A floating island is a mass of floating aquatic plants, mud, and peat ranging in thickness from several centimeters to a few meters. Floating islands are a common natural phenomenon that are found in many parts of the world. They exist less commonly as an artificial phenomenon. Floating

islands An island (or isle) is an isolated piece of habitat that is surrounded by a dramatically different habitat, such as water. Very small islands such as emergent land features on atolls can be called islets, skerries, cays or keys. An island ...

are generally found on

marshland A marsh is a wetland that is dominated by herbaceous rather than woody plant species.Keddy, P.A. 2010. Wetland Ecology: Principles and Conservation (2nd edition). Cambridge University Press, Cambridge, UK. 497 p Marshes can often be found at ...

lake A lake is an area filled with water, localized in a basin, surrounded by land, and distinct from any river or other outlet that serves to feed or drain the lake. Lakes lie on land and are not part of the ocean, although, like the much large ...

s, and similar

wetland A wetland is a distinct ecosystem that is flooded or saturated by water, either permanently (for years or decades) or seasonally (for weeks or months). Flooding results in oxygen-free (Anoxic waters, anoxic) processes prevailing, especially in t ...

locations, and can be many

hectare The hectare (; SI symbol: ha) is a non-SI metric unit of area equal to a square with 100- metre sides (1 hm2), or 10,000 m2, and is primarily used in the measurement of land. There are 100 hectares in one square kilometre. An acre i ...

s in size.

Natural occurrences

Sometimes referred to as ''tussocks'', ''floatons'', or ''suds'', natural floating islands are composed of vegetation growing on a buoyant mat of plant roots or other organic detritus. In aquatic regions of Northwestern Europe several hundred hectares or thousand acres of floating meadows (German ''Schwingrasen'', Dutch ''trilveen'') have been preserved, which are partly used as agricultural land, partly as nature reserves. They typically occur when growths of

cattail ''Typha'' is a genus of about 30 species of monocotyledonous flowering plants in the family Typhaceae. These plants have a variety of common names, in British English as bulrush or reedmace, in American English as reed, cattail, or punks, in ...

bulrush Bulrush is a vernacular name for several large wetland grass-like plants *Sedge family (Cyperaceae): **''Cyperus'' **'' Scirpus'' **''Blysmus'' **''Bolboschoenus'' **'' Scirpoides'' **'' Isolepis'' **'' Schoenoplectus'' **'' Trichophorum'' * T ...

sedge The Cyperaceae are a family of graminoid (grass-like), monocotyledonous flowering plants known as sedges. The family is large, with some 5,500 known species described in about 90 genera, the largest being the "true sedges" genus '' Carex'' ...

, and

reed Reed or Reeds may refer to: Science, technology, biology, and medicine * Reed bird (disambiguation) * Reed pen, writing implement in use since ancient times * Reed (plant), one of several tall, grass-like wetland plants of the order Poales * ...

s extend outward from the shoreline of a wetland area. As the water gets deeper the roots no longer reach the bottom, so they use the oxygen in their root mass for

buoyancy Buoyancy (), or upthrust, is an upward force exerted by a fluid that opposes the weight of a partially or fully immersed object. In a column of fluid, pressure increases with depth as a result of the weight of the overlying fluid. Thus the ...

, and the surrounding vegetation for support to retain their top-side-up orientation. The area beneath these floating mats is exceptionally rich in aquatic lifeforms. Eventually, storm events tear whole sections free from the shore, and the islands thus formed migrate around a lake with changing winds, eventually either reattaching to a new area of the shore or breaking up in heavy weather. Some

cenote A cenote ( or ; ) is a natural pit, or sinkhole, resulting from the collapse of limestone bedrock that exposes groundwater. The regional term is specifically associated with the Yucatán Peninsula of Mexico, where cenotes were commonly used ...

s in northern Mexico have natural floating islands. In the Brazilian Amazon, floating islands form in lakes on the floodplains of white-water rivers and are known as Matupá and range in size from a few square meters to a few hectares. In

Crow Wing County, Minnesota Crow Wing County is a county in the East Central part of the U.S. state of Minnesota. As of the 2020 census, the population was 66,123. Its county seat is Brainerd. The county was formed in 1857, and was organized in 1870. Crow Wing County i ...

a floating bog over in size moved about the area resulting in docks and boat lifts being destroyed. As decaying mass decomposes it releases gases which keep the bog floating.

Pumice rafts

Another type of natural floating island is the

pumice raft A pumice raft is a floating raft of pumice created by some eruptions of submarine volcanoes or coastal subaerial volcanoes. Biologists suggest that animals and plants have migrated from island to island on pumice rafts. Pumice rafts have uniqu ...

, which is created by an explosive

volcanic eruption Several types of volcanic eruptions—during which lava, tephra (ash, lapilli, volcanic bombs and volcanic blocks), and assorted gases are expelled from a volcanic vent or fissure—have been distinguished by volcanologists. These are oft ...

, and can float on the ocean for months or even years before becoming fully saturated and sinking. They may assist in the migration of plants and animals.

Artificial islands

Floating

artificial island An artificial island is an island that has been constructed by people rather than formed by natural means. Artificial islands may vary in size from small islets reclaimed solely to support a single pillar of a building or structure to those th ...

s are generally made of bundled reeds, and the best known examples are those of the

Uros The Uru or Uros ( ure, Qhas Qut suñi) are an indigenous people of Bolivia. They live on an approximate and still growing 120 self-fashioned floating islands in Lake Titicaca near Puno. They form three main groups: the Uru-Chipaya, Uru-Murat ...

people of

Lake Titicaca Lake Titicaca (; es, Lago Titicaca ; qu, Titiqaqa Qucha) is a large freshwater lake in the Andes mountains on the border of Bolivia and Peru. It is often called the highest navigable lake in the world. By volume of water and by surface area, i ...

Peru , image_flag = Flag of Peru.svg , image_coat = Escudo nacional del Perú.svg , other_symbol = Great Seal of the State , other_symbol_type = National seal , national_motto = "Firm and Happy f ...

, who build their villages upon what are in effect huge rafts of bundled totora reeds. The Uros originally created their islands to prevent attacks by their more aggressive neighbours, the

Inca The Inca Empire (also known as the Incan Empire and the Inka Empire), called ''Tawantinsuyu'' by its subjects, ( Quechua for the "Realm of the Four Parts", "four parts together" ) was the largest empire in pre-Columbian America. The adm ...

s and Collas. The

Aztec The Aztecs () were a Mesoamerican culture that flourished in central Mexico in the post-classic period from 1300 to 1521. The Aztec people included different ethnic groups of central Mexico, particularly those groups who spoke the Nahuatl ...

capital,

Tenochtitlan , ; es, Tenochtitlan also known as Mexico-Tenochtitlan, ; es, México-Tenochtitlan was a large Mexican in what is now the historic center of Mexico City. The exact date of the founding of the city is unclear. The date 13 March 1325 was ...

, was surrounded with ''

chinampa Chinampa ( nah, chināmitl ) is a technique used in Mesoamerican agriculture which relies on small, rectangular areas of fertile arable land to grow crops on the shallow lake beds in the Valley of Mexico. They are built up on wetlands of a lake o ...

s'', small artificial islands used for agriculture known as "floating gardens" (though not really floating). Floating gardens on a large scale have been demonstrated with

aquaponics Aquaponics is a food production system that couples aquaculture (raising aquatic animals such as fish, crayfish, snails or prawns in tanks) with hydroponics (cultivating plants in water) whereby the nutrient-rich aquaculture water is fed to hydr ...

systems in China growing rice, wheat and canna lily on islands, with some installations exceeding . Spiral Island was a more modern one-person effort to build an artificial floating island, on the Caribbean coast of

Mexico Mexico (Spanish language, Spanish: México), officially the United Mexican States, is a List of sovereign states, country in the southern portion of North America. It is borders of Mexico, bordered to the north by the United States; to the so ...

. Modern artificial islands mimicking the floating reedbeds of the Uros are increasingly used by

local government Local government is a generic term for the lowest tiers of public administration within a particular sovereign state. This particular usage of the word government refers specifically to a level of administration that is both geographically-loc ...

s and

catchment A drainage basin is an area of land where all flowing surface water converges to a single point, such as a river mouth, or flows into another body of water, such as a lake or ocean. A basin is separated from adjacent basins by a perimeter, ...

managers to improve

water quality Water quality refers to the chemical, physical, and biological characteristics of water based on the standards of its usage. It is most frequently used by reference to a set of standards against which compliance, generally achieved through tr ...

at source, reducing

pollutants A pollutant or novel entity is a substance or energy introduced into the environment that has undesired effects, or adversely affects the usefulness of a resource. These can be both naturally forming (i.e. minerals or extracted compounds like o ...

in surface water bodies and providing

biodiversity Biodiversity or biological diversity is the variety and variability of life on Earth. Biodiversity is a measure of variation at the genetic ('' genetic variability''), species ('' species diversity''), and ecosystem ('' ecosystem diversity'') ...

habitat In ecology, the term habitat summarises the array of resources, physical and biotic factors that are present in an area, such as to support the survival and reproduction of a particular species. A species habitat can be seen as the physical ...

. Examples include Gold Coast City Council in Australia. Artificial floating reedbeds are commonly anchored to the shoreline or bottom of water body, to ensure the system does not float away in a storm event or create a hazard. During

World War II World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the World War II by country, vast majority of the world's countries—including all of the great power ...

, the British

Project Habakkuk Project Habakkuk or Habbakuk (spelling varies) was a plan by the British during the Second World War to construct an aircraft carrier out of pykrete (a mixture of wood pulp and ice) for use against German U-boats in the mid- Atlantic, which w ...

proposed the construction of

aircraft carrier An aircraft carrier is a warship that serves as a seagoing airbase, equipped with a full-length flight deck and facilities for carrying, arming, deploying, and recovering aircraft. Typically, it is the capital ship of a fleet, as it allows a ...

s made of ice-like

Pykrete Pykrete is a frozen ice composite, originally made of approximately 14% sawdust or some other form of wood pulp (such as paper) and 86% ice by weight (6 to 1 by weight). During World War II, Geoffrey Pyke proposed it as a candidate material ...

. Its size and speed made it more of an artificial

iceberg An iceberg is a piece of freshwater ice more than 15 m long that has broken off a glacier or an ice shelf and is floating freely in open (salt) water. Smaller chunks of floating glacially-derived ice are called "growlers" or "bergy bits". The ...

or island than a ship. Commercial development of floating islands has begun taking place. Floating habitat islands were installed with

salicornia ''Salicornia'' is a genus of succulent, halophytic (salt tolerant) flowering plants in the family Amaranthaceae that grow in salt marshes, on beaches, and among mangroves. ''Salicornia'' species are native to North America, Europe, Central As ...

salt marsh plants at

Sydney Olympic Park Authority Sydney Olympic Park is a suburb of Greater Western Sydney, located 13 kilometres west of the Sydney central business district, in the local government area of the City of Parramatta Council. It is commonly known as Olympic Park but officially ...

in 2011 providing nesting sites for local and migratory birds including

black swan The black swan (''Cygnus atratus'') is a large waterbird, a species of swan which breeds mainly in the southeast and southwest regions of Australia. Within Australia, the black swan is nomadic, with erratic migration patterns dependent upon ...

black-winged stilt The black-winged stilt (''Himantopus himantopus'') is a widely distributed very long-legged wader in the avocet and stilt family ( Recurvirostridae). The scientific name ''H. himantopus'' is sometimes applied to a single, almost cosmopolitan sp ...

red-necked avocet The red-necked avocet (''Recurvirostra novaehollandiae'') also known as the Australian avocet, cobbler, cobbler's awl, and painted lady, is a wader of the family Recurvirostridae that is endemic to Australia and is fairly common and widespread t ...

Pacific black duck The Pacific black duck (''Anas superciliosa''), commonly known as the PBD, is a dabbling duck found in much of Indonesia, New Guinea, Australia, New Zealand, and many islands in the southwestern Pacific, reaching to the Caroline Islands in the no ...

s and

chestnut teal The chestnut teal (''Anas castanea'') is a dabbling duck found in Australia. It is protected under the National Parks and Wildlife Act 1974. Taxonomy The chestnut teal was described by the English naturalist Thomas Campbell Eyton in 1838 under ...

s, using the Aqua Biofilter product. The world's largest vegetated floating islands in size were installed in 2004 using Aqua Biofilter™ product with

Canna (plant) ''Canna'' or canna lily is the only genus of flowering plants in the family Cannaceae, consisting of 10 species.The Cannaceae of the World, H. Maas-van der Kamer & P.J.M. Maas, BLUMEA 53: 247-318 Cannas are not true lilies, but have been ass ...

Lake Tai Taihu (), also known as Lake Tai or Lake Taihu, is a lake in the Yangtze Delta and one of the largest freshwater lakes in China. The lake is in Jiangsu province and a significant part of its southern shore forms its border with Zhejiang. ...

, China using materials including a combination of polyurethane open cell filter foam, closed cell polyethylene flotation foam, bamboo and coconut fibre filter foam mix with wicking ability to supply water to plant roots. A commercially produced floating island was installed in the river otter enclosure at Zoo Montana in 2007. In 2009 and the beginning of 2010, a few larger islands were launched to provide nesting habitat for

Caspian tern The Caspian tern (''Hydroprogne caspia'') is a species of tern, with a subcosmopolitan but scattered distribution. Despite its extensive range, it is monotypic of its genus, and has no accepted subspecies. The genus name is from Ancient Greek ' ...

colonies. The largest of the islands, at a record-setting , was launched into the water at Sheepy Lake. These islands are a collaboration between the

United States Army Corps of Engineers , colors = , anniversaries = 16 June (Organization Day) , battles = , battles_label = Wars , website = , commander1 = ...

Oregon State University Oregon State University (OSU) is a public land-grant, research university in Corvallis, Oregon. OSU offers more than 200 undergraduate-degree programs along with a variety of graduate and doctoral degrees. It has the 10th largest engineering ...

, and Floating Islands West, a Floating Island International license holder. A recent US Army Corps of Engineers project was built in

The Hideout, Pennsylvania The Hideout is a private community and census-designated place (CDP) in Lake and Salem Townships in Wayne County, Pennsylvania, United States. The community's population was 3,013 at the time of the 2010 United States Census. Demographics As ...

as part of a

watershed management Watershed management is the study of the relevant characteristics of a watershed aimed at the sustainable distribution of its resources and the process of creating and implementing plans, programs and projects to sustain and enhance watershed funct ...

project. The floating island was created to mimic nature; help improve water quality, including reducing

phosphorus Phosphorus is a chemical element with the symbol P and atomic number 15. Elemental phosphorus exists in two major forms, white phosphorus and red phosphorus, but because it is highly reactive, phosphorus is never found as a free element on Ea ...

levels; and buffer habitats against surges in nutrients and pollution. Buoyancy in artificial floating reedbeds is commonly provided by polyethylene or polyurethane foam, or polyethylene plastic containing air voids. Growth media include coconut fibre; mats made of polyester or recycled PET bottles; synthetic geotechnical mat; jute; soil; and sand. Artificial floating islands are sometimes made by planting cattails and other plants on floating plastic rafts in order to reduce phosphorus levels in the water. In

Cleveland Cleveland ( ), officially the City of Cleveland, is a city in the United States, U.S. U.S. state, state of Ohio and the county seat of Cuyahoga County, Ohio, Cuyahoga County. Located in the northeastern part of the state, it is situated along ...

Cuyahoga River The Cuyahoga River ( , or ) is a river located in Northeast Ohio that bisects the City of Cleveland and feeds into Lake Erie. As Cleveland emerged as a major manufacturing center, the river became heavily affected by industrial pollution, so m ...

floating rafts were made to restore fish populations.

Locations

Africa

Lake Victoria Lake Victoria is one of the African Great Lakes. With a surface area of approximately , Lake Victoria is Africa's largest lake by area, the world's largest tropical lake, and the world's second-largest fresh water lake by surface area after ...

Uganda }), is a landlocked country in East Africa. The country is bordered to the east by Kenya, to the north by South Sudan, to the west by the Democratic Republic of the Congo, to the south-west by Rwanda, and to the south by Tanzania. The ...

Lake Kyoga Lake Kyoga (literally 'the place of bathing' in Runyoro language) is a large shallow lake in Uganda, about in area and at an elevation of 1,033 metres. The Victoria Nile flows through the lake on its way from Lake Victoria to Lake Albert. The m ...

Lake Malawi Lake Malawi, also known as Lake Nyasa in Tanzania and Lago Niassa in Mozambique, is an African Great Lake and the southernmost lake in the East African Rift system, located between Malawi, Mozambique and Tanzania. It is the fifth largest f ...

, Africa *

Lake Upemba Lake Upemba is a lake in Bukama, Haut-Lomami District, the Democratic Republic of the Congo. It, and nearby Lake Kisale, is surrounded by the Upemba Depression in Upemba National Park. The nearest town is Nyonga, and the nearest hospital is locat ...

, Democratic Republic of the Congo *

Lake Chad Lake Chad (french: Lac Tchad) is a historically large, shallow, endorheic lake in Central Africa, which has varied in size over the centuries. According to the ''Global Resource Information Database'' of the United Nations Environment Programme ...

, Chad, Niger, Nigeria and Cameroon *

Hartbeespoort Dam Hartbeespoort Dam (also known as ''Harties'') is an arch type dam situated in the North West Province of South Africa. It lies in a valley to the south of the Magaliesberg mountain range and north of the Witwatersberg mountain range, about 35 kil ...

, North West, South Africa

Asia

Loktak Lake , image = , caption = Different scenes of the Loktak lake of Manipur , alt = View of Loktak Lake and Phumdis , image_bathymetry = , caption_bathymetry = , location = Manipur , coords ...

Manipur Manipur () ( mni, Kangleipak) is a state in Northeast India, with the city of Imphal as its capital. It is bounded by the Indian states of Nagaland to the north, Mizoram to the south and Assam to the west. It also borders two regions of ...

state, India *

Prashar Lake Prashar Lake (also spelled Parashar Lake) is a freshwater lake located at an altitude of in the Mandi district of Himachal Pradesh, India. It lies east of the town of Mandi, and has a three storied pagoda-like temple dedicated to the sage Pr ...

Mandi Mandi may refer to: Places * Mandı, Azerbaijan India * Mandi, Jammu and Kashmir, a town on the Mandi River in the Poonch district of Jammu and Kashmir * Mandi, Himachal Pradesh, a city in Himachal Pradesh ** Mandi State, former princely s ...

Himachal Pradesh Himachal Pradesh (; ; "Snow-laden Mountain Province") is a state in the northern part of India. Situated in the Western Himalayas, it is one of the thirteen mountain states and is characterized by an extreme landscape featuring several pea ...

state, India * Chamli gul, Takab, Iran *

Maldives Floating City Maldives (, ; dv, ދިވެހިރާއްޖެ, translit=Dhivehi Raajje, ), officially the Republic of Maldives ( dv, ދިވެހިރާއްޖޭގެ ޖުމްހޫރިއްޔާ, translit=Dhivehi Raajjeyge Jumhooriyyaa, label=none, ), is an archipelag ...

, Maldives *

Inle Lake Inle Lake (, ), a freshwater lake located in the Nyaungshwe Township of Shan State, part of Shan Hills in Myanmar (Burma). It is the second largest lake in Myanmar with an estimated surface area of , and one of the highest at an elevation of ...

, Myanmar * Çat Lake, Çelikhan,

Adıyaman Adıyaman ( ku, Semsûr) is a city and district in southeastern Turkey, and the capital of the Adıyaman Province. The inhabitants of the city are mostly Kurdish. Etymology An unverified theory is that the former name of the city ''Hisn-Mansur'' ...

, Turkey * Aksakal Lake, Solhan,

Bingöl Bingöl ( diq, Çolig; ku, Çewlik; hy, Ճապաղջուր, translit=Chapaghjur) is a city in Eastern Turkey and the capital of Bingöl Province. Etymology One of the historical names for the city, ''Bingöl'' literally means ''thousand lake ...

, Turkey

Australia

* Lagoon of Islands, Tasmania, Australia

Europe

Danube Delta The Danube Delta ( ro, Delta Dunării, ; uk, Дельта Дунаю, Deľta Dunaju, ) is the second largest river delta in Europe, after the Volga Delta, and is the best preserved on the continent. The greater part of the Danube Delta lies in Ro ...

, Romania * Lake Visitor, Montenegro * Marais Audomarois, France *

Vlasina Lake Vlasina Lake ( sr, Власинско језеро, Vlasinsko jezero) is a semi-artificial lake in Southeast Serbia. Lying at an altitude of , with an area of , it is the highest and largest artificial lake in Serbia. It was created in 1947–51 w ...

, Serbia * Semeteš Lake, Serbia *

Sommen Sommen () is a lake in the South Swedish highlands lying across the border of the provinces of Östergötland and Småland. Situated about 147 metres above mean sea level, the lake has an area of and has a maximum depth of 60 metres. The lake is ...

, Sweden * Das schwimmende Land, Waakhausen, Germany * Schwimmendes Moor, Jade, Germany *

Waterland Waterland () is a municipality in the Netherlands, located in the province of North Holland. It is situated north of Amsterdam, on the western shore of the Markermeer. It is well-known for comprising the touristy towns of Broek in Waterland and M ...

, The Netherlands *

Lochan Saorach Lochan Saorach or Lochan Dùn Saoraich (NN451272) is a small lake situated in Glen Dochart ( gd, Gleann Dochard), below Dun Saorach, Perthshire, Scottish Highlands, Scotland. The glen extends from Crianlarich eastwards to Killin with the River D ...

, Scotland * Swiebodzinka, Poland

North America

* Lake Yarbo, Winter Garden, Florida *

Lake Buckeye Lake Buckeye, a natural freshwater lake in eastern Winter Haven, Florida, United States, is somewhat oval in shape. This lake has a surface area. This lake is bordered on the west side by residences and along most of the north and east by woods. ...

Winter Haven, Florida Winter Haven is a city in Polk County, Florida, United States. It is fifty-one miles east of Tampa. The population was 49,219 at the 2020 census. According to the U.S. Census Bureau's 2019 estimates, this city had a population of 44,955, making ...

* Lake Idyl, Winter Haven, Florida * Lake Mary Jane,

Orlando, Florida Orlando () is a city in the U.S. state of Florida and is the county seat of Orange County. In Central Florida, it is the center of the Orlando metropolitan area, which had a population of 2,509,831, according to U.S. Census Bureau figures re ...

Umbagog Lake Umbagog Lake is a wilderness lake located in Coös County, New Hampshire, and Oxford County, Maine. It is one of the most pristine lakes in the state of New Hampshire. It lies in the towns of Errol, New Hampshire, and Upton, Maine, as well as the ...

, Maine and New Hampshire, United States * Mill Pond,

Alton, New Hampshire Alton is a town in Belknap County, New Hampshire, United States. The population was 5,894 at the 2020 census, up from 5,250 at the 2010 census. It is home to Alton Bay State Forest and Mount Major State Forest. The primary settlement in town, ...

* Island Pond, Springfield, Massachusetts, United States * Prairie Lake, Barron County, Wisconsin, United States * Bolton Lakes,

Bolton Bolton (, locally ) is a large town in Greater Manchester in North West England, formerly a part of Lancashire. A former mill town, Bolton has been a production centre for textiles since Flemish weavers settled in the area in the 14th ...

and Vernon,

Connecticut, United States Connecticut () is the southernmost state in the New England region of the Northeastern United States. It is bordered by Rhode Island to the east, Massachusetts to the north, New York to the west, and Long Island Sound to the south. Its ca ...

Lake Ontario Lake Ontario is one of the five Great Lakes of North America. It is bounded on the north, west, and southwest by the Canadian province of Ontario, and on the south and east by the U.S. state of New York. The Canada–United States border sp ...

, New York, United States and

Ontario, Canada Ontario ( ; ) is one of the thirteen provinces and territories of Canada.Ontario is located in the geographic eastern half of Canada, but it has historically and politically been considered to be part of Central Canada. Located in Central Ca ...

* Whitingham, Vermont Lake Sadawga *

Kettle Moraine Kettle Moraine is a large moraine in the state of Wisconsin, United States. It stretches from Walworth County in the south to Kewaunee County in the north. It has also been referred to as the ''Kettle Range'' and, in geological texts, as the ' ...

, Wisconsin, United States *

Duwamish River