Boise Creek
Coho salmon (Oncorhynchus kisutch) populations have declined dramatically in the Klamath River watershed due to eutrophication, raised water temperatures and decreased stream flows induced by the construction of dams, especially in years of drought. In addition, the dams have blocked access for salmon spawning grounds on over 300 miles of Klamath River watershed. The Coho salmon in the Southern Oregon - Northern California Coast (SONCC) Evolutionarily Significant Unit (ESU) are federally listed as threatened and are also listed as threatened by the California Department of Fish and Game since 2002.
Access to Boise Creek for salmon has been blocked by a bedrock falls 13.5 feet high near the creekmouth (see figure) so the Mid Klamath Watershed Council proposed, in February 2010, creation of an engineered logjam to divert flows into historic side channels which would re-connect the creek to the Klamath River mainstem and bypass the falls. Before the logjam could be constructed, beaver coincidentally constructed a dam across Boise Creek at the proposed site, and numerous Coho salmon, Chinook salmon (Oncorhynchus tshawytscha) and Steelhead trout (Oncorhyncus mykiss) are now accessing the stream from the Klamath, opening several new miles of historic spawning habitat to the fish.
The beaver dam has also created off-channel ponds which have been shown to benefit coho by providing refuge from high flow conditions in the main river and a productive summer rearing habitat, leading to as much as a five-fold increase in coho abundance as well as increased size. It has also been shown that off-channel wetlands enhance chinook salmon growth and survival.
See also
References
- ^ "Boise Creek". Geographic Names Information System. United States Geological Survey, United States Department of the Interior.
- ^ David L. Durham (2001). Durham's Place Names of the California North Coast: Includes Del Norte, Humbolt, Lake, Mendocino & Trinity Counties. Quill Driver Books. p. 35. ISBN 978-1-884995-26-2. Retrieved May 19, 2010. Title [sic].
- ^ Erwin G. Gudde; William Bright (2004). California Place Names:The Origin and Etymology of Current Geographical Names. University of California Press. p. 23. ISBN 0-520-24217-3. Retrieved May 19, 2010.
- ^ Endangered and threatened fishes in the Klamath River Basin: causes of decline and strategies for recovery. National Academies Press. 2004. p. 263. ISBN 978-0-309-09097-1. Retrieved May 19, 2010.
- ^ "Oregon Wild". Retrieved May 19, 2010.
- ^ Will Harling (2010-11-16). "Restoring Coho Salmon in the Klamath River, One Beaver At A Time". Forest and River News. Archived from the original on 2010-11-16. Retrieved 2010-02-17.
- ^ Swales, S. & C. D. Levings (1989). "Role of Off-Channel Ponds in the life Cycle of Coho Salmon (Oncorhynchus kisutch) and Other Juvenile Salmonids in the Coldwater River, British Columbia" (PDF). Canadian Journal of Fisheries and Aquatic Sciences. 46 (2): 232–242. doi:10.1139/f89-032. Retrieved May 20, 2010.
- ^ T. R. Sommer; et al. (2001). "Floodplain rearing of juvenile chinook salmon evidence of enhanced growth and survival". Canadian Journal of Fisheries and Aquatic Sciences. 58 (2): 325–333. doi:10.1139/f00-245. Archived from the original on July 7, 2012. Retrieved May 20, 2010.