Harmful algal blooms (HABs) are a significant global environmental management challenge, especially with respect to microalgae that produce dangerous natural toxins. Examples of HAB toxin diseases with major global health impact include: ciguatera poisoning, paralytic shellfish poisoning (PSP), amnesic shellfish poisoning (ASP), diarrhetic shellfish poisoning (DSP), and neurotoxic (brevetoxin) shellfish poisoning (NSP). Such diseases affect communities globally and contribute to health inequalities within the United States and beyond. Sharing data and lessons learned about the factors determining bloom occurrence and associated exposure to contaminated seafood across locations can reduce public health risks. Knowledge sharing is particularly important as ongoing global environmental changes seem to alter the intensity, location, and timing of toxic HAB events, reducing the reliability of conventional guidance where toxin risks have been endemic and leading to emerging challenges in new settings. Political changes that disrupt membership in knowledge-sharing networks may impede efforts to share scientific expertise and best practices. In this commentary, we stress the importance of community and expert knowledge sharing for reducing HAB risks, both for vulnerable communities in the United States and globally. Considering the impacts of political changes, we note the indirect engagement sometimes required for continued participation in international coordination programs. As an example, we highlight how lessons learned from a Native-led toxin monitoring and testing program (the Southeast Alaska Tribal Ocean Research partnership) can inform programs in other settings. We also describe how international knowledge is mutually valuable for this program in Southeast Alaska.

Many communities in Southeast Alaska harvest shellfish such as mussels and clams as an important part of a subsistence or traditional diet. Harmful algal blooms (HABs) of phytoplankton such as Alexandrium spp. produce toxins that can accumulate in shellfish tissues to concentrations that can pose a hazard for human health. Since 2013, several tribal governments and communities have pooled resources to form the Southeast Alaska Tribal Ocean Research (SEATOR) network, with the goal of minimizing risks to seafood harvest and enhancing food security. SEATOR monitors toxin concentrations in shellfish and collects and consolidates data on environmental variables that may be important predictors of toxin levels such as sea surface temperature and salinity. Data from SEATOR are publicly available and are encouraged to be used for the development and testing of predictive algorithms that could improve seafood risk assessment in Southeast Alaska. To date, more than 1700 shellfish samples have been analyzed for paralytic shellfish toxins (PSTs) in more than 20 locations, with potentially lethal concentrations observed in blue mussels (Mytilus trossulus) and butter clams (Saxidomus gigantea). Concentrations of PSTs exhibit seasonality in some species, and observations of Alexandrium are correlated to sea surface temperature and salinity; however, concentrations above the threshold of concern have been found in all months, and substantial variation in concentrations of PSTs remain unexplained.

Shellfish harvesting is central to coastal Alaska Native ways of life, and tribes in Southeast Alaska are committed to preserving sustainable and safe access to subsistence foods. However, consumption of non-commercially harvested shellfish puts Alaska Native communities at elevated risk of exposure to shellfish toxins. To address a lack of state or federal toxin testing for subsistence and recreational harvesting, tribes across Southeast Alaska have formed their own toxin testing and ocean monitoring program. In this study, we interviewed environmental managers responsible for tribes' testing and others with shellfish toxin expertise to report on perceptions of barriers to tribally led testing in Southeast Alaska. Tribal staff identified 40 prospective key informants to interview, including all environmental managers responsible for shellfish toxin testing at subsistence sites in Southeast Alaska. All 40 individuals were invited to participate in an interview and 27 individuals were interviewed. The most frequently discussed barriers to shellfish toxin testing in Southeast Alaska relate to logistical and staffing difficulties associated with communities' remote locations, inconsistent and inadequate funding and funding structures that increase staff burdens, risk communication challenges related to conveying exposure risks while supporting subsistence harvesting, and implications of climate change-related shifts in toxin exposures for risk perception and risk communication. Participants stressed the social origins of perceived barriers. Disinvestment may create and sustain barriers and be most severely felt in Native communities and remote places. Climate change impacts may interact with social and cultural factors to further complicate risk management.