In a groundbreaking new study published in the journal Nature, an international team of over 150 scientists from 26 countries combined movement data from nearly 2,000 sharks tracked with satellite tags. Using this tracking information, researchers identified areas of the ocean that were important for multiple species, shark “hot spots”, that were located in ocean frontal zones, boundaries in the sea between different water masses that are highly productive and food-rich. Researchers then calculated how much shark hotspots overlapped with global longline fishing vessels – the type of fishing gear that catches most open-ocean sharks. The study found that 24% of the space used by sharks in an average month falls under the footprint of longline fishing. For commercially exploited sharks such as blue and shortfin makos sharks in the North Atlantic, the overlap was much higher, with on average 76% and 62% of their space use, respectively, overlapping with longlines each month. Even internationally protected species, such as great whites, had over 50% overlap with longline fleets.
“Our results show major high seas fishing activities are currently centered on ecologically important shark hotspots worldwide” says Professor David Sims, who led the study as part of the Global Shark Movement Project based at the Marine Biological Association Laboratory in Plymouth, UK.
Read more at University of Miami Rosenstiel School of Marine & Atmospheric Science