Interactions between the Lessepsian and the native fishes in the Northeastern Mediterranean coast of Türkiye

Abstract

There has been a noticeable increase in the reports of Lessepsian fish entering the Mediterranean, with their numbers reaching 124 by 2021. These newcomers have also triggered interactions with the native species. The Mediterranean Sea's resemblance to the Red Sea in terms of abiotic factors like temperature and salinity has played a pivotal role in facilitating the migration of Lessepsian species into the Mediterranean. Drifted along by coastal cyclonic currents, these fish have typically formed dense populations in the northeastern Mediterranean. Throughout both the initial settling phase and the subsequent population growth, the most significant interactions between these newcomers and the local species have revolved around sharing habitats, competing for food sources, and feeding patterns. Some of these species have succeeded in boosting their population sizes significantly by taking advantage of ecological niches that haven't been fully exploited by the Mediterranean's native species. Notably, in İskenderun Bay, the percentage of fish species originally from the Red Sea in the catch has recently risen to 80%. Out of the 124 Lessepsian fish species that have made their way into the Mediterranean, 20-30 of them hold economic importance due to their significance in commercial fisheries.