Japanese stock chum salmon leave their natal river for the North Pacific Ocean via the Sea of Okhotsk and arrive at the Bering Sea. For several years afterwards, they spend their summers in the Bering Sea and winters in the Gulf of Alaska, homing to their natal river in the year they spawn. The hypothalamus, which is the center of instinctive behavior and endocrine function, is important for control of homing migration at the molecular level, the basis for this behavior. The functions of nervous and endocrine systems are however impaired when the homing is hindered by the strengthened Kuroshio under global warming.