# Project 1: Drivers of interannual and intrabloom toxicity dynamics in Gulf of Maine HABs

> **NIH NIH P01** · WOODS HOLE OCEANOGRAPHIC INSTITUTION · 2024 · $188,113

## Abstract

Project Summary
Alexandrium catenella and Pseudo-nitzschia spp. threaten human health through their production of potent
neurotoxins that respectively cause Paralytic Shellfish Poisoning and Amnesic Shellfish Poisoning. Both are
widespread across coastal waters of the U.S. and globally. Climate change is altering marine ecosystems in
many unanticipated ways, and a major concern is that the occurrence of these harmful algal blooms (HABs)
and their concomitant human health impacts will grow. This project addresses key uncertainties regarding the
impact of climate change on the timing and severity of HABs through detailed biological and ecological study of
Alexandrium and Pseudo-nitzschia blooms within the Gulf of Maine (GOM). The GOM is an ideal system not
only because of already observed impacts from climate change, but also the long history of regional HAB
issues and associated groundbreaking research by WHCOHH. Comprehensive studies of bloom physiology,
toxicity, and oceanographic drivers have led to construction of coupled physical-biological models that have
improved our understanding of key HAB dynamics and set the stage for continued interdisciplinary
investigation of mechanisms at the cellular-to-GOM scale that are relevant to human exposure and health. In
particular, the physiological responses of these HABs — growth, toxicity, and life cycle transitions — to shifting
environmental conditions remain uncertain. We hypothesize that long-term HAB trends in the GOM are
inherently linked to interactions between the environment and cells' physiological processes, particularly
transitions between sexual and asexual life cycle stages. Studies within this project aim to directly observe life
cycle processes and other physiological responses that are often highly ephemeral in situ. We apply a wide
variety of innovative approaches for study of natural bloom populations, leveraging a unique region-scale HAB
observing system (HABON-NE). Aims 1 and 2 focus on A. catenella and seek to characterize cyst dormancy
cycles, cyst formation, and subsequent bloom termination. These aims build upon prior successful approaches
and models from study of inshore systems, asking the question if open water populations of the GOM are
governed by similar dynamics. Aim 3 investigates the physiology underlying the emerging bloom dynamics of
Pseudo-nitzschia in the GOM with in situ physiological observation coupled with targeted metatranscriptomics.
Through the direct assessment of life cycle processes and physiology of HABs in the GOM, the results from
this work will be directly applicable to the successful integration of physiology into climate response projections
(Project 2) and inform estimates of potential risk for human exposure to HAB toxins (Project 3).

## Key facts

- **NIH application ID:** 10732089
- **Project number:** 2P01ES028938-06
- **Recipient organization:** WOODS HOLE OCEANOGRAPHIC INSTITUTION
- **Principal Investigator:** Michael Brosnahan
- **Activity code:** P01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2024
- **Award amount:** $188,113
- **Award type:** 2
- **Project period:** 2018-09-30 → 2029-02-28

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10732089

## Citation

> US National Institutes of Health, RePORTER application 10732089, Project 1: Drivers of interannual and intrabloom toxicity dynamics in Gulf of Maine HABs (2P01ES028938-06). Retrieved via AI Analytics 2026-06-14 from https://api.ai-analytics.org/grant/nih/10732089. Licensed CC0.

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