It is one of the largest breeding sites of Great Cormorant in Japan. Great Cormorants have occurred in this site since around 1829 and they were historically well protected because their droppings could be utilized as fertilizer. Around 12.17 ha of the area surrounding Unoyama has been designated as a National Natural Monument for the breeding colony of Great Cormorant.
BirdLife International (2022) Important Bird Areas factsheet: Unoyama. Downloaded from
http://www.birdlife.org on 25/09/2022.