The Long Island Sound and surrounding New York and Connecticut coastal embayments receive excess nitrogen from wastewater, runoff, and other sources. This makes the area a hot spot for harmful algal blooms (HABs). Nitrogen enrichment and coastal acidification both affect HAB development and toxicity, but the linkages among these coastal stressors and their synergistic impacts are not well understood. This project aims to determine how HABs and their toxins are related to water quality, acidification parameters, and nutrients in the Long Island Sound area. Project results will help resource managers, shellfish farmers, and others assess HAB risks to water quality and shellfish.
Why We Care
Urban estuaries like Long Island Sound are affected by excess nitrogen and coastal acidification. These factors can cause HABs, which produce toxins that can harm marine life and human health, leading to economic losses for industries like shellfish farming and tourism.
While nitrogen pollution and ocean acidification have been studied individually, their combined impacts on HABs are not well understood. Managers and stakeholders in Long Island Sound have requested research to address this gap. Current methods for predicting HABs are not sufficient to inform management responses and prevent costly shellfish harvest losses.
What We Are Doing
This project will investigate how nitrogen and coastal acidification work together to affect HABs in Long Island Sound, focusing on species that are a concern for local managers.
The project team will conduct field surveys and experiments to:
- Identify where and when key HABs and their toxins appear, and how they relate to water quality and nitrogen levels.
- Measure important ocean acidification parameters in the water.
- Test how different HAB species respond to nitrogen in areas with varying acidification conditions.
- Create publicly available maps that show the risk of HABs based on these combined factors.
The project team will work closely with HAB and shellfish managers in New York and Connecticut, as well as staff from the Connecticut National Estuarine Research Reserve.
Benefits of Our Work
This research is expected to provide fundamental knowledge on how the combined stressors of nitrogen and ocean acidification influence HAB development and toxicity, helping managers understand the environmental conditions that lead to high-risk bloom conditions. Data-driven tools and assessments will be integrated into existing HAB and shellfish management activities. This will lead to more accurate bloom forecasts and more efficient use of resources, potentially resulting in cost savings by anticipating when costly toxin testing or intensified monitoring is needed. The findings from this study will be broadly applicable to other urban estuaries worldwide facing similar environmental stressors.
Dianne Greenfield of the City University of New York (CUNY) co-leads the project with Penny Vlahos of the University of Connecticut.
The project is funded through the NCCOS Ecology and Oceanography of Harmful Algal Blooms (ECOHAB) Program and authorized under the Harmful Algal Bloom and Hypoxia Research and Control Act (33 U.S.C. §§ 4001 et seq.), which authorizes NOAA to detect and monitor harmful algae.