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Freshwater ecosystem. Freshwater ecosystems are a subset of Earth's aquatic ecosystems that include the biological communities inhabiting freshwater waterbodies such as lakes, ponds, rivers, streams, springs, bogs, and wetlands. [1] They can be contrasted with marine ecosystems, which have a much higher salinity. Freshwater habitats can be ...
These organisms can affect natives via competition for prey or habitat, predation, habitat alteration, hybridization, or the introduction of harmful diseases and parasites. [6] With regard to native species, invaders may cause changes in size and age structure, distribution, density, population growth, and may even drive populations to ...
Organisms in marine ecosystems tolerate salinity, while many freshwater organisms are intolerant of salt. The degree of salinity in an estuary or delta is an important control upon the type of wetland (fresh, intermediate, or brackish), and the associated animal species. Dams built upstream may reduce spring flooding, and reduce sediment ...
Aquatic animals (especially freshwater animals) are often of special concern to conservationists because of the fragility of their environments. Aquatic animals are subject to pressure from overfishing/hunting, destructive fishing, water pollution, acidification, climate change and competition from invasive species.
Freshwater molluscs are those members of the phylum Mollusca which live in freshwater habitats, both lotic (flowing water) such as rivers, streams, canals, springs, and cave streams (stygobite species) and lentic (still water) such as lakes, ponds (including temporary or vernal ponds), and ditches.
Oxsjön, a lake in Sweden. Freshwater biology focuses on environments like lakes. A pond in the Oconee River Floodplain in Georgia, whose surface is covered in duckweed but still contains fish. Freshwater biology is the scientific biological study of freshwater ecosystems and is a branch of limnology. This field seeks to understand the ...
Like humans and other animals, fish suffer from diseases and parasites. Fish defences against disease are specific and non-specific. Fish defences against disease are specific and non-specific. Non-specific defences include skin and scales, as well as the mucus layer secreted by the epidermis that traps microorganisms and inhibits their growth.
Fresh water is the water resource that is of the most and immediate use to humans. Fresh water is not always potable water, that is, water safe to drink by humans. Much of the earth's fresh water (on the surface and groundwater) is to a substantial degree unsuitable for human consumption without treatment.