Michael B. Rust

Interactions of Atlantic salmon in the Pacific northwest: V. Human health and safety

The paper discusses potential issues for human health and safety from net-pen salmon farming in the Pacific northwest region. A brief introduction to global and national responsibilities for food safety is followed with a review of the chemicals and chemical contaminants in materials used in farm production operations. Possible sources include metallic paints, feed ingredients, and chemotherapeutants. Concerns for the transmission of diseases follow, and the common pathogenic diseases are reviewed. After a section on the processing and quality of farm products, specifically the proximate composition of farm fish and differences between farm and wild salmon species, the concerns for worker safety on the farm are considered. The paper ends with some conclusions on the varying degrees of risk carried by these issues.

Transitioning Coho Salmon Broodstock to a Docosahexaenoic Acid (DHA)-Rich Diet during Vitellogenesis: Effects on Egg Composition and Embryo and Fry Quality

Abstract Female coho salmon Oncorhynchus kisutch were fed one of two broodstock diets during vitellogenesis to evaluate the contribution of dietary lipids to egg lipids and to assess any embryo or fry quality differences that were attributable to treatment. The diets contained lipids with different fatty acid profiles and carbon stable isotope signatures (δ13C). Diets were formulated by top-dressing a low-fat salmon broodstock feed with either sardine oil (fish oil feed) or an algal oil–corn oil blend (algal oil feed). The added oils were balanced for total n-3 fatty acid content but contained markedly different levels of linoleic acid (LA), eicosapentaenoic acid, and docosahexaenoic acid (DHA). Analysis of δ13C revealed that dietary lipids were significantly incorporated into egg lipids during vitellogenesis and that polar and neutral lipid fractions were equally affected. Eggs of fish in the algal oil treatment group had significantly higher levels of DHA and significantly lower protein content than the...

Uptake and selective partitioning of dietary lipids to ovarian and muscle tissue of maturing female coho salmon, Oncorhynchus kisutch, during secondary oocyte growth

Female coho salmon, Oncorhynchus kisutch, were fed one of two experimental feeds containing lipids with markedly different stable 13C isotope signatures during the late cortical alveolus, lipid droplet, and vitellogenesis stages of secondary oocyte growth. Ovarian and muscle lipids fatty acid concentrations were significantly affected by treatment during all three stages of development. Stable 13C isotope analyses confirmed that dietary lipids were incorporated into both ovarian and muscle lipids during all three stages and revealed that ovarian lipids were more affected than muscle lipids during vitellogenesis. Arachidonic acid (ARA) was incorporated into ovarian lipids at the highest rate of all fatty acids examined with the greatest uptake observed during the cortical alveolus and lipid droplet stages of development. Docosahexaenoic acid (DHA) was incorporated into ovarian lipids at the next highest rate with the greatest uptake observed during the lipid droplet stage of development. The presence of an ovary specific, fatty acid transfer mechanism is proposed. Results from this study demonstrate the ability to greatly alter the fatty acid composition of ovarian lipids through a dietary change during secondary oocyte growth and may be of great interest to producers of farmed salmon and salmon broodstock programs.