Certain migratory shark species may delay their southern migrations from the northeast coast due to warming ocean temperatures, according to a study led by researchers at Stony Brook University’s School of Marine and Atmospheric Sciences (SoMAS). The research tracked six shark species over five years using tagging and acoustic tracking methods.
The study, published in Conservation Biology, found that ocean warming postponed the migration of five shark species by one to 29 days. Lead author and SoMAS PhD student Maria Manz stated, “Both temperature and photoperiod (length of sunlight) influenced the timing of the sharks’ southernly migration.”
The research team included graduate advisor Professor Michael Frisk, Professor Robert Cerrato, Assistant Professor Oliver Shipley, and other east coast scientists. They discovered that sandbar sharks had the greatest predicted delay with a median delay of 29 days. In contrast, sand tiger and white sharks experienced only a one-day delay under future sea surface temperature scenarios.
Manz explained that their model predictions indicated delayed initiation of southern migratory timing for certain species. She noted regional and species variation in these delays.
The study’s findings suggest potential impacts on conservation strategies for sharks and Atlantic Ocean ecosystems. Sea surface temperatures and photoperiod were identified as strong predictors of migration patterns during the study period from 2018 to 2022.
A total of 155 sharks including blacktip, dusky, sand tiger, sandbar, thresher, and white sharks were tracked. Acoustic tagging was used to monitor their movements along the Atlantic shelf’s latitudinal regions.
Overall results indicate that increased sea surface temperatures could lead to prolonged stays in northern habitats for coastal sharks. The research received support from the New York State Department of Environmental Conservation (DEC) with permits granted by DEC, NOAA, and New Jersey’s Department of Environmental Protection.
