How Climate Change Impacts Rhode Island Oyster Farming

The Rhode Island aquaculture industry generated nearly $9 million in 2024, with Eastern oysters accounting for 99% of production across 89 active farms. But beneath this economic success, questions linger about how changing ocean conditions affect these calcifying organisms. Jacqueline Rosa, a graduate student at the University of Rhode Island’s Graduate School of Oceanography, spent 18 months investigating exactly that.

Her research addresses a critical gap: understanding the relationship between environmental stressors and oyster performance in working aquaculture operations. The timing couldn’t be more urgent, as ocean acidification accelerates and farming operations expand across Narragansett Bay’s 392.5 acres of aquaculture sites.

Monitoring the Invisible Shifts

Rosa deployed a sophisticated sensor array at Wickford Oyster Company’s four-acre farm in May 2024, positioning instruments at both surface and bottom depths. Each week, she returned to collect water samples, later analyzing them at URI’s Ocean Carbon Laboratory for pH, salinity, alkalinity, and dissolved inorganic carbon.

These measurements reveal the carbonate chemistry dynamics that govern shell formation. When pH drops or dissolved oxygen declines, oysters struggle to build the calcium carbonate structures essential for survival. Rosa’s weekly sampling regime captured these fluctuations across seasons, creating the first comprehensive baseline for oyster-farming waters in the lower west passage of Narragansett Bay.

“These carbonate chemistry parameters help us understand trends in ocean acidification and how changing conditions may impact calcifying organisms,” Rosa explained. “Shifts in carbonate chemistry can influence shell formation, growth rates, and survival, particularly during early-life stages, making these measurements critical for understanding potential stressors for farmed oysters.”

Over 127 water samples later, Rosa had documented the environmental reality oyster farmers navigate daily, often without realizing the chemical complexities at play beneath their boats.

The Equipment Question

Traditional oyster farming relies on surface cages and bottom gear, both vulnerable to biofouling (the accumulation of algae, barnacles, and other organisms that clog mesh and restrict water flow). This biological reality translates to increased labor costs, reduced growth rates, and higher mortality. Rosa wanted to quantify these effects and test whether newer equipment could address these challenges.

In August 2024, she placed approximately 2,700 juvenile oysters across three gear types at Rome Point Oyster Farm: traditional surface gear, traditional bottom gear, and FlipFarm, a mechanized system designed to reduce biofouling through periodic flipping. From August through December, Rosa worked alongside farmers, monitoring survival rates, measuring shell growth, and collecting specimens for laboratory analysis.

The differences proved substantial. FlipFarm demonstrated significant biofouling reduction, and its mechanical design promised labor reductions of up to 60%, according to manufacturer estimates. Lower maintenance costs, reduced fuel consumption, and decreased vessel time could reshape aquaculture economics, though Rosa noted the system has its own limitations.

“Aquaculture gear is rapidly evolving, making it critical for farmers to select equipment that is most effective for their operations,” Rosa observed. “Traditional grow-out methods are highly susceptible to biofouling, which can reduce growth rates, restrict water flow, and increase mortality. Surface and bottom gear are also labor and time intensive to maintain. The FlipFarm Oyster Growing System addresses several of these challenges, although it’s not perfect and has its drawbacks.”

Connecting Environmental Data to Oyster Survival

Rosa’s advisor, Assistant Professor Hongjie Wang, who leads the Ocean Carbon Laboratory, emphasized the research’s practical applications. Wang’s lab studies ocean biogeochemistry to answer questions about carbon and oxygen cycles under climate change and anthropogenic pressures.

“Jacque’s research fills a critical data gap by establishing baseline water quality conditions in oyster-farming areas,” Wang said. “Our hypothesis is that oyster mortality is linked to specific, abnormal environmental conditions, such as low dissolved oxygen and/or pH. By pairing continuous water quality observations with oyster performance data, this project provides the foundation needed to evaluate whether observed mortality events are environmentally driven.”

This connection between environmental monitoring and oyster health could transform how farmers respond to changing conditions. Rather than attributing mortality to unknown causes, farmers might anticipate stressful conditions and adjust stocking densities, harvest timing, or gear deployment accordingly.

What the Data Will Reveal

Rosa is currently evaluating her 18 months of field data and writing her master’s thesis this spring. The findings will support Rhode Island’s expanding aquaculture industry by identifying optimal cultivation strategies for a changing ocean.

“These findings will support Rhode Island’s growing aquaculture industry by optimizing cultivation strategies to meet the growing demand for sustainable seafood,” Rosa said.

Wang has been impressed with Rosa’s initiative throughout the project. “Jacque has taken ownership of the work and is leading the project independently, from field operations to laboratory processing and data organization,” she noted.

A Career at the Science-Industry Interface

After graduating in May, Rosa plans to remain in Rhode Island, pursuing research that bridges scientific inquiry and industry practice. Her vision centers on work that supports local, sustainable seafood while maintaining strong community connections.

“I’m interested in conducting research and community outreach that supports local, sustainable seafood and continues to bridge the gap between science and industry,” Rosa said.

Her research embodies this bridging role: rigorous environmental monitoring paired with practical equipment testing, academic investigation meeting farmer expertise, and climate science informing aquaculture operations. As ocean conditions continue shifting, this integration of science and practice may prove essential for the industry’s resilience.

The Rhode Island aquaculture sector’s nearly $9 million valuation depends on oysters’ continued ability to build shells in increasingly challenging water chemistry. Rosa’s work provides the data needed to understand those challenges and the tools to address them.

Attribution: This article draws on information from a press release by the University of Rhode Island Graduate School of Oceanography; aquaculture production data from the Rhode Island Coastal Resources Management Council 2024 report; research findings on oyster carbonate chemistry and environmental monitoring from the Ocean Carbon Laboratory at URI; field research on oyster farming equipment and biofouling conducted at Wickford Oyster Company and Rome Point Oyster Farm; and interviews with graduate researcher Jacqueline Rosa and Assistant Professor Hongjie Wang from URI’s oceanography program.