Estimation of phytoplankton biomass using HPLC pigment analysis in the southwestern Black Sea

The phytoplankton population of the southwestern Black Sea in May 2001 was studied by taxonomic analysis using microscopic examination and by pigment analyses using high-performance liquid chromatography (HPLC). Pigment data, which identified phytoplankton assemblages dominated by dinoflagellates, diatoms and coccolithophores in May 2001, were compared to phytoplankton cell counts and biomass. There were significant (p < 0.002-0.01, r=0.56-0.67) relationships between the taxon-specific pigment concentrations and the taxon-specific cell numbers during this sampling period. The ratios of chlorophyll-a to the dominant accessory pigments calculated by multiple linear regressions were 1.2 (chlorophyll-a: peridinin) in dinoflagellates, 1.8 (chlorophyll-a: fucoxanthin) in diatoms, and 2.66 (chlorophyll-a: 19'-hex on oyloxyfucoxanthin) in coccolithophores. HPLC-determined chlorophyll-a biomass correlated well with the sum of the group-specific pigment biomass (p < 0.001, r(2) = 0.95). The phytoplankton assemblage as revealed by the microscopic and HPLC analyses was thus made up of common Black Sea groups showing that HPLC pigment analysis can be used to quantify phytoplankton assemblages in the Black Sea based on simple ratios. (c) 2006 Elsevier Ltd. All rights reserved

Estimation of Phytoplankton Biomass Using HPLC Pigment Analysis in the Southwestern Black Sea

The phytoplankton population of the southwestern Black Sea in May 2001 was studied by taxonomic analysis using microscopic examination and by pigment analyses using high-performance liquid chromatography (HPLC). Pigment data, which identified phytoplankton assemblages dominated by dinoflagellates, diatoms and occolithophores in May 2001, were compared to phytoplankton cell counts and biomass. There were significant (po0.002–0.01, r ¼ 0.56–0.67) relationships between the taxon-specific pigment concentrations and the taxon-specific cell numbers during this sampling period. The ratios of chlorophyll-a to the dominant accessory pigments calculated by multiple linear regressions were 1.2 (chlorophyll-a: peridinin) in dinoflagellates, 1.8 (chlorophyll-a: fucoxanthin) in diatoms, and 2.66 (chlorophyll-a: 190-hexonoyloxyfucoxanthin) in coccolithophores. HPLC-determined chlorophyll-a biomass correlated well with the sum of the group-specific pigment biomass (po0.001, r2 ¼ 0.95). The phytoplankton assemblage as revealed by the microscopic and HPLC analyses was thus made up of common Black Sea groups showing that HPLC pigment analysis can be used to quantify phytoplankton assemblages in the Black Sea based on simple ratios.JRC.G.3-Agricultur

Phytoplankton distribution in the Caspian Sea during March 2001

Phytoplankton abundance, biomass and species composition of the Caspian Sea were evaluated by using samples collected from the Iranian (southern Caspian Sea) and southern Kazakhstan (eastern Caspian Sea) surface waters in March 2001. A total of 45 taxa were found in the samples (20 diatoms, 17 dinoflagellates amd 8 others). Abundance and biomass of diatoms were high at the eastern stations, while dinoflagellates were dominant in terms of both biomass and abundance in the southern region. Average abundance and biomass were 40000±35000 cell l-1 and 580±690 ug l-1. the mean biomass value found here for the Middle and south Caspian Sea in March are difficult to compare with the past due to limited information, but seems higher than previously registered values. Higher chlorophyll values were also apparent from the SeaWiFS images in 2001 compared to those in 1998. This is suggested to be due to decreased grazing of phytoplankton by zooplankton which is voraciously preyed by the recent invasive ctenophore Mnemiopsis leidyi.JRC.H.5-Rural, water and ecosystem resource