Frigatebirds, Boobies & Sharks accompany eDNA Expedition in Cocos Islands National Park
Early morning of 6 December 2022, Costa Rican Park rangers & volunteers sailed out to Cocos Island National Park to filter environmental DNA (eDNA) from the water. The local sampling is part of the global eDNA expeditions initiative that UNESCO currently conducts across 25 marine World Heritage sites to better understand ocean biodiversity and the effects of climate change thereupon.
After a 2-day sea voyage from the mainland of Costa Rica, the 4-person crew reached the remote shores of Cocos Islands National Park – a place recognized as UNESCO World Heritage because of its globally outstanding abundance of pelagic species such as sharks, rays, tuna and dolphins.
Accompanied by frigate birds and boobies that traditionally nest at the site, the crew filtered eDNA material from water samples at six locations reflecting the most important areas where sharks and other pelagics are known to aggregate. The sampling was facilitated by the Cocos Island National Park, the Cocos Marine Conservation Area, and the National System of Conservation Areas (SINAC).
While shark monitoring is common at Cocos Islands National Park, the UNESCO eDNA expedition initiative allowed local scientists and park rangers to reflect on the possible benefits the innovate eDNA approach might bring in comparison to the use of traditional research methods.
“We usually monitor pelagic species, reef fishes and other species yet some are very shy. The eDNA sampling could give us more data for less effort, without disturbing those fascinating creatures and their habitat.”
Environmental DNA is an innovative scientific method that can be used to monitor and evaluate ocean biodiversity without the need to extract organisms from their environment. Just one liter of water may contain genetic material from hundreds of species and may help determine the area’s biodiversity richness.
The UNESCO environmental DNA Expedition initiative is being rolled out across 25 marine World Heritage sites between September 2022 and April 2023. The eDNA data is expected to provide a one-off snapshot of biodiversity richness across marine World Heritage sites, particularly for fish species.
By combining the resulting biodiversity data with Intergovernmental Panel on Climate Change (IPCC) heat scenario projections, the initiative aims to provide a first glimpse of potential geographic and distribution shifts of fish species as a result of climate change which then in turn can inform conservation decision-making.
Resulting data will be available at the UNESCO Ocean Biodiversity Information System, the world’s largest open science marine species database. Final results are expected to be available in Spring 2024.
The UNESCO eDNA initiative is a joint collaboration between the Intergovernmental Oceanographic Commission and the World Heritage Centre. It is made possible with the support of the Government of Flanders (Kingdom of Belgium) and implemented in the context of the United Nations Decade of Ocean Science for Sustainable Development (2021-2030).
About the Cocos Island National Park World Heritage site
Cocos Island National Park (Costa Rica) was inscribed on the World Heritage List in 1997 and extended in 2002. Its underwater world has become famous due to the attraction it holds for divers, who rate it as one of the best places in the world to view large pelagic species such as sharks, rays, tuna and dolphins. The site protects the most diverse coral reefs of the entire Eastern Tropical Pacific, as well as some 300 recorded fish species. The World Heritage site is of irreplaceable global conservation value, reminding us what parts of tropical oceans historically looked like.
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