Temporal variation in dissolved oxygen concentration in the bottom layer in the innermost of Tokyo Bay (2003−2008)

In Tokyo Bay, because of the huge amount of organic matter, nitrogen, and phosphorus, loaded from land, as well as the semienclosed shape of the bay that prevents watermass exchange with the adjacent open ocean, eutrophication such as red tides and hypoxia is a chronic problem. Japan Coast Guard has carried out continuous monitoring of various environmental parameters of Tokyo Bay at the monitoring post at Chiba Light from 2003, as part of “Tokyo Bay Renaissance Project”. We report the data from 2003 to 2008 obtained at the monitoring post in this paper, showing a good correlation between the temporal variation in dissolved oxygen (DO) and that in intensity of stratification. We then estimate the effect of the policy to improve the water quality of Tokyo Bay by removing the influence of natural phenomena such as annual variation in the climate. Removing the influence of the temporal variation in intensity of stratification from that in bottom DO, it is suggested that bottom DO tends to have increased slightly in Tokyo Bay during the study period.

Bibliographic Details

Main Authors:	Watanabe, Naoko, Yamao, Sstoshi
Format:	Journal Contribution biblioteca
Language:	Japanese
Published:	2010
Online Access:	http://hdl.handle.net/1834/15691
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