Freshwater animals

THRUSH M.A. MURRAY A.G. BRUN E. WALLACE s. and PEELER E.J. (2011), The application of risk and disease modelling to emerging freshwater diseases in wild aquatic animals. Freshwater Biol, 56, 658-675. 

Zinc, like most metals, is found in all natural waters and soils as well as the atmosphere and is an important trace element in plant and animal life (see Mineral nutrients). Rocks of various kinds contain 20—200 ppm zinc and normal soils 10—30 ppm (average ca 50 ppm) in uncontaminated areas. The average zinc content of coal is 33 ppm. Seawater contains 1—27 )-lg/L (median ca 8 p.g/L), and uncontaminated freshwater usually <10 / g/L. 

In reality, the demands upon most freshwaters, whether from human potable supply, animal watering, aquaculture, recreation, or amenity are increasing, and a need exists to monitor the types, location and levels of cyanobacterial toxins. 

The most evident damage from acid depositions is to freshwater lake and stream ecosystems. Acid depositions can lower the pH of the water, with potentially serious consequences for fish, other animal, and plant life. Lakes in areas with soils containing only small amounts of calcium or magnesium carbonates that could help neutralize acidified rain are especially at risk. Few fish species can survive the sudden shifts in pH (and the effects of soluble... 

Much building material has been derived from two monomineral sedimentary rocks gypsum (composed of hydrated calcium sulfate) and limestone, which consists of calcite (composed mostly of calcium carbonate). Freshwater and seawater contain dissolved calcium carbonate and calcium sulfate. Most limestone and gypsum are formed when, as a consequence of the evaporation of water, calcium sulfate and calcium carbonate precipitate out of the water solutions as either gypsum or limestone. Limestone is also formed as a result of the activity of living organisms. Many sea- and freshwater animals, such as snails, clams, and corals, as well as some water plants, draw... 

Molecular hydrogen is an important intermediate in the degradation of organic matter by microorganisms in anoxic habitats such as freshwater and marine sediments, wet land soils, and the gastrointestinal tract of animals. In these particular conditions H2 is produced during fermentation of carbohydrates, lipids, nucleic acids, and proteins by anaerobic bacteria and,... 

Chromium concentrations in field collections of selected species of marine, freshwater, and terrestrial plants and animals... 

Table 2.3 Chromium Concentrations in Field Collections of Selected Species of Marine, Freshwater, and Terrestrial Plants and Animals (Values shown are in mg Cr/kg [ppm] whole organism or designated body part fresh weight [FW], dry weight [DW], or ash weight [AW] ... 

Diet is the most important route of copper accumulation in aquatic animals, and food choice influences body loadings of copper. For example, whole-body copper concentrations in aquatic insects from copper-contaminated rivers are highest in detritovores (as high as 102 mg/kg DW), followed by predators (54 mg/kg DW) and omnivores (43 mg/kg DW Cain et al. 1992). Little or no biomagnification of copper is evident in freshwater food chains (Stokes 1979). 

---