Sugar Creek Beaver Pond Juvenile Coho Salmon Monitoring Study, Siskiyou County, California 2011-2012
Author | Publisher | Year | Pages | Resource Type |
---|---|---|---|---|
Mary Olswang | CDFW | 01/11/2015 | 21 | PDF |
Sugar Creek Beaver Po11dJ uvenile Coho Salmon Monitoring Study, Siskiyou County, 2011-2012 presents important information for understanding stream alterations caused by beaver dams and ponds in relation to coho salmon (Oncorliynclms kisutch) recovery in the Scott River watershed and the Southern Oregon Northern California Coho (SONCC) evolutionary significant unit (ESU). The North American beaver (Castor canadensis) was widely abundant in Scott Valley, in fact Hudson's Bay Company trappers referred to it as Beaver Valley. Anthropogenic impacts, including water diversions, beaver trapping, and gravel dredging highly impacted the river's ecological systems and natural flow during the 19th and 20th centuries, which contributed to the decline of coho salmon. After coho salmon were slate listed in 2005, the Siskiyou Resource Conservation District along with federal and state partners implemented restoration projects, including screening water diversions to help protect juvenile fish and increase returning adults. Despite restoration efforts, the numbers of returning adults continued to decline. One of the main reasons for the recent decline was lack of surface flow, especially during irrigation season. Coho salmon usually exhibits a three year cycle that requires at least one year juvenile rearing in fresh water. Beaver dams hold back water that can provide habitat for summer and winter rearing when other parts of the stream may be dry.
This report describes data collected during the 2011-2012 juvenile coho rearing season. In particular, the author describes:
• Date tagged and fork length relationships before and after the pond freezing.
• Underwater observations in habitat affected by the presence of the dam.
• Timing of juveniles out-migrating from Sugar Creek into Scott River and the relationship with high flow events.
2011, 2012, Coho, Juvenile Salmon, Scott River, Sugar Creek, CDFW