# Project 1: Harmful algal bloom dynamics: assessing physiological and behavioral plasticity in natural populations

> **NIH NIH P01** · WOODS HOLE OCEANOGRAPHIC INSTITUTION · 2020 · $143,366

## Abstract

Alexandrium fundyense and Pseudo-nitzschia spp. present expanding public health threats through their
associated poisoning syndromes, paralytic shellfish poisoning and amnesic shellfish poisoning. A major
concern is the extent to which these harmful algal blooms (HABs) and their human health impacts will be
altered by a changing climate. The Gulf of Maine is an ideal setting to explore this problem due to its long
history of A. fundyense investigations examining bloom physiology, toxicity, and bloom dynamics, leading to
construction of a robust population dynamics model. Nevertheless realistic forecasts under changing climate
conditions remain challenging for both A. fundyense and Pseudo-nitzschia, an emerging and less studied
threat. Current models for A. fundyense rely on culture-based characterizations of behavior that are not valid in
the natural environment, as demonstrated by novel in situ observations made during our prior WHCOHH
program. Life cycle processes, growth, grazing and mortality rates, and swimming patterns have all been
found to be significantly different in situ, making culture-based data inadequate for model assessments. A
second challenge stems from the adaptive potential of these taxa, whose physiologies vary substantially
across their ranges. This project's scientific premise is that our ability to assess and predict short- and long-
term responses of these HABs and their human health impacts to climate change requires characterization of
critical rates and behavioral patterns in natural populations, generated, whenever possible, through in situ
observations. Based on the new finding of a chilling requirement regulating the dormancy period of A.
fundyense cysts in the Nauset Marsh estuary, Aim 1 will assess plasticity of this response across multiple
habitats and populations and explore whether the temperature conditioning requirements of A. fundyense are
adaptive across its range. Aim 2 will use in situ technologies to determine relationships between temperature
and A. fundyense division, grazing, accumulation, and toxicity onset across a range of habitats. Previous
WHCOHH work discovered unexpectedly high accumulation and division rates for A. fundyense in Nauset
Marsh. If growth is similarly elevated across other habitats, incorporation of these rates into growing degree-
day and more complex, mechanistic models promise improved predictions of bloom timing and toxicity and
climate change assessments. Aim 3 will establish how cell concentration thresholds, parasite infections, and
migration shifts contribute to A. fundyense bloom termination. Aim 4 will greatly expand the knowledge base for
Pseudo-nitzschia bloom dynamics by combining previous and new in situ and lab-based observations.
Pseudo-nitzschia species composition is a first order predictor of toxicity, so knowledge of species diversity
and differences between species' physiology and life cycle dynamics is needed for toxicity predictions. In
summary, the project...

## Key facts

- **NIH application ID:** 9968262
- **Project number:** 5P01ES028938-03
- **Recipient organization:** WOODS HOLE OCEANOGRAPHIC INSTITUTION
- **Principal Investigator:** Donald M. Anderson
- **Activity code:** P01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $143,366
- **Award type:** 5
- **Project period:** — → —

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9968262

## Citation

> US National Institutes of Health, RePORTER application 9968262, Project 1: Harmful algal bloom dynamics: assessing physiological and behavioral plasticity in natural populations (5P01ES028938-03). Retrieved via AI Analytics 2026-05-22 from https://api.ai-analytics.org/grant/nih/9968262. Licensed CC0.

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