Comparison of the species structure of fish communities in the thickets of higher aquatic vegetation and in the open part of the Curonian Lagoon.

The purpose of this study was to investigate the species composition of the ichthyofauna and to compare the structure of fish communities in the Curonian Lagoon among the coastal zone with stands of higher aquatic vegetation, the coastal zone without macrophytes, and areas beyond the macrophyte belt based on data collected in 2022–2025. During the study period, a total of 1 371 fishing operations have been conducted using set gillnets. Seventeen fish species have been recorded in the coastal zone with stands of higher aquatic vegetation, 15 species in the open-water area, and 8 species in the coastal zone without stands of higher aquatic vegetation. Analysis of fish community species structure has revealed the main differences in species composition among the studied zones and identified the species contributing most strongly to the differences among habitat types. The largest number of species making the greatest contribution to differences among habitat types has been characteristic of the macrophyte zone (three species), whereas one such species has been identified in both the open-water area and the coastal zone without macrophyte stands. Data analysis has resulted in the identification of three clusters corresponding to three habitat types. Statistical analysis has con-firmed the significance of the obtained results and the differences among fish communities formed in the respective zones. Stations located within the macrophyte zone have showed a higher degree of similarity in species structure to one another than stations located in the open-water area. Thus, habitat type is statistically significantly associated with fish community structure.