Diversity and pollution tolerance of Cladophorales (Chlorophyta, green algae) in the Aegean Sea

In this thesis, the species diversity of Cladophorales (Chlorophyta) along the coasts of the Aegean Sea, the relationship of the species with environmental parameters, and their heavy metal accumulation potentials were investigated. Samples were collected between 2021 and 2025 from 25 stations (Enez, Saros Gulf, Gökçeada, Yeniköy, Bozcaada, Küçükkuyu, Altınoluk, Ayvalık, Dikili, Çandarlı, Foça, İzmir, Urla, Ildır, Çeşme, Seferihisar, Kuşadası, Didim, Güllük, Bodrum, Akyaka, Gökova Gulf, Datça, Bozburun-1 and Bozburun-2) using SCUBA diving, free diving and shore collection methods. At each station, pH, temperature, dissolved oxygen, salinity, conductivity and turbidity of the surface water were measured, and water samples were transported to the laboratory in polyethylene bottles for phosphate and ammonium nitrogen analyses. Samples selected for heavy metal analysis were dried at room temperature, while subsamples to be used as reference material were fixed in 4-5% formaldehyde. The relationships between species distribution and environmental variables were evaluated using Bray-Curtis similarity analysis, Principal Component Analysis (PCA) and Canonical Correspondence Analysis (CCA). As a result of morphological examinations, 28 Cladophorales species (8 genus) were identified and the highest species diversity belonged to the genus Cladophora. Four of these species are reported as new records for the Turkish coasts (Cladophora battersii, Cladophora patentiramea, Lychaete herpestica, Valonia aegagropila). In molecular analyses, successful LSU rDNA sequences were obtained from 13 out of 32 samples. Heavy metal analysis results revealed that especially Ni and Zn accumulated above national and international threshold values. The results demonstrated that metal accumulation differed among species.