Costa Rican institutions come together to study seamounts at Cocos Island National Park
With remote underwater cameras, scientists study sharks and other pelagic species.
At least 14 species were detected in pelagic or offshore environments, including threatened species such as hammerhead, thresher, and silky sharks.
(San José, April 2022). In order to obtain scientific information on the abundance and diversity of species present in the seamounts Las Gemelas and West Cocos, a group of scientists visited this area located more than 500 km away from the Costa Rican coast.
These seamounts are part of the Cocos Volcanic Range, which connects Cocos Island National Park with Galapagos National Park, in Ecuador.
They are underwater mountains that rise from the seabed at a depth of about 3,000 meters, acting as barriers to cold and nutrient-laden ocean currents. By colliding with seamounts, these currents are forced to rise towards the surface, increasing the amount of nutrients available for marine organisms.
With 132 underwater remote cameras placed on metal baited structures to attract predators, the group of scientists collected data to study the distribution, variety, and numbers of sharks, tuna, and other pelagic species (species that spend most of their time in offshore environments). In addition, thanks to modern technology, they managed to measure the size of the individuals, a very important parameter for analyzing the health of the stocks.
“Preliminary results tell us that seamounts are a hotspot for marine biodiversity. With these data that we are analyzing and with data that we are going to collect in future expeditions, we will be able to better understand how the health status of these pelagic species changes and define effective strategies to guarantee their protection,” stated Martha Cambra, marine biologist and researcher at the Center for Research in Marine Sciences and Limnology (CIMAR).
Preliminary findings show at least 14 species detected in pelagic environments, including endangered species such as hammerhead, thresher, and silky sharks, as well as striped and black marlin, yellowfin tuna, dolphins, and other small fish species. Additionally, sharks were only detected in those cameras placed near seamounts compared to cameras placed at a certain distance from them, thus confirming their importance as species aggregation sites.
“Seamounts are biologically very important environments, but at the same time very vulnerable due to overfishing and illegal fishing. There is already scientific evidence that shows the importance of protecting this and other marine ecosystems to ensure connectivity in the oceans and conserve highly migratory species,” added Mario Espinoza, a CIMAR researcher.
This is the first of a series of expeditions to be carried out by the team of scientists from CIMAR of the UCR and officials from the Cocos Marine Conservation Area (ACMC), within the framework of the project “Strengthening of marine conservation and sustainable coastal development between the Central Pacific coast and the Cocos Marine Conservation Area in Costa Rica”, in a partnership among Friends of Cocos Island Foundation
(FAICO), CIMAR, Université de Bretagne Occidentale (UBO), and MarViva Foundation.
“The involvement of park rangers in this research strengthens capacities in research and monitoring tasks. The methodology used in this expedition allows us to expand our knowledge of pelagic species, particularly sharks, due to the ecological and economic importance they represent for marine ecosystems, mainly in CINP, which is a natural shark sanctuary,” said
Geiner Golfín, Manager of CINP Natural Resources Management Program.
