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Rivers, lakes, streams and freshwater wetlands are a key habitat, supporting more than a tenth of all known species, including around a third of vertebrates and half of animals, even though they ...
The researchers examined around 23,500 species of dragonflies, fish, crabs and other animals that depend exclusively on freshwater ecosystems. They found that 24% were at risk of extinction – classified as vulnerable, endangered or critically endangered – due to compounding threats from pollution, dams, water extraction, agriculture ...
The invasive freshwater zebra mussels, native to the Black, Caspian, and Azov seas, were probably transported to the Great Lakes via ballast water from a transoceanic vessel. [21] Meinesz believes that one of the worst cases of a single invasive species causing harm to an ecosystem can be attributed to a seemingly harmless jellyfish.
Epilobium hirsutum — Seed head. In the broadest sense, dispersal occurs when the fitness benefits of moving outweigh the costs. There are a number of benefits to dispersal such as locating new resources, escaping unfavorable conditions, avoiding competing with siblings, and avoiding breeding with closely related individuals which could lead to inbreeding depression.
Jack mackerel caught by a Chilean purse seiner Fishing down the food web. Overfishing is the removal of a species of fish (i.e. fishing) from a body of water at a rate greater than that the species can replenish its population naturally (i.e. the overexploitation of the fishery's existing fish stock), resulting in the species becoming increasingly underpopulated in that area.
Water pollution (or aquatic pollution) is the contamination of water bodies, with a negative impact on their uses. [1]: 6 It is usually a result of human activities.. Water bodies include lakes, rivers, oceans, aquifers, reservoirs and groundwa
Many cyanobacteria form motile filaments of cells, called hormogonia, that travel away from the main biomass to bud and form new colonies elsewhere. [54] [55] The cells in a hormogonium are often thinner than in the vegetative state, and the cells on either end of the motile chain may be tapered. To break away from the parent colony, a ...
Freshwater salinization is the process of salty runoff contaminating freshwater ecosystems, which can harm aquatic species in certain quantities and contaminate drinking water. [1] It is often measured by the increased amount of dissolved minerals than what is considered usual for the area being observed. [ 2 ]