Three and a half decade analysis of fish biodiversity in İzmir Bay, western Aegean Sea: Insights into fishing methods and habitat changes

Authors : Şule Gürkan, Bahar Bayhan, Ertan Taşkavak

Pages : 110-116

Doi:10.51756/marlife.1766212

View : 80 | Download : 200

Publication Date : 2025-12-30

Article Type : Research Paper

Abstract :This study evaluates the biodiversity of fish species caught using different fishing methods in relation to habitat distribution, based on 34 length-weight studies conducted in İzmir Bay between 1990-2024. The obtained data has been analysed in terms of traditional and modern fishing methods\\\' species distributions in coastal and offshore habitats and the state of the bay ecosystem. This study examines how fish species diversity in the bay fluctuates over time, analyzing the impact of habitat characteristics and fishing practices on these variations. In the study, data from 170,466 fish specimens belonging to 139 species were analyzed using the Biodiversity Pro program. According to Simpson’s Reciprocal Index analysis, trawling is the most dominant fishing method with 20.81% in terms of number of individuals, followed by trammel net with 13.12%. While trawling, the bay\\\'s most effective fishing gear, catches 97 species, trammel net catches 28 species. The fishing method capturing the least number of individuals is fishnet with 1%. According to life forms, demersal species constitute the dominant group (18.157%) in the bay, while bathypelagic species showed the lowest diversity (1%). According to the Margalef index, the highest species richness was observed in demersal species (M: 28.265), while the lowest was in bathydemersal species (M: 43.792). According to studies between 1990-2024, fish populations with a b value above 3 comprise 68.61% in İzmir Bay. The average b value of 3.078 indicates that fish populations in the bay consist of species prone to positive allometric growth. The findings provide important contributions to understanding the ecological preferences of fishing methods and fish species. These data offer significant recommendations for sustainable fishery and species diversity management in İzmir Bay.
Keywords : Biyoçeşitlilik, Balık populasyonları, Avcılık metodu, İzmir Körfezi, Ege Denizi, Türkiye, Türkiye

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