REYES, J.A.; SAK, K.; GALMIA, M.M.; ARMSTRONG, J.L.; KELLEY, K.M.; California State Univ., Long Beach; California State Univ., Long Beach; California State Univ., Long Beach; Orange County Sanitation District, Fountain Valley, CA; California State Univ., Long Beach: Altered Endocrine Physiology of Marine Flatfish Associated with Southern California Wasterwater Treatment Plant (WWTP) Outfalls – Stress and Growth

Connections between environmental contamination and impairment of endocrine mechanisms regulating stress responses and somatic growth in marine fish are not understood. Our studies are beginning to identify potential alterations in the endocrine physiology of local flatfish captured near the WWTP outfall of the Orange County Sanitation District (OCSD) and other southern California outfalls. Hornyhead turbot, Pleuronichthys verticalis, and English sole, Parophrys vetulus, are species typically present at depths and locations where the outfall pipes exist, thereby increasing their potential to be exposed to contaminants associated with the effluents. Fish caught by trawling at sites immediately proximal to the OCSD outfall were compared with fish caught at sites at varying distances therefrom. In comparison with fish from distant locations, individuals sampled near the outfall exhibited an impaired stress response, with significantly blunted plasma cortisol surges in response to trawling and handling stressors. In addition, fish from the outfall locations had significantly reduced plasma concentrations of the growth-stimulatory hormone, insulin-like growth factor-I (IGF-I). The connections between cortisol, IGF-I, growth, and contaminants will be discussed. In conclusion, the data suggest that essential endocrine systems, namely those regulating the ability to respond to stress and regulating growth and anabolism, are significantly impaired in fish putatively exposed to WWTP effluents. [Supported by NSF grant IBN-0115975 & CA Sea Grant College Program NOAA NA06RG042 2002-03, project # R/F-192]