LEE Choon Weng, I. Kudo, T. Yokokawa, M. Yanada, and Y. Maita (2004) The role 
of microbial respiration on the occurrence of a suboxic layer in Funka Bay, Japan. In: 
Phang SM, Chong VC, Ho SC, Mokhtar N, and Ooi JLS (eds), Marine Science into 
the New Millennium: New Perspectives & Challenges. University of Malaya 
Maritime Research Centre (UMMReC), Kuala Lumpur: 229-240

Abstract. We studied the temporal variations of dissolved oxygen, nutrient 
concentrations, and oxygen utilization rates (< 0.7 痠 fraction) in Funka Bay, 
Hokkaido, Japan, for about two years. Dissolved inorganic nitrogen ranged 0 - 26 然, 
whereas phosphate and silicate ranged 0 - 2 然 and 1 - 64 然, respectively. From 
the dissolved nutrient distribution, we saw evidence of nitrogen limitation. Dissolved 
oxygen concentration ranged 130 - 440 然, and decreased to < 150 然 in the 
bottom layer in summer seasons. Oxygen utilization rates which was attributed to 
bacterial respiration ranged 0.6 - 9.3 然 d-1 for the 10 m depth samples, and 0.8 - 
5.0 然 d-1 for the 90 m depth samples, and was the principal mechanism causing the 
annual dissolved oxygen decrease in the bottom layer in the summer.