June 27, 2018 — Increased computing power has given fisheries researchers new tools to identify “hotspots of risk,” where ocean fronts and eddies bring together masses of fish, fishermen and predators, raising the risk of entangling non-target fish and protected species such marine mammals, sea turtles and sharks.
Using a novel, high-resolution “Lagrangian Coherent Structures” mapping technique, scientists are able to model dynamic features in ocean surface currents. The capacity for improved, near real-time mapping of ocean fronts and eddies may now help alert fishermen and fisheries managers to the increased risk so they can try to avoid those protected species and better target the species they are after, the scientists wrote in an article published today in Proceedings of the National Academy of Sciences.
“Understanding how pelagic fish and marine predators interact with the environment can help fishers and managers avoid bycatch of non-target and protected species, while maintaining the catch of commercial species,” said Kylie L. Scales of the University of the Sunshine Coast (USC) in Australia, and lead author of the new research. “Our findings give managers information at the broad scales they need, which could help inform development of dynamic ocean management.”
Lagrangian Coherent Structures are known from the field of fluid dynamics and represent areas of mixing, where different water masses meet and tend to concentrate marine life and in turn fishermen. The new approach uses high-resolution ocean modeling to help detect and predict the areas as they form and move through the ocean, and highlight the elevated risk they may present.