A research vessel has returned safely to the Seychelles after a two week cruise in the Indian Ocean to study the behaviour 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. Some were captured and equipped with electronic tags, which allows the team to remotely observe the behaviour 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 behaviour 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”.
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.
