Meeting Abstract
87.2 Thursday, Jan. 7 Evidence for Thyroid Endocrine Disruption in Wild Fish in San Francisco Bay. Relationships to Contaminant Exposures. BRAR, N.K.*; WAGGONER, C.; REYES, J.A.; FAIREY, R.; KELLEY, K.M.; California State University, Long Beach; California State University, Long Beach; Pacific Coast Environmental Conservancy [pceconservancy.org]; Moss Landing Marine Laboratories; California State University, Long Beach kmkelley@csulb.edu
It is well documented that many coastal and estuarine environments adjacent to developed, industrialized urban centers, such as the San Francisco Bay Area, are significantly contaminated by human-derived chemicals. However, it is not well understood to what extent existing contaminants, many with continuing inflows into the environment, may impact exposed wildlife. This study characterized thyroid endocrine-related effects and their relationship to accumulated contaminants in two indigenous fish species sampled from different SF Bay study sites. Plasma concentrations of thyroxine (T4) were significantly reduced in fish sampled from highly impacted locations such as Oakland Inner Harbor and San Leandro Bay as compared with fish from other locations representing relatively lower human impact, including Bodega Bay, Redwood City and Catalina Island. Triiodothyronine (T3) also exhibited significant location-associated changes, with increased T3/T4 ratios in fish from some locations suggestive of enhanced peripheral 5’-deiodinase activity. The alterations in thyroid endocrine parameters were significantly correlated with hepatic concentrations of environmental contaminants, particularly PCBs, which were inversely correlated with T4 but positively correlated with T3 and T3/T4 ratio. Some relationships between chlorinated pesticides, but fewer relationships with PAHs, were also observed. These findings suggest that the fish thyroid endocrine system may be disrupted in SF Bay, which is significantly related to exposures of the fish to contaminant chemicals such as PCBs.
