A research vessel visited 8 FADs in the Indian Ocean. (Photo: MADE Project/FIS)
Tuna fishing study in Indian Ocean takes off
Wednesday, July 06, 2011, 23:30 (GMT + 9)
A research vessel has returned safely to the Seychelles after a two-week cruise in the Indian Ocean to study the behavior of sharks and other fish species swimming around fish aggregating devices (FADs). The project went on the water despite the very real threat of piracy in the region.
Security personnel protected the boat while the crew and scientists were conducting experiments to determine the best methods fishers can use to avoid catching sharks and other unwanted species.
The vessel visited eight different FADs in the Indian Ocean near the Seychelles islands and conducted several scientific experiments. Scientists dived into the water to document the composition of different species around FADs and also observed the behavior of sharks around these floating objects.
|Laurent Dagorn, managing the Indian Ocean project. (Photo: ISSF)
Some were captured and equipped with electronic tags, which allows the team to remotely observe the behavior of each tagged specimen for several weeks.
"Scientists are still trying to determine why several fish species form large aggregations around floating objects", said Laurent Dagorn, who is managing the Indian Ocean project. "Scientific cruises such as this one are essential to collect key data on the behavior of fish that help the development of ecologically-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," Dagorn continued.
The research team 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. More, when associated with a FAD during the day, it is possible to attract them up to several hundred meters, which is promising for the design of fishing techniques to mitigate bycatch.
|Tuna purse seiner. (Photo: MADE Project)
This cruise was funded by the International Seafood Sustainability Foundation (ISSF) and the European-funded project Mitigating Adverse Ecological impacts of open ocean fisheries (MADE). This scientific effort was the result of an international collaboration with participation of scientists from the French Institute of Research for the Development (IRD), the Seychelles Fishing Authority (SFA) and the Spanish research foundation AZTI, including students from South Africa and Mauritius, as a global effort to reduce bycatch.
MADE is a European-funded research that aims at proposing measures to mitigate adverse impacts of fisheries targeting large pelagic fish in the open ocean. Focusing on tropical tuna purse seiners using FADs and pelagic longliners, the goal is achieved through studies on the behavioral ecology of species (sharks in particular), as well as on the fishing techniques themselves. It gathers 13 research institutes from eight different countries.
- ISSF scientists to help improve fishing methods
- Conservation groups seek sustainable tuna fishing methods