Nature Seychelles project keeps "tags" on fish
The Rabbit fish (Kordonyen blanc) that you find on your plate can swim fantastic distances. This was one of the delightful anecdotes that our fish researcher shared with us recently as we chatted about her project. "A Rabbit fish leaves Cousin Island and swims 3 km during the full moon to a spawning site," Tove says as she starts doing her maths. "It weighs an average of 300 grams, so it’s the equivalent of a normal-sized human swimming 600 km. That's pretty far; it's one third of the distance from the Seychelles to Tanzania!" she jokes.Tove is looking at information she has gathered under a Nature Seychelles' project that is investigating the habitats and migratory movements of commercially valuable fish species within and outside the Cousin Island Marine Protected Area (MPA).
Fish spawning areas around Cousin, fish movement between the MPA and fished areas, and the connectivity between the MPA and nearby fish spawning aggregations are under study. The Government of Seychelles-GEF-UNDP
funded project is being carried out in collaboration with the Seychelles Fishing Authority (SFA) and local fishermen.
Tove and her team have collected members of the target fish species within the Cousin Island MPA, and tagged and released them to track their range of movement during spawning.
The tags, which are secured to the outside of fish, contain a unique number identifying the individual fish as well as contact information of Nature Seychelles. This kind of tagging is dependent on the fish being recaptured to recover the tag. This way information on where the fish was tagged and where it was picked up can be recorded.
Tove tells us that the tags deployed on the fish inside the MPA are now getting back to her, thanks to the help of fishers in Praslin who get rewarded for every tag they return.
"The tags have a telephone number, so the fishermen call us or just drop them off. This is not a new concept - the SFA has already done similar work with fishers in Praslin so it's familiar to them and they are keen to help," she says.
"We have gotten to know the fishermen quite well and they've seen us at the spawning sites in our little boat," she adds.
Thanks to the returned tags, she also knows when and where the fish are spawning and the kind of habitats they like.
"A couple of days before the spawning, we see the fish gathering at a point of the MPA we call the bus station. They then start moving and are not seen again until they are at the spawning sites," she says.
Apart from the conventional tags, Tove will also be deploying acoustic tags, which send out sound and allow remote tracking of fish as they move.
"SFA already have their listening stations at the different spawning sites and I have them inside the MPA. So the next step is to deploy the tags into the fish inside the MPA," she says.
Photos: Top left - Fish Reseracher Tove Jorgensen on Cousin Island. Right: Fish tagging
