Use of a Sodium Chloride Refuge to Improve Survival of Larval Morone Species during Transfer to Rearing Ponds


A.C. Mauldin II, T. Barrett, J.M. Grizzle-2002
North American Journal of Aquaculture, 64(1): 85–89

Abstract:

Experiments with striped bass Morone saxatilis and sunshine bass, a hybrid of female white bass M. chrysops and male striped bass were conducted in earthen ponds at two Georgia hatcheries to determine the benefits of a temporary NaCl refuge during transfer to production ponds. All ponds were stocked by placing larvae into a 166-L perforated container floating in the pond and then allowing pond water to flood the container. Fish were released into the pond after the 3 h it took for the container to fill with pond water. For 38 ponds 5 g NaCl/L was added to the water in the stocking containers; the 35 control ponds were stocked without the use of NaCl. At the Richmond Hill Hatchery in Richmond Hill, Georgia, survival at the end of the 4–5-week culture period was 26.4% for striped bass and 29.4% for sunshine bass stocked with the NaCl solution. Control fish survival was 21.2% for striped bass and 19.9% for sunshine bass, not statistically different from the bass stocked in NaCl (P > 0.05). Striped bass survival was also similar for the two treatments at the McDuffie Hatchery near Dearing, Georgia (control, 34.5%; salt, 35.2%). Although we found no statistical difference between treatments, our results indicated that further study of the benefits of salt during pond stocking is justified and that the sinking-container method that we used reduced the labor required for stocking ponds.

(Georgia Department of Natural Resources, Wildlife Resources Division, Social Circle, Georgia 30025, USA)

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