Available nursery space and adult escapement are considered the primary limiting factors to natural enhancement of sea-run cutthroat trout in the Lower Mainland. Four methods of instream natural enhancement are recommended, and include fry releases, habitat complexing, flow augmentation, and obstruction removal and/or utilization of presently inaccessible reaches. Increasing habitat complexity and fry densities to recommended levels in anadromous reaches can theoretically expand the present sea-run cutthroat trout population from 10,062 to 25,057 first returning (i.e. 1 ocean summer) adults. Suggested methods of increasing habitat complexity include planting of stream-side vegetation, and rootwad/boulder placement. Flow augmentation and barrier removal can theoretically add 2,884 and 2,791 adults respectively to the previous figure, boosting the total adult sea-run cutthroat population to an optimum of 30,521 fish. The above options are identified on a reach specific basis for selected streams within the study area and can account for 60% of the Regional cutthroat trout production target.
De Leeuw, A. D., Stuart, K. M.. 1981. Small Stream Enhancement Possibilities for Sea-Run Cutthroat Trout in the Lower Mainalnd and Sechelt Peninsula: Enhancement Options (Volume 4 of 4). Fish and Wildlife Branch. Fisheries Report