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Focus Areas

Harmful Algal Blooms

A harmful algal bloom that spanned across the New England region in 2016 resulted in a bay-wide closure of shellfish harvesting for the first time in closed Narragansett Bay.

Sea Grant-funded research supported projects that focused on improving the understanding of plankton species that create harmful algal blooms in Rhode Island waters to help coastal management respond to future events.

Socioeconomic impacts of offshore wind

The nation’s first offshore wind farm was established in the waters off of Block Island in 2015, presenting new opportunities for renewable energy into the region but also introducing new challenges.

Sea Grant-funded research focused on understanding the socioeconomic impacts of wind energy on tourism, commercial and recreational fishing, and coastal and water-dependent businesses and other sectors.



How Bacteria Influences the Production of Domoic Acid




Principal investigator: Matthew Bertin, University of Rhode Island
Affiliate: Bethany Jenkins, University of Rhode Island

Pseudo-nitzschiaa genus of plankton that can produce domoic acid, a neurotoxin that, if ingested in dangerous amounts, can cause illnesses ranging from gastrointestinal problems and lethargy to short-term memory loss and seizures.

Although this type of plankton is always present in the bay and elsewhere, it is not always producing domoic acid.

Sea Grant-funded researchers are examining the specific species of phytoplankton that produce domoic acid, as production rates vary among species within the Pseudo-nitzschia genus, to determine whether a bloom has toxic potential. They are also looking at how partner bacteria that accompany the phytoplankton may have a role in influencing the amount of domoic acid the phytoplankton produces.


Researchers found that multiple Pseudo-nitzschia (PN) strains are associated with domoic acid production at the long-term plankton time-series site near Fox Island and that domoic acid concentrations are generally highest at the passages mouths in Narragansett Bay. Researchers have observed distinct strains are prevalent during different times of the year with spikes of domoic acid in September/October in 2017 as well as June and September/October in 2018.

Findings also show that particulate domoic acid concentrations are greater than dissolved concentrations by examining phytoplankton cells and filtered water, indicating that domoic acid concentration is not correlated with cell count.

Impacts of the Block Island Wind Farm on Recreational Fishing





Principal investigator: David Bidwell, University of Rhode Island
Affiliates: Tiffany Smythe, Coastal Resources Center/Rhode Island Sea Grant; Tracey Dalton, Department of Marine Affairs, University of Rhode Island; Julia Livermore, Rhode Island Department of Environmental Management

The 30-MW, 5-turbine wind farm off of Block Island has received a great deal of attention as the first operational offshore wind energy project in the U.S. and is expected by many to kick-start a broader development of the technology off the Atlantic coast. When confronted with proposals for offshore wind energy, the public frequently raises concerns about impacts of offshore wind to recreation and tourism. Recreational fishing (an in-state activity) and fishing tourism (including anglers who travel from out-of-state to fish in Rhode Island) are both integral to Rhode Island’s tourism economy.

A 2007 study reported that saltwater recreational fishing in Rhode Island resulted in $70 million in direct expenditures, $24 million in wages, and 1,000 jobs, generating a total economic impact of $160 million. There is little data, however, on actual impacts of wind farms on recreational fisheries in the U.S. and abroad, and no such data to date for the Block Island project.

Sea Grant-funded researchers are investigating how the Block Island Wind Farm is affecting anglers’ perceptions of their experience of recreational saltwater fishing in Rhode Island through interviews, surveys, and a legal analysis, and includes a comparison of anglers’ perceptions of the ecology of the wind farm area with findings from ecological data collected at the site.

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Researchers Look at How the Block Island Wind Farm Impacts Recreation and Tourism


Nitrogen from the Sediment May Fuel Harmful Algal Blooms in Narragansett Bay




Principal investigator: Robinson Fulweiler, Boston University
Affiliates: Christopher Gobler, Stony Brook University

Since wastewater treatment advances have dramatically reduced the amount of nitrogen these facilities discharge into Narragansett Bay, another source of nitrogen likely caused the growth of the harmful algae that closed the bay to shellfish harvesting in 2016. There is currently a lack of updated information accounting for nutrient fluxes from sediments in Narragansett Bay, which is needed to better predict the occurrence of harmful algal bloom events, and how that compares to land-based nutrients sources.

Sea Grant-funded researchers are investigating the role of benthic nutrient sources with the hypothesis that organic matter from the harmful algal bloom decreases denitrification and creates a positive feedback loop and thereby retaining nitrogen in the system to further promote harmful algal blooms.

Sediment cores will be collected at various sites to measure net exchange of various gases and dissolved nutrients between the sediment and overlying water, followed by isotope tracer experiments to quantify the individual processes making up the net measurements.



Researchers have collected sediment and in situ water column samples four times over the past year from four stations in Narragansett Bay near areas of known harmful algal blooms–Providence River, the midbay region, and near Wickford.

Currently, sediment property data (e.g., sediment chlorophyll, C:N) are being processed, as is the data analysis phase for the net denitrification (including N2O fluxes) and sediment oxygen demand.

Rhode Island Sound’s Role in Harmful Algal Blooms in Narragansett Bay





Principal Investigator: Christopher Kincaid
Affiliates: David Ullman and Lucie Maranda, University of Rhode Island Graduate School of Oceanography

Since nutrient reductions from wastewater treatment plants that discharge into Narragansett Bay have been implemented, the nutrients that fueled the 2016 HAB event in Narragansett Bay likely came from elsewhere. One hypothesis is that Rhode Island Sound feeds nutrients into Narragansett Bay that may fuel harmful algal blooms.

During that event, significant concentrations of the HAB species Pseudo-nitzschia were observed in Rhode Island Sound east of the mouth of Narragansett Bay. Recent work indicates that meteorologically driven intrusions of these waters into Narragansett Bay occur sporadically during the summer. This project seeks to better understand the role of these intrusions on HABs in Narragansett Bay.

Improved scientific understanding of and management strategies for the relationship between estuarine-shelf physics, nutrient dynamics and healthy versus unhealthy blooms requires improved data and modeling tools. Rhode Island Sea Grant-funded researchers are investigating the relationship between estuarine-shelf physics, nutrient dynamics, and healthy versus unhealthy blooms by applying the Regional Ocean Modeling Systems (ROMS), developed from previous funding, to better assess shelf-estuary exchange physics and the associated nutrient-biological exchange fluxes.

To obtain volume and nutrient flux measurements, two moored stations in the lower East Passage and off Brenton Point. Mussels, provided by American Mussel Harvesters, will be sampled weekly to monitor the presence of harmful algae. Data will be used along with realistic Bay/shelf models to produce improved estimates of nutrient intrusion flux, how these products move into the estuary and interact with terrestrial sources for driving different styles of blooms.

The outcomes of this project are intended to improve the predictability of harmful algal blooms in Narragansett Bay.

Researchers have compiled the first-ever characterization of water flux, including seasonal variances, through the mouth of Narragansett Bay. The analysis shows that intrusions are larger, more frequent, and long-lasting than previously thought. Data obtained show the physical processes of intrusions representing Rhode Island Sound and Narragansett Bay in ways that can be used to improve the next generation of modeling tools when included with harmful algal bloom data will fill an essential component for better understanding blooms in the bay.

Impact of Offshore Wind on Home Values




Principal investigator: Corey Lang, University of Rhode Island

One of the top concerns expressed by the public regarding offshore wind development is a potential reduction in home values. Other economic losses are also a fear.

While studies suggest that onshore wind turbines in Rhode Island do not affect property values for those in the viewshed, it is unclear whether the same is true for offshore turbines. A challenge in studying this issue is that surveys that depend on respondents’ stated preferences may be biased due to people’s feelings about climate change, which is connected to the push for offshore wind development.

Sea Grant-funded researchers will examine price-based data related to home sales and rental prices before the wind turbines were proposed and before and after they were installed off Block Island. This project aims to estimate the socio-economic impacts of the Block Island wind farm to give state and local managers the information necessary to more accurately anticipate effects from future offshore wind development on local housing markets and recreational activity.


Satellite Imaging of Harmful Algal Blooms





Principal investigator: Colleen Mouw, University of Rhode Island Graduate School of Oceanography
Affiliate: Melissa Omand, University of Rhode Island Graduate School of Oceanography

To better detect and predict harmful algal blooms in Rhode Island, Sea Grant-funded researchers will form a coastal observatory from the dock at the University of Rhode Island’s Graduate School of Oceanography to continuously observe and identify phytoplankton community composition at the cellular level. This data will be supplemented with regional ocean color and sea surface temperature satellite remote sensing imagery to visually observe harmful algal presence.

The researchers are working in collaboration with the Brown University Center for Computation and Visualization to develop a web portal to readily access and visualize the dock data. In addition to the web portal, the team is developing an immersion experience that will allow users to see microscopic phytoplankton in the bay in three dimensions, either at the Brown University Ultimate Reality Theatre (YURT) or using their own virtual reality viewers.




Researchers have deployed imaging instruments including the Imaging Flow CytoBot (IFCB) and digital imaging holographic microscope (DIHM) at the Graduate School of Oceanography dock to collect images of phytoplankton that allow for continuous real-time characterization of phytoplankton communities. Sensors on the instruments also allow for the collection of temperature, salinity, as well as chlorophyll and phycoerythrin data.

The most recent images of particles or phytoplankton have been taken from the aquatic environment and are currently hosted online for public sharing that researchers across the state, including the Rhode Island Department of Environmental Management, have been routinely using to understand the phytoplankton composition variability.

<< 2020–2022


For more information or application questions please contact Alan Desbonnet at


Rhode Island Sea Grant has funded scientific research relevant to the Narragansett Bay and Rhode Island Sound in service of residents who conserve, enjoy, and make these coastal and marine resources.

The funded projects advance scientific knowledge through the publication of peer-reviewed journal articles.

Current and past publications can be accessed through the National Sea Grant Library.

National Sea Grant Library