Lake Towada ASI-23

Lat.40.468 Lng.140.883 Alt.401
Riparian Nation(s) Japan
Surface Area 59 km2 Mean Depth 71 m Volume 4.2 km3
Shoreline 27.5 km Catchment Area 129 km2 Residence Time 8.5 yr
Frozen Period Dec-Mar Mixing Type Dimictic Morphogenesis/Dam Volcanic
Related Info/Site

Description

Lake Towada is located in Towada-Hachimantai National Park, which occupies a mountainous area on the border between the two Prefectures, Aomori and Akita. It is known as a typical double caldera of volcanic origin, encircled by sommas about 800 m in altitude. The lake water drains from the northeastern part via Oirase River and eventually to the Pacific Ocean. A small town on the southern shore, Yasumiya, is the tourist centre with Towada Science Museum, hotels and shops.

Though L. Towada remains oligotrophic, the local governments are trying to maintain and increase fish production by the artificial hatching and breeding of fry since the first success with sockeye salmon (Oncorhynchus nerka) in 1903. The salmon has recently been decreasing, while Japanese smelt (Hypomesus nipponensis) and common brackish gobby (Acanthogobius flavimanus) are increasing since 1984 (Q).