Covered Species Distribution. The current North American range of coho salmon extends from Point Hope, Alaska, south to streams in Santa Xxxx County, California. Within this coastal area, NMFS designated seven ESUs of coho salmon, each with its own distinct geographic range. The coho salmon in the Shasta River belong to the SONCC coho salmon ESU, which includes 40 populations of coho salmon in coastal streams from the Elk River near Cape Xxxxxx, Oregon, through and including the Mattole River near Punta Gorda, California. Spanning Oregon and California, SONCC coho salmon can be found in 13 counties: Coos, Xxxxxxx, Xxxxx, Xxxxxxxxx, Xxxxxxx, Klamath, Del Norte, Siskiyou, Humboldt, Trinity, Mendocino, Lake, and Xxxx. The Shasta River is tributary to the Klamath River and is one of the largest tributary sub-basins in the Upper Klamath River watershed. The current distribution of coho salmon spawners in the Shasta River watershed is concentrated in the Shasta River Canyon from its confluence with the Klamath River to about river mile (RM) 7, and in the Big Springs Complex, which consists of the mainstem Shasta River from RM 32 to about RM 36, Big Springs Creek, and lower Parks Creek (NMFS 2014). Juvenile rearing is also occurring in these same areas. This distribution is both a small fragment of the current Shasta River stream network and of the modeled IP habitat identified for SONCC coho salmon in the basin (NMFS 2014). Moreover, excessive water temperatures in the Shasta River Canyon typically preclude year-round juvenile coho salmon rearing. As such, the Big Springs Complex is recognized as the core habitat area for coho salmon in the Shasta River watershed (e.g., Xxxxxx et al., 2012). The Shasta River coho salmon population evolved in areas of large spring complexes, which provided sustained sources of cold, clean, high quality water, and abundant areas for rearing during hot, dry summer months (NMFS 2014). Data indicate that water quality and hydrologic function can be improved for the Shasta River coho salmon population. According to NMFS (2014), the most vital habitat in the Shasta River basin are its cold springs, which create cold water refugia for juvenile coho salmon, decrease overall water temperatures throughout the basin, and allow for successful summer rearing of individuals in natal and non-natal creeks and mainstem areas. Impaired water quality, altered hydrologic function, impaired mainstem function, increased disease/predation/ competition, lack of floodplain and channe...
Covered Species Distribution
