Wind Turbines as Reefs: A URI Ph.D. Student Reads the Chemical Fingerprints of Jonah Crabs

The American lobster is moving north. Decades of warming Gulf of Maine water temperatures have pushed the species toward colder, deeper habitats, and Southern New England fishermen have spent the past several seasons adapting their gear, their grounds, and the species they target. One of the most consequential pivots has been to the Jonah crab, Cancer borealis: a stocky, brown-shelled cousin of the rock crab that, until recently, was dismissed as bycatch. It is now one of the region’s most important commercial species.

That economic and ecological reshuffling is happening at the same moment that a new variable is being installed across the same waters: the foundations of offshore wind farms. A first-year Ph.D. student at the University of Rhode Island’s Graduate School of Oceanography is one of the people quietly working out what those two trends mean when they meet.

Emmanuel Oyewole, originally from Ilé-Ifẹ̀ in southwestern Nigeria, is conducting a study (partly funded by a grant from The Nature Conservancy) into how offshore wind farm structures are influencing the growth, habitat use, and movement of Jonah crabs in Southern New England waters. The question matters far beyond Rhode Island. As global offshore wind capacity expands (the US alone has more than 50 gigawatts of permitted projects in development), the ecological footprint of turbine foundations is becoming one of the most important uncertainties in marine spatial planning.

A “mini ecosystem” on the seafloor

When a turbine foundation is sunk onto the seafloor, its hard surface immediately becomes prime real estate for sessile marine life. Algae attach first, then barnacles and mussels. Smaller invertebrates colonize the crevices. Within a few seasons, the structure functions, ecologically, like an artificial reef: a hard substrate in an otherwise soft-bottom environment, drawing in predators, prey, and the species that exploit the new edges.

That distinction (between production and attraction) is the central scientific puzzle in offshore wind ecology, and it has been a sticking point in the academic literature for years. If a turbine concentrates fish and crabs already living nearby, the structure may be redistributing biomass without adding to it, potentially making fisheries more efficient in the short term but more vulnerable to overharvest. If it actually supports new biological production, by feeding more juveniles into the system, it is closer to a genuine restoration tool. The honest scientific answer, from the European North Sea to the US Atlantic, has been “it depends”: on species, depth, current regime, and how long the structure has been in place (Methratta & Dardick, Reviews in Fisheries Science & Aquaculture, 2019; Degraer et al., Oceanography, 2020).

Oyewole’s contribution is to bring that question down to a single, commercially essential species at a moment when fishing communities need answers.

Fieldwork before sunrise

For the last year, Oyewole has boarded lobster vessels at Point Judith, Rhode Island, twice a month, long before sunrise. He works alongside commercial fishermen as they haul ventless traps from ten stations near the Revolution Wind and South Fork Wind project sites. The data he collects will feed back into the Commercial Fisheries Research Foundation, a nonprofit founded by local fishermen, whose collaboration is built into the study’s design.

That orientation runs through the work. The project is deliberately structured to run field sampling, lab analysis, and data interpretation concurrently rather than sequentially, with each phase informing the next. The aim is research that produces useful information at the speed regulators and fishermen actually need it.

Reading the crabs’ chemical fingerprints

The lab side of the study takes place at the Ocean Ecogeochemistry Laboratory on URI’s Narragansett Bay Campus, under the supervision of Associate Professor Kelton McMahon. The technique is tissue-specific stable isotope analysis: a method that measures the ratios of carbon, nitrogen, and other stable isotopes in different tissues of an animal to infer where it has been feeding and at what trophic level.

Different tissues turn over at different speeds. Muscle integrates feeding signals over weeks to months. Carapace integrates over a longer timeframe, sometimes years. By comparing isotope ratios across tissues from the same crab, Oyewole can begin to reconstruct a residency timeline: a crab whose muscle and carapace both signal wind-farm feeding is settling in; one whose muscle alone bears the signal is a recent visitor. The technique has been applied to migratory fish for decades, and is increasingly powerful for slower-moving benthic invertebrates whose movement patterns are otherwise hard to track without expensive tagging.

From Ilé-Ifẹ̀ to Narragansett Bay, and back

Oyewole grew up in a region where fisheries are both economically vital and environmentally vulnerable. That early exposure to the trade-offs between resource use and long-term sustainability shaped the direction of his research.

For SEVENSEAS readers tracking the offshore wind buildout, the timing of his work matters. Revolution Wind and South Fork Wind are among the first US commercial-scale offshore wind projects in operation. The baseline ecological data from these years (before the network of mid-Atlantic projects fully comes online) is exactly the kind of evidence that future regulators, marine spatial planners, and fishing communities will need to balance energy ambition with marine biodiversity. The fact that some of that evidence is being collected by a first-year doctoral student, working at dawn with the fishermen most affected by the answer, is the kind of detail that makes the work feel honest.

Reporting based on a release from the University of Rhode Island, dated 14 May 2026, and quotes provided by Neil Nachbar, Public Information Specialist at URI. SEVENSEAS Media thanks Neil Nachbar and Emmanuel Oyewole for sharing the work. To learn more about URI’s Graduate School of Oceanography, visit web.uri.edu/gso.