Recording Changes in the Condition of the River While Returning It to Its Natural State

In the spring of 2013, surveying work, including using a motorized paraglider to take aerial images, was done along the river. Besides being used to help in planning restoration work, this information was used to compare the state of the river before and after restoration work.

In July, construction machinery was used to place rocks in three locations along the upstream and midstream sections of the river. The river had strayed from its original path, and the rocks were to center the river channel. Although heavy rains in October and November carried away some of these rocks, fortunately the river was able to be diverted to within the path intended by this restoration work, and it is apparent that the river environment is gradually improving.

Fish Such as Salt-Water Trout and Cherry Trout Discovered Living Upstream

In 2013, in addition to a survey of fish living in the Iwaobetsu River, a survey was also done on the upstream side of a dam in the upper river basin of the Iwaobetsu River. This dam is almost three meters high, so its upstream side was isolated since fish could not get past it to go upstream.

But the survey discovered that even in such an isolated environment there are fish such as salt-water trout, as well as cherry trout that had been released there in the past.

Bears Lifestyle Gradually Coming Into Focus

In June 2013, a new survey got underway using automated cameras and hair traps to collect images and DNA samples of bears, an animal rarely seen close up by humans. Bears are lured close to the cameras by the smell of deer meat hanging from trees, and when they step over low barbed wire fences around the perimeter they trigger camera operation. Bear hair caught on the barbed wire is used to extract DNA samples. This survey confirmed the existence in the area of eight males and one female, all previously unknown.

As a result of the many tests conducted on samples collected during this and previous surveys, it was discovered that dominant males move over a wide area of the peninsula and have fathered many cubs in various locations, and that at a young age males often move from their birthplace to somewhere else and die there.

This was one of the few examples worldwide of successful research that includes bears' genetic information. The collection of DNA samples from so many individual bears is expected to answer questions regarding the blood relations and social structure of brown bears living in the Rusha district.

For First Time in Japan, Bears Taken Alive with Tranquilizer Guns and Affixed with GPS Tracking Devices

What are bears movement patterns throughout the year in the Rusha district? The answer to this question could help in creating measures to avoid unpleasant encounters between bears and humans. But this mystery cannot be solved through only DNA analysis and bear observations. It was therefore decided to capture bears and affix to them GPS tracking devices not unlike GPS car navigation systems.

In June 2013, a two-year-old male named Beeko was captured using a tranquilizer gun. Capturing a wild bear with a tranquilizer gun was considered extremely difficult; in fact, this was the first time it had ever been done in Japan. The GPS tracking device attached to the bear records location information once every hour.

This information told researchers that Beeko moves around mainly in the vicinity of the Ubushinotta River, slightly to the north of the Rusha district, occasionally venturing into the Rusha district.

This tracking work will continue so that researchers can determine the bears' pattern of movement.

Map showing Beeko's tracks over the summer