Search results
Results From The WOW.Com Content Network
Aquaculture involves cultivating freshwater, brackish water, and saltwater populations under controlled or semi-natural conditions and can be contrasted with commercial fishing, which is the harvesting of wild fish. [2] Aquaculture is also a practice used for restoring and rehabilitating marine and freshwater ecosystems.
Algae grow very quickly and communities may represent fast changes in environmental conditions. [35] In addition to community structure, responses to freshwater stressors are investigated by experimental studies that measure organism behavioural changes, altered rates of growth, reproduction or mortality. [6]
Phosphorus and nitrogen are the two main nutrients that cause cultural eutrophication as they enrich the water, allowing for some aquatic plants, especially algae to grow rapidly and bloom in high densities. Algal blooms can shade out benthic plants thereby altering the overall plant community. [24]
Brackish water, sometimes termed brack water, [1] [2] is water occurring in a natural environment that has more salinity than freshwater, but not as much as seawater. It may result from mixing seawater (salt water) and fresh water together, as in estuaries, or it may occur in brackish fossil aquifers. The word comes from the Middle Dutch root brak.
The salinity levels in brackish marshes can range from 0.5 ppt to 35 ppt. [2] Marshes are also characterised by low-growing vegetation and bare mud or sand flats. [3] Due to the variations in salinity, brackish marshes create a distinctive ecosystem where plants from either freshwater or saltwater marshes can co-inhabit. [4]
When phosphates are introduced into water systems, higher concentrations cause increased growth of algae and plants. Algae tend to grow very quickly under high nutrient availability, but each alga is short-lived, and the result is a high concentration of dead organic matter which starts to decompose.
Most of the Colorado River basin water used by humans is used to grow feed for livestock—more than four times the amount used for crops for direct human consumption. [75] The main cause of water scarcity as a result of consumption is the extensive use of water in agriculture/livestock breeding and industry.
Fast growth allows the suspension feeders to access higher levels of the water column than their competitors, and to be large enough to resist displacement; species employing this response, such as the aptly named Megabalanus, can reach 7 cm (3 in) in length.