How sea critters and wind turbines co-exist
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URI Ph.D. student Emmanuel Oyewole conducting field work at the South Fork Wind farm turbines. (Photos courtesy Emmanuel Oyewole) |
As lobsters migrate to
colder waters due to climate change, Jonah crabs are becoming one of the most
important species for fisheries in Southern New England.
“As the biomass of the American lobster declines due to
climate-related changes and shifting ocean conditions, many fishermen have
adapted by targeting other valuable species, and the Jonah crab has become a
major alternative,” said Emmanuel Oyewole, a first-year Ph.D. student in the
University of Rhode Island’s Graduate
School of Oceanography.
“The Jonah crab used to be considered a bycatch
species and thrown back because lobster was so lucrative. As lobsters became
less abundant, people started to realize that the Jonah crab is a viable and
delicious alternative.”
Oyewole is conducting a study that is partly funded by a
grant from The Nature Conservancy into how offshore wind farm structures are
impacting the growth and habitats of Jonah crabs.
Oyewole prepares Jonah crab muscle
samples for analysis in URI’s Ocean Ecogeochemistry Laboratory.
“Ecologically, Jonah crabs also play an important role in
the marine food web,” said Oyewole, who is from Ilé-Ifẹ̀, Nigeria, a town in
the southwestern part of the country. “They are both predators and prey,
helping to maintain balance within benthic ecosystems. Because they are closely
connected to seafloor habitats, they can help us understand how offshore wind
farm structures may influence local biodiversity, habitat use, and the
productivity of fisheries.”
When turbine foundations are installed on the seafloor,
their hard surfaces become desirable habitats for marine organisms to attach,
grow, and live, just as they do on natural rock or reefs. As algae, barnacles,
mussels, and other small marine life, settle on these structures, these smaller
organisms attract larger species such as crabs and fish that come to feed,
hide, or seek shelter.
“The turbines can create a kind of ‘mini ecosystem.’ They
provide food and habitat, which can draw marine life into the area and
potentially change how species use the surrounding environment,” said Oyewole.
“The question is whether they are increasing the overall amount of marine life
in the ocean by creating new production or simply concentrating animals that
were already living in the surrounding areas.”
The data Oyewole collects and analyzes will benefit
the Commercial Fisheries Research
Foundation, a nonprofit organization founded by local commercial fishermen.