After a two-week cruise in the Indian Ocean to study the behavior of sharks and other fish species surrounding around fish aggregating devices (FADs), a research vessel has returned to the Seychelles with important information to reduce bycatch..
The effort was the result of an international collaboration with participation of scientists from the French Institute of Research for the Development, the Seychelles Fishing Authority and the Spanish research foundation AZTI, including students from South Africa and Mauritius, as a global effort to reduce bycatch.
Funded by the International Seafood Sustainability Foundation and the European-funded project Mitigating Adverse Ecological impacts of open-ocean fisheries, crew and scientists conducted experiments to determine the best methods fishermen can use to avoid catching sharks and other species caught accidentally.
The vessel visited eight different FADs in the Indian Ocean near the Seychelles islands and conducted several scientific experiments. Scientists documented the composition of different species around FADs and also observed shark behavior around these floating objects. Some were captured and equipped with electronic tags, which allows the team to remotely observe the behavior of each tagged specimen for several weeks.
Researchers also tested ways to draw sharks way from floating objects. One of the most striking observations was that sharks often leave the FAD at night and come back in the early morning. Researchers also discovered that sharks can be attracted up to several hundred meters away, which is promising for the design of fishing techniques that mitigate bycatch.
“Scientists are still trying to determine why several fish species form large aggregations around floating objects,” said Laurent Dagorn, project manager. “Scientific cruises such as this one are essential to collect key data on the behavior of fish that help the development of ecological-friendly fishing practices.
More than the pure scientific results collected during the cruise, I was very impressed by the full cooperation of French and Spanish fishers who provided information that were crucial to the success of this cruise as they understand the need to protect sharks, key species of the pelagic ecosystem.”
