Japan can expect to see some of its fish catches decline by as much as 70 percent over the next century due to global warming, an official at the National Research Institute of Fisheries Engineering said Saturday.

The institute's prediction is based on the assumption that water temperatures will have risen by 1.4 to 2.9 degrees by 2100. It studied 34 varieties of fish and possible changes in catches at fishing ports.

This is the first detailed study in the world to predict the impact of global warming on fish varieties and regions, the official said.