Present status and future subjects for integration of phytoplankton biodiversity data: From a view point of ecosystem change study

Recent retrospective studies have demonstrated usefulness of community level analysis on plankton for better understanding of marine ecosystem response to climatic forcing of decadal to multi-decadal as well as anthropogenic warming trend, that could not be detected by merely analyzing biomass/abundance. In Japan, based on the seasonal time-series of diatom species composition collected by Japan Meteorological Agency, phenological change responding to warm-cool cycle of Pacific Decadal Oscillation was detected in the Oyashio and Japan Sea. In Tokyo Bay, monthly monitoring by Tokyo University of Marine Science and Technology revealed the marked change in diatom community structure from the late 1980s to 1990, responding to the changes in wintertime climatic condition. In Ariake Bay and Yatsushiro Bay, data of harmful algae bloom collected by Japan Fisheries Agency were analyzed and provided us with useful information for environmental assessment after the closure of inner part of Isahaya Bay. In the North Atlantic, through over 50 years CPR (Continuous Plankton Recorder) survey, they found a major phytoplankton shift from diatoms to dinoflagellates occurred in the mid 1980s associated with change in the North Atlantic Oscillation, which was previously reported to induce changes in zooplankton and higher trophic level productivity. All these studies proved importance of continuous monitoring and data mining on phytoplankton community in terms of climate-ecosystem link study. Nevertheless, there is no integrated open database for phytoplankton community/species composition with a few exceptions, e.g. Harmful Algae Bloom Programme. To construct such the integrated phytoplankton database, a rigid international framework must be established.