Coastal State Series

Researchers across New England have been focused on better understanding a phytoplankton species known for producing domoic acid, a neurotoxin that can harm wildlife and humans, ever since an unprecedented harmful algal bloom in 2016 prompted the recall of more than five tons of shellfish in Maine and the first bay-wide precautionary closure for shellfishing in Rhode Island.

“An increase in bloom events and domoic acid production represents a significant risk to the state’s shellfish industry and local populations as domoic acid is responsible for amnesic shellfish poisoning,” says Dr. Matthew Bertin, who has been studying the production of cytotoxic compounds by harmful algal blooms for the last several years.

On December 12, Dr. Bertin, an expert in medicinal chemistry and chemical ecology at Case Western Reserve University and formerly URI, will discuss recent findings regarding the drivers of this particular phytoplankton species in Narragansett Bay and implications for future blooms. The Bertin laboratory’s work has shown distinct seasonal maxima of domoic acid that is the likely result of toxin-producing species assemblages. Additionally work has shown that there is likely episodic introduction of certain species to the bay including P. australis, which is a species of concern due to its high capacity for toxin production. The newest research implicates nutrient limitation as a trigger for toxin production, though this research is ongoing.

“This information will be valuable to resource managers and stakeholders in order to forecast times when domoic acid is at its highest concentration in Narragansett Bay and to establish a robust time series data set that can set the stage for further forecasting of blooms and toxin production. Additionally, determination of toxin triggers will result in mitigation strategies that will serve the shellfishing community and the general public.”

Estuary ecosystems are some of the most complex, where freshwater meets saltwater, creating a mosaic of habitats essential for commerce, recreation, and fishing. These ecosystems have adapted to this duality, but how they have and will respond to changes in activities along the coast, rising seas, and warming temperatures is unknown.

Researchers at the University of Rhode Island and The Nature Conservancy are looking to better understand these changes by studying the benthic ecosystem of the seafloor across Narragansett Bay. This ecosystem plays a major role in water filtration, nutrient cycling, shoreline buffering, food and habitat for fishes and birds, and seafood for human consumption. It is also a historical archive of ecological changes in the Bay.

Dr. Jeremey Collie from the University of Rhode Island’s Graduate School of Oceanography, along with GSO graduate Shaina Harkins and Heather Kinney from TNC, will share their research looking into how changes in temperature and water quality have affected benthic biodiversity in the Bay over the last several decades. This includes investigating whether the state’s nitrogen reduction efforts from wastewater treatment facilities have been practical, which have long been considered the primary cause of nutrient over-enrichment linked to harmful algal blooms and hypoxic events.

Co-sponsors: University of Rhode Island Graduate School of Oceanography and The Nature Conservancy

Scientists have touted Narragansett Bay as the cleanest it has been in 150 years—a long journey to restoration from its history as a dumping ground for toxic metals, sewage, and other pollutants since the Industrial Revolution. 

With improvements in wastewater treatment facilities and controlling storm runoff, Rhode Island has exceeded its goal of a 50% reduction in nitrogen. Nitrogen reduction has been a steadfast focus for the state in cleaning up the Bay to reduce harmful algal blooms that lead to low dissolved oxygen levels, which can lead to fish kills, such as occurred in 2003 in Greenwich Bay. And while there are many nitrogen sources, wastewater facilities have been identified as the primary source in Narragansett Bay.

However, some critics say that reducing nitrogen has made the bay “too clean” by reducing the amount of an important food source of phytoplankton that supports local fisheries.

How the Bay will fully respond to reduced levels of nitrogen with the addition of warming waters is still unknown. “We need to watch trends of [secondary impacts],” says Dr. Candace Oviatt, a professor of oceanography at the University of Rhode Island’s Graduate School of Oceanography.

Oviatt and her colleagues have been exploring these changes in nitrogen loading into the bay and the secondary impacts of warming waters over the last several years to provide managers with a clearer picture of the changing trends in the timing and availability of nitrogen in Narragansett Bay. This will help resource managers forecast and understand the bay’s changes, such as harmful algal bloom dynamics or fisheries resources (e.g., shellfish). 

Oviatt will be joined by URI Masters student Michael Potter II and Dr. Robinson Fulweiler from Boston University as part of the Coastal State Discussion webinar series to share current research findings and plans for ongoing research.

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+ URI Researcher Proposes Limited Return of Nutrients to Narragansett Bay

Today, almost everyone in the world comes into contact with plastics daily. These plastics are lightweight, durable, inexpensive, and easily modified, making them the ubiquitous material of the modern economy. However, in 2017 alone, ~348 million tons of plastics were produced worldwide, and production is expected to triple by 2050. The U.S. recovers less than 10% of its annual plastic production, and it is the fastest-growing component of municipal waste. 

Nearly 85% of all marine debris is plastic, and all studied ecosystems on Earth have been found to contain plastics. With a growing demand for plastics, there remain simple questions:

What do we do with this waste?

What can we replace it with?

What impacts do plastics have on human and environmental health? 

Over the last several years, researchers at the University of Rhode Island have been characterizing marine plastic pollution in various habitats.

Speakers Dr. Andrew Davies and Dr. Coleen Suckling, along with Ph.D. candidate Sara Davis, discussed their work exploring the distribution of plastics, including microplastics, within the surface waters of Narragansett Bay. They shared the challenges in characterizing microplastics within complex marine habitats and show early research findings as they aim to produce the first robust estimates of microplastics within Rhode Island’s coastal waters.

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+ URI researchers identify links between climate crisis and plastics pollution

Rhode Island is long overdue for a major hurricane. Even a brush with Superstorm Sandy in 2012, which caused $11.2 million in damages and left 122,000 Rhode Islanders without power, was not a worst-case scenario, but a reminder of our exposure and vulnerability. And a record-setting hurricane season in 2020 with 30 named storms, 12 of which made landfall in the U.S., was another reminder of how a changing climate makes rising seas and storm-flooding more devastating. 

Storm surge barriers, levees, and other coastal flood protection megaprojects are being investigated as strategies to protect U.S. cities against devastating coastal storms and rising sea levels. But these projects are large-scale and complex, often taking years to decades to complete and costing billions of dollars with long-lasting impacts on the economy, environment, and society. Additional layers of social conflict and other political factors also cast doubt on their status as practical climate adaptation options. 

Dr. Paul Kirshen, professor of climate adaptation at the University of Massachusetts Boston, and Dr. D.J. Rasmussen, an engineer and climate scientist who recently graduated from Princeton University’s School of Public Policy & International Affairs, will discuss the technical, environmental, economic, and political factors of why some coastal flood protection megastructures break ground in the U.S. while others do not, using Boston Harbor and Rhode Island’s Fox Point Hurricane Barrier in Providence–the first gated hurricane-protection structure in the U.S.– as case studies.

This free webinar is part of the annual Coastal State Discussion Series hosted by Rhode Island Sea Grant and co-sponsored by the University of Rhode Island’s Coastal Institute, Marine Affairs Department, and The Policy Lab at Brown University.

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• Coastal Megaprojects Past and Present Show Mitigation Challenges of Climate Crisis

An unprecedented harmful algal bloom that spanned from Long Island to Maine in 2016 prompted a recall of over 5 tons of potentially infected shellfish in Maine and the first-ever bay-wide closure for shellfishing in Rhode Island.

Researchers across the region have since been focused on better understanding the species that drive harmful blooms and the types of toxins they produce, such as domoic acid, which is a that can infect shellfish and be harmful to consumers.

Rhode Island Sea Grant hosted a virtual Coastal State Discussion led by Dr. Matthew Bertin, an assistant professor in the Department of Biomedical and Pharmaceutical Sciences at the University of Rhode Island, who discussed ongoing work investigating why these organisms produce harmful toxins and how these compounds can be leveraged into potential drug leads for either treatment of the disease or new drugs.

“The 2016 event and the continued detection of domoic acid in the bay suggest that either species composition has shifted to more toxic strains of these species, or environmental conditions have made resident species more toxic,” says Bertin. “An increase in bloom events and domoic acid production represents a significant risk to the state’s shellfish industry and local populations as domoic acid is responsible for amnesic shellfish poisoning.”

In addition to studying the human and environmental impact of toxins such as domoic acid, Bertin and his colleagues have also been studying two cyanobacterial communities, Microcystis and Trichodesmium, in a search for new therapeutic lead molecules that could treat neuroinflammation, which is a driver in diseases such as Alzheimer’s.

“In four years, we have discovered over 30 new-to-science molecules, many with promising biological activities,” he says.

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+ Algal Blooms: Toxic, But with Possible Drug Potential