Organic contaminants (OCs) such as PCBs, chlordanes, and DDT and metabolites have been documented to accumulate to high levels in upper trophic level predators such as elasmobranch fishes. However, very little is known about the patterns of bioaccumulation across many age classes of male and females or the influences of maternal offloading on contaminant accumulation in these species. The round stingray (Urobatis halleri) was used as a model elasmobranch to examine these processes in detail. Mature females were found to offload contaminants to offspring via two pathways: ovulated eggs and uterine milk. Mature males had significantly greater contaminant concentrations than females due to their inability to depurate via reproductive pathways. OCs of mainland stingrays were compared to a reference population at Santa Catalina Island. Island stingrays had significantly lower contaminant concentrations and bioavailability. While mainland stingrays experience higher levels of contaminant exposure the negative implications of this remain to be determined.
|Advisor:||Lowe, Christopher G.|
|Commitee:||Goodmanlowe, Gwen, Gossett, Richard, Kelley, Kevin M.|
|School:||California State University, Long Beach|
|School Location:||United States -- California|
|Source:||MAI 52/03M(E), Masters Abstracts International|
|Subjects:||Ecology, Toxicology, Surgery, Zoology, Aquatic sciences|
|Keywords:||Bioaccumulation, Elasmobranch, Maternal offloading, Organic contaminants, Round stingray, Santa Catalina Island, Urobatis halleri|
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