Coastal Cutthroat Trout as Sentinels of Lower Mainland Watershed ...

71is now affecting cutthroat streams in the townships of Coquitlam, Maple Ridge, Langley,Mission, and Abbotsford; and (3) increased concerns about the interaction of hatcherycutthroat and wild cutthroat as a result of declines in the historically healthy cutthroatstocks and the fisheries they supported in both Oregon and southern Washington State.While evidence is only circumstantial that the major sea-run cutthroat declines in the USPacific Northwest were contributed to by excessive stocking of hatchery sea-runcutthroat, trend data in the Lower Mainland indicates that this is an area where fisherymanagers need to be most vigilant. The fact that the sea-run cutthroat stocking programin Oregon has been abandoned suggests that a cautious approach is advisable in southcoastal British Columbia. Threats of expanding urbanization and fishing pressure oncutthroat, including elevated bait-hooking mortality on stream cutthroat, are othersignificant risks. The Lower Mainland Region’s cutthroat fishery for sea-run and riverruncutthroat is indeed valuable (>100,000 angler days with an economic value of 4million at $40 per angler day). Thus, it is well worth the management effort to provideadequate resources for both habitat management and stock monitoring.Seven (7) management strategies are recommended based on the forgoing review toassure conservation of cutthroat trout in the Lower Mainland Region, with priority onsea-run stream stocks (order not prioritized except habitat management over angler use):Management Strategy 1: Watershed-based Fish Sustainability via a “SentinelSpecies” StrategyHabitat protection remains of highest priority to ensure conservation of cutthroat troutand other fish species because urbanization is advancing rapidly in the Lower MainlandRegion. As emphasized in the introduction, cutthroat trout are an appropriate sentinel ofaquatic health in urban and agricultural watersheds because they are distributed aboveanadromous barriers in most watersheds, they reside in streams for much longer periodsthan salmon, and they are more sensitive to deteriorating conditions. Thus, it is importantfor watershed health that land development planning and maintenance of stream channelsin both urban and agricultural settings accounts for potential impacts on fish habitats bysupport of monitoring.Coastal cutthroat trout are sensitive to water quality and flow conditions, as confirmed ina study of agricultural drainages in the District of Kent at Agassiz. Coho juveniles werewidely distributed in summer and widespread in winter, but in striking contrast, cutthroattrout were highly restricted in distribution owing to low dissolved oxygen levels and highwater temperatures (Slaney and Northcote 2003). Thus a key strategy for increasing theprofile of cutthroat trout is to provide public education on the value of coastal cutthroat assentinels of watershed quality and health, similar to the concept of the canary in the coalmine (Reeves et al. 1997), but based on comparisons to benchmark abundances ofjuvenile cutthroat as indicators of stream/watershed health.Some opportunities and tools to elevate the profile of cutthroat trout as sentinels ofstream/watershed health are: