Materials, energy, and organisms from groundwater serve as resource subsidies to lotic systems. These subsidies influence food production and post-emergent fish growth and condition through nutrient inputs and water temperature changes. To test whether post-emergent fish grew faster in gaining sites, we grew hatchery post-emergent salmon in enclosures, sampled periphyton, benthic invertebrates, and wild salmon, and modeled fish growth across a gradient of groundwater – surface water exchange. Fish grew almost twice as fast in gaining (2.7%·day⁻¹) than in losing (1.5%·day⁻¹) sites. Fish from transient sites grew as much as gaining sites, but their condition was significantly lower (18.3% vs. 20.7%). Results suggest that groundwater – surface water exchange affects fish growth and energetic condition through direct and indirect pathways. Elevated nitrogen concentrations and consistently warmer water temperature in gaining sites have a strong effect on basal production with subsequent effects on invertebrate biomass, fish growth, and condition. Findings highlight the importance of groundwater – surface water exchange as a subsidy to rearing salmon and may inform strategies for restoring fish rearing habitat.

Groups of 0+ Atlantic salmon (Salmo salar) smolts were transferred to duplicate seawater tanks, and subjected to five different ration levels, 0% (starved), 25%, 50%, 75% or 100% (full fed). Waste feed was collected after each meal. After six weeks all groups were re-fed in excess. During the trial period body weight and length increased significantly in the 50, 75 and 100% groups, while no significant changes in body weight were observed in the 0% and 25% groups. A significant decrease in SGR was observed in the 0 and 25% groups during the first month in sea water. After re-feeding, SGR increased in all groups. All groups, except the previously starved group, showed peak SGR between weeks 6-8 and 8-12. Food restriction at 0% and 25% of full ration for a period of six weeks resulted in significant osmotic disturbances. After six weeks in sea water, plasma Cl⁻ levels were higher in the 0% group than in the other groups. Branchial Na⁺,K⁺-ATPase activity increased in all groups following exposure to seawater. Re-feeding caused a transient increase in branchial Na⁺,K⁺-ATPase activity after two weeks in the previously starved group, with a concurrent reduction in plasma Cl⁻ levels. Previous exposure to different ration levels significantly influenced growth rate and mean body size. Compensatory growth and partial size compensation was seen in the 0, 25 and 50% feed deprivation groups, whereas full size compensation was found in the 75% group.

Bactericidal activity of neutral electrolyzed water (NEW), quaternary ammonium (QUAT), and lactic acid‐based solutions was investigated using a manual spraying technique against Salmonella Typhimurium, Escherichia coli O157:H7, Campylobacter jejuni, Listeria monocytogenes and Staphylococcus aureus that were inoculated onto the surface of scarred polypropylene and wooden food cutting boards. Antimicrobial activity was also examined when using cutting boards in preparation of raw chopped beef, chicken tenders or salmon fillets. Viable counts of survivors were determined as log₁₀ CFU/100 cm² within 0 (untreated control), 1, 3, and 5 min of treatment at ambient temperature. Within the first minute of treatment, NEW and QUAT solutions caused more than 3 log₁₀ bacterial reductions on polypropylene surfaces whereas less than 3 log₁₀ reductions were achieved on wooden surfaces. After 5 min of treatment, more than 5 log₁₀ reductions were achieved for all bacterial strains inoculated onto polypropylene surfaces. Using NEW and QUAT solutions within 5 min reduced Gram‐negative bacteria by 4.58 to 4.85 log₁₀ compared to more than 5 log₁₀ reductions in Gram‐positive bacteria inoculated onto wooden surfaces. Lactic acid treatment was significantly less effective (P < 0.05) compared to NEW and QUAT treatments. A decline in antimicrobial effectiveness was observed (0.5 to <2 log₁₀ reductions were achieved within the first minute) when both cutting board types were used to prepare raw chopped beef, chicken tenders or salmon fillets.