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

44juvenile fish and non-target species. Elevated hooking mortality rates of this type canconflict with wild release regulations (Gresswell and Harding 1997).In regards to catch-and-release stream fisheries for cutthroat trout in Region 2, it isanticipated that the use of baited hooks is resulting in elevated levels of hookingmortality. In the area from Jervis Inlet north, where up to two wild cutthroat trout may beretained per day providing that the minimum size limit of 30 cm has been achieved,cutthroat of less than 30 cm caught-and-released with the use of bait can be expected toexperience greater risk of injury and death than if bait had not been used. Similarly, it isanticipated that a relatively high bait-hooking mortality may be incurred by anglersseeking to retain two hatchery trout in the remainder of Region 2 south of Jervis Inlet.Owing to a high percentage of undersized cutthroat (or “feeders”), it is common to catchfour or more wild adult cutthroat in the mainstem Fraser River before retention of ahatchery cutthroat (B. Usher pers. comm. 2004). Even greater catch-and-release ratesmay apply in some Fraser River tributaries, such as the Stave River (>90 %; ARAConsulting Group Inc. 1993). With elevated mortality rates expected from catch-andreleasefisheries that involve the use of bait, the actual number of cutthroat “killed” perday may exceed the legal limit of two per day.Given the unprecedented risks of the day associated with reduced survivals of cutthroattrout in the marine environment (Pearcy 1997), advancing urbanization, expandingangling pressure in the Lower Mainland/Fraser Valley, and some uncertainty regardingimpacts of hatchery cutthroat stocking, elevated rates of hooking mortality from the useof bait may further compromise conservation of some stocks.5. STATUS OF PACIFIC NORTHWEST COASTAL CUTTHROATUnfortunately, compared to the US Pacific Northwest, little long-term trend data oncoastal cutthroat trout populations is available in south coastal British Columbia. Smolttrend data is only available from a single stream in the Lower Mainland Region, and norecent data is available on cutthroat densities from a sample of nursery streams. A statusreview of anadromous salmon and trout was completed as part of a Pacific-wide review,and concluded that the overall status of anadromous cutthroat stocks in BC is not wellknown (Slaney et al. 1997). Based largely on interviews, five stocks in the LowerMainland Region were rated as at high risk of extinction. In contrast to BC, longer termtrend data on cutthroat stocks is available from other jurisdictions in the PacificNorthwest, including Oregon, Washington and Alaska. Some of the US trends on largestreams provide an acute awareness of conservation risks associated with management ofhabitat and fisheries of sea-run cutthroat trout. They readily demonstrate the need forlong-term records of counts of smolt yields and/or adult runs in the rapidly urbanizingLower Mainland.5.1 Population Trends in Other Pacific Northwest StreamsCalifornia: As in British Columbia, little trend data on smolts and adults is available innorthern California, other than from creel surveys. A series of standardized seine hauls in