Salmon Steward

salmon Steward magazine 7 Net Gains C an marine net pens help boost Chinook stocks – and by extension help alleviate starvation within the Southern Resident Killer Whale population? "With net pens, fish are held for about an extra month to adjust to the marine environment, fatten up and be protected from predators. In some cases, the use of these pens gives juvenile Chinook a greater chance of survival – maybe doubling their survival. That's not bad considering the normal survival rate is one per cent," says Pacific Salmon Foundation CEO Brian Riddell. The issue first made headlines in 2016, when a group of sport fishermen and members of the T'Sou-ke Nation received federal approval to introduce 200,000 Chinook smolts to the Sooke Basin, after raising them at the Department of Fisheries and Oceans' Nitinat Hatchery. They and other partners (including the Juan de Fuca Salmon Restoration Society and the Pacific Whale Watchers Association) hoped to turn the enhancement initiative into a multi-year project, possibly increasing releases to two million a year. Since then, other groups have been developing the sea pen idea. PSF believes the use of these pens to boost Chinook stocks is worth continued study. "So far the results are mixed, but if a good program could be mounted with solid planning behind it, I don't see why we shouldn't consider this method as a way to improve Chinook production," says Riddell. As for this being a method to feed starving whale populations, Riddell says only time will tell: "If you really want to help orcas, you need the geographical freedom to experiment, with a variety of stocks, in di—erent seasons. We need to consider where and when to target the additional Chinook to best assist the Southern Residents, and we need to be cautious about the release of di—erent genetic stocks anywhere. I expect it will take time to reach agreement on all this." SALMON HEALTH The Strategic Salmon Health Initiative has uncovered a virus that could be linked to Chinook decline T he Strategic Salmon Health Initiative was launched by the Pacific Salmon Foundation to determine which diseases could be undermining the productivity and performance of B.C. salmon. Earlier this year, the initiative discovered a link between Piscine Reovirus and jaundice/anemia in Chinook. The results of the study showed, for the first time, strong evidence that the same strain of PRV that causes heart and skeletal muscle inflammation in Atlantic salmon is likely to cause disease in at least one species of Pacific salmon. The study also identified eight new salmon viruses from aquaculture and wild salmon showing signs of disease. While still early in analyses, studies have determined that three of the new viruses detected on fish farms are also detected in migratory salmon, most notably Chinook. More work is required to determine if exchange of these viruses is occurring between farmed and wild salmon, and if there is a relationship between stress levels of Chinook from different areas and the expression of disease. PHOTO: ANDREAS BERGLUND / PORT RENFREW SALMON ENHANCEMENT SOCIETY PSF GRANTS HAVE SUPPORTED NET PEN PROJECTS SINCE 1989, INCLUDING THE FOLLOWING COMMUNITIES: Bowen Island Campbell River Cowichan Gold River Port Hardy Port McNeil Port Renfrew Quadra Island Sooke Tofino West Vancouver Conservation net pens give young Chinook a fighting chance against predators A net pen operated by the Port Renfrew Salmon Enhancement Society. CHINOOK & ORCAS Emiliano DiCicco studies disease in a biocontainment lab at the Pacific Biological Station.

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