Marmara Sea event alerts coastal communities to growing threat to marine biodiversity 

Erdek, 29 September 2023 – The Atlantic starfish may look benign and to many are a symbol of the sea. But appearances are deceptive: they are wreaking havoc along Türkiye’s coastline. In an effort to protect native shellfish, the United Nations Development Programme (UNDP) mobilized coastal communities to fight an invasion of the innocent-looking but highly destructive Atlantic Ocean starfish. In a two-day event organized in Erdek, on the Marmara Sea coast, on 27-28 September 2023, local divers and marine biologists investigated local seabed starfish populations and divers learned the hard facts about the starfish: it grows fast; reproduces rapidly; adapts quickly; faces no natural predators; and has a ravenous appetite for mussels and mollusks.

Asterias rubens, the Atlantic starfish has expanded its presence across the Mediterranean and over two decades has reached Turkish coastal waters, including the Sea of Marmara and the Black Sea. For Türkiye’s coast, the starfish are an invasive species, arriving as hitchhikers in freighters’ ballast tanks and consuming native shellfish species including mussels, an important local marine resource for coastal Türkiye.

“Marine invasive alien species are a growing threat for coastal Türkiye’s biodiversity and shellfish and aquaculture livelihoods, and global warming increases this risk,” said UNDP Resident Representative Louisa Vinton. “Ultimately, this is a problem that will require international and regional agreements governing how marine vessels and freighters operate, to help prevent new threats from entering Turkish waters.”

To help the country tackle this threat, UNDP is implementing the Marine Invasive Alien Species (MarIAS) initiative jointly with the General Directorate of Nature Conservation and National Parks in the Ministry of Agriculture and Forestry, with US$3.3 million in funding from the Global Environment Facility (GEF).

Over the past two days in Erdek, local divers participated in a small-scale tournament, competing to collect starfish from the shores of the Marmara Islands, and the winners were rewarded with a scuba dive computer, a dive bag and a dive torch. The participation of local coastal communities is important to create awareness among the public, and the culling of starfish is instrumental as a short-term solution to seeking to control the population of the marine invasive alien species. Unlike the lionfish, another invasive species in Turkish coastal waters, the starfish is not considered edible for human consumption.

“Many marine species all around the world end up outside their native habitat due to maritime shipping, and global warming creates a suitable environment for these species to adapt fast in new territories,” said MarIAS Project Manager Mehmet Gölge. “We are here to raise awareness among coastal communities about invasive species and the threat they may represent to local biodiversity and livelihoods.”

The common Atlantic Starfish was first observed in the Marmara Sea in 1993, and the Black Sea in 2003. The ballast waters of maritime shipping were the probable transmitters that enabled this invasive species to arrive in Türkish waters. UNDP’s MarIAS project will organize the International Symposium on Ballast Water and Biofouling Management in Invasive Alien Species Prevention and Control on 28-30 November 2023 in Antalya to support Türkiye in coping with invasive alien species. Also, the project will launch its open access marine invasive alien species database in November 2023 to provide the public with up-to-date information about the threat at seas.

UNDP’s MarIAS initiative seeks to enhance the resilience of marine and coastal ecosystems by combatting invasive alien species in Turkish waters with the active participation of marine fisheries experts, biologists and coastal communities. The total production of fisheries in Türkiye was 799,000 tons in 2021, according to the 2022 Fisheries Report of the Ministry of Agriculture and Forestry, over 4,000 of which was mussel farming, while total fishery export revenue was US$1.37 billion. Among hundreds of alien species found in Turkish waters, 105 are deemed invasive and are considered threats to native species. In addition to the lionfish and starfish, the UNDP initiative is focused on pufferfish, water hyacinth and veined rapa whelk.

For more information

Umut Dulun, Communications Associate for UNDP in Türkiye, umut.dulun@undp.org