Body of water in the context of "Thermocline"

The salinity of water bodies varies widely, being lower near the surface and the mouths of large rivers and higher in the depths of the ocean; however, the relative proportions of dissolved salts vary little across the oceans. The most abundant solid dissolved in seawater is sodium chloride. The water also contains salts of magnesium, calcium, potassium, and mercury, among other elements, some in minute concentrations. A wide variety of organisms, including bacteria, protists, algae, plants, fungi, and animals live in various marine habitats and ecosystems throughout the seas. These range vertically from the sunlit surface and shoreline to the great depths and pressures of the cold, dark abyssal zone, and in latitude from the cold waters under polar ice caps to the warm waters of coral reefs in tropical regions. Many of the major groups of organisms evolved in the sea and life may have started there.

A drainage basin is an area of land in which 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, the drainage divide, made up of a succession of elevated features, such as ridges and hills. A basin may consist of smaller basins that merge at river confluences, forming a hierarchical pattern.

Other terms for a drainage basin are catchment area, catchment basin, drainage area, river basin, water catchment, water basin, and impluvium. In North America, they are commonly called a watershed, though in other English-speaking places, "watershed" is used only in its original sense, that of the drainage divide line.

The Caspian Sea is the world's largest inland body of water, described as the world's largest lake and usually referred to as a full-fledged sea. An endorheic basin, it is situated in both Europe and Asia: east of the Caucasus, west of the broad steppe of Central Asia, south of the fertile plains of Southern Russia in Eastern Europe, and north of the mountainous Iranian Plateau. It covers a surface area of 371,000 km (143,000 sq mi) (excluding the highly saline lagoon of Garabogazköl to its east), an area approximately equal to that of Japan, with a volume of 78,200 km (19,000 cu mi). It has a salinity of approximately 1.2% (12 g/L), about a third of the salinity of average seawater. It is bounded by Kazakhstan to the northeast, Russia to the northwest, Azerbaijan to the southwest, Iran to the south, and Turkmenistan to the southeast. The name of the Caspian Sea is derived from the ancient Iranic Caspi people.

The lake stretches 1,200 km (750 mi) from north to south, with an average width of 320 km (200 mi). Its gross coverage is 386,400 km (149,200 sq mi) and the surface is about 27 m (89 ft) below sea level. Its main freshwater inflow, Europe's longest river, the Volga, enters at the shallow north end. Two deep basins form its central and southern zones. These lead to horizontal differences in temperature, salinity, and ecology. The seabed in the south reaches 1,023 m (3,356 ft) below sea level, which is the third-lowest natural non-oceanic depression on Earth after Baikal and Tanganyika lakes.

Climate is the long-term weather pattern in a region, typically averaged over 30 years. More rigorously, it is the mean and variability of meteorological variables over a time spanning from months to millions of years. Some of the meteorological variables that are commonly measured are temperature, humidity, atmospheric pressure, wind, and precipitation. In a broader sense, climate is the state of the components of the climate system, including the atmosphere, hydrosphere, cryosphere, lithosphere and biosphere and the interactions between them. The climate of a location is affected by its latitude, longitude, terrain, altitude, land use and nearby water bodies and their currents.

Climates can be classified according to the average and typical variables, most commonly temperature and precipitation. The most widely used classification scheme is the Köppen climate classification. The Thornthwaite system, in use since 1948, incorporates evapotranspiration along with temperature and precipitation information and is used in studying biological diversity and how climate change affects it. The major classifications in Thornthwaite's climate classification are microthermal, mesothermal, and megathermal. Finally, the Bergeron and Spatial Synoptic Classification systems focus on the origin of air masses that define the climate of a region.

An aquatic animal is any animal, whether vertebrate or invertebrate, that lives in a body of water for all or most of its lifetime. Aquatic animals generally conduct aquatic respiration by extracting dissolved oxygen in water via specialised respiratory organs called gills, through the skin or across enteral mucosae, although some are secondarily aquatic animals (e.g. marine reptiles and marine mammals) evolved from terrestrial ancestors that re-adapted to aquatic environments, in which case they actually use lungs to breathe air and are essentially holding their breath when living in water. Some species of gastropod mollusc, such as the eastern emerald sea slug, are even capable of kleptoplastic photosynthesis via endosymbiosis with ingested yellow-green algae.

Almost all aquatic animals reproduce in water, either oviparously or viviparously, and many species routinely migrate between different water bodies during their life cycle. Some animals have fully aquatic life stages (typically as eggs and larvae), while as adults they become terrestrial or semi-aquatic after undergoing metamorphosis. Such examples include amphibians such as frogs, many flying insects such as mosquitoes, mayflies, dragonflies, damselflies and caddisflies, as well as some species of cephalopod molluscs such as the algae octopus (whose larvae are completely planktonic, but adults are highly terrestrial).

A lagoon is a shallow body of water separated from a larger body of water by a narrow landform, such as a reef, a barrier island or islands, a barrier peninsula, or an isthmus. Lagoons are commonly divided into coastal lagoons (or barrier lagoons) and atoll lagoons. They have also been identified as occurring on mixed-sand and gravel coastlines. There is an overlap between bodies of water classified as coastal lagoons and bodies of water classified as estuaries. Lagoons are common coastal features around many parts of the world.

An inland sea (also known as an epeiric sea or an epicontinental sea) is a continental body of water which is very large in area and is either completely surrounded by dry land (landlocked), or connected to an ocean by a river, strait or "arm of the sea". An inland sea will generally be brackish, with higher salinity than a freshwater lake but usually lower salinity than seawater. As with other seas, inland seas experience tides governed by the orbits of the Moon and Sun.

In geography, a pole of inaccessibility is the farthest (or most difficult to reach) location in a given landmass, sea, or other topographical feature, starting from a given boundary, relative to a given criterion. A geographical criterion of inaccessibility marks a location that is the most challenging to reach according to that criterion. Often it refers to the most distant point from the coastline, implying the farthest point into a landmass from the shore, or the farthest point into a body of water from the shore. In these cases, a pole of inaccessibility is the center of a maximally large circle that can be drawn within an area of interest only touching but not crossing a coastline. Where a coast is imprecisely defined, the pole will be similarly imprecise.

Fishing is the activity of trying to catch fish. Fish are often caught as wildlife from the natural environment (freshwater or marine), but may also be caught from stocked bodies of water such as ponds, canals, park wetlands and reservoirs. Fishing techniques include trawling, longlining, jigging, hand-gathering, spearing, netting, angling, shooting and trapping, as well as more destructive and often illegal techniques such as electrocution, blasting and poisoning.

The term fishing is also used more broadly to include catching aquatic animals other than fish, such as crustaceans (shrimp/lobsters/crabs), shellfish, cephalopods (octopus/squid) and echinoderms (starfish/sea urchins). The term is not normally applied to harvesting fish raised in controlled cultivations (fish farming). Nor is it normally applied to hunting aquatic mammals, where terms like whaling and sealing are used instead.

An oceanographic water mass is an identifiable body of water with a common formation history which has physical properties distinct from surrounding water. Properties include temperature, salinity, chemical - isotopic ratios, and other physical quantities which are conservative flow tracers. Water mass is also identified by its non-conservative flow tracers such as silicate, nitrate, oxygen, and phosphate.

Water masses are generally distinguished not only by their respective tracers but also by their location in the Worlds' oceans. Water masses are also distinguished by their vertical position so that there are surface water masses, intermediate water masses and deep water masses.