Salish sucker (Catostomus sp.) and Nooksack dace (Rhinichthys sp.) are endangered species whose distribution is limited to a very small number of headwater streams in the Fraser Valley. Canadian populations are in steep decline due to habitat loss. This paper discusses enhancement techniques with potential to restore sucker and dace populations based on known life history information, and presents an inventory of current habitat conditions within their Canadian range. Enhancement needs within each watershed are presented and prioritized at three spatial scales: a watershed overview, an intermediate 'segment' scale, and the reach scale at which the survey was conducted. Cave Creek requires low summer flow augmentation (potentially through restoration of a headwater wetland), improved fish passage to the upper reaches over a dam, and localized livestock fencing and riparian planting. Bertrand Creek suffers from high temperatures in its productive lower reaches, lack of in-stream structure and off-channel habitat through its middle and upper reaches, and extensive livestock damage through the middle reaches. Upper Pepin Creek is heavily impacted by siltation originating from gravel pits in the area. A history of repeated dredging and channelization for flood control has dramatically simplified the habitat of the entire Fishtrap Creek watershed and construction of extensive ponds in the headwaters is causing severe temperature elevation in some upper reaches during late summer. All of the creeks show severe bank erosion and low summer flows, suggesting that runoff has increased and groundwater infiltration has decreased in recent years. A survey of landowners indicates that interest in maintaining healthy creek ecosystems is high, but that understanding of the sources of degradation is poor.
Pearson, Mike. 1998. Habitat Inventory and Enhancement Needs for the Endangered Salish Sucker (Catostomus sp.) and Nooksack Dace (Rhinichtthys sp.). Ministry of Fisheries. Fisheries Project Report. 76