After an epic three-year and 4600km transatlantic odyssey, a female shark has linked three established basking shark hotspots in Ireland, Scotland and the USA for the first time. The tracking study, published in the Journal of Fish Biology, was undertaken by the Irish Basking Shark Project in collaboration with their partners at Queens University Belfast and the Lough’s Agency. The findings highlight the wide-ranging movements by these oceanic citizens and the need for stronger international partnership in the promotion and implementation of conservation measures for the species.
The female shark of approximately 5 meters was fitted with a unique satellite tracker (designed and built by Wildlife Computers and Customised Animal Tracking Solutions) at Malin Head in August 2014. From Ireland the shark travelled north along the Malin frontal system into Scottish waters. Here she resided for up to a month in the newly proposed Sea of the Hebrides Basking Shark Marine Protected Area before disappearing under the surface. In an amazing stroke of good fortune, sub-aqua videographer Eric Savetsky recorded the shark off Nauset Beach (Massachusetts, USA) in June 2017 - a 4632km straight line displacement from the original tagging location after over 993 days. Due to the limitations of current animal tracking technologies (satellite transmitters only work when the shark is on the surface), it remains unknown where the shark travelled between those dates.
Linking three of the world’s top basking shark hotspots through the movements of an individual shark demonstrates the wide range covered by these animals over multiple years. This single re-sighting cements the value of our re-sighting programme. Furthermore, the speed of movement between Malin Head and the Scottish MPA highlights the difficulty in establishing population estimates and implementing conservation measures by using discrete geographical locations such as ‘Irish’ or ‘Scottish’ waters. Indeed, data from this shark suggests the two areas may be linked. The Irish Basking Shark Project continues to use its research findings to promote the collaborative conservation of basking sharks at home in Ireland and on the international stage. For more information you can find the article here: https://onlinelibrary.wiley.com/doi/10.1111/jfb.14163 (or check out our project pages).