Implementation Of Community Based Psp Testing For Subsistence And Recreational Shellfish Harvesting In Southwestern Alaska (Nprb Project 1616 Final Report)

Project objectives were (1) develop a paralytic shellfish poisoning (PSP) field test method, (2) determine PSP toxins in butter clams from Kodiak and the Aleutian Islands’ sites, (3) examine climate change and PSP risk and (4) validate butter clam cleaning methods to reduce risk of PSP. An improved ELISA test using a chemical reduction step was developed but is not practical for a field test at this time. The laboratory-based assay has been commercialized and is currently being used in three major ongoing studies to document the flux of saxitoxins into Alaskan coastal food webs. Community-based monitoring of butter clams revealed PSP toxin levels were above regulatory limits most of the time at the study sites. Results were provided to each community to better inform harvesting decisions. Locally collected shellfish should be held until they can be tested to ensure they are safe to eat. Comparison of sea surface temperature anomalies and shellfish toxicity demonstrated that increasing water temperatures associated with changing climate will substantially increase the risk of PSP events in coming years. This increased risk will adversely impact human and animal health in the coming decades and have significant implications for how resource managers and public health officials document and communicate this risk to the public. The experiment on how various cleaning methods affect toxicity unambiguously demonstrated no cleaning methods reliably reduced the PSP risk of butter clams. This information is being communicated to communities throughout Alaska.