Atoll definition. Other natural resources. Fresh water, flora and fauna of the atolls
ATOLL
ring-shaped coral reef surrounding the water area. Coral reefs distributed in tropical and subtropical latitudes, most widely in the Pacific and Indian Oceans. The word "atoll" comes from the name used by the peoples of Oceania for reefs that form a chain of small islands, rising 4-6 m above the surface of the water. Sometimes reefs are flooded, and between their individual parts there are deep straits. The lake-like waters within the atolls are called lagoons. Usually their depth is 18-30 m, but sometimes it reaches 90 m.
Structure. The main material from which coral reefs are built is limestone, formed as a result of the accumulation of skeletons of marine animals and plants containing calcium carbonate, mainly corals and coralline algae. Islets scattered along the reefs usually consist of limestone fragments and crumbs - products of wave activity. Often, small dunes are formed from this material under the influence of wind. The outer coast of most of the atoll islands is a rather narrow strip of fringing reefs, often with an even border of massive pink calcareous algae and steep, narrow beaches composed of limestone fragments. Behind the coastal ridge of the beach, coarse-grained material is replaced by crushed stone, which is further replaced by gravel as it is crushed. In the center of the islet there is often a depression filled with saline soil stained with humus. The interior of the islet is usually composed of coarse-grained coral sand or fine gravel, while the central parts of the beach are composed of fine calcareous sand. If the atoll is completely raised above sea level, then the limestones composing it usually erode and form a rough surface - "macatea". The groundwater level is very close there, and small wells are often dug near the center of the islands. If the island is large or there is a lot of rainfall, then the groundwater is almost fresh, but if it is small or located in an area with little rainfall, then the groundwater is brackish or saline.
Flora. The vegetation cover is the most remarkable characteristic of the surface of the atolls. It is sparse and most often consists of several species of widespread herbaceous plants and tree species that live in the coastal strip. In the distribution of vegetation, a certain zonality is observed in the direction from the outer edge of the atoll to the inner one. She may be in in general terms described for the entire Indo-Pacific region, where atolls are especially numerous, and their flora is of the same type. The outer zone is represented by shrubs, among which the shrub scaevola (Scaevola frutescens) predominates. This is followed by forests, mainly from such halophytes as silver messerschmidia (Messerschmidia argenta) and roofing pandanus (Pandanus tectorius). Even farther from the coast, there are fewer halophytes, and cordia (Cordia), large pisonia (Pisonia grandis), ochrosia (Ochrosia) and other species appear. In the center, in more mesophytic conditions, the primary vegetation cover probably consisted of such trees as the magnificent leopard (Guettarda speciosa), lime-shaped hibiscus (Hibiscus tiliacens), ficus, pisonia, pandanus, Asian barringtonia (Barringtonia asiatica), terminalia (Terminalia) and etc. On most of the islands, these forests were subsequently replaced by plantations of coconut palms and breadfruit. The inner zone of the beaches is characterized by a narrow strip of trees such as hernandia, calophyllum, pandanus, thespesia, cordia. On sandbars Suriana maritima and scaevola are usually found between the islets, and sour pemphis (Pemphis acidula) at rock outcrops. In places, in the inner parts of the islets, waterlogged depressions are found, and in some of them they are confined to hard rocks. In such conditions, some tree species typical of mangrove swamps are found. Other islets are swampy and treeless, dominated by grasses and sedges. On inhabited islands, soil is taken out of these depressions and filled with humus, and then used to grow taro, sugar cane and other plants. Due to the salinity of the soil, few (except those listed above) cultivated plants can grow on low coral islets. Taro, breadfruit and coconuts are the main food of the population, in addition, coconuts are a source of drinking water.
Other Natural resources.
The vast majority of the atolls are inhabited, and there, crop production depends on the potential fertility of nutrient-poor saline soils. The main crop is coconuts. Along with the above plants, the basis of the diet of the population is fish and shellfish, which abound in lagoons, reefs and adjacent open water areas. Other trade items are guano, pearls, shells for making buttons and dried holothurians. The most fertile are the large atolls that rise above sea level, especially if they are confined to very humid areas. They feature much more lush vegetation, richer flora, and a much more diverse array of crops. Apparently, all this is associated with lower soil salinity. On the uplifted atolls, there are often large deposits of phosphorites (probably formed from ancient deposits of guano). Such atolls include the islands of Makatea, Nauru, Ocean, Angaur. Guano deposits on many atoll islands were formed as a result of the life of sea birds - gannets, frigatebirds, terns and tropical birds that breed here. In addition to the listed birds and land crabs, including the palm thief, the terrestrial fauna is poor: rats dominate, and fruit bats (fruit-eating bats) are numerous in the western Pacific Ocean. The waters abound with turtles, spiny lobsters, giant bivalves, and many kinds of fish. The rich fauna of the reefs includes many species of invertebrates.
famous atolls. The largest groups of atolls in the Indian Ocean are the Maldives and Laccadives; V pacific ocean- Caroline, Marshall, Gilbert Islands in Micronesia, Tuamotu and others in Polynesia; a large number of atolls are scattered throughout Melanesia. IN Atlantic Ocean there are several atolls in the Lesser Antilles group, in addition, the Bahamas include a number of atolls that are not typical. The largest atoll in terms of area (with a relatively small lagoon in the center) is Christmas Island in the equatorial Pacific Ocean. The largest lagoon is apparently located on Kwajalein Atoll (Marshall Islands), although lagoons of almost the same size are found on some other atolls.
See also CORAL REEFS.
LITERATURE
Ravikovich A.I. Recent and fossil reefs. M., 1954 Geography of the atolls of the southwestern part of the Pacific Ocean. M., 1973
Collier Encyclopedia. - Open society. 2000 .
Synonyms:See what "ATOLL" is in other dictionaries:
Modern Encyclopedia
- (Atoll) lagoon reef, a special kind of island. A ring-shaped strip of land surrounding an inland shallow lake or lagoon. Usually A. rises above sea level by several meters. The depth in the lagoon is small; 60 150 m (30 80 sea fathoms), while ... ... Marine Dictionary
Coral island, reef Dictionary of Russian synonyms. atoll n., number of synonyms: 9 bikinis (5) ... Synonym dictionary
atoll- a, m. atoll m., eng. Coral island. Atolian oh, oh. Sometimes the tentacles of an octopus were pushed into the hole, which, apparently, methodically ransacked the atoll jar. A. Kim Fish Simplicitas. // NM 1997 4 102. Lex. Dal: atol; Toll 1863: atoll; SAN 1891 ... Historical Dictionary of Gallicisms of the Russian Language
Atoll- (from the Malay adol closed), a coral building with a shallow lagoon in the middle, connected to the ocean through one or more straits. The base of an atoll is usually the summit. underwater volcano. Distributed in tropical latitudes ... ... Illustrated Encyclopedic Dictionary
A coral structure, in the form of a solid or broken ring, surrounding a shallow lagoon. The base of an atoll is usually the summit of an underwater volcano. Widespread in the tropical latitudes of the Pacific and Indian Oceans ... Big Encyclopedic Dictionary
ATOLL, a ring-shaped CORAL REEF surrounding a shallow LAGOON. The reef appears initially as a frame for an island slowly sinking into the water, usually of volcanic origin. As the island sinks, the coral continues to grow... Scientific and technical encyclopedic dictionary
ATOLL, atoll, husband. (Malay). Ring-shaped coral island. Explanatory Dictionary of Ushakov. D.N. Ushakov. 1935 1940 ... Explanatory Dictionary of Ushakov
ATOLL, a, husband. Ring-shaped coral island. | adj. atoll, oh, oh. Explanatory dictionary of Ozhegov. S.I. Ozhegov, N.Yu. Shvedova. 1949 1992 ... Explanatory dictionary of Ozhegov
There are a huge number of islands in the world, some of them appeared tectonically, that is, due to the movements of the earth's crust. Others broke away from the mainland. Finally, there are those for the origin of which living organisms are responsible. The article will tell you what atolls are, how they appeared, what are their features.
Etymology
The noun "atoll" comes from the Maldivian word "atolhu" (atolhu), which, in turn, comes from the root atollon, which in the language of the natives means "closed, closed." Already this information is enough to suggest that the word "atoll" means something closed.
Meaning
Referring to any dictionary, you can find out the meaning of the term. What is an atoll? This is an island created by corals, in the form of a ring (often closed, although an interrupted version is acceptable), located in the lagoon. It should also be noted that this is a certain elevation in the ocean, on which, thanks to coral organisms, a kind of land arose. Since such an elevation is located on ocean floor most often on the crater of a dormant volcano, its corresponding shape is cone-shaped.
Considering what an atoll is, we note that it belongs to biogenic islands, that is, created by living organisms.
Structure
Of particular interest is the structure of such an island. It has 3 parts:
- The outer slope of the reef. Most of the time, he's pretty cool. It is here that two opposite processes take place - the formation of coral material and its destruction under the influence of waves.
- Platform. It is a platform, the width of which can reach several hundred meters and even kilometers.
- Lagoon (water area inside the atoll). As a rule, it has a shallow depth and a flat bottom.
The average height of the atoll, as a rule, is 3-4 meters, the sizes can be very different. So, Kwajalein - the largest of the atolls - exceeds 2300 km, more than 90% of which falls on the lagoon, which stretches for 300 km.
In the next video you can see amazing beauty atoll and learn some about it Interesting Facts.
Briefly about education
Considering what an atoll is, it is important to pay attention Special attention how the island was formed. Most often, the process looked like this: around the crater of an extinct volcano, a coral reef gradually appeared, forming a ring. With a slight decrease in the water level, such an “island” appeared on the surface. And so the atoll was born. There are a lot of similar formations in the Pacific and Indian oceans, in tropical and subtropical latitudes.
The reverse process is also possible - immersion of the atoll in water. In this case, the so-called bank, or submerged atoll, is formed.
The main material from which such unusual islands are created is limestone, accumulated from the skeletons of dead plants and animals, primarily corals. The surface of such islands, as a rule, is adorned with a rather poor vegetation cover, which includes several species of trees and grasses located in zones. The most common are shrub scaevolla, roofing pandanus, ochrosia and others. Closer to the center, away from the coast, you can find ficuses, hibiscus, as well as artificially planted breadfruit trees and coconut palms.
Other atolls are swampy, and other plants, except for sedge, cannot survive on them.
So, considering the meaning of the word "atoll", it should be noted that this is an oceanic island created from limestone - the remains of dead living organisms, primarily corals, which has a lagoon and is covered with some types of vegetation. Because of its picturesque and unusual similar islands very attractive to tourists.
Let's continue our acquaintance with the atolls. What this word means, we have already considered, now it is necessary to distinguish the term from a group of similar ones, first of all it is volcanic island and coral reef.
So, an island of volcanic origin is a piece of land located on the crater of an extinct volcano; it has nothing to do with the life of corals and other organisms. A coral reef is a deposit of dead corals located underwater on a volcanic crater.
If the water level drops and sediments are partially on the surface, an atoll is obtained.
The sequence can be represented as follows:
- Corals settled on the crater of an extinct volcano, gradually a kind of underwater organic backbone formed from their remains. This is a coral reef.
- When it was partially above the water column, an atoll turned out.
Therefore, these terms are not synonymous, although they are close in meaning. We can say that the atoll is a certain type of coral reef, having a round shape with a lagoon located in the central part, on which several tiny islands can be located.
In the photo you can see that the ocean waters surrounding the atolls have a striking turquoise color. It is connected with the fact that the inner part of the island is gradually dying and decomposing.
We looked at what an atoll is, how it differs from similar terms, and what it consists of.
What is an atoll? The atoll is a ringed coral reef that partially or completely surrounds the lagoon. In other words, an atoll is a narrow stretch of land that borders and is surrounded by water at the same time. This is what distinguishes an atoll from an ordinary island. While an island is just a piece of land surrounded by water, an atoll contains a body of water within it.
Another curious detail about atolls is the fact that they are not actually made of soil, but of coral. The corals have to grow fast enough to replace parts of the atoll that are destroyed by erosion in order for the atoll to remain intact. Since corals thrive only in warm waters, atolls can only be found in the tropics and subtropics. Hence, the atolls are unique coral land masses consisting of a crystal clear lagoon and spectacular colorful reefs teeming with amazing marine life. Sounds exciting, doesn't it?!
Let's go on an amazing journey through the tropics. From the stunning Aitutaki Atoll in the Cook Islands to the extraterrestrial beauty of atolls in the Maldives, here are 25 of the world's most astounding atolls.
25. Takapoto, French polynesia
Takapoto, measuring 20 kilometers by 7 kilometers, is an atoll located in the Tuamoto archipelago in French Polynesia. The atoll, discovered by the Dutch navigator Jacob Le Maire in 1616, is now home to about 380 people.
24. Aitutaki, Cook Islands
Approximately 2,000 people live on Aitutaki Atoll. It is the second most visited island in the Cook Islands. The atoll, which the authorities have saved from mass tourism, is famous for its turquoise waters of the central lagoon and picturesque beaches lined with palm trees.
23. Ulithi, Caroline Islands
Ulithi, part of the Federated States of Micronesia, is an atoll of 40 islets surrounding one of the largest lagoons in the world. The atoll was the main springboard for the US Navy during the Great Patriotic War. Several sunken ships are still at the bottom of this lagoon.
22. Tubbataha Reef, Philippines
Tubbataha Reef, located in the middle of the Sulu Sea (Sulu Sea), is a marine and bird sanctuary, consisting of two large atolls - North and South Atoll. This protected area boasts amazing biodiversity and contains 75 percent known to science coral species and 40 percent of reef fish species.
21. Tarawa, Kiribati
Tarawa is an atoll and the capital of the Republic of Kiribati, located in the central Pacific Ocean. The atoll, which is home to almost 60,000 people, boasts a wide reef teeming with fish and a large lagoon spanning over 500 square kilometers.
20. Tikehau, French Polynesia
Tikehau, located 340 kilometers northeast of Tahiti on the Tuamotu Islands, is an oval-shaped atoll and tourist destination famous for pink sandy beaches lined with coconut palms and stunning marine life and flora.
19. Maafushi, Maldives
Maafushi, which is part of the Kaafu Atoll, is one of the inhabited islands in the Maldives. The atoll was badly damaged by the 2004 tsunami but quickly recovered. Nowadays, Maafushi boasts a thriving local economy based on fishing and tourism.
18. St. Francois Atoll, Seychelles
Saint Francois Atoll, consisting of the two islands of Saint Francois and Bijoutier, is an uninhabited atoll in the western part indian ocean. The atoll is home to numerous species of birds, including the Fairy Tern, Curlew, Turnstone, Tules and so on.
17. Rangiroa, French Polynesia
, one of the largest atolls in the world, consists of approximately 415 tiny islets and shoals, with a total area of about 170 square kilometers. In the center of the atoll, there is a large lagoon where black pearl oysters are bred.
16. Palmyra Atoll, North Pacific Equatorial Region
Palmyra Atoll, located between Hawaii and American Samoa, is an unoccupied atoll consisting of an extensive reef, lagoons and 50 islets. The atoll is officially administered by the United States and is covered with coconut, scaevola, and pisonia trees.
15. Nukuoro (Nukuoro), Federated States micronesia
Surrounding a lagoon 6 kilometers in diameter, Nukuoro is a remote atoll with a population of nearly 400 people. There is no tourism on the island, except for occasional visits by passing sailing yachts.
14. Ontog Java Atoll, Solomon Islands
Ontong Java Atoll is sometimes also called Lord Howe Atoll. It is a large shoe-shaped atoll, consisting of more than 120 low-lying islets. There are two large villages on the atoll - Luaniua (Luaniua) and Pelau (Pelau) - where most of the population of the atoll lives.
13. Nukumanu, Papua New Guinea
Nukumanu is a medium-sized atoll that is part of papua new guinea and located in the southwestern Pacific Ocean, 4 degrees south of the equator. The atoll consists of 20 sandy islands surrounding a large lagoon.
12. Lihou Reef, Territory of the Islands coral sea
Lihou Reef, located in the Coral Sea, northeast of Queensland, Australia, is the second largest atoll in the world in terms of total area. Surrounding a 2,500 square kilometer lagoon, the atoll is an important nesting site for many bird species.
11. Cayo Bolivar, Colombia
Cayo Bolivar, located 25 kilometers from San Andrés, a Colombian coral island in the Caribbean, is an uninhabited atoll consisting of two islands - East and West Cay. Its diversity of marine life and beautiful beaches made it popular place for tourist excursions.
10 Aldabra, Seychelles
Aldabra, uninhabited and extremely isolated, is a large atoll virtually untouched by man. Known as one of the "crown jewels" of the Indian Ocean, it has a distinct island fauna, including the largest population of giant tortoises in the world.
9. Ari Atoll, Maldives
Ari Atoll is a natural atoll located in the Maldives. This is one of the largest atolls in the world and is located in the western part of the archipelago. More than 20 islands are scattered here, most of which were developed for tourist resorts, and each of them is autonomous and has places for living and recreation.
8. Bangaram Atoll, India
Bangaram Atoll, located in the Union Territory of Lakshadweep, India, is a popular tourist destination offering numerous recreational activities including scuba diving, snorkeling and deep sea fishing. It features white sandy beaches, a tranquil lagoon and stunning coral reefs.
7. Chagos Islands, British Territory in the Indian Ocean
The Chagos Islands are a group of seven consisting of more than 60 individual tropical islands in the Indian Ocean. These reefs, notable for their amazing biodiversity, are home to at least 371 coral species, 784 fish species and 2 turtle species.
6. Pearl and Hermes Atoll, Hawaii
Pearl and Hermes Atoll, which is part of the Northwest Islands Hawaiian archipelago, is a small Hawaiian atoll named after two English whaling ships that were wrecked on this atoll in 1822. Once the center of the pearl trade, the atoll is now a bird sanctuary.
5. Osprey Reef, Coral Sea Islands Territory
Osprey Reef, part of the northwestern group of islands in the Coral Sea, is an oval-shaped submerged atoll. The depth of the waters surrounding this atoll is 2 kilometers and the slopes of its reef are home to a variety of marine life, including the rare dwarf nautilus pompilius.
4. Diego Garcia Atoll, British Indian Ocean Territory
Diego Garcia Atoll, located in the central Indian Ocean just 7 degrees south of the equator, was settled by the French in the 1790s and was later ceded to the British crown. It has the largest continuous landmass of any atoll in the world.
3. Kwajalein Atoll, Marshall Islands
Kwajalein, which is part of the Republic of the Marshall Islands, is one of the largest atolls in the world, judging by the area body of water which it surrounds. It consists of 97 islands and islets, and its land area is 16 square kilometers. It surrounds a giant lagoon with an area of 2174 square kilometers.
2. Kure Atoll, Hawaii
Kure Atoll, politically part of Hawaii, is the most northern atoll in the world. This atoll is sometimes also referred to as Ocean Island. It is home to hundreds of thousands of seabirds and numerous marine animals, including the monk seal.
1. Ducie Island, Pitcairn Islands
Ducie Island, located in the South Pacific Ocean, is a small uninhabited atoll on the Pitcairn Islands. Despite the sparse vegetation, the atoll is home to a range of bird species. More than 90 percent of the world population of Murphy's Typhoon nests on Ducie.
An atoll is a coral island that looks like a full or partial ring. In other words, the atolls are made up of turquoise lagoons, colorful reefs that blend seamlessly with marine life and are reminiscent of the wild and colorful life of the hero of Daniel Defoe's novel, Robinson Crusoe. I suggest you admire the most beautiful atolls of the world from different corners our planet. See picturesque photos, learn interesting facts and share your impressions in the comments to this article. Most of the atolls have already written separate stories, so follow the links for more information.
1. Funafuti.
Tuvalu is Island state, which is located in the Pacific Ocean, on the way between Hawaii and Australia. It is the second least populated sovereign state in the world (the Vatican City legitimately took the primacy, with a smaller number of inhabitants). Due to the remoteness of the country, very few tourists visit it.
2. Bikini Atoll.
3. Tubbataha reef.
Tubbataha Reef is one of the best diving spots in the world. Located in the Philippines, the reef consists of two atolls: North and South, which are separated by an 8-kilometer wide channel. Coral reefs are not only perfect place for diving, it is also an excellent habitat for many colonies of exotic fish.
4. Big blue hole.
Lighthouse Reef is probably the most popular of the atolls in the world, and this is due to the large blue hole, which is located in the very center of the atoll. This is a real unexplored paradise for divers who flock here from all over the world. The deeper one goes into blue hole, the clearer the water and the more breathtaking scenery.
5. Tikehau.
Tikehau is part of the Tuamotu chain of atolls, covering an area in the Pacific Ocean that is the same size as Western Europe. This place attracts tourists with its white - pink sand islands, inside which turquoise lagoons serve as shelters for all kinds of exotic fish. The research team of Jacques Cousteau, who visited these places, came to the conclusion that this place has the largest concentration of fish in French Polynesia.
6. Caroline Island
Europeans first saw the island in 1606. Carelyn is now part of the Republic of Kiribati. Despite more than 300 years of human activity on this island, it is one of the world's most pristine tropical islands and the world's most pristine atoll. Caroline Island and its neighbor Flint Island are home to the world's largest crab populations. The islands are located at an altitude of 6 meters above sea level, which means that they are in danger of disappearing due to the constantly rising sea level. According to scientists' calculations, the islands could be completely submerged by 2025.
7. Aitutaki Atoll.
Aitutaki consists of several coral and volcanic islands that have a triangular lagoon. Classical palm island turquoise shallow water, corals, exotic fish - all this you will find when you get to Aitutaki. The most popular is the island of Tapuaetai - a small island in the southeast of the lagoon.
8. Aldabra.
Aldabra is one of the Outer Islands of the Seychelles, over 1100 kilometers (700 miles) from Mahe, the big island in the Seychelles. It is the second largest atoll in the world after Kiritimati. Due to the difficulty of accessing Aldabra Atoll, it is virtually untouched by man. About 152,000 giant tortoises live on its territory.
9. Rangiroa.
Rangiroa is one of the largest atolls in the world and the largest atoll in the Tuamotu archipelago. This place is ideal for diving, because of the deep lagoon, full of abundance marine life. You can also see sharks here sea turtles and dolphins.
10. Atolls Maldives.
The tiny country in the Maldives, in the middle of the Indian Ocean, is made up of about 1,200 tiny coral islands grouped into 26 atolls. The main occupation for tourists here is the study of alluring depths, which is accessible due to excellent visibility. Depth exploration includes the exploration of wrecks, which can be found with the help of guides.
Every person has heard the word "atoll" at least once in their life. It came to us from Do you want to get to know this concept better and find out what an atoll is? Then let's start with a brief description.
Describing the concept
An atoll is called which looks like a complete or broken ring. Inside it is a lagoon, that is, a shallower body of water, which is separated from sea or ocean waters by a narrow strip of coast. More exact description of what an atoll is - an elevation rising from the bottom of the ocean, on which a coral superstructure has formed. In shallow water, corals form reefs and groups of islands, between which there are straits. At their expense, the lagoons communicate with the ocean. But if the atoll is formed as a closed ring, then the waters in the lagoon have less salinity than in the surrounding ocean. They usually form on extinct volcanoes. The meaning of the word "atoll" can be found in any dictionary.
The structure and stages of the formation of atolls
For the first time Charles Darwin tried to explain the stages of formation of atolls. In the future, his assumptions were confirmed by numerous observations of modern scientists.
At the first stage, a volcano begins to act on the ocean floor. Volcanic islands rise slightly above the surface of the ocean. The slopes are gradually overgrown and the volcano itself is slowly sinking. Before a colony of polyps reaches the surface, a long period of time passes. Most of today's atolls formed after ice age. In order for such a formation to take the form of a closed ring, the sinking of the volcano and the growth of corals must proceed at approximately the same speed, otherwise the ring will be broken.
However, volcanoes may not sink into the ocean, in which case a volcanic island remains inside the lagoon. This formation is called somewhat aggressively - a nuclear atoll. There can be many islands formed by coral colonies.
Each atoll has 3 components:
- outer reef slope;
- dense reef platform;
- internal body of water, that is, the lagoon.
The average height rarely exceeds 4 meters above sea level, but the area of \u200b\u200bsuch formations can be quite large. So, the largest atoll on the planet is Kwajalein, which is included in the archipelago Marshall Islands. Its area is more than 2300 km². But 92% of this area falls on the lagoon. And about 15 km² remains on the island land.
Reef building material
Do you already understand what an atoll is? And what does the building material from which reefs are built look like? belong to the class of invertebrate benthic organisms. Those types of polyps that have a calcareous skeleton participate in reef formation. Most often, reefs consist of stony corals and several types of algae that are able to release lime from the surrounding water. Place of formation of coral reefs - shallow waters of tropical seas. Most of them are located in the Indian and Pacific Ocean.
Where does fresh water come from? How does vegetation appear?
Knowing what an atoll is, many are surprised at where coral islands fresh water and vegetation are taken. There are practically no rivers, streams and other sources of drinking fresh water on the atolls. comes here only in the form of rain.
Waves, like giant millstones, grind some of the hardened corals and apply a layer of sand to the surface of the atolls. Seeds of various unpretentious plants get into this mixture. Most often, coconuts brought by the ocean sprout. Gradually limestone rocks are covered with palm trees and shrubs. Usually there are no animals on the atolls, but there is a huge variety of insects. And in the surrounding waters there are many species of fish.
