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Why is Comprehensive Environmental Monitoring Expected Now? -- Masahiko Isobe

Why comprehensive environmental monitoring is expected now


Professor, The University of Tokyo

Modern learning has been developed by departmentalizing research fields. Although we have various findings in each field by the departmentalization, there have not been enough viewpoints that overlook the environment in a wide area, such as apace and region.

Let me take recent case of the°°Ariake Sea as an example. The outbreak of red tide on an enormously large scale has caused poor seaweed crop. But we have not yet reached the point where particular situations that cause red tide can be determined on a comprehensive perspective. Although researchers in individual fields have appropriate data, nobody has ever tried the way of research on the basis of an integration of data from each field. Integrating the professionally collected data to seek a concrete approach to improve water quality is perhaps an important objective to be achieved. Therefore, it has become the factor that accelerates the movement toward comprehensive environmental monitoring.

Urgent need for date collection

It is very important to choose an approach employed for monitoring environment and collecting data. For example, when investigating Tokyo Bay for revitalization plan of Sanbanze tideland, not only do we have to observe within the bay but we also have to collect relevant data with different viewpoints. First, we focus our attention on the inflow of the water that runs into bay. We are making observations of how people's activities and their lives affect the river basin, and what things they are putting into the river as waste. Then, constantly flowing water itself is observed. By carrying periodical research on the water flow and quality in the whole area of the bay at many points, change of water quality during a year in Tokyo Bay is figured out. Meanwhile, relationship between changes of weather conditions and red tide is closely observed as well as measuring nutrient salt such as nitrogen and phosphorous in numerical terms to see their effects on the outbreak of red tide.

Our laboratory members have continued such investigations at three points in Tokyo Bay by getting out on a boat once a week. As a result, we found that the concentration level of nitrogen is quite high. When red tide occurs, both nitrogen and phosphorous are consumed, however, whereas phosphorous runs short, a plenty of nitrogen was found in the water. Unknown facts like this will gradually be revealed if we measure the dynamics of water one by one and put results into data.

Furthermore, it is indispensable to monitor water quality as we compare it with the data taken in the ocean, since Tokyo Bay is linked to the Pacific Ocean. In this sense, integrating many kinds of data is very important. But currently data collection and its accumulation are not easily done as local observation on a regular basis needs money and labor. Therefore, it is necessary to discuss a new measure amongst cooperate organizations including government against the problem, which cannot be dealt with by individuals or each institution.

Use of collected information

The next stages of development we expect are to systemize the data collected and exploit a mechanism for easy access for anyone. Although data analysis is hard work, digitization of data has recently made it comparatively easy to interpret data. It is now also easy to produce graphs and tables. We can expect a certain result by integrating digitized data. Therefore, it is also an urgent need to make digitized data accessible, for example, using the Internet. That would be convenient for both users and researchers and it would accelerate future research on environmental monitoring study.

The important thing here is the fundamental idea of integrating data and releasing it to the public. In principle, it would be efficient and effective to build a system that researchers and organizations with collected data can easily access through the Internet. To do so, it is essential to organize the data. It also would be necessary that people who collected the data and the persons concerned check the quality and preciseness. On the public release of data, there must be respect for collected data; it is related to the issue of intellectual property right. All such relevant problems should be solved before the data is put into use. We still have not had any accumulation of data yet.

Currently, Ministry of the Environment has established water quality monitoring points in the public water area including Tokyo Bay, to carry out regular monitoring. But the frequency is only once a month. During the one-month-period, when water quality is not monitored, there are various weather changes such as rain and wind. The change in water quality according to weather changes cannot be determined from the data collected only once a month. Even though conventionally collected data has been used before, the data is definitely insufficient for the improvement of water quality in Tokyo Bay. In order to know what is happening and changing in Tokyo Bay including Sanbanze tideland in Chiba, both the frequency and the quality of monitoring have to be improved.

Attention to the development of equipment and five senses of human

In recent years, monitoring methods have been changed in accordance with the development of digital equipment. For example, geomagnetic electrokinetograph (GEK), which measures water current, came into practical use in 1980s. There had been no appropriate measuring apparatus before. GEK at that time was the apparatus connected an observation point and shore with a cable, and measuring was carried out on shore. Then, recording device such as a cassette tape was installed inside measuring apparatus to help to lighten its weight for convenience. Today, we can take measurements conveniently by transferring data wirelessly using instruments such as telemeters.

Like remote sensing, there is another monitoring method that uses photographs taken from a satellite. In the sea, changes of water temperature and approximate population of phytoplankton such as chlorophyll-A, of which excess number causes red tide, can be measured. The method is very effective since whole Tokyo Bay can be observed instantly.

However, in order to measure detailed data of water quality, we must actually take sample of the water at the spots and analyze it in the laboratory. This conventional method has remained unchanged long time. Therefore, we expect manufactures to develop sensors that could convert observation objects into something like electric signal. As well collecting data, it is also required to learn the knowledge of fishermen who go to the sea every day. When we learn from them, we should particularly pay attention to their unique expressions. For example, we researchers say °»Broken waves°… whereas they use a term °»snapped waves°…; moreover, they have an instruction for the moment when they come up to the surface of the sea after gathering abalones. °»If a big wave comes, withstand three more waves, because three big waves come in succession. Come up on shore when a small wave comes next.°… Their knowledge seems to correspond to the phenomenon of °»wave group°… in our scientific term.

Learning the meanings of their words often suggests directions for our research. We should not ignore their words since the dramatic changes in marine environment are so significant that even human can sense the changes. Understanding each other°«s language helps us find the way of improving water quality.

Future of comprehensive environmental monitoring

There are many environmental problems that we have not known at all. In order to understand the problem, we are trying to monitor, collect, and integrate data to analyze it, but there still will be things that we cannot fully understand. Therefore, researchers°« opinions might vary quite a lot. In order to put various opinions together and create a concrete content, it is thought that we need having objective view of natural science as well as social science and humanities to achieve °»agreement formation.°…

(At The University of Tokyo, February 19, 2002)

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