Distribution of marine benthic diatoms on the coasts of the sea of Marmara and their responses to environmental variables

The Sea of Marmara, located in northwest Turkey, comprises challenging environmental conditions and is an important bridge between the Black Sea and the Aegean Sea. In this study, we assessed the trophic situation of the coasts of the Sea of Marmara using the benthic diatom composition and their relation to the environmental variables in the spring and autumn of 2019 and 2020. A total of 120 samples were collected and 452 species were observed; Navicula Bory and Nitzschia Hassal were represented with the highest numbers of taxa. Analysis of Similarity (ANOSIM) revealed that diatom communities differed significantly between the spring-autumn periods and years. Canonical Correspondence Analysis (CCA) showed that diatoms grouped under water, temperature, salinity, dissolved oxygen, and TIN influence. TRIX observations revealed a highly mesotrophic-eutrophic status along the coasts. Our study contributes to the knowledge of diatom diversity, distribution and community changes in spring and autumn on the coasts Sea of Marmara. Our findings suggest that marine benthic diatoms could be used as eutrophication indicators in the coastal waters for long-term monitoring with the support of environmental parameters.

Automated summary

This study assessed the trophic situation of the coasts of the Sea of Marmara by examining the benthic diatom composition and their relation to environmental variables. The results showed significant differences in diatom communities between spring-autumn periods and years, with a highly mesotrophic-eutrophic status observed along the coasts. The study contributes to the understanding of diatom diversity, distribution, and community changes in the Sea of Marmara, and suggests that marine benthic diatoms can be used as indicators for long-term monitoring of eutrophication in coastal waters.