The Nooksack dace (Rhinichthys sp.) is a small, demersal fish whose Canadian range is restricted to only three streams in the expanding urban environment of the Lower Mainland of British Columbia. It is a member of the Chehalis fauna and is related to the common longnose dace (Rhinichthys cataractae). Although relatively abundant in this small geographical area, this survey indicates that their already restricted distribution is shrinking. Because of the continued destruction of this fish's habitat by man, the Nooksack dace has temporarily been given a 'threatened' species classification by the Committee on the Status of Endangered Wildlife in Canada (COSEWIC). Riffles with water velocities of approximately 0.28 msec and substrate comprised of loose gravel and cobbles is the preferred habitat for adult Nooksack dace. Young of the year were found in the slower waters of pools and glides adjacent to riffles containing adults. Habitat suitability curves were constructed and provide a frame-work for land use planning, including the development of protected areas for Nooksack dace. These measures are necessary due to increasing urban pressure on the few streams these fish inhabit. Without government and public action to preserve the habitat of the Nooksack dace, these fish will likely become extinct from Canadian streams in the near future.
Inglis, Susan D., Pollard, Susan M.. 1994. Distribution and Habitat of the Nooksack Dace (Rhinichthys sp.) in Canada. BC Ministry of Environment. LM237