ​​Okhotsk, the following water masses are distinguished. Surface water mass with spring, summer and autumn modifications. It represents the upper maximum of stability, mainly due to temperature. This water mass is characterized by temperature and salinity corresponding to each season, on the basis of which its mentioned modifications are distinguished.
The Sea of ​​Okhotsk water mass is formed in winter from surface water and in spring, summer and autumn it manifests itself in the form of a cold intermediate layer flying between horizons of 40–150 m. This water mass is characterized by a fairly uniform salinity (about 32.9–31.0 place to place temperature. In most of the sea, its temperature is below 0° and reaches -1.7°, and in the area of ​​the Kuril Straits it is above 1°.

The intermediate water mass is formed mainly due to the sinking of water along the slopes of the bottom, within the sea it is located from 100-150 to 400-700 m and is characterized by a temperature of 1.5 ° and a salinity of 33.7‰. This water mass is distributed almost everywhere, except for the northwestern part of the sea, Shelikhov Bay and some areas along the coast of Sakhalin, where the Sea of ​​Okhotsk water mass reaches the bottom. The thickness of the intermediate water mass generally decreases from south to north.

The deep Pacific water mass is the water of the lower part of the warm layer of the Pacific Ocean, which enters the Sea of ​​Okhotsk at horizons below 800–2000 m, i.e., below the depth of the waters descending in the straits, and manifests itself in the sea as a warm intermediate layer. This water mass is located on the horizons of 600-1350 m, has a temperature of 2.3°C and a salinity of 34.3‰. However, its characteristics change in space. The highest values ​​of temperature and salinity are observed in the northeastern and partly in the northwestern regions, which is associated here with the rise of waters, and the smallest values ​​of the characteristics are characteristic of the western and southern regions, where the waters sink.
The water mass of the Southern Basin is of Pacific origin and represents the deep water of the northwestern part of the Pacific Ocean from a horizon of 2300 m, corresponding to the maximum depth of the threshold in the Kuril Straits (Bussol Strait). The considered water mass generally fills the named basin from the horizon of 1350 m to the bottom. It is characterized by a temperature of 1.85° and a salinity of 34.7‰, which vary only slightly with depth.
Among the identified water masses, the Sea of ​​Okhotsk and the deep Pacific are the main ones and differ from each other not only in thermohaline, but also in hydrochemical and biological indicators.

Under the influence of winds and water inflow through the Kuril Straits, characteristic features of the system of non-periodic currents of the Sea of ​​Okhotsk are formed (Fig. 41). The main one is the cyclonic system of currents, covering almost the entire sea. It is due to the predominance of cyclonic circulation of the atmosphere over the sea and the adjacent part of the Pacific Ocean. In addition, stable anticyclonic circulations and extensive areas of cyclonic water circulation can be traced in the sea.

At the same time, a narrow strip of stronger coastal currents stands out quite clearly, which, continuing each other, seem to bypass the coastline of the sea counterclockwise; the warm Kamchatka current directed to the north into Shelikhov Bay; the flow of the western, and then the south-western direction along the northern and north- western coasts seas; the steady East Sakhalin Current going south, and the rather strong Soya Current entering the Sea of ​​Okhotsk through the Laperouse Strait.
On the southeastern periphery of the cyclonic circulation of the Central Part of the Sea, a branch of the Northeast Current is distinguished, opposite in direction to the Kuril Current (or Oyashio) in the Pacific Ocean. As a result of the existence of these streams, stable areas of convergence of currents are formed in some of the Kuril Straits, which leads to subsidence of waters and has a significant effect on the distribution of oceanological characteristics not only in the straits, but also in the sea itself. And finally, one more feature of the circulation of the waters of the Sea of ​​Okhotsk is two-way stable currents in most of the Kuril straits.

Non-periodic currents on the surface of the Sea of ​​Okhotsk are most intense off the western coast of Kamchatka (11–20 cm/s), in Sakhalin Bay (30–45 cm/s), in the region of the Kuril Straits (15–40 cm/s), over the South Basin ( 11-20 cm/s) and during the Soya (up to 50-90 cm/s). In the central part of the cyclonic region, the intensity of horizontal transport is much less than on its periphery. In the central part of the sea, velocities vary from 2 to 10 cm/s, with velocities below 5 cm/s predominating. A similar picture is also observed in the Shelikhov Bay, rather strong currents near the coast (up to 20–30 cm/s) and low velocities in the central part of the cyclonic gyre.

Periodic (tidal) currents are also well expressed in the Sea of ​​Okhotsk. Here their various types are observed: semidiurnal, diurnal and mixed with a predominance of semidiurnal or diurnal components. The velocities of tidal currents are different - from a few centimeters to 4 m/s. Away from the coast, the current velocities are low (5–10 cm/s). In straits, bays, and off the coast, the velocities of tidal currents increase significantly; for example, in the Kuril Straits they reach 2–4 m/s.
The tides of the Sea of ​​Okhotsk have a very complex character. A tidal wave enters from the south and southeast from the Pacific Ocean. The semidiurnal wave moves to the north, and at the 50° parallel it is divided into two branches: the western one turns to the northwest, forming amphidromic regions to the north of Cape Terpeniya and in the northern part of Sakhalin Bay, the eastern one moves towards the Shelikhov Bay, at the entrance to which arises another amphidrome. The diurnal wave also moves north, but at the latitude of the northern tip of Sakhalin it is divided into two parts: one enters Shelikhov Bay, the other reaches the northwestern coast.

There are two main types of tides in the Sea of ​​Okhotsk: diurnal and mixed. The most common are diurnal tides. They are observed in the Amur Estuary, Sakhalin Bay, the Kuril Islands, off the western coast of Kamchatka and in Penzhinsky Bay. Mixed tides are observed on the northern and northwestern coasts of the sea and in the area of ​​the Shantar Islands.
The highest tides were recorded in the Penzhina Bay near Cape Astronomichesky (up to 13 m). These are the highest tides for the entire coast of the USSR. In second place is the region of the Shantar Islands, where the tide exceeds 7 m. The tides are very significant in the Sakhalin Bay and in the Kuril Straits. In the northern part of the sea, the tides reach up to 5 m. In the southern part of the sea, the tides are 0.8–2.5 m. In general, tidal level fluctuations in the Sea of ​​Okhotsk are very significant and have a significant effect on its hydrological regime, especially in the coastal zone.
In addition to tidal fluctuations, surge fluctuations in the level are also well developed here. They occur mainly during the passage of deep cyclones over the sea. Surge rises in the level reach 1.5–2 m. The largest surges are noted on the coast of Kamchatka and in the Gulf of Patience.

The significant size and great depths of the Sea of ​​Okhotsk, frequent and strong winds over it determine the development of large waves here. The sea is especially stormy in autumn, and in ice-free areas in winter. These seasons account for 55–70% of storm waves, including those with wave heights of 4–6 m, and the highest wave heights reach 10–11 m. The most restless are the southern and southeastern regions of the sea, where the average frequency of storm waves is 35 -50%, and in the northwestern part it decreases to 25-30%. In case of strong waves, a crowd forms in the straits between the Kuril Islands and between the Shantar Islands.

Severe and long winters with strong northwest winds contribute to the development of intense ice formation in the Sea of ​​Okhotsk. The ice of the Sea of ​​Okhotsk is exclusively of local formation. There are both fixed ice (fast ice) and floating ice, which are the main form of sea ice. In one quantity or another, ice is found in all areas of the sea, but in summer the entire sea is cleared of ice. The exception is the region of the Shantar Islands, where ice can persist in summer.
Ice formation begins in November in the bays and bays of the northern part of the sea, in the coastal part of the island. Sakhalin and Kamchatka. Then ice appears in the open part of the sea. In January and February, ice covers the entire northern and middle parts of the sea. In ordinary years, the southern boundary of a relatively stable ice cover curves northward from the La Perouse Strait to Cape Lopatka. The extreme southern part of the sea never freezes. However, due to the winds, significant masses of ice are carried into it from the north, often accumulating near the Kuril Islands.

From April to June there is a destruction and gradual disappearance of the ice cover. On average, the ice in the sea disappears in late May - early June. The northwestern part of the sea, due to the currents and the configuration of the coasts, is most of all clogged with ice, which remains there until July. Consequently, the ice cover in the Sea of ​​Okhotsk persists for 6-7 months. Floating ice covers more than three-quarters of the sea's surface. Close-knit ice in the northern part of the sea is a serious obstacle to navigation even for icebreakers. The total duration of the ice period in the northern part of the sea reaches 280 days a year.

The southern coast of Kamchatka and the Kuril Islands are areas with low ice cover, where ice stays on average no more than three months a year. The thickness of the ice that grows during the winter reaches 0.8-1.0 m. Strong storms and tidal currents break the ice cover in many areas of the sea, forming hummocks and large leads. In the open part of the sea, solid immovable ice is never observed; usually, ice drifts here in the form of vast fields with numerous leads. Part of the ice from the Sea of ​​Okhotsk is carried into the ocean, where it breaks up and melts almost immediately. In severe winters, floating ice is pressed against the Kuril Islands by northwestern winds and clogs some of the straits. Thus, in the winter time in the Sea of ​​Okhotsk there is no such place where an encounter with ice would be completely excluded.

hydrochemical conditions.
Due to the constant water exchange with the Pacific Ocean through the deep Kuril Straits, the chemical composition of the waters of the Sea of ​​Okhotsk generally does not differ from that of the ocean. The values ​​and distribution of dissolved gases and biogenic substances in the open areas of the sea are determined by the inflow of Pacific waters, and in the coastal part, coastal runoff has a certain effect.

The Sea of ​​Okhotsk is rich in oxygen, but its content is not the same in different areas of the sea and varies with depth. A large amount of oxygen is dissolved in the waters of the northern and central parts of the sea, which is explained by the abundance of oxygen-producing phytoplankton here. In particular, in the central part of the sea, the development of plant organisms is associated with the rise of deep waters in the zones of convergence of currents. The waters of the southern regions of the sea contain a smaller amount of oxygen, since the Pacific waters, which are relatively poor in phytoplankton, come here. The highest content (7-9 ml/l) of oxygen is observed in the surface layer, deeper it gradually decreases and is 6-7 ml/l at the 100 m horizon, and 3.2-4.7 ml/l at the 500 m horizon, further, the amount of this gas decreases very rapidly with depth and reaches a minimum (1.2–1.4 ml/l) at horizons of 1000–1300 m; however, in deeper layers it increases to 1.3–2.0 ml/l. The oxygen minimum is confined to the deep Pacific water mass.

The surface layer of the sea contains 2–3 µg/l of nitrites and 3–15 µg/l of nitrates. With depth, their concentration increases, and the content of nitrites reaches a maximum at the horizons of 25-50 m, and the amount of nitrates sharply increases here, but the greatest values ​​of these substances are noted at the horizons of 800-1000 m, from where they slowly decrease to the bottom. The vertical distribution of phosphates is characterized by an increase in their content with depth, which is especially noticeable from horizons of 50–60 m, and the maximum concentration of these substances is observed in the bottom layers. In general, the amount of nitrites, nitrates and phosphates dissolved in the waters of the sea increases from north to south, which is mainly due to the rise of deep waters. Local features of hydrological and biological conditions (water circulation, tides, degree of development of organisms, etc.) form the regional hydrochemical features of the Sea of ​​Okhotsk.

Economic use.
The economic significance of the Sea of ​​Okhotsk is determined by the use of its natural resources and maritime transport. The main wealth of this sea is game animals, especially fish. Here, mainly its most valuable species are mined - salmon (chum, pink salmon, sockeye salmon, coho salmon, chinook salmon) and their caviar. Currently, salmon stocks have decreased, so their production has decreased. The catch of this fish is limited. In addition, herring, cod, flounder and other types of sea fish are caught in the sea in limited quantities. The Sea of ​​Okhotsk is the main area for crab fishing. Squid are being harvested in the sea. One of the largest herds of fur seals is concentrated on the Shantar Islands, the extraction of which is strictly regulated.

Sea transport lines connect the Okhotsk ports of Magadan, Nagaevo, Ayan, Okhotsk with other Soviet and foreign ports. Various cargoes come here from different districts Soviet Union and foreign countries.

The largely studied Sea of ​​Okhotsk still needs to solve various natural problems. In terms of their hydrological aspects, an essential place is occupied by studies of the water exchange of the sea with the Pacific Ocean, general circulation, including vertical movements of waters, their fine structure and eddy-like movements, ice conditions, especially in the prognostic direction of the timing of ice formation, the direction of ice drift, etc. The solution of these and other problems will contribute to the further development of the Sea of ​​Okhotsk.

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SOURCE OF INFORMATION AND PHOTO:
Team Nomads
http://tapemark.narod.ru/more/18.html
Melnikov A.V. Geographical names of the Russian Far East: Toponymic Dictionary. — Blagoveshchensk: Interra-Plus (Interra+), 2009. — 55 p.
Shamraev Yu. I., Shishkina L. A. Oceanology. L.: Gidrometeoizdat, 1980.
Lithosphere of the Sea of ​​Okhotsk
The Sea of ​​Okhotsk in the book: A. D. Dobrovolsky, B. S. Zalogin. Seas of the USSR. Moscow publishing house. un-ta, 1982.
Leontiev V.V., Novikova K.A. Toponymic Dictionary of the North-East of the USSR. - Magadan: Magadan book publishing house, 1989, p 86
Leonov A.K. Regional oceanography. - Leningrad, Gidrometeoizdat, 1960. - T. 1. - S. 164.
Wikipedia site.
Magidovich IP, Magidovich VI Essays on the history of geographical discoveries. - Enlightenment, 1985. - T. 4.
http://www.photosight.ru/
photo: O.Smoly, A.Afanasiev, A.Gill, L.Golubtsova, A.Panfilov, T.Selena.

This natural reservoir is considered one of the deepest and largest in Russia. The coolest Far Eastern sea is located between the waters of the Bering and the Sea of ​​Japan.

The Sea of ​​Okhotsk separates the territories of the Russian Federation and Japan and is the most important port point for our country.

After reviewing the information in the article, you can learn about the richest resources of the Sea of ​​​​Okhotsk and the history of the formation of the reservoir.

About the name

Previously, the sea had other names: Kamchatskoe, Lamskoe, Hokkai among the Japanese.

The current name of the sea was given by the name of the Okhota River, which in turn comes from the Even word "okat", which translates as "river". The former name (Lamskoe) also came from the Even word "lam" (translated as "sea"). Hokkai literally translates to "North Sea" in Japanese. However, due to the fact that this Japanese name now refers to the sea of ​​the North Atlantic Ocean, its name was changed to Ohotsuku-kai, which is an adaptation of the Russian name to the norms of Japanese phonetics.

Geography

Before proceeding to the description of the richest resources of the Sea of ​​Okhotsk, we briefly present its geographical position.

The reservoir, located between the Bering and the Seas of Japan, strongly goes into the land of the mainland. The arc of the Kuril Islands separates the waters of the sea from the waters of the Pacific Ocean. The reservoir has for the most part natural boundaries, and its conditional borders are with the Sea of ​​Japan.

The Kuriles, which are about 3 dozen small areas of land and separating the ocean from the sea, are located in a seismically hazardous zone due to the presence of a large number of volcanoes on them. In addition, the waters of these two natural reservoirs are separated by the island of Hokkaido and Kamchatka. The largest island in the Sea of ​​Okhotsk is Sakhalin. The largest rivers flowing into the sea are Amur, Okhota, Bolshaya and Penzhina.

Description

The area of ​​the sea is approximately 1603 thousand square meters. km, the volume of water - 1318 thousand cubic meters. km. The maximum depth is 3916 meters, the average is 821 m. The type of sea is mixed, continental-marginal.

Several bays pass along the rather even coastal boundary of the reservoir. The northern part of the coast is represented by many rocks and rather sharp cliffs. Storm is a frequent and quite common occurrence for this sea.

Features of nature and all resources of the Sea of ​​Okhotsk are partly related to climate conditions and unusual terrain.

For the most part, the seashores are rocky and high. From the sea, from afar on the horizon, they are distinguished by black stripes, framed on top by brownish green spots of sparse vegetation. Only in some places (the western coast of Kamchatka, the northern part of Sakhalin), the coastline is low, fairly wide areas.

The bottom in some respects is similar to the bottom of the Sea of ​​Japan: in many places there are hollows under water, which indicate that the area of ​​\u200b\u200bthe present sea in the Quaternary period was above sea level, and huge rivers flowed in this place - Penzhina and Amur.

Sometimes, during earthquakes, waves appear in the ocean, reaching several tens of meters in height. There is an interesting historical fact connected with this. In 1780, one of these waves during an earthquake deep into the island of Urup (300 meters from the coast) brought the ship "Natalia", which remained on land. This fact is confirmed by the record preserved from those times.

Geologists believe that the territory of the eastern part of the sea is one of the most "troubled" areas on the globe. And today quite large movements of the earth's crust are taking place here. In this part of the ocean, underwater earthquakes and volcanic eruptions are often observed.

A bit of history

The rich natural resources of the Sea of ​​Okhotsk began to attract the attention of people from its very discovery, which occurred during the first campaigns of the Cossacks to the Pacific Ocean through Siberia. It was then called the Lam Sea. Then, after the discovery of Kamchatka, trips along the sea and the coast to this richest peninsula and to the mouth of the river. Penzhins have become more frequent. In those days, the sea already bore the names Penzhinskoe and Kamchatskoe.

After leaving Yakutsk, the Cossacks moved east not straight through the taiga and mountains, but along the winding rivers and channels between them. Such a caravan path eventually led them to a river called the Hunt, and along it they were already moving to the seashore. That is why this reservoir was named Okhotsk. Since then, many significant and important major centers. The name that has been preserved since then testifies to the important historical role of the port and the river, from which people began the development of this vast, richest sea area.

Features of nature

The natural resources of the Sea of ​​Okhotsk are quite attractive. This is especially true for the regions of the Kuril Islands. This is a very special world, consisting of a total of 30 large and small islands. This range also includes rocks of volcanic origin. Today the islands have active volcanoes(about 30), which clearly indicates that the bowels of the earth are here and now restless.

Some islands have underground hot springs (temperature up to 30-70°C), many of which have healing properties.

Very severe climatic conditions for life on the Kuril Islands (especially in the northern part). Fogs are kept here for a long time, and in winter very often there are strong storms.

Rivers

Many rivers, mostly small ones, flow into the Sea of ​​Okhotsk. This is the reason for the relatively small continental flow (about 600 cubic km per year) of water into it, and about 65% of it belongs to the Amur River.

Other relatively large rivers are the Penzhina, Uda, Okhota, Bolshaya (in Kamchatka), which carry a much smaller volume of fresh water into the sea. Water flows to a greater extent in spring and early summer.

Fauna

The biological resources of the Sea of ​​Okhotsk are very diverse. This is the most biologically productive sea in Russia. It provides 40% of domestic and more than half of the Far Eastern catches of fish, crustaceans and mollusks. At the same time, it is believed that the biological potential of the sea is underutilized today.

A huge variety of depths and bottom topography, hydrological and climatic conditions in certain parts of the sea, a good supply of fish food - all this determined the richness of the ichthyofauna of these places. The northern part of the sea contains 123 species of fish in its waters, the southern part - 300 species. Approximately 85 species are endemic. This is the Sea - real paradise for lovers of sea fishing.

Fishing, seafood production and production of salmon caviar are actively developing on the territory of the sea. The inhabitants of the sea waters of this region: pink salmon, chum salmon, cod, sockeye salmon, flounder, coho, pollock, herring, saffron cod, chinook salmon, squid, crabs. On the Shantar Islands, hunting (limited) for fur seals is carried out, and the extraction of kelp, mollusks and sea urchins is also becoming popular.

Of the animals, the white whale, seal and seal are of particular commercial value.

Flora

The resources of the Sea of ​​Okhotsk are inexhaustible. Flora of the reservoir: arctic species predominate in the northern part, species of the temperate region prevail in the southern part. Plankton (larvae, mollusks, crustaceans, etc.) provides abundant food for fish throughout the year. The phytoplankton of the sea is represented mainly by diatoms, and the bottom flora contains many species of red, brown and green algae, as well as extensive meadows of sea grass. In total, the composition of the coastal flora of the Sea of ​​Okhotsk includes about 300 species of vegetation.

In comparison with the Bering Sea, the benthic fauna here is more diverse, and in comparison with the Sea of ​​Japan, it is less rich. The main food fields for deep-sea fish are the northern shallow waters, as well as the East Sakhalin and western Kamchatka shelves.

Mineral resources

The mineral resources of the Sea of ​​Okhotsk are especially rich. Only the water of the sea contains almost all the elements of the table of D. I. Mendeleev.

The bottom of the sea has exceptional reserves of globigerin and diamond silts, consisting mainly of shells of unicellular tiny algae and protozoa. Sludge is a valuable raw material for the production of insulating building materials and high quality cement.

The shelf of the sea is also promising for prospecting for hydrocarbon deposits. The rivers of the Aldan-Okhotsk watershed and the lower reaches of the Amur have long been famous for placers of valuable metals, which indicates that there is a possibility of finding underwater ore deposits in the sea. Perhaps there are still many unexplored raw materials in the Sea of ​​Okhotsk.

It is known that the lower shelf horizons and part of the continental slope adjoining them are enriched in phosphorite concretions. There is another more realistic prospect - the extraction of rare elements contained in the bone remains of mammals and fish, and such accumulations are found in deep-sea sediments of the Yuzhno-Okhotskaya basin.

It is impossible to keep silent about amber. The very first finds of this mineral on the eastern coast of Sakhalin date back to the middle of the 19th century. At that time, representatives of the Amur expedition worked here. It should be noted that Sakhalin amber is very beautiful - it is perfectly polished, cherry-red and highly appreciated by specialists. The largest pieces of wood fossil resin (up to 0.5 kg) were discovered by geologists near the village of Ostromysovsky. Amber is also found in the oldest deposits of the Taigonos Peninsula, as well as in Kamchatka.

Conclusion

In short, the resources of the Sea of ​​Okhotsk are extremely rich and diverse, it is impossible to list all of them, let alone describe them.

Today, the importance of the Sea of ​​Okhotsk in the national economy is determined by the use of its richest natural resources and sea transportation. The main wealth of this sea are game animals, primarily fish. However, already today, a rather high level of danger of pollution of the sea fishing zones with oil products as a result of discharges of oily waters by fishing vessels creates a situation that requires certain measures to increase the level of environmental safety of the work being carried out.

The Sea of ​​Okhotsk is a marginal sea in the northwestern part of the Pacific Ocean.

The Sea of ​​Okhotsk is almost completely limited by continental and island coastlines, located between the coasts of Eastern Eurasia, its Kamchatka Peninsula, the chain of the Kuril Islands, the northern tip of Hokkaido Island and the eastern part of Sakhalin Island. It is separated from the Sea of ​​Japan in the Tatar Strait along the line of Cape Sushchev - Cape Tyk, in the La Perouse Strait along the line of Cape Crillon - Cape Soya. The border with the Pacific Ocean runs from Cape Nosyappu (Hokkaido Island) along the Kuril Islands to Cape Lopatka (Kamchatka Peninsula). The area is 1603 thousand km2, the volume is 1316 thousand km3, the greatest depth is 3521 m.

The coastline is slightly indented, the largest bays are: Academies, Aniva, Sakhalin, Patience, Tugursky, Ulbansky, Shelikhova (with Gizhiginskaya and Penzhinskaya lips); Tauyskaya, Udskaya lips. The north, northwestern shores are predominantly elevated and rocky, mostly abrasion, in some places strongly altered by the sea; in Kamchatka, in the northern parts of Sakhalin and Hokkaido, as well as in the mouths of large rivers - low-lying, largely accumulative. Most of the islands are located near the coast: Zavyalova, Spafareva, Shantar, Yamsky, and only small island Iona is on the high seas.

Relief and geological structure of the bottom.

The bottom relief is very diverse. The shelf occupies about 40% of the bottom area, it is most common in the northern part, where it belongs to the submerged type, its width varies from 180 km near the Ayano-Okhotsk coast to 370 km in the Magadan region. Up to 50% of the bottom area falls on the continental slope (depths up to 2000 m). In the south part is the deepest (more than 2500 m) area of ​​the sea, which occupies St. 8% sq. bottom. In the central part of the Sea of ​​Okhotsk, the rises of the Academy of Sciences and the Institute of Oceanology are distinguished, dividing the sea basin into 3 basins (troughs): TINRO in the northeast (depth up to 990 m), Deryugin in the west (up to 1771 m) and the deepest - Kuril in the south (up to 3521 m).

The basement of the basin of the Sea of ​​Okhotsk is heterogeneous; the thickness of the earth's crust is 10-40 km. The uplift in the central part of the sea has a continental crust; the uplift in the southern part of the sea consists of two uplifted blocks separated by a trough. The deep-water Kuril Basin with oceanic crust, according to some researchers, is a captured section of the oceanic plate, according to others, it is a back-arc basin. The Deryugin and TINRO basins are underlain by a transitional type of crust. In the Deryugin Basin, an increased heat flow compared to the rest of the territory and hydrothermal activity have been established, as a result of which barite structures have been formed. The sedimentary cover has the greatest thickness in the basins (8-12 km) and on the northern and eastern shelves, it is composed of Cenozoic terrigenous and siliceous-terrigenous deposits (near the Kuril Islands with an admixture of tuffaceous material). The ridge of the Kuril Islands is characterized by intense seismicity and modern volcanism. Earthquakes regularly observed in the area often cause the formation of dangerous tsunami waves, for example in 1958.

Climate.

The Sea of ​​Okhotsk is characterized by a monsoonal climate of temperate latitudes. The sea is located relatively close to the Siberian Pole of Cold, and the ridges of Kamchatka block the way for warm Pacific air masses, so it is generally cold in this area. From October to April, the sea is dominated by the combined influence of the Asian anticyclone and the Aleutian depression with strong stable northwestern and northern winds at speeds of 10-11 m/s, often reaching storm strength. Most cold month- January, temperature from -5 to -25 °C. From May to September, the sea is under the influence of the Hawaiian anticyclone with weak southeast winds of 6-7 m/s. In general, the Pacific (summer) monsoon is weaker than the Asian (winter). Summer air temperatures (August) from 18 °C in the southwest to 10 °C in the northeast. The average annual precipitation is from 300-500 mm in the north to 600-800 mm in the west, in the southern and southeastern parts of the sea - over 1000 mm.

hydrological regime.

Large rivers flow into the Sea of ​​Okhotsk: Amur, Bolshaya, Gizhiga, Okhota, Penzhina, Uda. The river runoff is about 600 km3/year, about 65% falls on the share of the Amur. Desalinization of the surface layer of the sea is noted. water due to the excess of river runoff over evaporation. The geographical position of the Sea of ​​Okhotsk, in particular, its large extent along the meridian, the monsoon wind regime, water exchange through the straits of the Kuril ridge with the Pacific Ocean determine the features of the hydrological regime. The total width of all the Kuril straits reaches 500 km, but the depths above the rapids in the straits vary greatly. For water exchange with the Pacific Ocean, the most important are the Bussol straits with a depth of more than 2300 m and Kruzenshtern - up to 1920 m. This is followed by the Frieze, Fourth Kuril, Rikord and Nadezhda straits, all with depths at the thresholds of more than 500 m. The remaining straits have depths of less than 200 m and small cross-sectional areas. In shallow straits, unidirectional flows into the sea or ocean are usually observed. In deep straits, two-layer circulation prevails: in the near-surface layer in one direction, in the near-bottom one in the opposite direction. In the Bussol Strait, Pacific waters enter the sea in the surface layers, and in the bottom layers there is a runoff to the ocean. In general, the flow of the Sea of ​​Okhotsk waters predominates in the southern straits, while the inflow of the Pacific Ocean waters predominates in the northern straits. The intensity of water exchange through the straits is subject to means. seasonal and annual variability.

In the Sea of ​​Okhotsk, a subarctic structure of waters is observed with well-defined cold and warm intermediate layers; its Okhotsk, Pacific and Kuril regional varieties are distinguished. There are 5 large water masses in the Sea of ​​Okhotsk: the surface layer is a very thin (15-30 m) upper layer, which is easily mixed and, depending on the season, takes on spring, summer or autumn modifications with the corresponding characteristic values ​​of temperature and salinity; in winter, as a result of a strong cooling of the surface layer, the Okhotsk Sea water mass is formed, which in spring, summer and autumn exists as a cold transitional layer at horizons from 40 to 150 m, the temperature in this layer is from -1.7 to 1 ° C, salinity is 31 -32.9‰; the intermediate one is formed as a result of the sliding of cold waters along the continental slope, is characterized by a temperature of 1.5 ° C, a salinity of 33.7‰ and occupies a layer from 150 to 600 m; deep Pacific is located in a layer from 600 to 1300 m, consists of Pacific water entering the Sea of ​​Okhotsk in the lower horizons of the deep Kuril straits, and exists as a warm intermediate layer with a temperature of about 2.3 ° C and a salinity of 34.3‰, deep Kuril the southern basin is also formed from Pacific waters, located in a layer from 1300 m to the bottom, water temperature is 1.85 ° C, salinity is 34.7‰.

The distribution of water temperature on the surface of the Sea of ​​Okhotsk strongly depends on the season. In winter, the water cools down to about -1.7 °C. In summer, the waters are warmest at about. Hokkaido up to 19 ° C, in the central regions up to 10-11 ° C. Salinity on the surface in the eastern part near the Kuril ridge is up to 33‰, in western regions 28-31‰.

The circulation of surface waters is predominantly cyclonic in nature (counterclockwise), which is explained by the influence of the wind situation over the sea. The average current velocities are 10-20 cm/s, the maximum values ​​can be observed in the straits (up to 90 cm/s in the La Perouse Strait). Periodic tidal currents are well expressed, tides are mainly diurnal and mixed in size from 1.0-2.5 m in the southern part of the sea, up to 7 m near the Shantar Islands and 13.2 m in Penzhina Bay (the largest in the seas of Russia). Significant level fluctuations (surging surges) up to 2 m are caused on the coasts during the passage of cyclones.

The Sea of ​​Okhotsk belongs to the Arctic seas, ice formation begins in November in the bays of the northern part and by February spreads to most of the surface. Only the extreme southern part does not freeze. In April, the melting and destruction of the ice cover begins, in June the ice completely disappears. Only in the area of ​​the Shantar Islands can sea ice partially persist until autumn.

Research history.

The sea was discovered in the middle of the 17th century by Russian explorers I.Yu. Moskvitin and V.D. Poyarkov. The first maps of the coasts were compiled during the Second Kamchatka expedition (1733-1743) (see Kamchatka expeditions). I.F. Kruzenshtern (1805) made an inventory of the eastern coast of Sakhalin. G.I. Nevelskoy (1850-1855) explored the southwestern shores of the Sea of ​​Okhotsk and the mouth of the Amur River and proved the island position of Sakhalin. The first complete report on the hydrology of the sea was compiled by S.O. Makarov (1894). In Soviet times, comprehensive research work was launched in the Sea of ​​Okhotsk. Systematic studies have been carried out over the years by the Pacific Research Fisheries Center (TINRO-Center), the Pacific Oceanological Institute of the Far Eastern Branch of the Russian Academy of Sciences, several large expeditions were carried out by the Institute of Oceanology on the Vityaz vessel, as well as by ships of the Hydrometeorological Service (see the Russian Federal Service for Hydrometeorology and Monitoring environment), the Oceanographic Institute and other institutions.

Economic use.

In the Sea of ​​Okhotsk, there are about 300 species of fish, of which about 40 species are commercial, including cod, pollock, herring, saffron cod, sea bass. Salmonids are widespread: pink salmon, chum salmon, sockeye salmon, coho salmon, chinook salmon. Whales, seals, sea lions, fur seals live. Crabs are of great economic importance (1st place in the world in terms of stocks of commercial crab). The Sea of ​​Okhotsk is promising in terms of hydrocarbons, the explored oil reserves are over 300 million tons. The largest deposits have been discovered on the shelves of the Sakhalin Islands, Magadan and West Kamchatsky (see the article Okhotsk oil and gas province). Sea routes pass through the Sea of ​​Okhotsk, connecting Vladivostok with northern regions Far East and the Kuril Islands. Major ports: Magadan, Okhotsk, Korsakov, Severo-Kurilsk.

The Sea of ​​Okhotsk is often called harsh. And not in vain. However, the flora and fauna of this huge reservoir, it turns out, is very rich and diverse.

Before proceeding to the description of life in the Sea of ​​Okhotsk, its characteristic complexes of organisms - communities, or biocenoses, it is necessary to briefly characterize the main systematic groups of plants and animals found in the Far Eastern seas.

Marine flora is very different from land vegetation. If on land in most habitats higher, or seed, plants rarely predominate, other leafy or higher spore plants (mosses, horsetails, club mosses and ferns) are also very common, then in the seas the picture is completely different. The seabed in the coastal zone of the sea is most often inhabited by algae - lower spore plants, the body of which is not divided into stems, leaves and roots. Such a body, or thallus, often has branched formations - rhizoids, with which the alga is attached to the substrate; but, unlike the roots, they are not used to absorb mineral salts and water.

Algae can be unicellular, colonial, multicellular, or non-cellular. Some algae reach a length of several tens of meters, while others can only be seen through a microscope. Thallus of multicellular algae are in the form of simple or branched filaments, plates, tubes, cords, rods, balls and hemispheres, crusts, bubbles, maces or mushrooms. Sometimes the thallus of algae is dissected even more complex and outwardly resembles a higher plant. In a number of algae, the thallus is impregnated with lime, and they form massive crusts or jointed bushes.

One more important difference between marine and terrestrial vegetation can be noted. If on land all plants, with the exception of special dispersal stages, are closely associated with the soil, less often with other substrates, then in the sea, on the contrary, the bulk of the plants remain in suspension in the water column. This is mainly due to the much higher density of water (775 times) compared to air, as well as the presence in the water of salts, gases and microelements necessary for plant life.

Existence in suspension determined the evolution of algae. Since the specific gravity of the cellular contents, although not by much, but still exceeds the specific gravity of salty sea water, only very small organisms can cook in the water column.

With a relatively large specific surface area, they sink more slowly than larger forms. Therefore, the plants living in the water column (pelagial) are very small - their sizes range from a few thousandths of a millimeter to 1-2 mm.

Most algae are autotrophs, containing, like land plants, the green pigment chlorophyll and, thanks to photosynthesis, are capable of independently building organic substances of their body from inorganic ones. However, the color of algae is very diverse, since the green color of chlorophyll is often masked by additional pigments of yellow, brown, red or blue.

In a systematic sense, algae do not represent a single group. So, for a long time, blue-green algae, which have an extremely primitive organization, are devoid of a formed cell nucleus, flagellar mobile stages, and for which the sexual process is not characteristic, united with other algae. although they, together with bacteria, deserve to be singled out in a special kingdom of pre-nuclear organisms. This group of organisms, as well as fungi, many of the lower representatives of which live in our seas, we will not touch on in the future. The remaining groups of algae have a well-formed nucleus and, as a rule, reproduce sexually.

diatoms. Although microscopic in size, these solitary or colonial algae are considered the main creators of organic matter in our seas. They live both in the water column and at the bottom of reservoirs. Diatoms have an olive or yellowish-brown color, since in addition to chlorophyll they contain yellow and brown pigments. A silica-impregnated shell, consisting of two valves, is a characteristic feature of these plants.

brown algae. This includes multicellular algae of various shapes and structures. Some of them are real giants among marine plants and reach more than 40 m in length. A different quantitative ratio of green, yellow, orange and brown pigments gives brown algae an olive-green, yellowish-brown, brown or dark brown (nearly black in crust forms) color. Various carbohydrates, including sugars, are deposited as reserve nutrients, but starch is not formed. In the area (the action of ebbs and flows (i.e., in the littoral zone) in the Sea of ​​​​Okhotsk, almost everywhere on rocky and stony soils, fucus (Fucus evanescens) grows luxuriantly - a rather large brown algae, reaching a meter in length. This algae is ribbon-like, repeatedly forked branching thallus, which is attached to the substrate with the help of a rounded sole.The branches are flat, with a longitudinal vein in the middle.At the ends of the branches are swollen oval formations, dotted with small tubercles with holes in the center.Inside these tubercles, organs of sexual reproduction develop.In the southern part of the Sea of ​​\u200b\u200bOkhotsk Pelvetia (Pelvetia wrightii) grows above Fucus It differs from Fucus in its smaller size, not so wide, but thicker branches, devoid of a midrib, as well as a lighter color.

To the same order of the Fucus, although to a different family, belong the most complex outwardly arranged Sargassum algae, which grow below the Fucus, usually below the ebb zone. The thallus of these algae consists of branched thin cylindrical branches resembling the stem of higher plants. The similarity is further exacerbated by the presence on the branches of leaf-shaped plates with a midrib and short branches on which reproductive organs or berry-like swim bladders are located. Off the coast of the Sea of ​​Okhotsk, the Sargassum alga Cystoseira is often found; the main species of Sargasso live only in the southern part of the Sea of ​​Okhotsk.

The largest sizes not only among brown algae, but also among algae in general, are kelp algae, which form real underwater forests off the coast of the northern part of the Pacific Ocean, including in the Sea of ​​Okhotsk, at depths of up to 20 m. The thallus of kelp usually consists of a whole or dissected plate, a simple or branched stem and a sole or rhizoids, with which the alga is attached to the substrate. Many kelp algae are valuable fishery objects, are used in cooking, as well as fertilizers in the fields, go to feed livestock. Chemists obtain from them such valuable substances as mannitol and alginic acid. Even in ancient times, all kinds of preparations from seaweed in the form of a powder or tincture were widely used in medicine. Their therapeutic effect is due to the presence of iodine, bromine, vitamins A, B, C and various mineral salts in algae. On the coast of the Sea of ​​Okhotsk, different types of kelp, or seaweed, and alaria, or beaver cabbage, grow. These genera, belonging to different families, differ in that in kelp, the reproductive organs are located on the plate itself, and in alaria, on special lamellar appendages surrounding the stem at the base of the main plate. In the northern part of the Sea of ​​Okhotsk, lessonia similar to kelp grows, and in the south there are several more laminaria genera.

green algae. This group includes many both freshwater and marine forms of unicellular and multicellular organisms and a number of plants with a non-cellular structure. Among marine green algae, multicellular algae predominate, non-cellular ones are less common. Their color is usually green, as chlorophyll significantly predominates over yellow and orange pigments. The main reserve nutrient is starch. Many forms of green algae are known, but in terms of their diversity and size, these algae are noticeably inferior to brown algae. In our seas, forms with a filamentous, simple or branched, tubular, saccular or lamellar thallus predominate. Sea lettuce Ulva with a lamellar delicate light green thallus, which reaches a diameter of several tens of centimeters, can be eaten.

Red algae, or purple. These, undoubtedly, the most beautiful marine plants, in a number of essential ways, are sharply separated from real algae, for example, green and brown. Purples are completely devoid of mobile flagellar stages. Therefore, even the male sex cells in them are not capable of active movement. In addition, in addition to chlorophyll, crimson has additional pigments - blue fnkocyanin and red phycoerythrin. Interestingly, both of these features bring red algae closer to blue-green ones, from which, however, they differ in the presence of a nucleus and the ability to reproduce sexually.

Among the crimson, there are filamentous, cord-like, crust-like, lamellar, bag-shaped, bushy forms, in the form of a leaf with veins, etc. In some red algae, the body is so saturated with lime that it becomes hard as a stone. They form crusts or branching bushes, somewhat reminiscent of corals. Limy scarlets are also widespread in the Sea of ​​Okhotsk.

The mucus of some red algae, after appropriate thermal and other processing, turns into a dense jelly, which is called agar-agar. This substance is widely used in the food, paper and medical industries. Anfeltia crimson is a valuable raw material for the production of agar-agar in the USSR. In the Sea of ​​Okhotsk, it has been mined for many years in the south - in the Busse lagoon on the island of Sakhalin and in the Gulf of Change on the island of Kunashir (Kuril Islands).

Other groups of microscopic algae are also known, such as the flagellated peridinea. In most of them, the body is covered with a cellulose membrane, consisting of separate plates, less often it is naked. Some peridineans (like blue-green algae) are poisonous and, in case of excessive accumulation, cause mass death of fish and other marine animals, and sometimes people who have tasted poisoned food. But such a peridinea as the well-known night-lighter - Noctiluca, whose spherical body reaches 2 mm in diameter, is devoid of a cellulose membrane, incapable of photosynthesis due to the lack of chlorophyll, and feeds by swallowing and digesting microscopic plants and protozoa. It causes a beautiful greenish-bluish glow of the sea. In the Sea of ​​Okhotsk, there are up to 45,000 nightlights per liter of water.

sea ​​grass. Higher plants in the seas are not as common as on land. For the Far Eastern seas, only three types of Zostera and one type of Phyllospadix are characteristic, because of their strong leaves, known as sea flax. All these species also grow in the Sea of ​​Okhotsk.

Sea grasses, although they live in the aquatic environment, are true flowering plants that reproduce by seeds. They belong to the pondweed family, inhabiting freshwater basins. Sea grasses have long rhizomes and long, narrow, ribbon-like green leaves, the lateral edges of which are smooth in Zostera and serrated in Phyllospadix. Another characteristic feature is the presence of air cavities inside the leaves, thanks to which the sea grasses stay afloat. Their seeds develop in inflorescences, which are attached to a long flowering stem in Zostera, and near the rhizome in Phyllospadix. These two genera also differ in biology. Species of the zoster genus grow on sandy, silty-sandy and silty soils in non-surf or weakly surf areas, and phyllospadix takes root in rock crevices and between stones, often in a strong surf zone. Therefore, powerful, intertwined rhizomes of fnllospadix serve as a refuge for many inhabitants of the littoral, or dry zone.

Sea grasses have long been used by man. Lye and soda were obtained from their ash, while the ash was used both as a fertilizer and in the manufacture of glass. Dry sea grass was used for stuffing beds and furniture, was used as a thermal insulation material by builders, as well as in the manufacture of paper and in a number of other industries.

Unlike plants, the animal world of the seas and oceans is exceptionally rich. All types and most classes of animals originated in the oceans, and only a few classes of vertebrates and arthropods - on land. Some of them, for example, radiolarians, scyphomedusae, coral polyps, ctenophores, brachiopods, shellfish and cephalopods, horseshoe crabs, sea spiders, all echinoderms, bristle-jaws, pogonophores, ascidians and a number of others, i.e., 31 classes out of 72 known, to date time live only in the marine environment. Others - sponges, hydroids, nemerteans, bryozoans, polychaetes - live mainly in the seas and are few in fresh waters. However, in terms of the number of animal species, the marine environment is significantly inferior to the air, inhabited by an incredible variety of insect species, the number of which is approaching a million. In total, more than 150 thousand species of various animals live in the seas. Most of them are inhabitants of the tropics, in the Far Eastern seas there are much fewer of them - several thousand species each. Consider the main groups of marine animals inhabiting the Sea of ​​Okhotsk.

Protozoa. To the type of protozoan animals, zoologists still include not only all unicellular animals, but also a large number of unicellular plants - algae, which botanists have long and quite reasonably attributed to various departments (the same - types in zoology) of plants, for example, the entire type of peridine , which were mentioned above. Naturally, we will not touch on these groups.

To the class sarcode along with the well-known freshwater amoeba, there is an extensive group of sea inhabitants - foraminifera (translated from Latin - “carrying holes”). The fact is that in many foraminifera, the walls of calcareous shells, characteristic of most species of the group, are pierced with tiny pores through which numerous pseudopodia emerge. But in some of them, the skeleton is formed by grains of sand glued to the outer layer of the body. Most foraminifera lead a benthic lifestyle. Although they are single-celled animals, some of them reach 3 cm across the shell. More than 100 species of foraminifera inhabit the Sea of ​​Okhotsk.

Another group of protozoa - radiolarians, or rayfish, exists only in the water column. Radiolarians range in size from fractions of a millimeter to several centimeters in diameter, but such large forms are rare. Most of these beautiful organisms with delicate, often openwork skeletons made of silica or strontium sulfate live in warm seas. There are relatively fewer of them in the Far Eastern waters, but still, over 80 species have been recorded in the Sea of ​​Okhotsk.

Also, only in the water column live marine representatives of the most complex protozoa - ciliates, whose body is enclosed in a transparent thin house of organic matter. Because of some external similarity of the house with a bell, they got their name (in Latin, a bell is tintinnabulum). At least 30 species of these protozoa have been identified in the Sea of ​​Okhotsk.

A peculiar group of multicellular organisms, in many respects similar to real multicellular animals, are sponges. For many, the name "sponge" is associated with a bath sponge, although the "Greek sponge", which actually belongs to the group of organisms under consideration, has already moved into the realm of legends. In cosmetics, another sponge is used - freshwater bodyaga. Alas, the sponges that live in the Sea of ​​Okhotsk cannot be used in either respect. The fact is that in most of our shallow water sponges, although they seem soft to the touch, the internal skeleton contains microscopic needles made of silica.

We have significantly fewer sponges with a calcareous skeleton. Glass sponges are amazingly beautiful with their openwork skeleton consisting of six-rayed silica needles, but they are found on great depths. In total, over 100 species of sponges have been identified in the Sea of ​​Okhotsk. Their forms are very diverse. Sometimes these are crusts or pillows that are overgrown with rocks, stones and bases of large algae, or lumps, lobed, branched, bushy, funnel-shaped or other formations. Glass sponges often have a cylindrical, tubular or goblet body. Sponges are typical filter feeders, that is, they feed by filtering water through their bodies and retaining small organic particles suspended in it. Most of them have an unpleasant odor that repels enemies. In our everyday life, toilet sponges are used, the skeleton of which consists only of horny fibers, and freshwater bodyagi, and some glass sponges are used for jewelry.

Coelenterates- the most primitive type among true multicellular animals, from which more complex organisms probably originated. These animals got their name due to the fact that in their body, consisting of only two layers of cells, there is only one cavity, called the intestinal. Nevertheless, among the coelenterates there is a huge variety of forms. Most of these are colonial animals, forming settlements in the form of bushes, twigs, brushes, feathers, balls, goblets, etc., soft or hard, impregnated with lime. The well-known jellyfish and sea anemones belong to single coelenterates. The life cycle of many intestinal cavities is characterized by two alternating forms - asexual in the form of a single or colonial polyp living at the bottom, and sexual - in the form of a jellyfish floating in the water. In the tropical seas, colonial coral polyps with lime-impregnated skeletons are the main builders of coral reefs. There are no such reef-forming corals in the seas of the USSR. Despite their often immobile lifestyle, all coelenterates are predators. The tentacles surrounding their mouth are equipped with stinging cells and serve both for offense and defense.

At least 200 species of polyps and jellyfish live in the Sea of ​​Okhotsk, not counting sea anemones, which are almost not systematically studied. The largest size, up to 2 m in diameter, reaches the red color of the jellyfish - cyanide. Fortunately, her burns, like almost all intestinal - the inhabitants of the Sea of ​​\u200b\u200bOkhotsk, are harmless to humans. Severe and sometimes life-threatening burns are caused by the cross jellyfish, which is widespread in the Sea of ​​Japan. True, in the extreme south of the Sea of ​​Okhotsk, in the southern part of the Kuril Islands, we met single individuals of the godson, but they do not pose a real danger.

Close to coelenterates a small type ctenophores. If coelenterates live both at the bottom and in the water column of reservoirs, then almost all ctenophores lead a free-floating lifestyle, never touching the bottom, with the exception of single crawling species. The body of ctenophores, like that of jellyfish, is gelatinous. The water content in their body is 99%, which, apparently, is a kind of record in the animal world. Their body is round or bag-shaped, the mouth is in front. These animals got their name because of the 8 rows of plates, each of which is split and resembles a comb. Sea cucumber lives in the Sea of ​​Okhotsk.

The most primitive of all worms are the ciliary worms, which have retained many similarities with ctenophores. Their body is covered with cilia, with the help of which they move. The sense organs - the organs of balance, smell and perception of light, as well as the central nervous system in the form of longitudinal nerve trunks - are primitive. There is a mouth opening, but the intestines are not always developed. Usually ciliary worms are delicate small, with a very flattened body, but some species reach a length of 16 cm. The species composition of worms in the Sea of ​​Okhotsk is still very poorly studied.

A worm-like, often very long body is distinguished by nemerteans, which are distinguished as an independent type of animals. Their organization is much more complicated than that of ciliary worms. Unlike the latter, they are endowed with an anus and a circulatory system. Like ciliary worms, their body is covered with a ciliary cover. These are predatory animals, and their murder weapon is the trunk, which is usually screwed inside the body. In some nemerteans, the trunk is equipped with a sharp stylet and is equipped with a poisonous gland. The body length is usually several centimeters, although there are also forms that can stretch up to almost 30 m in length. The coloration is extremely varied. Golden-yellow, brown, white, scarlet and green animals look especially colorful, often decorated with spots or specks of other colors. Most nemerteans live at the bottom, but some species live only in the water column. The nemerteans of the Sea of ​​Okhotsk are still poorly studied; more than 25 species have been described off the coast of the Kuril Islands.

With roundworms, scientists bring together a small group of very peculiar animals, represented by only a few species. These are prnapulids, thick and valhovaty. Their mouth opening and pharynx are in front, and the pharynx is surrounded by a trunk armed with hooks and spikes, screwed inside in a calm state. With the help of this trunk, the animal is buried in the sand. In most priapulids, a grape-like appendage stands out at the posterior end of the body - the respiratory organ, or gills. There are no circulatory organs. the nervous system is arranged very primitively, there are no sense organs. Prnapulids lead a burrowing lifestyle. In length, these animals reach 10-15 cm. We found one of the species of priapulids in large numbers in the dry zone of the Gizhiginskaya Bay and the southern part of the Kuril Islands.

Annelids, in contrast to the lower ones - flat and round, scientists classify as higher worms, taking into account a number of features of their organization. Earthworms and leeches, well known to the reader, also belong to this group, but they are terrestrial or freshwater representatives of annelids. Marine species are more diverse, and many of them are distinguished by the perfection of forms. Their body consists of a head, a ringed body and a tail blade. On the sides of the body segments, there are usually organs of movement - parapodia in the form of blades, from which bristles protrude. The nervous system of annelids is quite developed and, in addition to cords, also consists of nerve nodes. The sense organs are also well developed - sight and smell. There are circulatory and excretory systems, but the respiratory organs are not always present. Polychaete rings, or polychaetes, are widespread in the seas. They got their name because their parapodia are covered with tufts of numerous bristles. Among them, both mobile, crawling and burrowing forms, as well as immobile, burrowing or located in stony or calcareous valleys, on rocks, stones and algae thalluses, have been identified. Most annelids lead a bottom lifestyle, and only a few species are free-swimming. In total, about 300 species of annelids are recorded in the Sea of ​​Okhotsk and near the Kuril Islands.

The latter now also include a small group of echiurids, although their body is not dissected. These animals burrowing in loose soil with a rounded ridged body, at the front end of which there is usually a trunk that can stretch or shrink, reach 20-30 cm in length. In the Sea of ​​Okhotsk, Echiurus and Urechis are often found, belonging to the largest e. khuridam.

Close to annelids and class sipunculid- a small group of typically marine animals. Their body, rounded in cross section, is devoid of any appendages, except for the trunk. The mouth opening, which ends the trunk, is surrounded by a corolla of tentacles. Sipunculids either burrow into the ground, or hide between the rhizomes of sea grasses, calcareous algae and corals, exposing their trunk to the outside. In the Sea of ​​Okhotsk, especially in its southern part, the Japanese fiskosoma sipunculid is common. It is easiest to find it between the rhizomes of sea flax - phyllospadix, which grows in abundance in the south of the Sea of ​​\u200b\u200bOkhotsk.

Undoubtedly, from annelids descended arthropods This is the most species-rich type of the organic world. Although at least 90% of the total number of arthropod species, which is much more than a million, are insects, that is, inhabitants of the air, still several tens of thousands of species of this type live in the sea. Most of them belong to the subtype of gill-breathers, including crustaceans that have two pairs of antennae, or antennae. Crustaceans breathe either with gills, or with the surface of some legs, or (especially small forms) with the entire surface of the body. The chitinous shell in crustaceans is usually impregnated with lime, and their body consists of a head, chest and abdomen with a tail plate. In many crustaceans, the posterior edge of the dorsal cover of the head grows strongly and covers the entire thorax from above and from the sides, or only its anterior part, forming a cephalothoracic shield, or carapace. The pectoral legs, biramous in the most primitive forms, in many crustaceans lose one of the branches. They usually serve for locomotion, often carrying gills; in many forms, the front legs are modified into claws, which makes it easier to grab food and protect. Abdominal legs are present only in representatives of the subclass of higher crustaceans. Of the five known subclasses of crustaceans, representatives of three subclasses live in the Sea of ​​Okhotsk.

They are not at all like them, and indeed like crayfish, barnacles, whose body shape is greatly modified due to a sedentary lifestyle. However, the free-swimming larva looks like a typical crustacean. In adult crustaceans, the body is enclosed in an outer skin - a mantle, which is protected from the outside by a limestone house made up of separate tablets. Rhythmically moving cirriform pectoral legs, filtering and aerating water, crustaceans provide themselves with food and oxygen for breathing. Usually barnacles are one of the main components of fouling of ships and hydraulic structures. At least 15 species of these maxillopods live in the Sea of ​​Okhotsk. Sea ducks settle on algae, logs and other floating objects, the body of which sits on a flexible stalk. coastal cliffs and the bottoms of the ships are overgrown with sea acorns, devoid of a stalk. On the skin of whales, especially baleen whales, a special sea acorn, the coronula, has taken root. Throughout the Sea of ​​Okhotsk, representatives of real sea acorns are widespread - balanus, the largest of which reaches a height of 20 cm. Unfortunately, the latter species lives in the Sea of ​​Okhotsk only at depths of 100 m or more. In the southern part of the Sea of ​​Okhotsk, in the upper part of the tidal strip, on the rocks, settlements of a small acorn - khtamalus, which already belongs to another family, are common.

higher crustaceans. Crustaceans of this subclass are characterized by a constant composition of the thoracic (8) and abdominal (6, rarely 7) segments, the presence of abdominal legs. Often one or more anterior thoracic segments are fused with the head, and their limbs are usually modified and transformed into mandibles. Higher crustaceans are very widely settled, and not only in the seas, but also in fresh waters and on land. This subclass includes most large crustaceans, including all commercial forms.

In a group of orders, development occurs without a true larva, and fertilized eggs are hatched in special brood bags located on the underside of the chest. The crustaceans from the order Mkzid have a cephalothoracic shield, the eyes are set on stalks, and the abdomen is thin; each thoracic peduncle consists of two branches, which is more primitive than a single-branched limb. These tiny crustaceans, rarely exceeding 2 cm in length, live both at the bottom and in the water column. In the summer somewhere on the surf sandy beach it is worth stamping your foot in the splash zone, as soon as some kind of quick swarming begins in the sand. It was we who disturbed the females of mysida Grebnitsky, who sailed here and buried themselves in the upper layer of sand for the period of gestation. Restless, but there is plenty of oxygen for the breathing of developing eggs. As the sea level rises or falls due to the tides, the females migrate up and down the coast, always remaining in the splash zone. The orders of amphipods and isopods are close to the mysids in terms of the way of bearing juveniles and some features, although they differ from them in single-branched pectoral legs and other signs of a higher organization. They do not have a cephalothoracic shield, so they do not look like a mysid. The eyes are sessile, without stalks.

Another group of orders of higher crustaceans is characterized by development with the change of several larval forms. Fertilized eggs, if hatched, are not in a bag on the chest, but between the abdominal legs; eyes always sit on stalks. The cephalothoracic shield fuses with all thoracic segments. This group includes two orders - Euphausian crustaceans and decapod crustaceans.

The Euphausian order includes a relatively small number (less than 100 species) of tiny, up to 8 cm long, crustaceans, with their elongated bodies somewhat reminiscent of mysids and shrimp. Their cephalothoracic shield is shortened, so that the gills on the sides of the chest are not covered. All eight pairs of thoracic legs are of the same structure, biramous. Euphausenidae are typical inhabitants of the water column, and some of them, especially the Antarctic krill, from which a variety of foodstuffs have now been learned, form huge aggregations. Euphausiids are the main food of many baleen whales, fish, and some marine mammals.

Much richer in species (over 8 thousand) is the order of decapod crustaceans, which includes almost all commercial crustaceans. Their gills are completely covered by the cephalothoracic shield. Body shapes are varied, with the most typical being shrimp, crustacean, and crab. The decapods got their name because of the eight pairs of thoracic limbs, the three anterior ones turned into maxillas, so that only five pairs, as a rule, are single-branched, serve for movement. Floating forms of decapods have an elongated, more or less laterally compressed body, a long abdomen, and strongly developed abdominal legs. Such crustaceans are called shrimp, shrimps, or chilims. The first of these names is of French origin, the second is of English origin, and the third, apparently, is the word "shrimp" distorted in the East. Shrimp meat, mainly the muscles of the abdomen, is wonderful in taste and is considered the most valuable delicacy product.

Off the coast of southern Sakhalin and in the south of the Kuril Islands, a green or brownish herbal shrimp, most often called chilim, is common. It lives at a shallow depth in thickets of sea grass, reaching a length of 15, rarely 18 cm. The same size is the shrimp bear cub, but it has a more massive body and a strong prickly shell. Several species of this genus have been found in the Sea of ​​Okhotsk, living at greater depths than grass shrimp. Many crawling and burrowing decapods have an elongated cylindrical or slightly flattened body in the dorsal-abdominal direction, outwardly somewhat resembling crayfish. Only in the south of the Kuril Islands was found a mole shrimp with a soft light gray shell, reaching a length of 9 cm. It lives in burrows dug by claws in the muddy sand.

The body shape of hermit crabs is very peculiar. The front part of their body is covered with a shell, while the rather massive long abdomen is naked and soft. His cancer hides in empty shells of gastropod mollusks. In connection with this way of life, the abdomen of the hermit crab is asymmetrical and twisted, since the cavity in the shell of the mollusk is also twisted in the form of a spiral, and it is held in it with the help of steering and shortened hind pectoral legs. As the animal grows, it must change its “home”. With the right claw, which is much larger than the left, the hermit crab covers the mouth of the shell in case of danger.

The most valuable invertebrate animal of the Sea of ​​Okhotsk - the king crab, from the point of view of scientists, is not a crab at all. Only the crab-like body shape, which is characterized by a weak development of the abdomen, brings it closer to real crabs. Bending under the powerful cephalothorax, which makes up the entire body of the animal visible from above, it is completely invisible. In fact, the king crab is closer to hermit crabs than real crabs, and belongs to the craboid family. In more primitive representatives of this family - small sculpin craboids and stone craboids - the abdomen is rather large, has the appearance of a soft air sac and is only partially bent under the cephalothorax. In real craboids, including commercial ones, the abdomen is small, flattened, calcified and completely bent under the cephalothorax. Outwardly, craboids are easy to distinguish from crabs: in addition to a pair of claws, they have not four, but three pairs of walking legs, since the posterior pair of pectoral legs is greatly reduced and bent down.

Kamchatka crab is one of the largest representatives of the arthropod type. The width of its cephalothoracic shield can reach 25 cm, the span of its legs is one and a half meters, and its weight is 7 kg. True, the average weight of a male caught in the Sea of ​​Okhotsk is much less - only 1800. The Kamchatka crab makes large migrations, so its pectoral legs are especially strongly developed. Delicacy products are made just from the muscles of the legs, while the internal organs located under the cephalothoracic shield are unsuitable for eating. The bluish blood of crabs contains a respiratory pigment, which includes copper, and not iron, as in the hemoglobin of vertebrates.

The king crab is widely distributed in the Sea of ​​Okhotsk, but forms the largest concentrations off the western coast of Kamchatka. Its shoals annually move here for distances from 70 to 180 km. The king crab winters in this area at a considerable depth exceeding 200 m. The water temperature here is noticeably higher than at shallower depths, and is + 1.5 ° C. In the spring, when the coastal waters begin to warm up, the king crab comes to the shore. At this time, females molt and after molting mate with males. The fertilized eggs are glued to the abdominal legs of the female, where they hatch. Later, molting occurs in males. Having completed the mating season, crabs migrate to forage fields, crawling from one field to another as they become scarce and eating small mollusks, crustaceans and polychaete worms. In the same genus as the king crab, there are two more species that are somewhat smaller, but just as tasty - spiny and blue crabs.

Real crabs are the largest group of decapod crustaceans, numbering about 4.5 thousand species, but they are distributed mainly in the tropics and subtropics. In the seas of the USSR, their fauna is very poor. In the coastal waters of the Sea of ​​Okhotsk, medium-sized quadrangular and pentagonal hairy crabs are often found; to the south, off the coast of southern Sakhalin and the southern part of the Kuril Islands, fast-running coastal crabs attract attention. All crabs are edible in principle, but only the snow crab can be of commercial importance, the diameter of the cephalothorax shell of which reaches 16 cm. relatives whose right claw is always much larger than the left. It got its name from the fact that, having sharp claws, it easily cuts the nets if it gets caught in them. In total, at least 100 species of decapod crayfish live in the Sea of ​​Okhotsk.

Sea spider class. This class is usually ranked, along with horseshoe crabs, as a subphylum of chelicerate arthropods, which includes a large group of mainly terrestrial arachnids. However, their association is largely arbitrary, since sea spiders are very different from real arachnids. They are usually small animals with a narrow body, disproportionately small compared to very long legs. The head section bears a trunk and a pair of clawed limbs, palps, oviparous legs and walking legs. The three subsequent segments each have a pair of legs, and the rear of them at the end, in addition, has a small tail. Sea spiders are sedentary animals and feed by sucking out hydroids, less often sponges, sea anemones or bryozoans. At least 30 species of sea spiders live in the Sea of ​​Okhotsk; the leg span of the largest of them reaches 20 cm.

type of shellfish. Along with crustaceans, mollusks are of the greatest commercial importance among invertebrates. The body of mollusks usually consists of a head with a mouth opening, a sac-like body in which the internal organs are located, and a muscular organ - the legs. Most mollusks are characterized by a calcareous shell, arranged differently in different groups. Often the shell covers the entire body of the animal, sometimes only part of it. In the course of a long evolution in the type of mollusks, various, outwardly very dissimilar forms have developed, which also differ in the level of organization.

Among the very primitive mollusks are shell mollusks, or chitons. Their body, elongated oval, convex from above and flat from below, is covered from above with a skeleton consisting of 8 calcareous plates, which are movably connected to each other. The chiton torn off from the ground immediately rolls up into a ball. In some chitons, calcareous plates are completely or partially hidden under the skin. With the help of the leg, which occupies most of the lower surface of the body, on both sides of which the gills are located, chitons slowly crawl along the bottom. Their nervous system is arranged extremely primitively and is devoid of the brain and any other nerve nodes. At least 20 species of chitons live in the Sea of ​​Okhotsk, including the largest of them, Steller's cryptochiton, reaching a length of 33 cm and weighing about a kilogram. The plates of this chiton are completely hidden under brown skin.

Gastropod molluscs, which make up a separate, most numerous (about 85 thousand species) class, are much more complex, their central nervous system consists of several pairs of nerve nodes, or ganglia; they have marked eyes, balance coordination, and other senses. Most gastropods carry a shell, usually spirally twisted, less often cap-shaped, ear-like or saucer-shaped. Gastropods live both on land (for example, slugs and snails) and in fresh waters (livebearers, pond snails and coils), but still most of them live in the seas.

On the rocky coast, you can always see sea limpets with a low-conical shell, capable of sticking very firmly to the rocks and therefore not afraid of the strongest surf. This mollusk has a well-defined “instinct at home”, and, slowly crawling along the rock and eating the smallest organisms, it always returns to the very place where it started the journey.

In the same place, in the tidal zone, small dark-colored coastal snails are found in large quantities - littorins with a rounded or kubariform shell. At low tide, they draw their body into the shell, and close the mouth with a horny cap. In a state of torpor, littorinas can stay up to a week or even more (different species have different ability to tolerate drying out). Shore snails feed mainly on plants.

The larger umbilical snail with a spherical strong shell is reputed to be a predator. The cap in some species is calcareous, in others it is horny. These snails have developed a number of adaptations for digging shells out of the ground and extracting food from them. The lime of the victim's shell is softened by an acidic secretion from the drill gland, and then a hole is drilled using a grater, which is found in most gastropods. The umbilical snail lays eggs in a rounded dark masonry of sand.

Carnivores and corpse-eaters are many of the most highly organized gastropods, including purple snails and trumpeters. These mollusks have a siphon in the lower part of their shell, i.e., a drawn lower part of the mouth with a channel in the middle. Trumpeters are the largest gastropods of our seas, covered by fishing; their shell reaches a height of 25 cm. Purple snails, close to trumpeters, got their name by analogy: from one of their species living in the Mediterranean Sea, in ancient times they mined dye for the purple clothes of Roman emperors.

Some gastropods lack shells. The most colorful of them - nudibranch mollusks - are so named because the respiratory organs - the gills are located directly on their body and are not covered by anything.

Most gastropod mollusks lead a benthic lifestyle. In more primitive forms, the larva develops in the water column, while in more complex forms, juveniles form inside the clutch. However, some groups of gastropods are known to live in the aquatic environment. These include pteropods, the leg of which forms lateral pterygoid lobes that are used for swimming.

At least 400 species of gastropods live in the Sea of ​​Okhotsk; several dozen of them may be of commercial importance.

The class of bivalves in terms of the abundance of species (about 15 thousand) ranks second after the gastropods, but their role in the economy of nature is more significant. Many bivalves (such as mussels) reach exceptionally high numbers in their habitats. The shell of these mollusks consists of. two - right and left - valves, connected by an elastic ligament and often, in addition, by special protrusions-teeth, which correspond to a notch on the opposite valve. Their body in connection with a sedentary or motionless way of life has become somewhat simplified. So, in the course of evolution, bivalves literally “lost their heads”, and at the same time all the organs associated with it, as well as their throats. The gills, on the contrary, have undergone significant complication and, in addition to the function of respiration, have acquired additional functions. It is they that form an important part of the water-propulsion device that creates currents of water, and play an important role in straining food from the water, which is sucked into the body of the mollusk and passes through the gills. Thanks to this adaptation, the most primitive bivalves were able to extract particles of organic matter from the soil, while most bivalves are filter feeders and feed on small organisms suspended in the water column.

The sizes of bivalves vary greatly - the length of their shell varies from 2 mm to 140 cm. The mass of the largest of them - tridacnids living in the tropical zone, can reach 200 kg (together with the shell). True, such giants are not found in the seas of the USSR. In total, about 15 thousand species of bivalve mollusks are known that have inhabited marine, brackish and fresh waters, about 4/5 of the total number of which lives in the seas. Bivalve molluscs settle on a variety of soils; among them there are forms that are movably or immovably attached to rocks, stones or shells, crawling on the surface of the soil, burrowing into loose deposits, and even drilling through wood or stones.

In the Far Eastern seas, scallops with a more or less rounded or rounded-triangular shell are of the greatest value. The scallops usually lie on the bottom on the right side, the lower (right) shell valve is more convex, and the upper (left) one is flattened. Both shell valves are furrowed with numerous ribs. A large, white or yellowish shell-closing muscle is used for food. The largest and commercially most valuable Hokkaido scallop is often incorrectly called seaside scallop. Its shell reaches a length of 18 cm. In the Sea of ​​Okhotsk, this scallop is common in Aniva Bay and in the south of the Kuriles. The main enemies of the scallop are predatory starfish, escaping from which it moves by jumping in a jet way.

Mussels are among the most common bivalves that live on both hard and soft soils. The edible mussel, or black shell, found almost along the entire coast of the Sea of ​​\u200b\u200bOkhotsk, is very numerous - triangular-rounded, medium-sized, black-brown or black-blue in color, the length of which approaches 9 cm. Even larger size (up to 20 cm in length) reaches Gray's mussel - a warmer-water species than the edible mussel. We hunt it mainly in the Sea of ​​Japan. In the Sea of ​​Okhotsk, Gray's mussel is found in Aniva and Patience bays off the coast of southern Sakhalin, as well as in the southern part of the Kuril Islands. Mussels are attached to rocks, stones or to each other by means of a bundle of very strong horn threads, or the so-called byssus. This method of attachment is called mobile, because. the mussel can tear off the threads of the byssus. crawl to a new place and stick again, highlighting new threads.

Motionlessly attached to the substrate, growing to it with a shell, oysters. The giant oyster living in the Far East is a relatively warm-water animal and is found in the Sea of ​​Okhotsk only in the warmest areas - in the Busse lagoon in the south of Sakhalin Island and in the extreme south of the Kuril chain.

Some bivalve mollusks are even able to penetrate hard substrates such as stone and wood. They belong to the group of drilling organisms - stone borers and wood borers. Off the coast of eastern Sakhalin and the southern part of the Kuril Islands, there is a stone borer - zirfeya. This is a large mollusk up to 10 cm long, with a white fragile shell. The front of the shell is covered with rows of teeth, with which the animal drills a shelter in limestone or other relatively soft rocks. Carpenter mollusks belong to the family of shipworms, so named because of their long, soft, thin, worm-like body, reaching over 25 cm in length. A small spherical white shell is located at the front end of the body, both of its wings are armed with serrated and serrated combs, with which the shipworm drills wood. As the clam drills into the board, it increases in size, and the diameter of its dwelling expands accordingly. As a result, the animal is immured in a tree for life. Interestingly, the sea worm does not feed on wood, but uses the wood substrate as a shelter. At the posterior end of its body there are inlet and outlet siphons, as well as 2 calcareous plates, which, if necessary, close the inlet.

In total, about 300 species of bivalves live in the Sea of ​​Okhotsk, of which about 20 species are of interest to fishers. Larger forms are suitable for eating, and small ones are suitable for making flour.

cephalopods. If, due to a sedentary or immobile lifestyle, the body of bivalve mollusks has noticeably simplified, then mobile and dynamic cephalopods have undergone significant progressive evolution and have become the most highly organized representatives of the world of invertebrates. It is no coincidence that cephalopods are sometimes called the primates of the sea. Their characteristic feature is the absence of a shell, which was gradually reduced and preserved only in the most primitive living cephalopod - the nautilus, an inhabitant of the tropics. The tentacles located around the mouth on the head, from which the cephalopods got their name, developed from the leg, on which gastropods, shellfish and other molluscs still crawl. In nautilus, the number of tentacles reaches several tens, in octopuses there are eight, and in squid and cuttlefish - ten. Each tentacle bears one or two, rarely three or four longitudinal rows of suckers. True, as some fiction writers claimed not so long ago, cephalopods cannot suck blood from the victim with the help of these suckers, since their bottom is closed. All cephalopods are predators, attacking not only small, but also rather large animals, such as crabs and fish. The prey is captured and held by tentacles with suction cups, and the horny beak, which is located in the muscular throat, serves to kill it. Cephalopods can move in water very quickly, and they do this with the help of a kind of jet engine. Its device is peculiar: the inner end of the tube, which is called a funnel, or siphon, and goes outside near the head of the mollusk, leads into the vast internal cavity of the animal. Having sucked water through the crack, the cephalopod then forcefully pushes it out through the funnel. In this case, a reactive force arises, which moves the mollusk in the direction opposite to the direction of the siphon.

Cephalopods have a highly developed nervous system, and the brain, which in octopuses is hidden in a cartilaginous capsule - some kind of skull, is distinguished by the complexity of the structure. The eyes of cephalopods are also complex and reach record sizes - up to 40 cm in diameter in giant octopuses, which is almost three times the diameter of the eye of the giant of the oceans - the blue whale.

Many cephalopods are able to change color, bringing it into line with the surrounding background. About one quarter of cephalopod species, especially those living at considerable depths, can glow.

Some of the cephalopods prefer the water column for life, while others prefer sheltered places on the bottom of the sea, from where they lie in wait for prey. Most squids and some octopuses are excellent swimmers, while cuttlefish and most octopuses lead a bottom-dwelling lifestyle. The main food of cephalopods is fish, crabs and bivalves, as well as cephalopods, including individuals of their species.

In the countries of Southeast Asia and the Mediterranean, even in ancient times, the taste and nutritional qualities of mollusks were valued. In the USSR, a significant number of cephalopods began to be hunted relatively recently, but already now the demand of the population for products from them has exceeded supply. Squids and octopuses are sold in the form of canned food, semi-finished products and in kind. In the Sea of ​​Okhotsk, commercial accumulations of cephalopods are found mainly near southern Sakhalin and in the south of the Kuril Islands; in total, over 40 species of these animals live in the Sea of ​​Okhotsk, including the Kuril region.

Type tentacled. Of this type of sessile, mainly marine animals, bryozoans are the most numerous and widespread. Their colonies are usually calcified and have a branched, bushy, leaf-like, crusty or lumpy shape, but sometimes they also form openwork nets. The color of the colonies is white, gray or bright, usually orange or red. Individual individuals of bryozoans rarely exceed 1 mm in length. In appearance, worm-like, these animals are enclosed in a calcareous or gelatinous cell with a hole. Protruding every now and then the front end, which carries the mouth with a simple or horseshoe-shaped corolla of tentacles around it, seated with cilia, bryozoans drive food particles to the mouth with them. In the tropics, along with coral polyps and calcareous algae, bryozoans play an important role in the formation of reefs. Building their skeletons of lime, many of them contribute to the accumulation of calcium carbonate on the bottom of the seas and oceans. Such soils with an abundance of shells and bryozoan skeletons are characteristic, for example, of the South Kuril Strait. Of the 3,000 known species of bryozoans, more than 200 live in the Sea of ​​Okhotsk. Some of them are found here in large numbers, especially on pebble soils at a depth of 30-50 m.

Brachiopod type. Their heyday passed many millions of years ago, back in the Paleozoic, when there were several thousand species of brachiopods, now a little more than three hundred are known. These are exclusively marine single attached animals, the body of which is enclosed in a bivalve shell, but, unlike mollusks, the valves cover the brachiopods not from the sides, but from the dorsal and ventral sides. The most primitive forms burrow into the ground with the help of a long fleshy stalk, or leg, which is attached to the bottom of the mink. Most prefer a solid substrate, growing to it with a shortened stem or lower valve. The body of the animal itself occupies only the lower part of the space between the valves. On both sides of the mouth, two "arms" extend - spirally twisted long outgrowths, seated with a double row of small tentacles, which in turn are covered with cilia. These "arms" occupy the front of the space inside the shell and. creating a current of water by the movement of cilia, they serve for nutrition and respiration. Only six species of brachiopods live in the Sea of ​​Okhotsk. In the north and near the Sea of ​​Okhotsk coast of the middle and northern Kuril Islands, one of them is found even at low tide.

Type of chaetognaths. The transparent body of these animals resembles an arrow and consists of the head, trunk and tail sections. The mouth located at the anterior end of the head is surrounded by a powerful chitinous trapping apparatus of bristles and teeth. Chaetognaths are typical marine predators; most of them spend their entire lives in the water column, although there are also crawling forms. For swimming, they have fins on the sides of the body and on the tail. Fish, including salmon, willingly eat chaetognaths, whose body length can reach 9 cm. Of the 140 known species of chaetognaths, only 13 live in the Sea of ​​Okhotsk, of which 7 are deep-sea.

Type echinoderm. This type includes many animals of extremely peculiar appearance: starfish, sea urchins, serpenttails, sea lilies and holothurians, or sea capsules. They are characterized by a calcareous skeleton, which in most groups is clearly visible from the outside, while in holothurians it consists of microscopic calcareous bodies, or needles. The vast majority of echinoderms lead a benthic lifestyle, but their larvae usually develop in the water column. The nervous system and sense organs are poorly developed.

Sea lilies class. Externally, sea lilies bear little resemblance to animals. Like the ancient fossil echinoderms, their mouth opening is at the top, and not on the underside of the body and not in front, like in the rest of the living echinoderms. This is due to the fact that the ancestors of echinoderms led an attached lifestyle, which today is inherited by only a part of sea lilies. The body of the sea line consists of a small body, or calyx, and five long rays, or arms, extending from it, which bifurcate near the base. This gives the impression that there are ten rays. In more primitive lilies, a long stem descends from the calyx, with which they are attached to the bottom. In other lilies that lead a floating lifestyle, the stalk is usually lost and a bunch of antennae develops instead. In the Sea of ​​Okhotsk, only three species of crinoids are known, living at depths of more than 120 m.

Sea stars justify their name - their body really looks like a star, there are usually five rays, less often six or more. The central disk, from which the rays depart, is by no means always clearly expressed, therefore the whole body consists, as it were, of one rays, connected by bases. The starfish moves with the help of soft small sucker legs located in the grooves on the underside of the rays. Despite their small mouth, underdeveloped musculature, and low speed of movement, most starfish are active predators, attacking mainly bivalve molluscs, as well as sea urchins, worms, and other large invertebrates, and even fish.

Opening the shells, the star takes not by force, but by patience. She clasps the shell with her rays, and with her legs firmly sticks to the wings. Stubbornly and methodically trying to move them apart, the predator achieves that the muscle-terminator of the shell of the mollusk is tired and relaxed. Then another wonderful mechanism comes into play: the starfish turns its stomach out through its mouth and envelops the soft body of the mollusk (or other victim) with it. Having digested the prey, the predator crawls to a new place. Starfish are a real disaster for oyster and indium jars, coral reefs, and cultivated invertebrate plantations. Their ability to regenerate is very well expressed: a whole star can grow from one torn off beam.

In most starfish, fertilization is external; larval development passes through several free-floating forms. But it is in the Far Eastern waters that stars without floating larvae are not uncommon. Their eggs mature either in clutches covered with a disk and rays, or in tangles near the mother's mouth, or the eggs and juveniles develop inside the mother's body, and then we can observe cases of live birth.

More than 80 species of starfish have been identified in the Sea of ​​Okhotsk. It was here, or rather in Broughton Bay on the Sea of ​​Okhotsk coast of Simushir Island (the middle Kuril Islands), that a few years ago an employee of the Institute of Marine Biology V.I. Lukin found the world's second largest and largest starfish in the USSR, reaching rays 98 cm.

Serpenttails, or brittle stars, are somewhat reminiscent of starfish, but their body is always sharply divided into a disk and thin, long, sometimes branching rays. Usually these are small animals with a ray span of 1-3 cm, but some forms, for example, a gorgonocephalus with branched tentacles, reach a ray span of 1 m with a disk diameter of up to 143 mm. At least 50 species of brittle stars are known in the Sea of ​​Okhotsk.

The mouth of starfish, serpentine, and sea urchins is at the bottom; they are crawling animals.

Sea urchins are globular, heart-shaped, or disc-shaped organisms; their body is covered with needles, the length and thickness of which varies greatly in different forms. Their whole body is enclosed in a shell, consisting of calcareous plates fastened together and pierced with holes. Needles are movably attached to the shell, which serve not only for protection, but also, along with sucker legs, for movement. The mouth opening is equipped with five teeth of a special chewing apparatus - the Aristotelian lantern. Hedgehogs eat both plant and animal food. Some species of them cause significant damage to seaweed thickets. Most hedgehogs crawl along the bottom, but many are able to burrow and live in minks. Round sea urchins are eaten, and in a number of countries their canned caviar is highly valued. About ten species of sea urchins live in the Sea of ​​Okhotsk, at least three of which may be of commercial importance.

Of all the echinoderms, lovers of sea delicacies are most familiar with sea capsules, or holothurians, which include the famous trepang. The body of holothurians is rather soft, more or less worm-like, the mouth is located at the anterior end and is surrounded by a corolla of short unbranched or long branched tentacles. Most of them have five double rows of sucker legs, but worm-like forms lacking legs are also known. Holothurians lead a bottom lifestyle, but one genus lives only in the water column. Over 30 species of holothurians live in the Sea of ​​Okhotsk, of which only two are commercial - trepang and Japanese cucumaria. Trepang is found in very small numbers in the extreme south of the Sea of ​​Okhotsk, off the coast of southern Sakhalin and Kunashir Island. Kuku City Hall is more widespread, but a significant concentration forms, apparently, a quiet in the South Kurnl Strait, between the islands of Shikotan and Kunashir.

Type chordates. This vast phylum, along with vertebrates, includes a number of much more primitive animals, of which we will focus only on tunicate subtype, or larval-chordates. They live alone or in colonies, in an attached or free-floating state; the dorsal string, or chord, is located in their tail section of the body. True, in most tunicates, the notochord exists only in larvae and subsequently disappears. In the Sea of ​​Okhotsk, representatives of ascidian class- solitary or colonial, almost exclusively attached organisms. Their body is in the form of a bag, one end attached to the substrate. At the opposite end there are two short protrusions - inlet and outlet siphons. The body of the tunicates is enclosed in a special dense shell, or tunic, consisting of a substance close to fiber.

In connection with the sessile-attached lifestyle, the organization of the body of adult ascidians is significantly simplified even in comparison with the structure of the larva; this especially applies to the nervous system and organs of vision - the latter are present in the larva, but absent in the adult animal. Some sea squirts form large ones; often brightly colored forms. Ascidia have no commercial value in our country, although some of their species could become a source of such a valuable element as vanadium, which they accumulate in their bodies.

Vertebrate subtype. Representatives of this subtype live in the Sea of ​​Okhotsk. fish classes And mammals; sea ​​snakes belonging to the class of reptiles are absent here.

Of the nearly 300 species of fish, over 20 species are anadromous and brackish and more than 50 species are deep-sea. The largest number of species (10 or more) in the Sea of ​​Okhotsk are families of flounders (25 species), northern gobies, or sculpins, or slingshots (over 40 species), sea chanterelles, or agony, similar in structure to slingshot gobies (18 species), eelpouts (more than 35 species), lipar, or sea slugs (41 species), lumpfish, or round-finned, sticheevy and salmon (10 species each).

Of this multitude of fish, only salmon occupy a leading place in the fishery, but even then not all of them, but only chum salmon, pink salmon, sockeye salmon, or red salmon, then coho salmon and chinook salmon. In third place are real salmon - Kamchatka salmon and loaches - kunja and malma. The role of sima is not so noticeable in the fishery, and near the Sakhalin coast - Sakhalin taimen, or lentils.

Flounder fish are less valued, the meat of which is much cheaper than salmon, with the exception, perhaps, only of white-skinned and black, or blue-skinned, halibut. Flounders belong to the order of flounders, which are very well adapted to the bottom lifestyle: their body is strongly flattened from the sides, on one of which (right or left - in different families of flounders in different ways) the fish lies on the ground. This side of the body is colored lighter, and the eyes are shifted to the functionally upper, darker side. In real flounders - representatives of the flounder family, which only live in the Sea of ​​\u200b\u200bOkhotsk, the eyes are on the right, although in some species there are separate left-sided forms. In addition to halibut, such flounders as yellow-bellied, yellow-finned, star-shaped, and some other species are of great importance in the Sea of ​​Okhotsk. Many flounders burrow into the ground, and they do this extremely quickly. These fish are also interesting in the ability to quickly change the color of their upper (eye) side of the body, amazingly accurately adjusting it to the color and pattern of the ground, so that they become almost invisible.

Scientists consider the whitefish, smelt and salanx families to be close relatives of salmon. Of the whitefish, mainly living in fresh waters, the Amur whitefish is found in the Amur Estuary and near northern Sakhalin. Of the smelt fish in the Sea of ​​Okhotsk, toothed and small-mouthed smelt, as well as capelin, or hake, are common.

Anadromous fish noodles belong to the Salanx family, sometimes invading the mouths of some rivers in masses. In the Sea of ​​Okhotsk, it is often found in the Amur Estuary and in the Baikal Bay in the north of Sakhalin Island.

The salmon-like order also includes some deep-sea and therefore little-known families of fish, for example, silverfish, bathylag, and some others.

One can not say much about the value of sturgeon, including the Sakhalin sturgeon, but it is very rare, only recorded in Aniva Bay and the Amur Estuary. In the same estuary, there are also Amur sturgeon and a much larger relative of sturgeon than sturgeons, a relative of the beluga - kaluga, reaching a length of 5.6 m with a mass of 380 kg. The main habitat of the Amur sturgeon and Kaluga is the Amur River. The catch of sturgeon fish in the Sea of ​​Okhotsk is extremely insignificant.

The Pacific herring is of much greater commercial importance, having chosen for spawning coastal areas in the north of the Sea of ​​Okhotsk and off the coast of Sakhalin and Kamchatka.

The only species of cyprinids that live not in fresh, but in brackish and sea waters is the Far Eastern rudd, or ugai. This fish reaches a length of 50 cm and weighs up to 1.5 kg. In the Sea of ​​Okhotsk, the rudd lives in the Aniva Bay, as well as in the west, in the Amur Estuary, the Bay of Happiness and to the north, up to the Shantar Islands. Ugay serves mainly as an object of amateur fishing.

Pacific cod is ubiquitous in the Sea of ​​Okhotsk, but its largest concentrations are noted off the western coast of Kamchatka. Being a subspecies of the Atlantic cod, pasha cod differs from it in a larger and wider head, bottom caviar and, unfortunately, coarser and less tasty meat. The length of the Pacific cod reaches 120 cm.

If cod is the most numerous cod fish in the Atlantic Ocean, pollock undoubtedly belongs to the Pacific Ocean. Pollock is much smaller than cod, its meat is less tasty, but its liver contains more vitamin A than the famous cod liver, from which medical fish oil is rendered. Pollock is widespread in the Sea of ​​Okhotsk, especially in its northwestern and northern parts, as well as off the coast of Sakhalin and Kamchatka.

Unlike cod, the Pacific saffron cod is so unlike its northern namesake that it is distinguished as an independent species. It is found off the coast of all the Far Eastern seas, is tasty and serves as an object of not only commercial, but also amateur fishing, usually in winter, when saffron cod is suitable for spawning.

Sticklebacks are a special family of small fish with foldable spines on their back and belly and often with bony plate armor on the sides of the body. Along the coast of the Sea of ​​Okhotsk there is a three-spined stickleback (with three spines on its back). The stickleback is considered a "weedy" fish, but its fat has valuable properties and is used in medicine for the treatment of wounds, as well as for technical purposes. Another species, the nine-spined stickleback, was noted at the mouth of the Amur and in the brackish waters of lagoons and bays. The male stickleback is known as a caring family man. The object of his special troubles is a nest, which he builds from various plant residues, sticking them together with sticky threads. Usually it is fixed either on the ground (in the three-spined stickleback), or on the stems of underwater plants (in the nine-spined stickleback),

The perch-like order includes a large number of fish families of a very diverse, often rather bizarre shape. True, only a few of them are of commercial importance in the Sea of ​​Okhotsk. To the suborder of dog-like perch-like fish belong fish with an elongated, often eel-shaped body, bearing very long dorsal and anal fins and covered with small scales. Many of them, especially those without scales, are called by the local population "loaches" or "burbots", although real loaches are freshwater fish from the cyprinid order, and burbots are freshwater and marine fish from the cod-like order.

Large sizes, over 1 m in length, reach the eastern catfish. Its relatively large head is armed with large teeth, giving it an intimidating appearance. This fish is equipped not only with sharp teeth in front, but also tubercular and conical teeth located on the palate and on the lower jaw behind the canine-shaped anterior ones. Such an “arsenal” is required for catfish not so much for defense or attack, but for tearing off mollusks, crustaceans and echinoderms from the bottom, on which it mainly feeds. Its meat is quite tasty, but catfish are almost never caught in the Sea of ​​Okhotsk; in the Sea of ​​Okhotsk, the eastern catfish is found in the Ayan region, in Aniva Bay and in the south of the Kuril Islands.

The eastern viviparous eelpout is interesting in that it does not spawn, but gives birth to (usually several dozen) fry. The Germans still call the European subspecies close to it "the acne mother". According to legend, for a long time German fishermen could not find out how and where the common eel breeds, and innocently believed that the eel gives birth to eels. The same family of eelpouts also includes lycods, some of which reach 0.7-1 m in length. These cold-water bottom fish usually live on silty bottoms, sometimes burrowing into loose substrate.

The well-known Japanese mackerel, numerous in Peter the Great Bay, off the coast of southern Sakhalin and in the south of the Kuril Islands, belongs to the mackerel suborder. In favorable years for her, she also penetrates to the north - up to Okhotsk. Mackerel length 50-60 cm with a maximum weight of 1.5-1.7 kg. Making constantly significant migrations, this fish penetrates into our seas only when the waters warm up to 8-10 ° and more.

Also numerous in the Sea of ​​Okhotsk is a detachment of scorpionfish close to the perciformes. The scorpionfish family includes commercial sea bass, scorpionfish, or sea ruffs, and spiny cheeks. In contrast to the scorpionfishes, which are widespread in various oceans, the suborder of the greenlings inhabited only the northern part of the Pacific Ocean. Only two families belong to it, one of which, which includes coal fish valuable in its taste, unfortunately, is absent in the Sea of ​​Okhotsk. Representatives of another family of greenlings - one-feathered and eyebrowed greenlings - are common here. They can be distinguished by a long dorsal fin, which in a single-finned greenling has no notch, while in a browed one it has a noticeable notch approximately in the middle. In the Sea of ​​Okhotsk, several species of browed greenlings are of commercial importance: brown, spotted and red, or hare-headed. The one-finned greenling is found in small numbers in Aniva Bay and in the south of the Kuril Islands. The meat of different species of these fish varies in taste and even in color. In some species, it is green or bluish, but when cooked, however, it becomes discolored. In the trading network, greenlings are often sold under the name sea bass, which is not true.

The scorpion-like order also includes an extensive suborder of sculpins, the skin of which is usually not covered with normal scales and is either naked or bears plates, spines or tubercles. Many representatives of this suborder are often called gobies, although real gobies belong to another order - perciformes. The appearance of sea chanterelles is peculiar: their body is covered, like armor, with regular longitudinal rows of plates. These are small, up to 20 cm in length, bottom fish, the body shape of which often resembles a spindle. They are not eaten, but after soaking in a solution of formalin and alcohol, followed by drying, original souvenirs come out of them.

Sea slugs, completely devoid of scales, large-headed, with soft muscles and thin, often transparent skin, and you can’t even call fish right away - they so strikingly resemble tadpoles. Their ventral fins merge and form a sucker. The genus Kaleprocts is especially richly represented in our country, for which the Sea of ​​Okhotsk, apparently, is the ancestral home. In any case, about half of all known species of this genus (22 out of 48) live in the Sea of ​​Okhotsk. Sea slugs spawn in winter. The female by this time grows an ovipositor in the form of a long leathery tube. With the help of this device, she lays mature eggs in the peribranchial cavity of the king crab. Here, the eggs are inaccessible to predators and are provided with oxygen, since the gills of the crab are constantly washed by water.

Of the few representatives of cartilaginous fish in the Sea of ​​Okhotsk, only one species of small spiny shark, or katran, rarely reaches a length of 2 m and weighs about 14 kg. This shark does not spawn, but gives birth to small (20-26 cm long) sharks. The spiny shark is edible, and many find its meat even delicious. One or two species of skates recorded in the Sea of ​​Okhotsk - strongly flattened benthic cartilaginous - have no commercial value.

mammals. The Sea of ​​Okhotsk with the Kuril Islands adjacent to it has long been mastered by marine hunters. A number of valuable mammals lived here, such as the sea otter, or sea otter, seal, various whales, etc. But in the second half of the 19th century, as a result of the invasion of poachers from the USA, Canada, Germany, Norway, Japan and England, the stocks of marine mammals in Sea of ​​Okhotsk were severely undermined, some species were completely exterminated (walrus and bowhead whale) or were on the verge of extinction. Particularly affected was the sea otter, or sea otter, the only marine representative of a vast order of predators. The sea otter belongs to the marten family, and, indeed, is quite close to another representative of the marten - the river otter. The fur merchants, who called it the sea, or Kamchatka, beaver, apparently drew attention to some external similarity between the fur of the beaver and the sea otter, but the beaver belongs to another order - rodents. The sea otter is a rather large animal, especially in comparison with its relatives: the body length of the male can reach almost 1.5, and the female - 1.3 m with a weight of up to 42 and 36 kg, respectively. The delicate and silky fur of the sea otter is extremely durable, which naturally further enhances its value. Despite its marine "registration", the sea otter is less adapted to the aquatic lifestyle than pinnipeds and cetaceans. In particular, he has practically no subcutaneous fat. Sea otters keep close to the coast and are not inclined to embark on long journeys.

An elongated valky body with a shortened neck, hind limbs strongly shifted to the lower end of the body and a shortened flattened tail prevent the sea otter from moving freely on land, but it helps him when hunting for various marine animals. Sea otters feed mainly on sedentary large invertebrates: sea urchins, crabs, gastropods and bivalves, usually endowed with a solid external skeleton. In this regard, their molars are very wide, strongly flattened and millstone-shaped. Back in the 18th and even partly in the 19th century, sea otters were found in abundance in the Sea of ​​Okhotsk off the coast of southwestern Kamchatka, all the Kuril Islands and southeastern Sakhalin. Nowadays, the sea otter is common only off the coast of some islands in the northern and middle parts of the Kuriles.

pinnipeds. By structure, pinnipeds are close to terrestrial predatory animals, but stand out as an independent detachment adapted to an aquatic lifestyle. Their body is elongated, spindle-shaped, balky, the head, devoid of a neck constriction, smoothly passes into the body. With the help of flippers, the fingers of which are connected by swimming membranes, pinnipeds move in the water. The hind limbs, strongly shifted back, impart a forward movement to the animal, bending like the tail of a fish. The front flippers act as rudders. A thick subcutaneous fat layer, and in young seals, as well as fur seals, and warm fur help to endure low temperatures in the aquatic environment. Pinnipeds feed on fish, mollusks, crustaceans and other large invertebrates.

Pinnipeds include families of eared and true seals, as well as walruses, which were once found in the Sea of ​​Okhotsk. Recently, many researchers believe that eared and true seals originated from different groups of predators: eared seals from primitive bear-like seals, and true seals from primitive mustelids. Spending most of their lives in the water, the pinnipeds, however, could not completely break away from the land, at least from a solid substrate. In the first days of life, seal cubs, once in the water, die from the wetting of the fur cover and subsequent hypothermia. Since the pup of many seals occurs directly on the ice, their milk contains up to 40% fat. The assertion that seals cause significant damage to fisheries is without sufficient grounds. Most of them feed on low-value fish, except for the spotted seal. does not encroach at all on shoals of salmon and herring.

Two species of eared seals and four species of real ones live in the Sea of ​​Okhotsk.

Eared seals (seals and fur seals) when moving on the ground rely on their hind limbs, bending them forward. The largest of them is the sea lion, or sea lion, reaching a length of 4 m and weighing up to 800 kg. True, only males are such healthy men. Although females are inferior to them, they are not at all so small - up to 2.5 m in length with a weight of up to 350 kg. The fur cover of the sea lions consists of coarse sparse hair. Coloration changes with age, from chestnut in juveniles to straw in adults. Their rookeries for breeding young sea lions arrange on secluded rocks or on uninhabited islands. Males acquire "harems", which can include up to several dozen females. "Bachelors" and "youth" lie at a distance from both harems and from each other.

In the Sea of ​​Okhotsk, sea lion rookeries have been noted near the Shantar Islands, on the Zavyalov, Yamsky, Iona, Kuril Islands, and sometimes in Zabiyak and Babushkin Bays. Animals live here only in summer, and then they swim south.

The fur seal is undoubtedly the most valuable commercial pinniped animal. It is much smaller than the sea lion, although the male reaches an impressive size - up to 2 m in length. The female is smaller than the male, her body length does not exceed 1.25 m. Not all fur is valued in a cat - the hair itself, like that of other seals, is hard, but soft, thick underfur, which is absent in other seals. Seals come to our seas only for the summer-autumn period for breeding. Like the sea lions, the cat is a polygamous animal. Within the Sea of ​​Okhotsk, fur seals are found on some of the Kuril Islands. On Tyuleniy Island, near Sakhalin, a wildlife reserve has been organized with strictly limited hunting for these animals.

Unlike eared seals, real seals do not have auricles, the hind limbs cannot bend forward and, when animals move on land, they drag along the ground. Four species of true seals live in the Sea of ​​Okhotsk - ringed seal, lionfish, spotted seal and bearded seal.

The inhabitants of the coast of the Sea of ​​Okhotsk often call the ringed seal also akiba, or akipkon. This is the smallest of the Far Eastern seals: its body length does not exceed 140 cm, and its weight is 55 kg. Akiba settled along the western coast of the Sea of ​​\u200b\u200bOkhotsk - from the Tauiskaya Bay to the Shantar Islands and Sakhalin Bay, as well as along the eastern shores of Shelikhov Bay and Sakhalin Island. She whelps in early spring, in March - April, on the ice near water holes and polynyas, sometimes making holes herself. The fur of puppies, white, soft and very fluffy, perfectly protects them from the cold and at the same time disguises them. In an adult akiba, light rings clearly appear on the body on a blackish-gray, gray or brownish background. Its coat, relatively denser and longer than that of other true seals, is used for making fur products.

The lionfish is also called Ilyar, hilar, young fish, shelduck, or piebald seal. It is larger than the akiba and reaches a length of 180-190 cm with a mass of up to 100 kg. The lionfish is less connected to the shore than other seals and spends most of its life on the high seas. An air sac located under the skin and communicating with the trachea helps it float on water. It is worth letting the air out of it, as the lionfish immediately sinks.

The male is dark, black or black-brown, the female is gray or brown; against a dark background, light stripes stand out on the sides of the body and in the form of a collar on the neck, as well as in the region of the sacrum. The lionfish does not climb onto the ice floe, clinging to it with its front flippers, as other seals do, but jumps out without touching the edge. In the Sea of ​​Okhotsk, this piebald seal lives mainly northeast of Sakhalin and south of Babushkin Bay. It lies on high clear ice.

Spotted seals, spotted seals, or spotted seals are characterized by numerous black or brown spots on a yellow or gray background; the flippers are also spotted. The length of the body in rare cases can exceed 2 m. Pied usually settles in lagoons, bays and small bays, penetrating south to the coast of Japan and Korea, that is, further than our other seals. Feeding mainly on fish - in the summer, mainly salmon, - during their course, the spotted seal often rises into the rivers for considerable distances. In summer, in the northern part of the Sea of ​​Okhotsk, almost everywhere you can observe its coastal haulouts. Animals remain here until the onset of ice or even further. In the north of the Sea of ​​Okhotsk, spotted seals breed in April. Its commercial accumulations are noted in the southern part of Shelikhov Bay and near southern Sakhalin.

Lakhtak, or sea hare, is the largest representative of the true seal family in the Far Eastern seas. Its body reaches a length of 230 cm and weighs up to 280 kg. The color is monophonic, ashy or gray, without spots. Unlike akiba, lionfish and spotted seals, bearded seal cubs are not white, but light ashy in color. Bearded seals feed not on fish, but on large benthic invertebrates - molluscs, echinoderms, crustaceans, etc. Therefore, bearded seals usually stay near the coast, foraging at depths of up to 100 m.

In the Sea of ​​Okhotsk bearded seal is most numerous in the northern and western regions, as well as in the Gulf of Patience.

cetaceans. In contrast to the sea otter and pinnipeds, cetaceans have become typical aquatic animals, although they breathe, like all mammals, atmospheric air. Most cetaceans, especially large ones, die when they dry out, suffocating under the weight of their own body. With their torpedo-shaped body, these animals resemble fish, but the blades of the caudal fin are not located in a vertical, like in fish, but in a horizontal plane. The auricles, coat and hind limbs of cetaceans have completely disappeared, and the forelimbs have turned into flippers and function as rudders. The tail serves as the main organ of movement in the water.

All neoplasms in this detachment are purely adaptive. The dorsal fin gives the animal greater stability. Bare, elastic, non-wetted skin weakens the friction of water on the surface of his body during rapid movement. Other adaptations include a powerful subcutaneous fat cover, the development of bundles of blood vessels in the fins of a special device important for thermoregulation, a sharply increased content of respiratory pigments - hemoglobin in the blood and myoglobin in the muscles ... Thanks to these and a number of other acquisitions, cetaceans can be in water up to 50 minutes, and sperm whales up to 1.5 hours, plunging hundreds of meters deep.

For life in the sea, an echolocation apparatus is indispensable, which has become the main means of orientation in the water for cetaceans. The exceptionally high calorie content of milk, containing up to 53% fat and up to 13.4% protein, should also be attributed to the number of adaptations to an aquatic lifestyle. The fact that the cub is born with its tail, and not head first, allows it not to suffocate during childbirth.

The cetacean order includes two suborders - baleen and toothed. Until now, disputes about their origin do not stop. Some scientists believe that these suborders originated from common ancestors - some ancient predators. Others deduce the genealogy of baleen and toothed whales from different groups, and explain the similarities by adaptation to an aquatic lifestyle.

The suborder of baleen whales includes the families of minke whales, right whales and gray whales. It was baleen, especially smooth, whales that for a long time were the object of predatory fishing by foreigners in the Sea of ​​Okhotsk. That's why there aren't many of them now. Making extensive migrations in the ocean, baleen whales enter the Sea of ​​Okhotsk in the summer for fattening. The filtering apparatus with which they extract food is noteworthy. This is nothing more than a set (130-400 on each side) of horny plates - a whalebone, with which the palatine processes of the maxillary bones are equipped. The inner edge of the plate is split into a mass of bristles resembling a fringe. Teeth in adult baleen whales are completely absent.

The largest whale and, in general, the largest animal that has ever existed on Earth is the blue whale, whose length can reach 33 m. Nowadays, this giant can only occasionally be seen in the Sea of ​​Okhotsk, where it sometimes comes for feeding, holding on mainly in the Kuril region.

The second largest minke whale, reaching 27 m in length, is the herring whale, or fin whale. This is one of the most important commercial whales, often visiting the Sea of ​​Okhotsk during the warm season. In the south of the Kuril Islands, not as large as blue and herring whales, willow whales, or sei whales (up to 18.6 m in length) are quite numerous. A frequent visitor to the Sea of ​​Okhotsk and the Kuril Islands, and the smallest of minke whales (up to 10 m in length) is small.

The humpback whale, or humpback whale, belongs to another genus, but to the same family of striped whales. The humpback whale's body is thicker and less slender than that of minke whales; pectoral fins are very large. The length of humpbacks is up to 17 m.

The food of striped whales depends on their location. They feed mainly on various crustaceans, mainly Euphausiidae, fish and, to a lesser extent, cephalopods and pteropods.

Of the smooth whales in the Sea of ​​Okhotsk, only the Japanese whale is found - the North Pacific subspecies of the southern right whale, reaching a length of 20 m. Previously, this whale was found in large numbers near the Shantar Islands, in the Ola-Tauisky Bay, Penzhinskaya Bay and Kambalnaya Bay, but because of predation foreign whalers (in the middle of the 19th century, up to 250 ship crews beat whales annually in the Sea of ​​​​Okhotsk), its reserves were sharply undermined. In the days after right whales were legally protected in 1946, the Japanese whale herd is gradually recovering. But the bowhead whale, represented in the Sea of ​​Okhotsk by a small form - "poggy", could not be saved: "poggy" were completely exterminated in the last century. Right whales feed on small copepods and euphausian crustaceans, as well as pteropods.

Unlike minke whales and smooth whales, the gray whale, allocated to a separate family, gets food at the bottom. The basis of its diet is benthic and benthic crustaceans, mainly amphipods. In the Far Eastern seas of the USSR, the gray whale feeds from May to October. In the Sea of ​​Okhotsk, it is usually found off the Shantar Islands and off the western coast of Kamchatka. In length, the gray whale reaches 15 m with a mass of up to 30 tons. Currently, ship fishing for this whale is prohibited.

The suborder of toothed whales is more numerous and rich in species than baleen whales. Representatives of the sperm whale, beaked and dolphin families live in the Far Eastern seas. The appearance of sperm whales is very unattractive: due to the strong development of the fat pad, the head is disproportionately large, and its front part is much longer than the lower jaw. While the upper jaw of sperm whales is almost toothless, the narrow lower jaw is seated with conical teeth, the number of which varies from 8 to 30 pairs. Of the two species of this family - the sperm whale and the pygmy sperm whale - only the sperm whale, the largest of the toothed whales, is found in the Sea of ​​Okhotsk. The male is much larger than the female - its length can exceed 20 m, while the female does not even reach 16 m. The sperm whale is the best diver among whales. There are cases when sperm whales got entangled in telegraph cables at depths up to 1128 m and perished. The food of these whales is cephalopods and, to a lesser extent, fish. In the Sea of ​​Okhotsk, sperm whales can often be found in the south and near the Kuril Islands.

Beaked whales are relatively large or medium-sized toothed whales. Their mouth is located at the front end of the head, which is pulled forward, forming a kind of beak. There are no teeth in the upper part, and only one or two pairs (rarely more) in the lower part. In the Sea of ​​Okhotsk and in the region of the Kuril Islands, the northern swimmer is quite common. This is a medium-sized whale - up to 12 m in length. It feeds mainly on squid, less often on fish. In the USSR, it was almost not mined, especially since its meat and fat are inedible.

The dolphin family is the largest and includes a significant number of small and medium-sized cetaceans, the length of which does not exceed 10 m. Both jaws of most dolphins are full of teeth!

In the cold waters of the seas of the North Arctic Ocean, as well as in the northern regions of the Atlantic and Pacific oceans, there is a beluga whale - a large, up to 6 m long, dolphin, without a dorsal fin. The color of the body in adults is white or yellow, in young ones it is darker. Chasing shoals of salmon, the voracious predator sometimes rises thousands of kilometers upstream the Amur. Once it was discovered even in Argun! Beluga whale lives at the expense of fish, but does not disdain invertebrates and even algae.

The killer whale is the largest representative of the dolphin family. It got its name because of the highly developed and raised dorsal fin, resembling a scythe. This is the most dangerous predator of all marine animals. Its diet consists of fish, cephalopods and marine mammals - cetaceans, pinnipeds and sea otters, and if you're lucky, then birds. Hunting in herds, killer whales attack even very large cetaceans. The swimming speed of killer whales can reach 55 km per hour.

Of the other dolphins in the Sea of ​​Okhotsk, the white-winged porpoise, the common dolphin are found, and in the area of ​​the Kuril Islands, in addition, the striped dolphin, northern cetacean, Pacific short-headed and gray dolphins, pilot whale and small, or black, killer whale.

The Sea of ​​Okhotsk is one of the largest and deepest seas in Russia. Important sea routes pass here, connecting Vladivostok with the northern regions of the Far East and the Kuril Islands. Major ports on the coast of the mainland - Magadan and Okhotsk; on Sakhalin Island - Korsakov; on the Kuril Islands - Severo-Kurilsk.

The Sea of ​​Okhotsk was discovered by Russian explorers I. Yu. Moskvitin and V. D. Poyarkov in the first half of the 17th century. In 1733, work began on the Second Kamchatka Expedition, whose members compiled detailed maps of almost all of its shores.

The Sea of ​​Okhotsk, also called the Lamsky or Kamchatka Sea, is a semi-enclosed sea in the northwestern part of the Pacific Ocean. It washes the shores of Russia and Japan (Hokkaido Island).

From the west, it is bounded by the mainland Asia from Cape Lazarev to the mouth of the Penzhina River; from the north - the Kamchatka Peninsula; from the east by the islands of the Kuril chain and from the south by the islands of Hokkaido and Sakhalin.

The Sea of ​​Okhotsk is connected to the Pacific Ocean through the Kuril Straits. There are more than 30 such straits and their total width is more than 500 kilometers. It has communication with the Sea of ​​Japan through the Nevelskoy and La Perouse straits.

Characteristics of the Sea of ​​Okhotsk

The sea is named after the river Okhota, which flows into it. The area of ​​the Sea of ​​Okhotsk is 1,603,000 square kilometers. Its average depth is 1780 meters, with a maximum depth of 3916 meters. From north to south, the sea stretches for 2445 kilometers, and from east to west for 1407 kilometers. The approximate volume of water enclosed in it is 1365 thousand cubic kilometers.

The coastline of the Sea of ​​Okhotsk is slightly indented. Its length is 10460 kilometers. Its largest bays are: Shelikhov Bay, Sakhalin Bay, Udskaya Bay, Tauyskaya Bay and Academy Bay. The northern, northwestern and northeastern shores are high and rocky. At the confluence of large rivers (Amur, Uda, Okhota, Gizhiga, Penzhina), as well as in the west of Kamchatka, in the northern part of Sakhalin and Hokkaido, the coasts are predominantly low.

From October to May-June, the northern part of the sea is covered with ice. The southeastern part practically does not freeze. In winter, the water temperature near the sea surface ranges from -1.8 °C to 2.0 °C, in summer the temperature rises to 10-18 °C.

The salinity of the surface waters of the Sea of ​​Okhotsk is 32.8-33.8 ppm, while the salinity of coastal waters usually does not exceed 30 ppm.

Climate of the Sea of ​​Okhotsk

The Sea of ​​Okhotsk is located in the monsoon climate zone of temperate latitudes. For most of the year, cold dry winds blow from the mainland, cooling the northern half of the sea. From October to April, negative air temperatures and a stable ice cover are observed here.

In the northeastern part of the sea, the average temperature in January - February ranges from -14 to -20 ° C. In the northern and western regions, the temperature varies from -20 to -24 ° C. In the southern and eastern parts of the sea, it is much warmer in winter from -5 up to - 7 ° С.

Average temperatures in July and August, respectively, wound 10-12 ° C; 11-14°C; 11-18 ° C. The annual amount of precipitation in different places of the Sea of ​​Okhotsk is also different. So in the north, 300-500 mm of precipitation falls annually; in the west up to 600-800 mm; in the southern and southeastern parts of the sea - over 1000 mm.

According to the composition of organisms living in the Sea of ​​Okhotsk, it is more of an arctic character. Due to the thermal effect of oceanic waters, species of the temperate zone are predominantly inhabited by the southern and southeastern parts of the sea.

Numerous settlements of mussels, littorinas and other mollusks, barnacles, sea urchins, and many crabs are noted in coastal zones.

A rich fauna of invertebrates has been discovered at great depths of the Sea of ​​Okhotsk. Glass sponges, holothurians, deep-sea corals, decapods live here.

The Sea of ​​Okhotsk is rich in fish. The most valuable are salmon species: chum salmon, pink salmon, coho salmon, chinook salmon and sockeye salmon. There is an industrial catch of herring, pollock, flounder, cod, navaga, capelin and smelt.

Large mammals live in the Sea of ​​Okhotsk - whales, seals, sea lions and fur seals. There are many sea birds that arrange noisy "bazaars" on the coasts.

The UN recognized the enclave of the Sea of ​​Okhotsk as part of the Russian shelf

Inessa Dotsenko

The UN Commission on the Limits of the Continental Shelf recognized the enclave of the Sea of ​​Okhotsk with an area of ​​52,000 square kilometers as part of the Russian continental shelf.

According to ITAR-TASS, this was stated by Russian Minister of Natural Resources and Ecology Sergei Donskoy.

We have officially received a document from the UN Commission on the Continental Shelf on the satisfaction of our application to recognize the enclave in the Sea of ​​Okhotsk as the Russian shelf. This is an event that has actually taken place, so I would like to congratulate everyone on this,” he said.

The commission's decision, according to the minister, is unconditional and has no retroactive effect. Now the enclave is fully subject to Russian jurisdiction.

According to ITAR-TASS, Donskoy also said that Russia's application for the expansion of the continental shelf in the Arctic will be ready this fall.

All the resources that will be found there - everything will be mined exclusively within the framework of Russian legislation, - said Donskoy. He said that, according to geologists, the total volume of hydrocarbons discovered in this area exceeds one billion tons.

Magadan Governor Vladimir Pecheny believes that the recognition of the enclave in the middle of the Sea of ​​Okhotsk as part of the Russian continental shelf opens up new prospects for the economy of Kolyma and the entire Far East. First of all, it will relieve the fishermen of the region from numerous administrative barriers.

Firstly, fishing for fish, crabs, shellfish can be carried out freely anywhere in the Sea of ​​Okhotsk. Special permits from the border service will not be required both when going to sea and upon returning. Secondly, when not only the 200-mile zone, but the whole sea becomes Russian territory, we will get rid of poaching by foreign fishermen in our waters. It will be easier to keep the unique environment, - the press service of the government of the region quotes the words of Baked.

Reference

In the center of the Sea of ​​Okhotsk there is an elongated enclave of considerable size. Previously, all of it was considered "open sea". Vessels of any state could freely move and fish on its territory. In November 2013, Russia managed to prove the rights to 52,000 square kilometers of water in the center of the Sea of ​​Okhotsk. For comparison, this is more than the area of ​​Holland, Switzerland or Belgium. The center of the Sea of ​​Okhotsk ceased to be part of the World Ocean and became completely Russian. After approval at the UN session, the process of legally assigning the enclave to the Russian continental shelf can be considered fully completed.