Earth Science & Climate Change

Biography

Biography: Muhammet Turkoglu

Abstract

This investigation focused in daily variations in cell density toxic dinoflagellate Prorocentrum lima between 09 July 2013 and 06 August 2013 in the Dardanelles. The sampling period was excessive bloom period of both dinoflagellates and diatoms. The bloom of toxic dinoflagellate P.lima was recorded as a first time in the Turkish Straits System. During the bloom the cell density of P. lima reached to 2.40 x 106 cells L-1 and exhibited four excessive blooms over 1.0 x 106 cell L-1 during a month. The contribution of P.lima to both Prorocentrum spp. and dinoflagellates reached to 100%, particularly in the intervening period of the excessive bloom time and it was attested by regression (R2=700-800) and correlation findings (R=800-900). Nutrient concentrations were lower than previous concentration levels due to excessive blooms. Concentrations of NO-2+NO-3, PO-34 and SiO4 varied between 0.20 and 0.78 µM (average: 0.44 ± 0.17 µM), 0.08 and 0.18 µM (average: 0.12 ± 0.03 µM) and 0.25 and 0.65 µM (average: 0.41 ± 0.09 µM) respectively. During the bloom, nutrient ratios (N:P, Si:P and Si:N) were more different than Redfield ratios due to eutrophication and ratios of N:P, Si:P and Si:N varied between 1.57 and 7.50 (average: 4.04 ± 1.74), 1.67 and 6.50 (average: 3.79 ± 1.24) and 0.51 and 1.95 (average: 1.04 ± 0.36). Chlorophll a concentration varied between 1.57 and 8.52 mg L-1 (average: 4.82 ± 2.29 mg L-1) in the bloom period. During the bloom temperature, salinity, pH and dissolved oxygen (DO) levels were approximately constant and changed from 24.0 to 25.0 oC (average: 24.7 ± 0.44 oC), from 21.4 to 23.5 ppt (average: 22.9 ± 0.49 ppt), from 8.01 to 8.54 (average: 8.23 ± 0.15) and from 6.05 to 8.65 mg L-1 (average: 7.35 ± 0.60 mg L-1). The compact bloom of P. Lima, such as excessive blooms of other dinoflagellates and diatoms, was associated not only with eutrophication, but also with climate change interactions.