Comparative Profiling of Persistent Organic Pollutants in Alaskan Pink Salmon Roe and Muscle Tissue (Oncorhynchus gorbuscha)

Comparative Profiling of Persistent Organic Pollutants in Alaskan Pink Salmon Roe and Muscle Tissue (Oncorhynchus gorbuscha)

Alvin Sherman Library

Persistent organic pollutants (POPs) are toxins that bioaccumulate through food chains--especially in marine ecosystems. They are primarily classified as polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs), each with 209 congeners associated with adverse human health outcomes such as cancer. Despite bans placed during the 2004 Stockholm Convention on Persistent Organic Pollutants, POP concentrations have remained consistent. Alaskan pink salmon (Oncorhynchus gorbuscha) are integral to Southeast Alaskan River ecosystems as a major food source for humans and animals. Detecting POPs in roe provides evidence of maternal offloading, indicating that these pollutants persist across life stages and generations. Salmon roe is consumed directly for its nutrient content, therefore analyzing POP contamination in roe has both ecological and public health implications. Salmon roe samples were collected from Frederick Sound, a Southeast Alaskan marine estuary. Corresponding pink salmon muscle tissue was sourced from three Alaskan rivers: Salmon River, Hilda Creek, and Sheep Creek. The aim of the study was to elucidate the types and concentrations of polychlorinated and polybrominated POPs in pink salmon roe and muscle tissue to evaluate evidence of maternal offloading. Utilizing a systematic approach, samples underwent acid digestion followed by organic liquid-liquid extraction. Solvent layers were concentrated using solid phase extraction (SPE) columns, then analyzed via gas chromatography-mass spectrometry (GC-MS) to identify and characterize the POPs present. The data was analyzed with the goal of establishing a comprehensive understanding of the presence and distribution of POPs in pink salmon roe and pink salmon muscle from Southeast Alaska.