How far will you go for sex? If you are a fish, that is
“When I was growing up, I remember a lot of fishermen fishing outside Port Victoria, near what we used to call the ‘Far’, the Victoria harbor Light House. In those days there were spawning aggregations of a species of groupers called 'vyey davril' every April. Fishermen knew to fish there for a big catch. This spawning site vanished even before the land reclamation because of overfishing.” Dr Shah, Nature Seychelles CEO said in introducing a workshop looking at the movements of two species of “kordonye” or rabbitfish, herbivorous fish of importance to the local fishery, when they aggregate for spawning.
Tove's presentation was of interest not only to the funders but also organisations and scientists working in marine conservation
The presentation was delivered by Dr. Tove Jorgensen, a Nature Seychelles fish researcher. The workshop highlighted the findings vis-à-vis improved design and functioning of marine protected areas (MPAs). The project is aimed at studying spawning aggregations of the fish and how well they are protected by the marine reserve on Cousin Island so that this important biological function can be better protected.
Cousin Island Special Reserve and a spawning site 3 kilometers from Cousin called “Dividi” were the focus for the fish tagging project which was funded by the Global Environment Facility (GEF) and United Nations Development Program (UNDP) and which is now coming to a close.
Tove disecting for gonads
The presentation workshop held at Nature Seychelles’ boardroom in Roche Caiman was attended by representatives from the Ministry of Environment and Energy (MEE), Seychelles Islands Foundation (SIF), Global Vision International (GVI), government of Seychelles UNDP-GEF Project Coordinating Unit (PCU) and independent fisheries scientist Jan Robinson.
Tove first worked in the Seychelles several years ago with the Seychelles Fishing Authority (SFA) after completing her Masters degree, where she worked on spawning aggregations of groupers on one of the outer islands. “That is how I met Jan Robinson,” says Tove. “Ten years later, I met him again at a WIOMSA conference in Mombasa. He then introduced me to Dr. Shah when I told him I was interested in working on acoustic tagging. A year later I applied for a fish researcher position with Nature Seychelles.”
The acoustic tag is inserted inside the fish. It will then transfer electrical energy to ultrasonic sound
Tove’s presentation focused on acoustic and conventional fish tagging as well as the evaluation of telemetry equipment, outlining how these are carried out, her results and how effective the methodologies are. The components of her work however also included desktop review and gap analysis; fish utilisation of habitat; fish sampling and gonadsomatic index; and fish and substrate surveys around Cousin and Dividi.
“I would say the project has been a great success,” Tove stressed. “We now know much more about herbivore fish behavior and that for some species, small marine reserves are not sufficient to protect them. They need additional protection. The project has also shown clear links between how fish movement can affect coral reef management.”
The fish are keeping the algae down promoting coral recovery photo credit Tove Jorgensen
Following her eighteen months of research, Tove concluded that forktail rabbitfish (Siganus argenteus) appear to be protected at Cousin Island Special Reserve whereas the shoemaker spine foot (Siganus sutor) are vulnerable leaving the marine reserve regularly during spawning. She also pointed out that as juveniles none of the species are protected.
Recommendations from her presentation included a 100% increase on all sides of the marine reserve on Cousin, protection of spawning sites and the protection of juvenile fish habitats from land reclamation as well as in mangrove habitats. Tove stressed the importance of including the Praslin Fishing Authority in all management discussions and decisions, having worked so long and closely with local fishermen whose livelihoods depend on a healthy fish population.
“The Seychelles is very dependent on the ocean both for fishing and tourism and it is therefore very important to safeguard these resources” Tove concluded.
