Effects of Loading Density on Golden Shiner Survival during and after Hauling

Abstract

Four hauling trips of approximately 6 h each were conducted to investigate effects of loading density on survival of golden shiners Notemigonus crysoleucas. Commercially graded golden shiners (mean weight ± SE, 3.3 ± 0.04 g) were transported at densities of 120, 180, and 240 g of fish/L of water in insulated hauling tanks that were filled with fresh well water, chilled with unchlorinated block ice, and aerated with pure oxygen. The criterion for determining success or failure was golden shiner survival. Transportation at a given density was deemed successful if survival both at trip's end and at 18 h postdelivery was at least 99%. At all three hauling densities evaluated, survival exceeded 99% both at trip's end and at 18 h postdelivery. Furthermore, increasing loading density had no effect on whole-body cortisol concentrations, demonstrating that no significant stress response occurred. Un-ionized ammonia concentration increased with loading density (range, 0.05–0.46 mg/L) but had no effect on fish survival. Results of this study indicate that golden shiners can be successfully (≥99% survival) transported for up to 6 h at a density of 240 g/L in well water chilled with unchlorinated block ice and aerated with pure oxygen. Higher loading densities could mitigate the effect of escalating transport cost for commercial farmers.