PARENT SESSION
MP2 - Aquatic Toxicology
Chair: Spehar, Bob1, 1 U.S. EPA, Duluth, MN
Co-chair: Henry, Mary2, 2 U.S. Fish and Wildlife Service, Arlington, VA
2:10 PM to 5:30 PM - Monday, 18 November 2002
Room Ballroom J
(262) PCB Effects on Creek Chub Reproduction, Growth and Development: Integrating Ecotoxicology and Fish Management Endpoints.
Henshel, Diane*,1, Sparks, Daniel2, Simon, Thomas2, Tosick, Michael1, 1 Indiana University, Bloomington, IN, USA2 US Fish and Wildlife Service, Bloomington, IN, USA
ABSTRACT- Creek chub were collected from two sites downstream (~1 and 2 miles) from a landfill leaking PCBs into the creek, and from a reference creek in a nearby watershed. Fish at the two PCB-contaminated sites had been previously shown to carry PCB burdens high enough to mandate fish advisories on the creek. For this study, creek chub were collected throughout the year, and after fixation were weighed, measured (multiple measures of body lengths, as well as sub-measures of the eyes, jaw and fins), evaluated for DELTs, and the gonads were removed for analysis of reproductive maturity and abnormalities. When compared across classes, the fish from the PCB-contaminated stream were noted to grow more quickly in the first year especially. This was attributed, at least in part, to significantly greater competition at the reference site. The older age classes are missing, however, from the contaminated creek, indicating that the reference fish outlive the contaminated fish. Multiple measurements are significantly different between the fish from the reference and the contaminated sites. Excess body and liver fat were noted in many of the contaminated fish, and none in reference fish. Deformities were noted in the head, jaws and fins of the contaminated, but not the reference, fish. Many contaminated fish matured and held their eggs well past the "normal" spawning period. Ovarian developmental delays were noted at the more proximal (and more highly contaminated) PCB site, but not at the less contaminated, more distal, PCB site or the reference site. Ovarian and testicular atresia were noted in fish from the PCB contaminated sites, with more at the more contaminated, proximal site. Statistical analysis indicates that the best factors to use to assess the reproductive endpoints included site, year class, season and water temperature (typical fisheries management parameters). However, some of the measurement endpoints were better analyzed using site, month of age, julian date collected (the more precise measure of time of year), and water temperature (more typical ecotoxicological parameters). Gender did not significantly affect virtually all of the morphometric measurements evaluated, once the measurements were corrected for body size using either body weight or standard length.
Key words: organochlorines, asymmetry, deformities, steatosis