Volume 26, Issue 78, July - December, 2025

Comparison of the Seasonal Distribution of Phytoplankton Composition Inside and Outside Mersin Marina

Murat Demir, Nuray Çiftçi^♦, Deniz Ayas

Mersin University Faculty of Fisheries, Mersin, Turkey

^♦Corresponding Author
Nuray Çiftçi; Mersin University Faculty of Fisheries, Mersin, TURKEY

ABSTRACT

The objective of this study was to ascertain the impact of the marine operation and breakwater on the phytoplankton composition, as sampled from both within and without the marina, on a seasonal basis. A total of 110 taxa belonging to Bacillariophyceae, Coscinodiscophyceae, Mediophyceae, Dinophyceae, Prymnesiophyceae, Cyanophyceae, and Thecofilosea were identified. The Dinophyceae class made the highest contribution to the phytoplankton composition. The average phytoplankton abundance in the Mersin Marina marine area was 19082 cells/L, with a biomass of 4.61 μg/L recorded throughout the year. Emiliana huxley accounted for 98% of phytoplankton abundance and 66% of biomass. Therefore, the abundance and biomass of phytoplankton were recalculated, excluding E. huxley. The mean abundance of phytoplankton within the marina and its surrounding waters was determined to be 279 and 289 cells/L, respectively. The mean biomass was found to be 1.21 and 1.88 μg/L in these environments. Microplankton abundance (except autumn) and biomass were higher outside the marina in all seasons. The dominant microplankton species were Asterionellopsis glacialis, Chaetoceros curvisetus, Chaetoceros gracilis and Bacteriastrum comosum in autumn, Chaetoceros didymus and Chaetoceros lauderi in spring, Pseudo-nitzschia delicatissima, Gyrodinium fusiforme, Pseliodinium fusus and Heterocapsa pygmea in summer. According to the Shannon (H') index, species diversity was higher outside than inside the marina. As indicated by the results of the analysis, species diversity (H=2.48) and homogenity (J=0.78) exhibited higher values during the summer months, while autumn (d=1.38) was associated with higher richness.

Keywords: Phytoplankton, Species composition, Abundance, Biomass, Mersin Marina

Species, 2025, 26(78), e31s3149

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DOI: https://doi.org/10.54905/disssi.v26i78.e31s3149

Published: 25 July 2025