Marine life flourishes at the bottom of the Marmara Sea, but the outlook is not so bright closer to the surface. Turkey’s only landlocked sea, which was a victim of notorious sea snot or mucilage last year, is still an important habitat for abundant flora and fauna.
To further improve the habitat, a project by nongovernmental organizations (NGOs) and universities boosted the number of gorgonia corals in the sea but elsewhere, worsening climate change has dealt a blow to fish in the Marmara, experts warn, urging protective measures.
In 2019, the Marine Life Conservation Society, in cooperation with Istanbul University and the Scientific and Technological Research Council of Turkey (TÜBITAK), launched a gorgonia coral project off the coast Tavşan (Rabbit) Island, the smallest of the Princes’ Islands near Istanbul. In three years, some 300 corals transplanted to the area clung to life and flourished. NGO officials say some 70% of the transplanted corals survived, hailing it as a tremendous success in transplantation, compared to the average survival rate of 20%.
The corals were transferred from Democracy and Freedom Island and Sivriada, two islands in the Marmara where they are under the threat of marine waste, ghost nets and overall pollution. In the protected area off Tavşan Island, they find new life, in depths up to 40 meters (130 feet). The area was designated for conservation with a presidential decree last year, becoming the first such place off the coast of Istanbul. Corals are viewed as the first step to creating a new habitat for marine life.
Volkan Narcı, chair of the Marine Life Conservation Society, told Anadolu Agency (AA) on Tuesday that corals were a “key” for any habitat. “Coral reefs, which constitute up to 25% of life in the seas around the world, are also home to 30% of marine ecosystems. They are the favorable habitat of several species that use them as breeding ground,” he said.
Gorgonia corals are endemic only to the Mediterranean and Marmara, but Narcı said human activities have damaged their habitats. The NGO maps the coral transplantation areas and regularly monitors them through volunteers. “The first transplanted corals were about 10 centimeters (4 inches) long, but we now see 3-5 centimeter growth,” he said. Narcı added that though the area was preserved, more needs to be done to ensure it stays protected, including the installation of a camera system for monitoring it around the clock to ensure the sustainability of biodiversity.
Corals may live to see another day, but the fish are not so lucky, according to experts, pointing out a decline in stocks, species and oxygen levels due to climate change. Istanbul University's Faculty of Aquatic Sciences has monitored the impact of global warming on fish stocks in the Marmara since 2016. The faculty’s research ship observed the alarming situation for the fish. Faculty dean professor Melek Işinibilir Okyar told AA that global warming was already taking its toll on marine ecosystems and that they have seen negative changes in the Marmara Sea, where they collect samples four times every year. “Increasing water temperatures push species intolerant of this new condition to extinction or away from their usual habitat. Every disappearing species is replaced with ‘opportunistic’ species, which can easily shift to adapt to the environment and can cause ecological problems,” she said.
Okyar also pointed out the danger of invading species arriving from other seas near the Marmara, highlighting that their numbers are also increasing, again, due to climate change. She gave the example of jellyfish, which are also a public health concern. “The increasing number of jellyfish is a threat for fish stocks as they feed on fish larvae and food the fish species favor. For fishermen, they damage the fishing sector by obstructing nets, causing more energy consumption for catching fish,” she noted.
The Marmara Sea is an important source of income for thousands of fishermen in littoral cities and towns, she highlighted. “Yet, we see harmful marine organisms like jellyfish becoming dominant species. More depletion of fish stocks also means depletion of an important food resource, especially in case of food shortage. So, we need to take measures to boost fish stocks and biodiversity,” she said. Okyar also stressed that along with climate change, overfishing and pollution in the sea from land (including untreated waste discharged into sea) harmed fish stocks.
