A salmon spawning survey for portions of Ten Mile River, Caspar Creek and Garcia River, 1995-96

Spawning surveys were conducted in portions of three streams located in Mendocino County. These three coastal streams were the Ten Mile River, Caspar Creek and Garcia River. Spawning population estimates were derived with four separate estimation procedures using carcass mark-recapture techniques, area-under-the-curve live fish counts and two redd based methodologies. Indices of steelhead abundance are also developed for these areas. Coho spawning populations were estimated to be between 105 and 351 in the portions of the Ten Mile River surveyed but the most likely ranges was estimated to be between 190 and 250. The Ten Mile chinook run was estimated to be less than ten fish. In Caspar Creek, coho population estimates ranged from a low of 71 to a high of 323 fish. The most likely range was believed to be between 127 and 170. A comparison to past spawning surveys indicated the 1995-96 coho run in both Ten Mile and Caspar were the highest in recent years surveyed. No evidence of coho or chinook salmon spawning was found in the four tributaries of the Garcia River surveyed. The steelhead run in the Ten Mile was similar to other years based on late season redd densities and live steelhead observations. In Caspar Creek, this steelhead run was typical for recent years but considerably less than in the 1990-91 spawning season.

Ten Mile river coho carcasses were examined for returns of marked 1992 brood coho salmon. None were observed. The portion of the fish taken in an ongoing adult trapping program was evaluated . The 12 trapped adult coho taken for egg collection from the South Fork accounted for roughly 14 percent of the run and the 12 taken from Bearhaven Creek was estimated to be about 25 percent of that population. The results of spawning survey was used to make recommendations regarding. the best location to release trapped coho progeny.

Recent fish habitat structure installation work in Garcia River tributaries was evaluated with regard to ability to withstand high winter flows and degree utilized as cover by spawning. fish. Restoration work remained intact over winter. Spawning fish were not observed utilizing habitat structures for cover, however, limited sighting of spawning fish in area and limited number of surveys reduced the observation opportunities.