Instruct: Given a question, retrieve documents that can help answer the question.
Query: Do eddie's only occur in fresh water?
The major upwellings in the ocean are associated with the divergence of currents that bring deeper, colder, nutrient rich waters to the surface. There are at least five types of upwelling: coastal upwelling, large-scale wind-driven upwelling in the ocean interior, upwelling associated with eddies, topographically-associated upwelling, and broad-diffusive upwelling in the ocean interior.
For preference the hooded merganser lives on small bodies of water such as ponds and small estuaries where there is ample emergent aquatic vegetation, but it also inhabits larger wetlands, impoundments, flooded timber, and rivers. They prefer fresh water but do occur on brackish water bodies as well.
According to the WHO, each human being requires a bare minimum of 20 litres of fresh water per day for basic hygiene; this equals 7.3 cubic metres (about 255 ft) per person, per year. Based on the availability, access and development of water supplies, the specific usage figures vary widely from country to country, with developed nations having existing systems to treat water for human consumption, and deliver it to every home. At the same time however, some nations across Latin America, parts of Asia, South East Asia, Africa and the Middle East either do not have sufficient water resources or have not developed these or the infrastructure to the levels required. This occurs for many varied reasons. It has resulted in conflict and often results in a reduced level or quantity of fresh water per capita consumption; this situation leads toward disease, and at times, to starvation and death.
Many other species of catfish are also present in freshwater habitats; some species only occur in freshwater. In North and South America, about 43 species extend into brackish water or are found exclusively in fresh water.
Earth’s most dominant feature is the ocean, connected to major lakes, watersheds, and waterways and taking up approximately 70% of the planet’s surface. According to the United States Geological Survey (USGS), the scarcity of fresh water resource and the effort to improve water supply is already a growing issue, especially in many arid regions around the world. These dry regions do not have access to fresh water in common bodies of water such as lakes and rivers. Fresh water source in these areas is groundwater which is limited and quickly diminishing as it becomes contaminated. 
Fresh water is not the same as potable water (or drinking water). Much of the earth's fresh water (on the surface and groundwater) is unsuitable for drinking without some treatment. Fresh water can easily become polluted by human activities or due to naturally occurring processes, such as erosion.
From Fresh Water is a 1984 posthumous album by Stan Rogers. It was one of a series of concept albums Rogers intended to do about the regions of Canada. "From Fresh Water" is about the Great Lakes area of Canada, while "Fogarty's Cove" was an album about the Maritimes, and "Northwest Passage" was about the western provinces and the North.
In large rivers with high flow rates next to an obstruction, "eddy walls" can occur. An eddy wall is formed when the height of the river is substantially higher than the level of the water in the eddy behind the obstruction. This can make it difficult for a boater, who has stopped in that particular eddy, to reenter the river due to a wall of water that can be several feet high at the point at which the eddy meets the river flow.
It occurs in areas where fresh water is plentiful — wetlands and seasonal swamps, rivers, lakes, and rice paddies. Where it is the only occurring otter species, it lives in almost any suitable habitat. But where it is sympatric with other otter species, it avoids smaller streams and canals in favour of larger water bodies.
Although it is often found in saltwater near the coast, especially on smaller islands, it requires a nearby source of fresh water.
Pollution from human activity, including oil spills and also presents a problem for freshwater resources. The largest petroleum spill that has ever occurred in fresh water was caused by a Royal Dutch Shell tank ship in Magdalena, Argentina, on 15 January 1999, polluting the environment, drinkable water, plants and animals. Chemical contamination of fresh water can also seriously damage eco-systems.
The lake has the shape of India's map. This perennial fresh water lake, nestled among wooded hills, is only one of its kinds in Kerala. Pethia pookodensis, is a species of cyprinid fish known to occur only in Pookode Lake. The lake has abundance of blue lotus and fresh water fishes. The forests surrounding the lake hold many wild animals, birds and flies.There are groups of Blue water lily flowers scattered here and there in the lake.
Ninety percent of this region is covered in wetlands; as high a proportion as is found in the world. The land slopes gradually into Hudson Bay to the north, continuing the process of draining what was once an ocean with relative speed. In some areas, the land rises at about one meter per century. The inland areas are primarily peat bogs and shallow open waters. Along the coast, tidal flats and marshes are broken by raised beaches formed the receding ice sheets. Long, cold winters keep much of this region's water frozen; although increasing temperatures are proving to have effects on both the plains and the bay.
The Hudson Plains greatly influence the bay to the North. During the brief summer months, fresh water ice melt pours into the bay. This warm water causes convection patterns which influence water temperatures throughout the year. Additionally, melting of surface ice on the bay itself also occurs during this time. Not only do these thawing events introduce warm water into the bay; they affect the salinity also. Hudson Bay has a very high portion of freshwater. Currently, researchers are exploring the role of this interplay between hot and cold, as well as fresh and saltwater. Studies have shown that spring thaw of ice sheets on the bay is occurring 5.6 days earlier per decade. This could possibly influence the convection and stratification patterns of water in the bay due to the warm temperature of run-off water and ice melt. Differences in salinity can also affect these convection patterns. One study showed that run-off water stayed largely in the coastal current; but also reached deeper waters. This happens when there is sufficient brine rejection from ice formation to force run-off into deeper waters. Some studies suggest the effects of climate change could be quite deleterious to this current balance. As climate change occurs, it continues to increase ice melt on land and sea. Both surface water melt and river discharge are occurring earlier and in greater volume. The result of this may be a decrease in convection currents, further stratifying what is already a very stratified body of water in the late summer. As a result, it has a low production rate, especially in euphotic zones. This stratification can affect temperature and light availability in deeper waters, further decreasing the abundance of primary producers.
Some flora naturally occurring on the beach head requires fresh water runoff from the land. Diversion of fresh water runoff into drains may deprive these plants of their water supplies and allow sea water incursion, increasing the saltiness of the ground water. Species that are not able to survive in salt water may die and be replaced by mangroves or other species adapted to salty environments.
Replication of "Cryptomonas" occurs in early summer when fresh water species are also reproducing. "Cryptomonas" replicates via mitosis that only takes about ten minutes. Sexual reproduction is not observed in this genus as many other genera of Cryptophytes also do not reproduce sexually.
Lithuania has one of the largest fresh water supplies, compared with other countries in Europe. Lithuania and Denmark are the only countries in Europe, which are fully equipped with fresh groundwater. Lithuanians consumes about 0.5 million cubic meters of water per day, which is only 12–14 percent of all explored fresh groundwater resources. Water quality in the country is very high and is determined by the fact that drinking water comes from deep layers that are protected from pollution on the surface of the earth. Drilling depth usually reaches 30–50 meters, but in Klaipėda Region it even reaches 250 meters. Consequently, Lithuania is one of very few European countries where groundwater is used for centralized water supply. With a large underground fresh water reserves, Lithuania exports mineral-rich water to other countries. Approved mineral water quantity is about 2.7 million cubic meters per year, while production is only 4–5 percent of all mineral water resources.
One major component of environmental degradation is the depletion of the resource of fresh water on Earth. Approximately only 2.5g% of all of the water on Earth is fresh water, with the rest being salt water. 69% of fresh water is frozen in ice caps located on Antarctica and Greenland, so only 30% of the 2.5% of fresh water 
is available for consumption. Fresh water is an exceptionally important resource, since life on Earth is ultimately dependent on it. Water transports nutrients, minerals and chemicals within the biosphere to all forms of life, sustains both plants and animals, and moulds the surface of the Earth with transportation and deposition of materials.
The banded archerfish inhabits the Indo-Pacific and waters off northern Australia, and less frequently those on the southern coast of Australia. It can be found from India eastwards to the Philippine Islands, southwards to Australia, as well as in waters off the Solomon Islands and the Indonesian Archipelago. It has been observed as far east as the New Hebrides (now known as Vanuatu).
The banded archerfish occurs mainly in areas of brackish water. Mangrove estuaries are its primary habitat, though it occasionally moves upstream into freshwater rivers. It is associated with reefs and has been reported to occur near overhanging vegetation. While they may move between fresh and salt water during their life cycle, they do not do so to breed.
The timing of advection from the eddy has important seasonal implications on the delivery of nutrients. The high-nutrient and high-iron coastal water is carried into the Gulf of Alaska from either the core of the eddy or the outer ring. The core of the eddy contains warm, fresh, nutrient-rich waters formed in winter, and with the addition of sunlight, produces strong spring blooms of primary productivity offshore. As the eddy drifts westward in late spring and summer, the outer ring mixes coastal and deep ocean waters in large arcs around the eddy edge. This process has an effect hundreds of kilometers offshore, and facilitates the exchange of nutrients between shelf to deep ocean from late winter to the following autumn.
Out of all the water on Earth, saline water in oceans, seas and saline groundwater make up about 97% of it. Only 2.5–2.75% is fresh water, including 1.75–2% frozen in glaciers, ice and snow, 0.5–0.75% as fresh groundwater and soil moisture, and less than 0.01% of it as surface water in lakes, swamps and rivers. Freshwater lakes contain about 87% of this fresh surface water, including 29% in the African Great Lakes, 22% in Lake Baikal in Russia, 21% in the North American Great Lakes, and 14% in other lakes. Swamps have most of the balance with only a small amount in rivers, most notably the Amazon River. The atmosphere contains 0.04% water. In areas with no fresh water on the ground surface, fresh water derived from precipitation may, because of its lower density, overlie saline ground water in lenses or layers. Most of the world's fresh water is frozen in ice sheets. Many areas suffer from lack of distribution of fresh water, such as deserts.
The planet's fresh water is also very unevenly distributed. Although in warm periods such as the Mesozoic and Paleogene when there were no glaciers anywhere on the planet all fresh water was found in rivers and streams, today most fresh water exists in the form of ice, snow, groundwater and soil moisture, with only 0.3% in liquid form on the surface. Of the liquid surface fresh water, 87% is contained in lakes, 11% in swamps, and only 2% in rivers. Small quantities of water also exist in the atmosphere and in living beings. Of these sources, only river water is generally valuable.
Fresh water (or freshwater) is any naturally occurring water except seawater and brackish water. Fresh water includes water in ice sheets, ice caps, glaciers, icebergs, bogs, ponds, lakes, rivers, streams, and even underground water called groundwater. Fresh water is generally characterized by having low concentrations of dissolved salts and other total dissolved solids. Though the term specifically excludes seawater and brackish water, it does include mineral-rich waters such as chalybeate springs.
The membranes used for reverse osmosis have a dense layer in the polymer matrix—either the skin of an asymmetric membrane or an interfacially polymerized layer within a thin-film-composite membrane—where the separation occurs. In most cases, the membrane is designed to allow only water to pass through this dense layer while preventing the passage of solutes (such as salt ions). This process requires that a high pressure be exerted on the high-concentration side of the membrane, usually 2–17 bar (30–250 psi) for fresh and brackish water, and 40–82 bar (600–1200 psi) for seawater, which has around 27 bar (390 psi) natural osmotic pressure that must be overcome. This process is best known for its use in desalination (removing the salt and other minerals from sea water to produce fresh water), but since the early 1970s, it has also been used to purify fresh water for medical, industrial and domestic applications.
Russia has thousands of rivers and inland bodies of water, providing it with one of the world's largest surface water resources. Its lakes contain approximately one-quarter of the world's liquid fresh water. The largest and most prominent of Russia's bodies of fresh water is Lake Baikal, the world's deepest, purest, oldest and most capacious fresh water lake. Baikal alone contains over one-fifth of the world's fresh surface water. Other major lakes include Ladoga and Onega, two of the largest lakes in Europe. Russia is second only to Brazil in volume of the total renewable water resources. Of the country's 100,000 rivers, the Volga is the most famous, not only because it is the longest river in Europe, but also because of its major role in Russian history. The Siberian rivers Ob, Yenisey, Lena and Amur are among the longest rivers in the world.
As Haida eddies break away from the coast into the subpolar gyre, they transport water properties such as temperature, salinity and kinetic energy. A common water mass in the area is the Pacific Subarctic Upper Water (PSUW) mass with conservative (constant through time and space) properties of salinity (32.6-33.6 psu) and temperature (3-15 °C). PSUW moves into the Alaska Current from the North Pacific Current and may be mixed via Haida eddies into the subpolar gyre. Fresh (low salinity) water from rivers are mixed into Haida eddies. They are also able to exchange potential energy and momentum from the coastal mean current, a process that takes energy away from the coastal current and advects it toward the middle of the gyre. On average, the Gulf of Alaska experiences 5.5 Haida eddies per year, with a typical eddy characterized by a dynamical height of approximately 0.179 m, propagation speed of 2 km per day, average core diameter of 97 km, total volume of approximately 3,000 to 6,000 km, and a duration of 30 weeks.
Aruvi Aru is the second longest river in Sri Lanka and runs through Mannar and Anuradhapura districts.
Mannar has artesian springs and aquifers. These water supply comes from Sri Lanka's central areas. The Northern Province has a supply of fresh water from aquifers and it was used in successful cultivation. It only exists in the areas where red yellow latosol exists. These types of aquifers do not exist where reddish brown earth is found. The rest of the Vanni area is void of perennial supply of fresh water.