ENSC 320 Lecture Notes - Lecture 8: White Nose Syndrome, Biomagnification, Bioaccumulation
21 Apr 2017
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Document Summary
Direct consumption of toxic or something contaminated with toxin. Sub-lethal: results in effects by way of altering behavior. Process whereby tissue concentrations of a chemical increase as it passes up the food chain through two or more tropic levels. Of particular concern when chemical does not break down in environment, or for chemicals that aren"t readily metabolized and are stored in fatty tissues. Became endangered in many parts of range due to use of organochlorine pesticide, specially ddt. Estimate of 324 north american breeding pairs in 1975. Shells thin by >18% when concentrations of dde are 15-20ppm. In arctic canada (1981-1985) eggs from failed nests had shells averaging. By 1964 nesting peregrines were extinct in the eastern us those still nesting in western us were classified endangered in 1970, 2years before ddt was banned. Later all north american peregrines were listed as either endangered or threatened. Populations have recovered somewhat since the ban, supported by protection and restoration efforts.
