Duffy, W. G., and E. P. Bjorkstedt. Demographics of Coastal Cutthroat Trout, Oncorhynchus clarki clarki, in Prairie Creek, California. In Press. Proceedings of the 2nd Conference on Sea Run Cutthroat Trout, Port Townsend, WA, 29 Sept - 1 Oct, 2005.
The southern distribution of coastal cutthroat trout Oncorhynchus clarkii clarkii terminates in northern California. Coastal cutthroat trout have received less attention in this region than they have further north and less is known of their ecology and abundance. We monitored population abundance in and gathered basic biological data from fish in three coastal streams in northern California during 2000-2004. Density ranged from 107-983 fish/ha during the period and varied among streams and years, although strong temporal trends were not apparent. Density was greater in pool and run habitats than in riffle habitats. Density was correlated with abundance of juvenile coho salmon, O. kisutch, in pool habitats, but not in run or riffle habitats. The size of 1,220 coastal cutthroat trout measured during the period ranged from 50-269 mm. Size of fish sampled differed among streams, years, and habitat types. Condition of coastal cutthroat trout also did not differ among streams or between seasons, but did differ among years. Our principal finding was that coastal cutthroat trout population abundance in northern California streams sampled appears stable, although abundance varies with habitat condition.