Characteristics of the productivity structure in the coastal areas along the Kansai International Airport Island, Japan

摘要

Prior to the second phase of work of the Kansai International Airport Island, areal surveys were conducted in 1998-1999 in the vicinity of the island and the annual production of phytoplankton, zooplankton, seaweed, phytal animals, sedentary animals and benthic animals were examined. Macrobenthic animals ranked first in carbon biomass (18.1 ton C) in the planned reclamation area, followed by seaweed (14.6 ton C) and phytoplankton (14.3 ton C). Annual production of carbon per unit area was highest for phytoplankton (392 gC/m~2/year), and then seaweed was 360 gC/m~2/year, which was comparable to the phytoplankton production. However, planktonic organisms accounted for 98% of the total production (3227 ton C) when the annual production of phytoplankton, zooplankton, seaweed, phytal animals, sedentary animals and benthic animals at the planned reclamation area were compared. Based on the results of the field surveys, we demonstrate that more attention should be paid to the annual production to evaluate the effects of reclamation on coastal ecosystems.