Press Release Back Number(2005)

Biotelemetry Technique to Track Movement of Freshwater Fish

September 7, 2005
Chubu Electric Power Co., Inc.

We have been working on ecological surveys and developing survey techniques designed to help reduce the ecological effects of river structures (such as hydroelectric dams) on freshwater fish and other aquatic creatures and to bring such structures into harmony with the natural environment.

As part of these efforts, we recently developed a technique referred to as "biotelemetry," in which a small radio device is attached to freshwater fish to permit analysis of their movements.

The conventional technique for tracking freshwater fish involves the release of tagged fish and subsequent recovery of the fish elsewhere. However, this technique only provides information on the locations in which the fish were released and then caught. Moreover, the percentage of fish recovered after tagging is not high.

We adopted our technique of biotelemetry to obtain detailed and reliable data on the movement of fish. When we tested this technique on small freshwater fish-two species of mountain trout (Oncorhynchus masou ishikawae and Salvelinus leucomaenis)-we obtained favorable results.

Subsequently, at the request of the National Institute for Rural Engineering, we applied biotelemetry to the study of a species of crucian carp (Carassius auratus grandoculis), which is found in Lake Biwa. We tracked the movement of these fish from the lake to the paddy fields where they spawn. We were able to analyze this movement in detail-noting, for example, how they swam through a temporary fishway in irrigation ditches.

We originally developed this technique to meet specific needs of our own relating to environmental issues. However, given the favorable results described above, we intend to make this technique available to research institutions. Techno Chubu Co., Ltd., one of our group companies, will be in charge of ecological surveys.