question: does water animals have a "home"?
comment: It depends on the critter and what you consider to be a "home". Lots of whale species are either migratory or hang around within roughly the same area with varying degrees of territoriality. Sometimes the migratory whales do so for mating reasons, but most of them migrate to where the food is. Whether you consider the Southern Ocean or the North Atlantic to be "home" or not depends on your definition, I suppose. Most turtles return to the same beaches to lay their eggs. However, they only lay their eggs one one night of the year and then they're back in the water. They're also probably pretty uncomfortable and nervous while they schlep up and down the beach and lay their eggs, so I'm not sure they'd feel particularly "at home" during the process. Fish are the most diverse vertebrate group on the planet so there are a bajillion strategies there. Some fish absolutely find a nice place to call home. A clownfish will have a home anemone, Moray eels live inside holes in rocks, all kinds of coral reef fish find safe places in and around the coral reef. However, large pelagic fish (those that live in open water and never come into contact with the bottom) are often found throughout huge areas (e.g. all of the tropics, most of the South Atlantic ocean, the entire Indian Ocean, etc.) Some pelagic fish, such as Great White Sharks, don't have a home region at all and just swim wherever they want. It all depends on the critter.
passages: Waterfowl such as Ducks, Coots, Geese, Swans, and Moorhens thrive in gardens and parks with access to water. Small populations can form around fountains and other ornamental features, far from natural bodies of water, provided there are adequate amounts of food such as aquatic plants growing in the fountain.
   Section::::Examples.:Industrial systems.
  
  In Florida, the Florida manatee ("Trichechus manatus latirostris") uses warm water discharged from power plants as a refuge when the temperature of the Gulf of Mexico drops. These warm areas replace the warm springs that manatees once naturally used in the winter. These springs have been drained or cut off from open water by human uses. American crocodiles ("Crocodylus acutus") have a similar habitat in the cooling canals of the Turkey Point power plant, where an estimated 10% of the total North American population of the species lives.
   For a parasitic organism, its habitat is the particular part of the outside or inside of its host on or in which it is adapted to live. The life cycle of some parasites involves several different host species, as well as free-living life stages, sometimes providing vastly different microhabitats. One such organism is the trematode (flatworm) "Microphallus turgidus", present in brackish water marshes in the southeastern United States. Its first intermediate host is a snail and the second, a glass shrimp. The final host is the waterfowl or mammal that consumes the shrimp.
  
  Section::::Extreme habitats.
   Section::::Interactions with humans.:Exploitation.
   Many pets have escaped or been released into the Everglades from the surrounding urban areas. Some find the conditions quite favorable and have established self-sustaining populations, competing for food and space with native animals. Many tropical fish have been released, but blue tilapias ("Oreochromis aureus") cause damage to shallow waterways by creating large nests and consuming aquatic plants that protect native young fish.
   Section::::Interactions with humans.:Habitat degradation.
   Herons have been observed visiting water enclosures in zoos, such as spaces for penguins, otters, pelicans, and seals, and taking food meant for the animals on display.
  
  Section::::Predators and parasites.
   Common seals are known to enter estuaries and freshwater rivers in pursuit of their prey. Colonies of common seals live in some lakes, such as seals of Iliamna Lake, Alaska, trapped there a long time ago. There is also a subspecies called the Ungava seal ("Phoca vitulina mellonae") that comprises less than 300 individuals landlocked in the fresh water of Lacs des Loups Marins, Petit Lac de Loups Marins, and Lac Bourdel in northern Quebec.
   Common loons ("Gavia immer") frequent the lower reaches of tidal creeks of all refuge divisions from late autumn through early spring. They are commonly observed feeding on green crabs and small fish. During spring, summer and autumn migration, 11 species of wading birds use the estuarine systems of the refuge.
  
  Section::::Wildlife and habitat.:Migratory birds.:Waterfowl.
   It is estimated that water birds comprise about 60% of the cat's diet with black rats being its secondary source of food at about 10–30% of its diet. Based on stool samples, birds represent 60% of their diet, black rats 30%, insects 30%, lizards and frogs about 15–20%, bats 3–17%, and wild pig less than 1%. In addition, fish and crustaceans appear roughly 3–4% of the time.
  
  Seasonal dietary changes have been observed. They eat rats and frogs year-round, lizards in the summer and spring, and crickets and bats more often in the fall and winter.
  
  Section::::Ecology and behavior.:Reproductive behavior.
   Section::::Conservation.:Ramsar Convention.
   In the comic novel and film "Cold Comfort Farm" by Stella Gibbons, one of the characters, Urk, refers to the subject of his unrequited love, Elfine Starkadder, as his little water-vole. Throughout the story, Urk spends a lot of time talking to the water-voles on the farm.
  
  C. S. Calverley a 19th-century writer of (among other things) light verse, in his poem "Shelter", beginning:
  
  poemBy the wide lake's margin I mark'd her lie—
  
  The wide, weird lake where the alders sigh—/poem
   GIWs have been identified as breeding site for birds, fish species, mammals (muskrats, otters), amphibians and reptiles. Fish species benefit from the temporary rise of water levels and creation of surface connections to migrate from GIWs to streams or others wetlands. Mammals and bird species serve as transport vectors for the dissemination of plants seeds, algae and invertebrates.
  
  Section::::Ecological functions.:Transformation function.
  
  Transformation function refers to the biogeochemical processing of organic and non-organic elements.
   Section::::Relationship with humans.:Status and conservation.
  
  Today the western swamphen is locally common, with the largest population in the Spain. It was formerly listed as "Rare" by the European Union, but has been delisted to "Localised".
   There are suggestions that during the rainy season, juveniles migrate downstream and that after 2 months, mature adults travel back upstream to spawn at the headwaters in the dry season. It would seem more likely that adult fish access headwaters during high water conditions.
  
  Section::::Conservation.
  
  This species is another mahseer currently assigned as Data Deficient by the IUCN. The vast majority of scientific work done on this species has been conducted on stock produced by artificial breeding, with assumptions made about the ecology of wild stocks. 
   Many escapees from captivity can also be found in similar watery habitats around the world. Sightings are fairly common in Florida, although a breeding population has not yet been confirmed. In 2011, one specimen was spotted on the Central Coast of California.
  
  Section::::Ecology.:Diet and predation.
   Examples are: Some breeds of dog swim recreationally. Umbra, a world record-holding dog, can swim 4 miles (6.4 km) in 73 minutes, placing her in the top 25% in human long-distance swimming competitions. Although most cats hate water, adult cats are good swimmers. The fishing cat is one wild species of cat that has evolved special adaptations for an aquatic or semi-aquatic lifestyle – webbed digits. Tigers and some individual jaguars are the only big cats known to go into water readily, though other big cats, including lions, have been observed swimming. A few domestic cat breeds also like swimming, such as the Turkish Van.
   Humans are one of the largest distributors due to the current trends in globalization and the expanse of the transportation industry. For example, large tankers often fill their ballasts with water at one port and empty them in another, causing a wider distribution of aquatic species.
  
  Section::::Patterns on large scales.
  
  On large scales, the pattern of distribution among individuals in a population is clumped.
  
  Section::::Patterns on large scales.:Bird wildlife corridors.
   "Nilopegamuys plumbeus" is specifically adapted to live near or in close contact with water. There are other rodents adapted to live in wetlands such as marsh rice rat' or the European water vole. Out of all other African aquatic rodents however, the Ethiopian amphibious rat has the most extreme adaptations to its environment. They have a pair of adapted “waders” on their feet recognizable as webbing. Since N. plumbeus is so specifically adapted to its environment it makes living elsewhere very difficult. This is why scientists think that with the degradation of its habitat, N. plumbeus is now likely extinct.
   In southeastern Massachusetts, several samples of "U. inflata" have been gathered from Federal Pond beginning in 1990, representing its first collection north of New Jersey on the east coast. Bruce Sorrie has identified a substantial population in this location. Sorrie indicated that human-aided introduction of this species to Massachusetts is likely since Federal Pond has been used for various purposes since the late 18th century, though Sorrie also notes that transfer of propagules by waterfowl or herons from "U. inflata"'s native range may be just as likely.
   When swimming and searching for food, the South American water rat is able to detect objects under water and lift them above the surface in order to inspect to see if the object is edible or not using olfaction and sight. When hunting on land it is able to secure prey but pouncing and grasping with its forepaws.
  
  Nests are generally built that are similar to those of birds and consists of dry twigs and leaves woven together. They are built inside dead trees alongside streams and under dense vegetation for protection.
  
  Section::::Transmission of disease.
   Section::::EFH Consultations.
   In North America, cattails ("Typha latifolia") are common in constructed wetlands because of their widespread abundance, ability to grow at different water depths, ease of transport and transplantation, and broad tolerance of water composition (including pH, salinity, dissolved oxygen and contaminant concentrations). Elsewhere, Common Reed ("Phragmites australis") are common (both in blackwater treatment but also in greywater treatment systems to purify wastewater).
  
  Plants are usually indigenous in that location for ecological reasons and optimum workings.
  
  Section::::Plants and other organisms.:Animals.
  
  Locally grown non-predatory fish can be added to surface flow constructed wetlands to eliminate or reduce pests, such as mosquitos. 
   The term "aquatic bird" is sometimes also used in this context. A related term that has a narrower meaning is waterfowl. Some birds of prey, such as ospreys and sea eagles, take prey from water but are not considered water birds. The term waterbird is also used in the context of conservation to refer to any birds that inhabit or depend on bodies of water or wetland areas. Examples of this use include the Agreement on the Conservation of African-Eurasian Migratory Waterbirds (AEWA) and the Wallnau Waterbird Reserve.
  
  Some examples of water birds are:
   Fish are more dependent on wetland ecosystems than any other type of habitat. Seventy-five percent of the United States' commercial fish and shellfish stocks depend solely on estuaries to survive. Tropical fish species need mangroves for critical hatchery and nursery grounds and the coral reef system for food.
  