Oxygen Budget of the Bottom Layer in the Southwestern Part of Suo-Nada

Abstract

To clarify the oxygen budget in the bottom layer of the southwestern part of Suo-Nada, we measured the oxygen consumption and production rates of the bottom sea water, sinking particles and bottom sediment in laboratory conditions from July to August, 1995. Then we also measured the contents of organic carbon, chlorophyll a and pheo-pigments in these substances. The mean total oxygen consumption rate in the bottom layer was 2.85g O₂/m²/day; ca. 72% was caused by the bottom sea water, ca. 26% by the bottom sediment and ca. 2% by the sinking particles. On the other hand, the mean total oxygen production rate was 1.40g O₂/m²/day; ca. 98% was caused by the bottom sea water and ca. 2% by the sinking particles. These results suggest that the oxygen consumption rates and the oxygen production rates by the bottom sea water play important roles in the formation of the oxygen deficient water mass in this water.