A government survey confirms that higher water temperatures around the Korean Peninsula changed the makeup and traits of fish and marine plants in the seas last year.

The Ministry of Oceans and Fisheries conducted a survey on the marine ecosystem in the East Sea and waters off the south coast and near Jeju Island last year and released the results on Thursday.

The findings showed that more kinds of marine plants were growing on underwater rocks than 2016 but that their average weight was down by 22 percent.

This is believed to be due to an increase in red algae, which prefer warm waters, and a decrease in larger brown algae, which typically reside in cold seas.

The survey also confirmed the habitation of 61 species of fish in maritime preservation areas, including Ulleung Island and the Dokdo Islets.

Forty-one, or about two thirds of the total, are warm water species such as damselfish.