東京湾における栄養塩類?溶存有機物濃度の長期変動(1989年?2015年)

摘要

Tokyo Bay is surrounded by world largest megacity and has experienced varying levels of water quality over time. Nutrient concentrations showed significant decreases from 1989 to 2015. The decreases reflect the reduced loading of nutrients into the bay due to the implementation of advanced wastewater treatment techniques. The ratios of total dissolved nitrogen to total dissolved phosphorus in the surface waters were much higher than the Redfield ratio for both stations, and these ratios increased significantly during the most recent decade. Continued declines in total dissolved phosphorus concentration could strengthen phosphorus limitation of primary production in Tokyo Bay.