# Project 2: Climate forcing of harmful algal blooms and toxicity exposure

> **NIH NIH P01** · WOODS HOLE OCEANOGRAPHIC INSTITUTION · 2024 · $109,328

## Abstract

1. Summary / Abstract
Our goal is to understand and predict how climate variability influences harmful algal bloom (HAB) dynamics
and exposure of human populations to HAB toxins, with implications for human health. We hypothesize that
climate-induced environmental changes will influence the composition, distribution, and severity of HABs in
ways that are predictable based on response to previous climate forcing. Our studies will focus on the
dinoflagellate Alexandrium catenella and diatoms of the genus Pseudo-nitzschia, organisms that produce
saxitoxin and domoic acid, respectively. Focusing on the Gulf of Maine (GOM), we will construct hindcast
simulations based on dynamically downscaled climate models from the Coupled Model Intercomparison
Project Phase 6 (CMIP6), into which a revised model of A. catenella model and a to-be-developed model of
Pseudo-nitzschia spp. will be incorporated. The A. catenella model revisions will incorporate the latest
advances in how cyst germination and loss processes affect bloom timing and development. Hindcasts will be
evaluated against climate data records assembled herein, documenting fluctuations in abundance of the target
species as well as toxicity (toxin accumulation) in coastal shellfish resources. A submodel will be developed to
estimate human exposure to these toxins. Discrepancies between the hindcasts and observations will guide
iterative model improvement. Once satisfactory agreement has been achieved, the models will be run in
forecast mode with various climate change scenarios. We will also assess potential climate impacts on HAB
dynamics in two other model systems: a temperate embayment with Nauset Marsh (NM) and the coastal
Arctic. The proposed research will be integrated into the WHCOHH in several ways: (1) what is learned about
bloom dynamics in Project 1 will be used to improve HAB models; (2) development of the exposure submodel
will be undertaken in collaboration with Project 3; (3) all three projects will participate in the analysis of climate-
forced variations in HABs and how they affect human exposure to toxins; and (4) results will be communicated
through the Community Engagement Core.

## Key facts

- **NIH application ID:** 10732090
- **Project number:** 2P01ES028938-06
- **Recipient organization:** WOODS HOLE OCEANOGRAPHIC INSTITUTION
- **Principal Investigator:** DAVID K RALSTON
- **Activity code:** P01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2024
- **Award amount:** $109,328
- **Award type:** 2
- **Project period:** 2018-09-30 → 2029-02-28

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10732090

## Citation

> US National Institutes of Health, RePORTER application 10732090, Project 2: Climate forcing of harmful algal blooms and toxicity exposure (2P01ES028938-06). Retrieved via AI Analytics 2026-06-14 from https://api.ai-analytics.org/grant/nih/10732090. Licensed CC0.

---

*[NIH grants dataset](/datasets/nih-grants) · CC0 1.0*