The effect of some physicochemical properties of seawater and sediment on the distribution of caulerpa taxifolia var. distichophylla (Sonder) verlaque, huisman & procaccini (Chlorophyta) in the northeastern mediterranean sea (Hatay-Adana, Turkey)

This study was carried out seasonally between May 2010 and March 2012 at 6 depth contours at 6 stations between Çevlik and Yumurtalık, in order to determine the distribution areas and depths of Caulerpa taxifolia var. distichophylla in İskenderun Bay and to determine the relationship between colonization levels and biomass with environmental parameters. It was determined that the macroalgae was mostly at the -10m depth contour in Iskenderun Bay, its distribution was between -10m and -30m depth contour, and a small colony was detected at -56m depth during ROV studies. During the study, it was observed that all colonies were small and scattered. Algae biomass values varied between 0.01 g/m2-18.66 g/m2. Gulf averages of environmental parameters obtained in a 2-year period are as the following: temperature was 23.76 ± 3.92 oC, dissolved oxygen was 6.59 ± 0.80 mg/l, salinity was 39.31 ± 1.17 ppt, pH was 8.17 ± 0.15, nitrate nitrite nitrogen was 0.72 ± 1.09 µM, orthophosphate was 0.39 ± 0.66 µM, ammonium nitrogen was 0.94 ± 0.75 µM, suspense solid matter was 2.83 ± 3.18 mg/l, chlorophyll-a was 0.52 ± 0.61 µg/l, % penetration was 10.57 ± 9.57, Secchi depth was 7.89 ± 3.29 m. In the sediment, average % water was 31.93 ± 9.10; % combustion loss was 5.04 ± 2.87; kjehdal nitrogen was 2886.58 ±-2045.36 mg/l; total phosphorus was 368.45 ± 136.52 mg/l. Caulerpa taxifolia var. distichophylla was mostly observed in the -10m depth contour of sand and sand-silt structure, and was observed in winter and spring seasons. In the statistical analysis, it was determined that temperature and orthophosphate phosphorus, which are among the physicochemical parameters of the water, and the presence of sand in the sediment, had a positive relationship with the probability of the presence of C. taxifolia var. distichophylla. Key Words: C. taxifolia var. distichophylla, invasive species, Eastern Mediterranean, Levant Sea, environmental factors