Comparison of biochemical compositions between small- and large-size phytoplankton at Korean Ocean Research Stations

Abstract

The variations of environmental factors by climate change could have effect on phytoplankton community which has important roles as primary producers and basic food sources in marine ecosystems. Indeed, the contribution of small-size phytoplankton (0.7-2.0μm) to total phytoplankton biomass has increased with water temperature (Mor&aacute n et al., 2010). Consequently, importance of the small phytoplankton is expected to increase in a recently warming ocean condition. Based on phytoplankton biochemical compositions (carbohydrates, CHO proteins, PRT and lipids, LIP) which provide important information for estimation of food quality as well as physiological conditions, the status of the phytoplankton community by different size (large: >2.0 μm small: 0.7-2.0 μm) was evaluated during the spring seasons (April, 2017) at two different Korean Ocean Research Stations (Ieodo and Socheongcho). The ship-based samples obtained from eight stations in the Yellow Sea onboard the R/V Ieodo during the summer seasons (August, 2016) were used for a comparison. In general, CHO was most dominant (> 50%) among other components for large and small-size phytoplankton communities fom Ieodo and Socheongcho stations. In addition, the samples in the Yellow sea during the summer season also showed overall distributions dominated by CHO (t-test, p<0.01) in both size phytoplankton (small: 52.2 ± 5.9% Large: 45.6 ± 9.6%). oplankton (0.7-2.0 μm) to total phytoplankton biomass has increased with water temperature (Mor&aacute n et al., 2010). Consequently, importance of the small phytoplankton is expected to increase in a recently warming ocean condition. Based on phytoplankton biochemical compositions (carbohydrates, CHO proteins, PRT and lipids, LIP) which provide important information for estimation of food quality as well as physiological conditions, the status of the phytoplankton community by different size (large: >2.0 μm small: 0.7-2.0 μm) was evaluated during the spring seasons (April, 2017) at two different Korean Ocean Research Stations (Ieodo and Socheongcho). The ship-based samples obtained from eight stations in the Yellow Sea onboard the R/V Ieodo during the summer seasons (August, 2016) were used for a comparison. In general, CHO was most dominant (> 50%) among other components for large and small-size phytoplankton communities fom Ieodo and Socheongcho stations. In addition, the samples in the Yellow sea during the summer season also showed overall distributions dominated by CHO (t-test, p<0.01) in both size phytoplankton (small: 52.2 ± 5.9% Large: 45.6 ± 9.6%).