Carbaryl, Carbofuran, and Methomyl - National Marine Fisheries ...

about WWTP effluent and fish endocrine disruption.
Fish communities are impacted by urbanization (Wheeler, Angermeier et al. 2005).
Urban stream fish communities have lower overall abundance, diversity, taxa richness
and are dominated by pollution tolerant species. Lead content in fish tissue is higher in
urban areas. Furthermore, the proximity of urban streams to humans increases the risk of
non-native species introduction and establishment. Thirty-nine non-native species were
collected in Puget Sound during the 1998 Puget Sound Expedition Rapid Assessment
Survey (Brennan, Higgins et al. 2004). Lake Washington, located within a highly urban
area, has 15 non-native species identified (Ajawani 1956).
PAH compounds also have distinct and specific effects on fish at early life history stages
(Incardona, Collier et al. 2004). PAHs tend to adsorb to organic or inorganic matter in
sediments, where they can be trapped in long-term reservoirs (Johnson, Collier et al.
2002). Only a portion of sediment-adsorbed PAHs are readily bioavailable to marine
organisms, but there is substantial uptake of these compounds by resident benthic fish
through the diet, through exposure to contaminated water in the benthic boundary layer,
and through direct contact with sediment. Benthic invertebrate prey are a particularly
important source of PAH exposure for marine fishes, as PAHs are bioaccumulated in
many invertebrate species (Varanasi, Stein et al. 1989; Varanasi, Stein et al. 1992;
Meador, Stein et al. 1995).
PAHs and their metabolites in invertebrate prey can be passed on to consuming fish
species, PAHs are metabolized extensively in vertebrates, including fishes (Johnson,
Collier et al. 2002). Although PAHs do not bioaccumulate in vertebrate tissues, PAHs
cause a variety of deleterious effects in exposed animals. Some PAHs are known to be
immunotoxic and to have adverse effects on reproduction and development. Studies
show that PAHs exhibit many of the same toxic effects in fish as they do in mammals
(Johnson, Collier et al. 2002).
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