I am Cem Dalyan, a marine biologist and associate professor in the Division of Hydrobiology at Istanbul University. My research brings together fish ecology, fisheries biology, and marine conservation. I study where marine species occur, how fish and invertebrate communities vary across habitats and depths, and how fishing, biological invasions, and other pressures affect these communities. My work spans the Black Sea, the Sea of Marmara, the Aegean Sea, and the eastern Mediterranean. My research on marine invasions began with my master’s study of Lessepsian fishes in İskenderun Bay. In a subsequent study of the bay’s trawl fishery, my colleagues and I recorded 27 Lessepsian fish species, nine of which were targeted by the fishery. Cartilaginous fishes accounted for about half of the discarded fish biomass. I have also co-authored a study of dietary overlap between native red mullet and two non-native goatfishes along the northeastern Levantine coast. More recently, our team published the first confirmed record of Steinhardt’s shrimp-goby in Turkish waters. Repeated diving observations in Kaş Bay between 2019 and 2025 provided evidence of a local population. My fisheries research also addresses the biology of commercially important species. In the southwestern Black Sea, I co-authored a study of turbot age, growth, and reproduction. The study found evidence that spawning continued into late June, a result we used to propose a later opening date for the fishing season in pla