Discuss using named examples, the use of and applicability of Essay

Discuss using named examples, the use of and applicability of bio-indicator organisms in the environmental assessment of fres - Essay Example According to Durranti, a bio- indicator is defined as a plant or animal species whose presence or absence gives information on the state of a given environment (Chu, Chanb and Chow 2005). The Use and Applicability of Various Bio-Indicator Organisms in the Environmental Assessment of Freshwater and Marine Systems There exist several bio-indicators that have been applied to measure the health status of freshwater and marine environments. To begin with, Chin argues that by identifying the kind of animal species present in a given water body, biologists are able to analyze the quality of water in that water body (Chin 2006). For instance, the presence of many carnivore fish species might suggest a higher quality of water compared to a water body dominated primarily by omnivores. A healthy water body supports life for many micro-organisms that are predated upon by the carnivore fish. For many years, fish have been used to indicate the quality of water bodies. This has been accomplished th rough determining the kind of fish that live in a given water body, measuring alterations in fish species composition and species proportion (Jackson 2001). Changes in fish length and tropic level can as well be used in determining the health of aquatic environment. ... From the experiment, it was established that samples from the lake had a high number of comets and mainly in second and third classes. Thus the results suggested that Lake Igapo is an aquatic environment that was characterized by a high level of genotoxicity and other pollutants. In Izmir Bay of Mediterranean (in Western Turkey), fish are used to determine the level of water pollution in the sea (Gonenc 1999). Izmir is an industrial and commercial centre. The presence of metals such as lead and zinc in freshwater and marine environments can be indirectly measured using inorganic acids, such as sulphuric acid and hydrochloric acid (Turner and Tessier1995). These acids are applied on intestinal specimens of different fish species. If the above metals are present, the acids react with the specimens to form oxides. Bonnan notes that some aquatic pollutants might remain active for many years and through several generations. Examples include mutagenic and carcinogenic compounds (Farris, J. et al 1993). Genotoxicity biomarkers can be applied in sentry organisms to enhance the identification and assessment of mutagenic hazards and their sources. One of the most suitable methods of identifying the response of organisms to such contaminants is by use of micronucleus (MN) test. This can be used as an index of the total genetic damage of cells during the lifespan of an organism. Fish and bivalves have been the main target for such experiments. Gill and haemocyte cells are the commonly used tissues. Due to rising carbon dioxide concentration s in the 21 century, the acidity of sea water has increased as well. Consequently, global temperatures have been driven up, including