In the past, capture surveys and measurement surveys using fishfinders were used to understand what kind of organisms live in the sea area, but this is laborious, time-consuming, and requires measurement equipment. There were problems such as the fact that specialized knowledge was essential and the results varied.
On the other hand, a method for determining whether or not a fish to be examined inhabits from the DNA released into seawater together with the mucus secreted by the body has already been reported. In June 2014, a research group led by Dr. Yamamoto examined whether it is possible to clarify the location of fish and the size of its school by combining measurement of the amount of environmental DNA and a DNA fragment proliferation method called "real-time PCR method". ..

One liter of seawater was collected from the surface and bottom of the sea at 47 locations in Maizuru Bay in the northern part of Kyoto Prefecture, and the amount of environmental DNA of horse mackerel contained in it was analyzed. It was found that it was consistent with the distribution judgment and accurately captured the amount of horse mackerel.At the same time, it was proved that this technique is effective even in a wide sea area where the environmental DNA of fish was thought to spread.The survey in Maizuru Bay was conducted over a wide area of ​​about 1 square kilometers, but the work that would take several days for capture and visual survey was completed in 11 hours.

If you know the DNA information of the fish you want to examine with this technology, you will be able to easily determine the presence or absence and amount of habitat in a short time.Furthermore, by applying this new technology, it is expected that the efficiency of investigating the distribution of fish stocks over a long period of time, such as year and season, will be dramatically improved.