Fish assemblages in the Kaş-Kekova MPA: A comparative study of Posidonia oceanica meadows, sandy-rocky and rocky habitats

This study investigates the fish assemblages within the Kaş-Kekova Marine Protected Area (MPA), focusing on the differences among Posidonia oceanica meadows, sandy-rocky and rocky habitats over three consecutive summer periods (2022–2024). We conducted an underwater visual census method to assess fish diversity, density, and the presence of native and non-indigenous fish species across four sampling points. Results indicate that Posidonia meadows support remarkably higher native fish density than other habitats, while number of native fish species were very close to each other among habitats. Evenness (J′) values ranged from 0.47 to 0.63 across different stations and habitats and lowest evenness was observed in Posidonia habitat. Shannon Diversity Index (H′) values ranged from 1.42 to 1.82, and the highest diversity was observed at sandy/rocky area. Our results provide insights into local habitat dynamics, broader surveys encompassing a wider range of habitats and environmental conditions are needed to develop a more comprehensive understanding of the factors influencing fish assemblages and the spread of non-indigenous species within the MPA. Future research should incorporate complementary methodologies, such as remote sensing and environmental DNA (eDNA) monitoring, to provide a more comprehensive understanding of fish community dynamics.