Spatial and temporal patterns of community utilization of a tribally run shellfish toxin testing program in the Gulf...

Rural shellfish harvesters, including many Alaska Native peoples, require safe access to wild shellfish for subsistence, food security, and cultural practices. However, wild shellfish may be contaminated with paralytic shellfish toxins, particularly those produced by the dinoflagellate genus Alexandrium, leaving harvesters with increased risks of significant illness or death. To manage these risks, the Sitka Tribe of Alaska Environmental Research Lab (STAERL) was established to test shellfish samples sent in by harvesters in the community and to support regular monitoring of select local beaches by tribal governments. Here, we investigated harvester utilization of this shellfish testing service from 2016 to 2024, comprising 299 samples sent in by local harvesters, and used negative binomial models to examine how annual testing rates varied by year, location, species, and species-based detoxification rates. We noted differences in testing utilization rates that may reflect the influences of risk perceptions or accessibility of harvesting. We find that testing utilization has increased through time, testing rates are highest in spring and broadly similar between the other three seasons, testing rates in Sitka are much higher than those outside of it, and neither road accessibility nor species-based detoxification rates strongly affect testing rate ratios. These findings suggest that shellfish testing behavior is consistent despite seasonal variations in risk and convenience, but that the STAERL individual testing program provides a pathway to maintain subsistence harvest practices while reducing poisoning risks.