Superfund Research Program
Sentinel Species: Xenobiotics, Toxicity, and Reproduction
Project Leader: Ian P. Callard
Grant Number: P42ES007381
Funding Period: 1995 - 2000
Previous observations relating to heavy metals have been confirmed by the sampling of the bioindicator species at surface-water sites that have been potentially impacted by contaminated groundwater plumes. These show sex, tissue specific and site specific differences. Project scientists are currently assessing sediment and groundwater values of heavy metals as correlates of these observations. Hepatic indices of toxic exposure (CYP 1A1, glutathione-S-transferase) in the turtle show significant seasonal differences which may be related to feeding activity, with coincident changes in males and females.
Reproductive indices continue to be monitored and thus far the scientists have assessed sperm number in turtles and found the number to decline slowly during the spring. This parallels changes in turtles from a different geographic location, but absolute sperm counts are about 5-fold lower at the Cape Cod sites. Follicular kinetics in females as well as body weights at maturity suggest some shifts in fertility, but the cause is uncertain at this time. These same parameters in catfish (sampled at lower numbers) will be completed in the coming season.
Freshwater mussels obtained from Cape Cod sites have been successfully tested in the laboratory for hepatopancreatic CYP 1A1 and glutathione-S-transferase activity and induction has been observed with hydrocarbon and heavy metal exposure. Control levels have been established for different sites. A sex-limited ovarian and coelomic fluid protein has been identified as a possible bioindicator molecule for exposure to xenoestrogens in this species, and vitellogenin assays for the catfish and turtle are in use currently. Groundwater from Cape sites will be tested using freshwater mussels during the coming summer. Vitellogenin, metalothionein and steroid hormone assays are all in use and a complete picture for all parameters in catfish and turtle will be available at the end of the 1998 season.