PURPOSE: To obtain an improved water bloom catcher to be used for catching water bloom breeding on the sea or lakes.

CONSTITUTION: Around the catcher body 1 floating on the water surface with a pump (1b) built therein, sucking together with water bloom 8 close to the water surface and bringing it via a hose (1d) to a working vessel 12, a fence 2 with an annular curtain wall 9 floating similarly on the water surface is formed. And, a water flow generator 3 is formed along the inner periphery of this fence 2, spouting water at the catcher body 1. The water jet then forces the water bloom 8 standing apart from the catcher body 1 move toward the catcher body 1, thus resulting in efficiently catching the water bloom.