Research

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

Pseudo-nitzschia, a 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.

RESULTS:

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.

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.

PRELIMINARY RESULTS:

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.

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.