Estimating the carbon biomass of marine net phytoplankton from abundance based on samples from China seas

Abstract

The relationship between carbon biomass and cell abundance in net phytoplankton was determined to improve standing stock research in marine ecology. Based on samples from six cruises in the Yellow Sea and the East China Sea, significant regression equations for all net phytoplankton cells, diatoms, dinoflagellates and each dominant genus were obtained. The relationships could be described by the equation log10y=k×log10x+b, where x represents cell abundance based on cell counts (cells m–3), y represents carbon biomass (μgCm–3), and k and b are constants. The values of k and b were 0.48 and 0.49 respectively for total net phytoplankton, 0.75 and –1.46 respectively for diatoms in summer, 0.54 and –0.11 respectively for diatoms in spring and autumn, and 0.92 and –0.90 respectively for dinoflagellates. Regression equations for Chaetoceros, Coscinodiscus, Pseudo-nitzschia, Skeletonema, Ceratium, Protoperidinium and Pyrophacus were also obtained. We suggest using these carbon biomass:cell abundance relationships established for net phytoplankton to assess phytoplankton standing stocks and for reanalysing historical data.