The sharp increase in the number of starfish in Tachibana Bay in Isahaya and Unzen in Nagasaki Prefecture is causing problems with shrimp fishing, now in its peak period. A survey ship in June caught 50 kilograms of starfish in just 30 minutes. The starfish had inhabited coastal areas of the bay, but now they have spread to the inner portions of the bay as well. The problem is so severe the prefecture has embarked on an emergency measure to catch 150 tons between now and the end of August. The reason for the explosive starfish growth is unclear.