{'fraction_non_alphanumeric': 0.03506405933917734, 'fraction_numerical': 0.028320971004720162, 'mean_word_length': 5.288135593220339, 'pattern_counts': {'":': 0, '<': 1, '<?xml version=': 0, '>': 1, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
TIME SERIES SEASONAL VARIATION OF BIOLOGICAL PRODUCTIVITY AT 43°N, 141°E IN THE WESTERN HOKKAIDO COAST, ISHIKARI BAY, JAPAN

We reported a complete seasonality of biological productivity at lower trophic level and elucidate the environmental drivers in the western Hokkaido coast, Ishikari Bay from September, 2006 to December, 2007. In the high biomass period, average phytoplankton biomass and productivity were 6.92 μg L and 36.12 μg C L d, respectively. Water column salinity profile suggests bottom nutrient upwelling especially in summerautumn when autotrophic production was at a maximum. Micro-size fraction accounted for >80% of the total contributions to phytoplankton biomass and productivity. Strong correlation of POC with Chl a (r = 0.875; P < 0.001; n = 16) suggests that living phytoplankton in POC may outweigh detrital and bacteria biomass. Stoichiometry of inorganic nutrients revealed a seasonal low (13) and high (25) DIN: PO4 ratio, and a seasonal low (30) and high (37) Si:PO4 ratio, suggesting that phytoplankton growth was possibly limited by nitrate and phosphate. Diatoms, Dinoflagellates, Prymnesiophytes, and Chrysophytes were the dominant alga groups in spring, summer-autumn and high biomass period. We conclude that wind-driven convection may still be a significant source of nutrients input in this oligotrophic coastal system, and hypothesize that zooplankton grazing might be a crucial factor in controlling the Chl a biomass, especially in spring.