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

6drainages where cutthroat trout were sparsely distributed in contrast to coho salmon(Slaney and Northcote 2003). Thus, a key strategy is to provide public education on theirvalues as sentinels of watershed quality and health. Provision of “benchmarks” ofabundance of juvenile cutthroat in streams should be used as indicators of populationhealth. Thus, it is important that urban municipal planning fully accounts for cutthroatinhabited watersheds, with cutthroat abundance as an indicator of watershed health.Some further work is needed to define benchmark densities and biomasses which varywith stream productivity.2. Habitat Protection via Land Acquisitions of Critical Cutthroat HabitatsAt several cutthroat streams, particularly in the Fraser Valley, there are small criticalnursery areas, many of which are located on alluvial fans at the base of mountain slopes.Some are wall-based channels where there is groundwater recharging of surface channels.These streams are often threatened by agricultural practices which include invasivedredging and riparian alterations. Further, some key nursery areas may be at risk fromfuture urban developments. Land purchases through the Habitat Conservation Trust Fund(HCTF) for conservation of these critical nursery habitats would ensure they wereprotected and preserved. Further, once secured for conservation, those nursery habitatsdamaged by past agricultural and land clearing impacts could be restored. Actionsrequired by the Ministry are (1) identification of these critical cutthroat-coho nursery fansand their land areas and status; (2) discussions with representatives of the AgriculturalLand Reserve and municipalities regarding land deposition subject to land owner interestin sale of specific small parcels of private land; and (3) negotiation of purchaseagreements with land owners subject to availability of conservation funding.Alternatively, these critical nursery reaches may be protected by purchasing conservationcovenants. Regardless of the approach, their identification should be a habitatmanagement priority.3. Recovery of Extirpated Cutthroat StocksOf a total of 657 streams located from Maple Ridge to the West Vancouver, 120 streamshave been lost (in-filled, culverted, paved over) during the past 100 years of landsettlement and urbanization (Precision Identification Biological Consultants 1997).Many of them were significant anadromous cutthroat producers which have been reducedto mere remnants such as Como Creek. Among other urban streams that still exist,cutthroat trout have been extirpated over their length or much of their length by culvertobstructions and/or poor water quality, as at Nelson Creek. As a first priority, a tally ofextirpated cutthroat streams and stream reaches needs to be completed. Thereafter, pilotrecovery projects of extirpated cutthroat streams should be funded and implemented togarner public interest and support, further advancing the concept of cutthroat trout assentinels of watershed health. A concerted effort should be made to gain activecooperative municipal involvement that results in pollution abatement, re-establishmentof native cutthroat by re-stocking juveniles and provision of fish access at culvertbarriers. Community stewardship is needed to monitor and maintain healthy conditions.