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

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82• Refinement of the minimum size regulation of 30 cm in freshwater (i.e., north ofJervis Inlet) to ensure a minimum of a first-time spawning by sea-run (or riverrun)cutthroat trout is advised. Facilitation of first-time spawning is a soundconservation measure which may require a 33-35 cm minimum size as in someUS jurisdictions (Gresswell and Harding 1997).Anadromous Cutthroat Stream Stocking Program:• Stocking of hatchery smolts (or fingerlings) in nursery streams should becarefully managed to minimize risks to wild stocks and wild-hatchery interactions(see research needs, under Management Strategy 5);Smolt stocking should be restricted to designated “hatchery rivers” and at 1-2sites in the Fraser mainstem. Perhaps the lower Alouette River should also bedesignated as a hatchery cutthroat river, considering its 25 year stocking history,subject to monitoring wild-hatchery interactions in this watershed. Yet, habitatrestoration and unfed cultured fry stocking of nursery streams is a soundalternative to increase wild cutthroat production, which was recommended forAlouette River tributaries by DeLeeuw and Stuart (1980). Prior to the hatcheryprogram in the fall-winter fishery of 1979, only 37 wild cutthroat were caught in4,600 hours of angling at the Alouette River (DeLeeuw 1981); thus, anglingpressure was very high, and in part incidental to the steelhead fishery.As an alternative intensive fishery, serious consideration should be given toadding Lower Capilano River as a “hatchery cutthroat stream” using a captiveBrothers Creek stock. The Capilano was rated as “the most popular of all riversfor cutthroat fishing in the Lower Mainland” (DeLeeuw and Stuart 1981). Thelower Capilano River has a highly manipulated hydrology, as well as hatcherysupportedsalmon and steelhead. These are highly unlikely to be altered, and thusthere are minimal risks to wild fish from a significant cutthroat stocking. Further,there is little conflict with steelhead if cutthroat stocking is restricted to the lowernon-canyon reach of the Capilano River.• Optimal smolt size at release needs refinement because the average smolt size iscurrently small (17-18 cm) compared to a more optimal size of 20 cm (Figure 8).However, a tradeoff is evident with a high percent residualism of large smolts aswas documented earlier from an experimental stocking of 112 g cutthroat smoltsin the Little Campbell River (38 %; Rempel et al. 1984). Furthermore, small (60g, 17 cm) sized smolts stocked within a “hatchery stream” is counter productivebecause only 5 % of about 5,000 cutthroat caught were harvested at Stave Riverin the year-round 1993 sport fishery. Thus, larger 20-22 cm smolts should beconsidered for Stave River, thus providing a higher quality catch and harvestalong with much greater returns of large sea-run cutthroat. Experimental releasesof two size groups at Stave River should be used to evaluate optimal smolt size atrelease, using underwater (snorkel) counts and spot creel checks of the catch rateand composition of cutthroat trout. Similarly, the Capilano River would be
83another prime target for release of large sea-run cutthroat smolts as discussedearlier.Coastal Cutthroat Lake Fisheries:• Lake cutthroat fisheries at wild stock lakes in the Lower Mainland Region shouldemphasis selective nursery stream restoration to recover historical parrrecruitment capacities to improve catch success for coastal cutthroat trout. Toimprove angling quality, maximum size regulations should be implemented atsome of the more productive wild cutthroat lakes capable of growing largepiscivorous cutthroat (e.g., Ruby Lake on the Sunshine Coast as a primeexample). Similarly, at hatchery supported cutthroat or cutthroat-rainbow lakes,innovative use and evaluation of piscivorous sterile (triploid) cutthroat is worthevaluating further and expanding where appropriate to improve fishing quality.
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Coastal Cutthroat Trout as Sentinel
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3Sea-run cutthroat caught and relea
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5EXECUTIVE SUMMARYA provincial stra
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74. Cutthroat Nursery Habitat Resto
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10Cutthroat trout are prized by man
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12Vancouver Island. Large streams w
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14excessively warm and too low in d
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16prefer pools in allopatric condit
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18that are warmer and more producti
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20Comparative benefits to densities
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222, 23 % saltwater age 3 and 15 %
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24are sexually immature (Leider 199
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26management concerns are related t
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28practices. Life-history profiling
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30available in south coastal Britis
Page 32 and 33: 32Cutthroat smolt survivals are abo
Page 34 and 35: 34unproductive or oligotrophic stre
Page 36 and 37: 36were only small variable numbers
Page 38 and 39: 38Populations of juvenile cutthroat
Page 40 and 41: 40Unlike flood boxes with sluice ty
Page 42 and 43: 42weight/m 2 /yr (Wipfli and Gregov
Page 44 and 45: 44juvenile fish and non-target spec
Page 46 and 47: 46Figure 12. Trend in sea-run cutth
Page 48 and 49: 48at Hood Canal in Puget Sound (Big
Page 50 and 51: 50years owing to operational constr
Page 52 and 53: 5249 adult cutthroat were counted (
Page 54 and 55: 54Table 4. Areas of anadromous and
Page 56 and 57: 56population estimation and samplin
Page 58 and 59: 58Clayburn Creek, Draper Creek, Win
Page 60 and 61: 60females in 2000; hatchery females
Page 62 and 63: 625.2.4. Cutthroat Stream Stock Man
Page 64 and 65: 64Table 7. Cutthroat lake (stream)
Page 66 and 67: 66because piscivorous Taylor Lake c
Page 68 and 69: 68and- Angler use was largely at th
Page 70 and 71: 70spawners. This suggests that prot
Page 72 and 73: 72• Public education initiative t
Page 74 and 75: 74Management Strategy 3: Recovery o
Page 76 and 77: 76successful (Ptolemy 1997), and fu
Page 78 and 79: 78It is widely assumed that most ad
Page 80 and 81: 80annual frequency of repeat spawne
Page 84 and 85: 848. ReferencesAndrusak, H. and T.G
Page 86 and 87: 86Clark, B.J. 1988. The status of c
Page 88 and 89: 88Glova, G. L.1987. Comparison of a
Page 90 and 91: 90Knight, R. and J. Teskey. 1992. H
Page 92 and 93: 92eastern Fraser Valley. Prepared f
Page 94 and 95: 94Thomson, A.R. and Associates. 200
Page 96 and 97: 969. GlossaryIt should be noted tha
Page 98 and 99: 98large woody debris (LWD): Entire
Page 100 and 101: 100Appendix 1. Known coastal cutthr
Page 102 and 103: 102CHEAMSLOUGHCHEEKYERIVERCHEHALISR
Page 104: 104CRANBY LAKE LAKE ERROCK SAKINAW
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Coastal Cutthroat Trout as Sentinels of Lower Mainland Watershed ...

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