Great paper, an A+ paper! Great paper! Paul Cordova L. Lehr December 11, 1995         An Ecosystem's Disturbance by a Pollutant         Freedman defines a pollutant as 'the occurrence of toxic substances or energy in a larger quality then the ecological communities or particular species can tolerate without suffering measurable detriment' (Freeman, 562). Although the effects of a pollutant on an organism vary depending on the dose and duration (how long administered). The impact can be one of sublethality to …showed first 75 words of 9971 total…

…showed last 75 words of 9971 total…not close to that which will affect the population. There is no good reason to suppose that there is a constant relationship for different pollutants or different species, between the dose needed to kill and that needed to impair an organism. Therefore, given the difficulties of studying an ecosystem, the most effective way to predict biological effects is likely to be by discerning the least exposure that produces a deleterious response in individual organisms (Moriarty, 1