Biodiversity / Food / Water

September 17, 2011


57 Percent of Rivers across Japan Clean, Aquatic Life Survey Indicates

Keywords: Ecosystems / Biodiversity Government 

Japan's Ministry of the Environment and Ministry of Land, Infrastructure, Transport and Tourism announced the results of a 2010 national aquatic life survey on June 6, 2011. The results show that 57 percent of the sampling points in rivers across Japan had "Clean Water." "Slightly Polluted" points accounted for 29 percent of the sampling, while "Polluted" points accounted for 10 percent, and "Very Polluted" points accounted for two percent. The remaining two percent were indeterminable. The results were roughly the same as those obtained in FY2009.

The two ministries have been conducting the survey every year since 1984 in cooperation with ordinary citizens in order to assess the general water quality of rivers using aquatic organisms as indicators. The survey also aims to raise public awareness on the environment.

The survey uses 30 indicator species commonly found living in rivers across Japan, easily identifiable, and highly indicative of water quality. Participants catch aquatic organisms in rivers, identify indicator species, and classify water quality based on the indicator species found at each point into the four levels: Clean Water, Slightly Polluted Water, Polluted Water, and Very Polluted Water. The indicator species in Clean Water include nine organisms such as sawagani (freshwater crabs), kawagera (water flies) and others.

A total of 81,395 people took part in the FY2010 survey, including approximately 46,000 elementary and junior high school students and 1,858 organizations such as citizen's groups, children's groups, and observation groups. The 3,000 sampling points included 539 Class A rivers and 2,461 other rivers. The largest number of survey participants was from Fukushima Prefecture, followed by Gifu and Iwate Prefectures.

Survey Shows 60% of Japanese Rivers Are 'Clean' (Related JFS article)

Posted: 2011/09/17 06:00:15 AM

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Ministry of the Environment official website