越喜来湾における栄養塩類の平均的季節変化と経年変化 Mean Seasonal Changes and Recent Trends of Dissolved Inorganic Nutrients in Okkirai Bay, Japan
Mean seasonal changes in water temperature, salinity, silicate, phosphate, dissolved inorganic nitrogen, and dissolved oxygen (DO) in Okkirai Bay, Japan, were presented based on the monthly averaged data measured from 1979 to 1995. Recent trends of these properties were presented using 12-month running means. As a result, isopleths of mean seasonal changes showed a high nutrient concentration in winter and spring, and the vertical profile tended to be uniform. Recent trends showed great effects due to the Oyashio cold water that is rich in nutrients and DO, which came close to coastal waters in 1984, and that the water temperature has gradually increased since then, in line with decreasing nitrate, ammonium nitrogen, and DO.
日本水産学会誌 63(2), 152-159, 1997-03-15