抄録
Blue tides, upwelling of anoxic water, are a major environmental problem in Tokyo Bay because they cause mortality of benthic animals in shallows and tidal flats. There are three types of sources of anoxic water containing hydrogen sulfide: dredged trenches, flat bottom at the head of the bay, and navigation channels. To consider remedies for this problem, it is important to clarify each contribution to occurrence of blue tide. It is, however, difficult because of the lack of time series data for the total amount of hydrogen sulfide in each of water. Thus, in the present study, focusing on dredged trenches as a first step, we developed a simple and reliable methodology for the estimation of the total amount of hydrogen sulfide. We utilized the data of pH and ORP collected using a water quality sensor, which have a good correlation with the concentration of hydrogen sulfide. Moreover, we found that the accuracy of estimation is quite improved if we use information of hydrogen sulfide concentration at the bottom. The proposed method is rather simple and very effective because those data are usually available in conventional monitoring.
