After over 50 years of overfishing, the porbeagle shark, the smallest of the mackerel shark family, has been making a comeback in the waters off the coast of Ireland, a new study shows.
Researchers used data taken analyzed from the Marine Sport Fish Tagging Programme which tagged 268 porbeagle sharks over 47 years, mainly in Irish waters.
University of Western Ontario professor Paul Mensink, along with collaborators from Queen’s University Belfast and Inland Fisheries Ireland, published the findings in the latest published by ICES Journal of Marine Science. They found that Irish waters may act as a persistent summer gathering site for juvenile porbeagles, and that those juveniles may return to the same or nearby sites year after year. Remarkably, one of the tagged sharks moved from Ireland all the way to Canada, marking the first time this type of transatlantic movement had ever been recorded.
“It’s incredible; there are 71 species of elasmobranchs—species like sharks, rays and skates—in Irish waters and several of them are now critically endangered,” Mensink said. “Our study demonstrates how citizen science programmes can help provide the vital information we so desperately need to develop robust and effective management plans for these species.”
The study also showed that porbeagles appear to be arriving into northern Irish coastal waters earlier and earlier each year, potentially indicating a shift in their long-term migratory movements.