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Caddisfly (order Trichoptera), a macroinvertebrate used as an indicator of water quality. [1] A bioindicator is any species (an indicator species) or group of species whose function, population, or status can reveal the qualitative status of the environment. The most common indicator species are animals. [2]
If a species can survive in both unpolluted and heavily polluted water, g is very small because finding the species in a survey has little predictive value. In practice, only indicator species with a weighting factor g ≥ 4 are used. For example, a caddisfly, Agapetus fuscipes, has a g value of 16, while the zebra mussel's value is g = 4.
Indicator bacteria themselves may not be pathogenic but their presence in waste may indicate the presence of other pathogens. [1] Similar to how there are various types of indicator organisms, there are also various types of indicator bacteria. The most common indicators are total coliforms, fecal coliforms, E. coli, and enterococci. [2]
Examples of proxies include stable isotope measurements from ice cores, growth rates in tree rings, species composition of sub-fossil pollen in lake sediment or foraminifera in ocean sediments, temperature profiles of boreholes, and stable isotopes and mineralogy of corals and carbonate speleothems. In each case, the proxy indicator has been ...
Global paleoclimate indicators are the proxies sensitive to global paleoclimatic environment changes. They are mostly derived from marine sediments.Paleoclimate indicators derived from terrestrial sediments, on the other hand, are commonly influenced by local tectonic movements and paleogeographic variations.
The delta smelt (Hypomesus transpacificus) is an endangered [1] slender-bodied smelt, about 5 to 7 cm (2.0 to 2.8 in) long, in the family Osmeridae.Endemic to the upper Sacramento-San Joaquin Estuary of California, it mainly inhabits the freshwater-saltwater mixing zone of the estuary, except during its spawning season, when it migrates upstream to fresh water following winter "first flush ...
Over 1500 species of fungi are known from marine environments. [109] These are parasitic on marine algae or animals, or are saprobes feeding on dead organic matter from algae, corals, protozoan cysts, sea grasses, and other substrata. [110] Spores of many species have special appendages which facilitate attachment to the substratum. [111]
Numerous biotic indices have been created to account for the indicator species found in each region of study. The concept of the biotic index was developed by Cherie Stephens in an effort to provide a simple measurement of stream pollution and its effects on the biology of the stream. [citation needed]