PRIMER-E Ltd, Plymouth, UKĬuster TW, Custer CM (1995) Transfer and accumulation of organochlorines from black-crowned night-heron eggs to chicks. The profile of individual PCB congeners also differed pre-and post-dredge and demonstrated significant changes as a result of dredging activities.Ĭlarke RK, Warwick RM (2001) Change in marine communities: an approach to statistical analysis and interpretation, 2nd edn. Even at reference locations, there was a very small amount (0.01–0.06 μg/day) of PCBs accumulated each day because of the prevalence of this contaminant in the environment. At less contaminated locations in Wisconsin and Ohio, the accumulation rate was reduced by dredging as well, but not to such a large extent (~50%). At the most contaminated site, Waukegan Harbor, Illinois, the accumulation rate decreased by 95% because of dredging. Egg and nestling concentrations of total PCBs and accumulation rate (μg of total PCBs accumulated per day) were compared pre- and post-dredge. It has the advantage over more commonly used metrics such as cubic yards of sediment removed or kg of a contaminant removed, because it assesses a biotic endpoint that has more societal understanding. Calculating accumulation rate, from the mass of a contaminant in tree swallow eggs and nestling carcasses, is a useful tool to assess the effectiveness of sediment removal. For comparative purposes, other locations where no dredging occurred were also assessed. Tree swallows ( Tachycineta bicolor) were used to assess the effectiveness of reducing polychlorinated biphenyl (PCB) exposure to wildlife as a result of contaminated sediment removal at locations across the Great Lakes under two dredging scenarios, full or spot dredging.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |