Recent environmental changes have been impacted on local fisheries, forcing them to respond to fluctuations and alternations of fishery resources. Suttsu town, located on the west coast of Hokkaido, recently faces severe decline of sand eel fishery. The crisis is exacerbated by the increasing bycatch of juvenile herring, which destroys the commercial value of sand eel. The herring fishery in Suttsu thrived until the early 20th century. The sand eel fishery, spatio-temporally overlapped with the herring fishery, was intensified to compensate for the loss of herring, thus increasing the economic importance of sand eel production. The recent competition between depleting sand eel and recovering herring should also be discussed in terms of extending the long-term dynamics of the social-ecological relationships.