Seasonal changes in the biomass and chemical compositions of macroalgae communities in the Sinop coasts of the Black Sea

This study was carried out to determine the seasonal changes of macroalgae flora with the changes of biomass in per unit area living in the rocky substrata of four station (Hamsilos, Akliman, DSİ, Karakum) in Sinop coast of the Black Sea and also to determine the chemical compositions of some common and economically important species. Algal samples were collected by hand with a 20x20 cm quadrat at 0-1 m depth as three replication throughout 2014. As a result of the study, a total of 30 taxa belonging to 8 Ochrophyta, 16 Rhodophyta and 6 Chlorophyta sections were identified. The result of this, the highest biomass value was obtained from Akliman (3303,19 g/m2, dry weight), followed by Hamsilos (3225,22 g/m2, dry weight), Karakum (3178,24 g/m2, dry weight) and DSİ (2776,68 g/m2, dry weight). Besides, the highest average biomass value (935,32±16,11 g/m2 dry weight) was obtained in winter and the lowest (588,19±85,35 g/m2, dry weight) in summer. As a rusult of statistical analyzes, the highest diversity index values of each station were calculated in the spring and the evenness index values were showed similarity with these results. The the chemical composition researhed, Cystoseira crinita Duby was determined to intense during the year, however Laurencia obtusa (Hudson) J.V. Lamouroux was not found in the station of DSİ. The suitable amount of Ulva intestinalis Linnaeus for the analysis during the autumn was not obtained in the stations. In terms of chemical composition of macroalgae except the oil amount were found statistically significant (p <0,05) between the seasons.