CHARACTERISTICS OF CARBON FLOW ON PELAGIC ECOSYSTEMS AT HYPERNUTRIENT AREA IN AMAGASAKI CANAL

Abstract

 The purpose of this study was to reveal the carbon flow from primary producer (phytoplankton) to secondary producers (zooplankton and Xenostrobus securis), transfer efficiency at hyper-nutrient area in the Amagasaki Canal of inner part of Osaka Bay. The primary production rate was higher than that of other water area, while zooplankton biomass and secondary production rate were lower. The production rate of X. securis was about 1/12 of that of phytoplankton, but biomass was about 29 times higher. Transfer efficiency from phytoplankton to zooplankton and X. securis was 0.76% and 7.8%, respectively. These results suggested that X. securis grew efficiently and fixed organic carbon, zooplankton were not functioning properly as intermediaries in the food chain between phytoplankton and fishes.