Salish Sea Marine Survival Project

72 Figure 4. SSHI research collecting samples from the Strait of Georgia. Photo by Mitch Miller. Other studies in the Cowichan River noted that hatchery- reared smolts were larger than wild smolts, ate larger prey, spent very little time in the estuary and disappeared from the bay earlier, due to emigration and mortality. The larger body size may be a disadvantage for hatchery smolts if it necessitates their leaving the estuary prema- turely to meet energy needs. For example, the onset of piscivory (fish diet) for Cowichan Chinook begins at a fork length of approximately 74 mm, which was less than the average fork length of the hatchery fish found in Cowichan Bay. These large Chinook may spend more time seeking less abundant larger prey and increasing their exposure to other predators. Leaving the safety of nearshore habitats, especially those providing eelgrass and kelp cover, may expose hatchery fish to increased predation risk and may contribute to the low survival rates of hatchery fish as compared to wild fish. 3. Efficacy of Hatcheries: Use of Parental-based Tagging of Hatchery Coho Salmon PSF, together with Genome Canada and DFO, assisted in funding the EPIC4 program (www.sfu.ca/epic4/), one component of which is applying parental-based tagging (PBT ) of hatchery Coho stocks in Southern BC in order to genotype (the genetic composition of a parent) the majority of hatchery Coho smolts released into the Salish Sea. This technology allows researchers to estimate contribution to fisheries, and ultimately the family-spe- cific survival rates of hatchery Coho Salmon, which may enable genetic selection programs that have never been tried as a tool to increase the effectiveness of hatchery Coho production. Currently, hatchery-bred Chinook and Coho Salmon are monitored by means of coded-wire tags (CWT ) implanted in juveniles prior to release from the hatchery, although only a small portion of releases are tagged. However, with PBT, essentially those hatchery Coho are "tagged" and identifiable as to when and where they were released. This information makes it possible to understand the impact of different hatcheries on salmon populations and how well hatchery fish survive in the wild, and allows us to compare productivity of hatchery versus wild fish. Similar work is now being carried out for Chinook. 4. Effects of Fish Health and Condition: The Strategic Salmon Health Initiative (SSHI) Within the SSMSP, the SSHI has provided the tools to assess the health and condition of fish, including their: 1) infec- tious health; 2) state of smolt readiness; and 3) presence of stress. These tools have been developed for application on non-destructive gill tissue in a tool called the Salmon Fit-Chip. In addition, biomarkers (DNA based) predictive of imminent mortality and state of inflammation, also often predictive of poor survival, have been developed. Application of these tools by hatcheries could help to: Optimize hatchery practices to minimize stress on the fish; Precisely identify when fish are ready to emigrate from freshwater to the ocean (smoltify); Identify and mitigate exposure to infective agents; and Develop means to optimize the health and condition of juvenile salmon for their release to improve their chance of survival. Research within the SSHI has revolutionized how the health and fitness of Pacific Salmon in any environment can now be monitored and evaluated with a statistically reliable sample size! NEXT STEPS PSF is undertaking a science-based review of hatchery programs in the DFO Pacific Region including community hatcheries and major facilities operated by DFO. This project will examine the effectiveness of current production, identify scientific advancements in recent years that may be applied to increase effectiveness, and ultimately inform the joint production of hatchery-based and wild Pacific Salmon for BC communities and ecosystems. Parental-based tagging (PBT): using gene5c markers to iden5fy the origin of salmon Parents Parents Male Female Male Female Babies Babies Sample in the ocean: who are their parents? Figure 3. Depiction of how PBT works. Graphic by EPIC4. Credit: Terry Beacham, DFO.

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