W9 AM Biomonitoring
Wednesday, 16 November 2005: 8:00 AM - 11:40 AM in 339-340
(BIR-1117-564798) Use of sunfish as real-time biomonitors of PCB contamination in freshwater streams.
Price, D.1, Birge, W.1, 1 University of Kentucky, Department of Biology, Lexington, KY, USA
ABSTRACT- A PCB monitoring study was conducted on moderate gradient freshwater streams in Kentucky. Stream water, sediment, and fish were analyzed for PCBs during 1987-1989, and 1991-2004. One component of this study focused on species-specific patterns of PCB residues in fish, especially the green sunfish (Lepomis cyanellus), longear sunfish (L. megalotis), and bluegill (L. macrochirus). In all, 718 fish were analyzed, including 289 green sunfish. Each fillet sample was analyzed for Aroclors 1248, 1254, and 1260. At the outset of the study, total PCBs in fish fillet ranged from 2.0 to 10.0 
g/g in more impacted areas. With reductions in PCB contamination, 1248 fillet residues decreased or became non-detectable in the green and other sunfish. During 1987-1989, 1248 was detected in 48% of green sunfish, but 1254 and 1260 were detected in 93 and 91% of specimens. During 1991-2004, 1248 occurred in 27% of green sunfish, whereas it was found in 34% and 41% of longear and bluegill, respectively. Total PCBs were found in 63, 77, and 66% of green sunfish, longear, and bluegill, respectively. At one problematic station, Aroclor 1248 in sunfish fillet decreased from 6.5 g/g to non-detect within 6 months. Most sunfish have low lipid content and relative short biological half-life for PCBs, particularly the green sunfish. This makes this organism a good real-time indicator of PCB pollution. Early work by Metcalf's group at the University of Illinois found this species to be particularly adept at metabolizing organochlorine compounds (DDT, DDE) and PCBs. This field study supports their laboratory findings. The green sunfish has a restricted home range; is easily colonized; and provides an effective way for assessing effectiveness of PCB remediations. The green sunfish either has an enhanced P450 system, or due to low lipid, more rapidly shunts PCBs into metabolic pathways that detoxify this compound.
Key words: PCBs, tissue residues, green sunfish, remediation