Lake Abashiri is a lake in Abashiri, Hokkaidō, Japan. It is located in Abashiri Quasi-National Park. The Abashiri and Memanbetsu Rivers flow into the lake. Water exits the lake through the Abashiri River again and flows 7 kilometres (4.3 mi) to the Sea of Okhotsk.The lake freezes over from December to April with ice up to a meter thick. The reduced inflow of water during the winter season causes saltwater to flow upstream from the Sea of Okhotsk and into the lake. Delta smelt, chum salmon and cherry salmon are the most important sport-fish. In 1980, approximately 650 tons of fish were caught. Ice Goby (Leucopsarion petersi) can also be found in the lake.