Marine scientists from Izmir Katip Çelebi University are conducting an underwater monitoring project to help protect the endangered grouper fish, a species crucial to the Mediterranean ecosystem. The project, taking place off the coast of Karaburun in western Türkiye's Izmir, aims to map the habitats of the grouper and track its population using advanced underwater video technology.
The grouper, which holds a vital position at the top of the food chain in the Mediterranean Sea, is being studied to assess its distribution, size, and weight. The scientists use the Baited Remote Underwater Video System (BRUVS) to capture footage, allowing them to gather important data without harming the fish. Every month, divers install cameras in designated locations, recording approximately 20 hours of footage that helps determine the number of individual groupers in the area.
The project is led by associate professor Tuğçe Şensurat Genç and Kaan Kırşan, a graduate student at the university's Institute of Science. It is supported by local diving schools, whose members help collect data. "We are using environmentally friendly methods that do not harm the fish," Genç told Anadolu Agency (AA). "Our findings so far have been promising."
In addition to underwater recordings, the team is conducting surveys with diving centers, recreational divers, and commercial fishermen. The project is financially supported by the Rufford Foundation, a U.K.-based charity that provides funding for conservation efforts.
"The grouper is ecologically significant, sitting high in the food chain," Genç explained. "It has a long life cycle, which makes it a valuable species. Our research, which began in February 2024, is aimed at understanding its population dynamics in the Mediterranean and Aegean Seas. We collect monthly data through surveys and video footage to estimate the size and weight of the fish using specialized software."
While the team has observed positive trends in the population, Genç emphasized that longer-term monitoring is required to make definitive conclusions about the population increase. "Based on data from divers and fishermen, there has been a noticeable rise in the number of groupers compared to last year. This can be attributed to the complete ban on grouper fishing in our waters," she added.
Grouper fishing, collection, and transportation have been banned since 2016, with the current ban extended until 2028. Genç stated that the ban, along with increased awareness, has positively impacted the species’ numbers.
Hamdullah Aras, a diving instructor involved in the project, noted that some groupers in the region are over 10 years old. "When they are protected, we observe that the same fish stay in the same area for years. During today's dive, we set up cameras and captured some great footage, including approaching a grouper within 1-1.5 meters," Aras said. "I’ve been monitoring one particular grouper for eight years; its weight has increased from 8 kilograms to 13-14 kilograms."
Listed as an endangered species in 2004 by the International Union for Conservation of Nature (IUCN), the grouper is protected under the Bern Convention, which safeguards wildlife in Mediterranean countries. This species is unique for its sequential hermaphroditism, starting life as female and transitioning to male around the age of 12. Slow growth, collective spawning behavior, and the capture of immature individuals have been factors in its population decline.
Groupers, which can live up to 50-60 years, reach lengths of 1.5 meters (4.92 feet) and weigh as much as 60 kilograms (132.28 pounds).
