1. Project 1 is also making major contributions to the limited literature taking into consideration the environmental physiology of shellfish as a key determinant of toxin exposure risks to people. There are experimental, integrative organismal physiology experiments led by Co-Investigator Schram to characterize how Alaskan shellfish process toxins under different experimental conditions (e.g., temperature and pCO2).
    
2. Project 1 will generate some of the first evidence regarding the role of ocean acidification in potentially exacerbating environmental health disparities in the United States (e.g., by increasing shellfish toxin concentrations in Alaska). Despite being one of the major established environmental consequences of atmospheric CO2 emissions that drive climate change, ocean acidification’s public health implications have received limited attention. 49 For example, a review on the topic of ocean acidification and public health49 published in 2020 only identified one paper on ocean acidification impacts on paralytic shellfish poisoning toxins [increasing toxicity] that was specific to the East China Sea50 and therefore of unclear relevance to Alaska Native population risks. We are unaware of any social cost of carbon components that account for the public health harm from ocean acidification. The United States Office of Climate Change and Health Equity is focused on the impact of climate change on the populations of the United States, and to support its mandate there should be evidence coming from United States coastlines on ocean acidification impacts on toxin exposure risks; this Center will address that knowledge gap through research led by communities that face disproportionate risks of paralytic shellfish poisoning.

We recognize the value of Traditional Ecological Knowledge (TEK) and aim to complement it with scientific experimentation. TEK offers historical insight and community wisdom, while science provides tools for prediction and precision. Project 1 brings both together to build a more complete picture of toxin risks.

Our major scientific aims for the COAST project are to:

Continue to collect shellfish for toxin analysis

At the Sitka Tribe of Alaska and develop models using environmental predictors to better understand the drivers of harmful algal blooms in this region in the present and future.

Analyze spatial and temporal trends in ocean acidification

Using community collected data and determine impacts of ocean acidification on shellfish toxin accumulation in subsistence species.

Experimentally assess shellfish toxin dynamics

In subsistence species with warming ocean temperatures and increased ocean acidification using controlled laboratory experiments.

It is and will continue to be our goal

To communicate these findings with tribal communities, the scientific community, and the general public in our region through presentations, meetings, and publications.

1. Project 2 will explicitly test whether the assumptions are valid for the Toxic Equivalency Factors (TEF) model used for saxitoxin congeners by the World Health Organization and Food and Agriculture Organization of the United Nations, and United States Food and Drug Administration. The TEF model assumes toxicological concentration additivity (i.e., parallel dose-response curves) with only potency differing across different congeners. The Bayesian Multiple Index Model (BMIM) will test this assumption, comparing a single index model (equivalent to this assumption) against a more flexible multiple-index model. If TEF’s assumptions seem to hold when actually tested, then Project 2 will provide updated estimates for TEF based on larger (and tribally generated) datasets, which may have a major impact on public health guidance.
    
2. Project 2 is one of the first research programs in climate change mixture molecular toxicology. There is a growing interest in climate change impacts on the exposome (human exposure to complex mixtures of chemical and non-chemical stressors), 51-53 but the toxicological community has had limited engagement with climate change research. While air pollution epidemiology has increasingly considered the impacts of mixture combinations, 54,55 there is much less information available on climate-impacted dietary exposure mixture toxicity. This project uses some of the most cutting-edge approaches for assessing the complex health effects of exposure mixtures, including Bayesian Multiple Index Modeling, to examine how paralytic shellfish poisoning toxins whose bioavailability56 and congener distributions are anticipated to shift under climate change may collectively contribute to changes in molecular toxicity (sodium receptor channel binding).

Project 2 is pioneering a new direction in mixture molecular toxicology — combining climate science with cutting-edge statistical models. This includes exploring how toxin mixtures interact within human biology under changing environmental conditions, a field that remains underexplored.

Transdisciplinary (drawing on indigenous, oceanographic, social science, epidemiological and toxicological epistemologies) science with impact.
 

1. Compare predictions of shellfish saxitoxin-related toxicity using a bioassay (RBA) measuring total toxicity with estimates based on measurement of individual saxitoxin congeners (via HPLC) plus TEFs from FAO/WHO.
2. Test whether saxitoxin congeners adequately predict RBA using the TEF model.
3. Improve TEF estimates by regressing RBA against saxitoxin congener concentrations using new mixtures methods.

Project 3 will holistically examine community impacts of paralytic shellfish poisoning through integrative and co-generated convergence science by applying best practices in survey research, applied epidemiology, environmental social science, and indigenous research methods including “story telling” (Smith 1999, p.144) to impart collective local knowledge – which in Tlingit culture is often orally transmitted, “celebrating survival” (Smith 1999, p.145) of traditions, “remembering” historical trauma (page 146), and “revitalizing” traditions by encouraging uptake among the youth (Smith 1999, p.147-148) are all critically important for achieving a holistic appreciation for how human health and changing marine environments are intertwined for the peoples living in the Gulf of Alaska. There will be extensive input from the Community Voices Panel. There will also be a tailored and community-driven risk assessment of seafood safety, which is innovative beyond traditional risk assessment approaches.

Revitalizing tradition is a key aim. Through educational programming and intergenerational knowledge sharing, the project supports youth in reconnecting with safe harvesting practices and environmental stewardship.

1. Investigate individual perceptions of local and regional climate change and health risks for persons and communities in southeast Alaska, inclusive of PSP. We hypothesize that average perceptions of local and regional risks will differ across communities based on historical and cultural practices and experiences. This Aim will be realized through mixed-methods research involving qualitative research in a sample recruited from 5 remote communities using grounded theory approaches (n~10 per community) (see III.2.B) and a quantitative survey with target sample size of 1,023 participants optimized for estimating of PSP prevalence among residents of communities where there has been PSP (see III.3.A).
2. Characterize community dietary patterns, with emphasis on subsistence foods. We hypothesize that dietary patterns vary spatially and temporally. This Aim will be achieved through mixed-methods research involving qualitative research in 5 rural communities to identify locally important foods (see III.2.B), and food frequency questionnaire items on the community survey (see III.3.A); our informed consent will also request permission to recontact survey participants for dietary research (e.g., 24hr diet recalls) in the future. We will also do a retrospective analysis of data on Kodiak Island community subsistence harvest collected since 1982 by the Alaska Department of Fish & Game (see III.3.B).
3. Integrate information on toxin risks and dietary practices into tailored risk characterization products co-generated by and meant to be useful for the community. This will be achieved through synthesis of the findings from the community dietary intake survey (see III.3.A) with measured levels of toxins in shellfish from the routine monitoring program as well as community-provided samples analyzed by the Facility Core lab. We will apply probabilistic risk assessment methods for evidence-based insights on seafood safety.