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United States Department of Agriculture

Agricultural Research Service

Research Project: IMPROVING PRODUCTION EFFICIENCY OF POND-RAISED CHANNEL CATFISH

Location: Warmwater Aquaculture Research Unit

Title: Bacterial Bioaugmentation of Channel Catfish Ponds

Authors
item Tucker, C -
item Kingsbury, S -
item Mischke, C -

Submitted to: North American Journal of Aquaculture
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: November 1, 2008
Publication Date: January 1, 2009
Citation: Tucker, C.S., Kingsbury, S.K., Mischke, C.C. 2009. Bacterial Bioaugmentation of Channel Catfish Ponds. North American Journal of Aquaculture. 71:315-319.

Interpretive Summary: Pond aquaculture production is limited by the capacity of the pond microbial community to treat wastes produced during culture. A proposed approach to increasing the waste-treatment capacity of ponds is to increase microbial activity by supplementing naturally occurring microflora with organisms produced in culture in the process called bioaugmentation. This study evaluated the effect of a Bacillus-based bioaugmentation product on water quality and production of channel catfish (Ictalurus punctatus) in a 2-year, double-blind study. In the first year, bioaugmentation did not affect water quality. In the second year, ponds treated with the bacterial product had more phytoplankton biomass and lower concentrations of nitrite and ammonia. Reductions in dissolved inorganic nitrogen concentrations were more likely due to increased phytoplankton growth than to a direct effect of bacterial inoculation. The mechanism by which bioaugmentation may have enhanced phytoplankton growth is unknown and contradicts several past studies. Net fish production and feed conversion ratios were not affected by bacterial treatment in either year. There is therefore no economic incentive to use Bacillus bacterial bioaugmentation products in channel catfish ponds.

Technical Abstract: Twelve, 0.1-ha earthen ponds at Stoneville, Mississippi were used in a 2-year, double-blind study of the effects of a Bacillus-based bacterial bioaugmentation product on water quality and production of channel catfish Ictalurus punctatus. Each year, six ponds were treated weekly with the microbial product from late May or early June through October, and six ponds were designated as untreated controls. Mean concentrations of chlorophyll a, nitrite-N, and total ammonia-N did not significantly differ (P > 0.05) between bacteria-treated and untreated ponds in the first year; however, in the second year, mean chlorophyll-a concentrations were higher (P < 0.05) and nitrite-N and total ammonia-N concentrations were lower (P < 0.05) in bacteria-treated ponds than in untreated ponds. Reductions in dissolved inorganic nitrogen concentrations were more likely due to increased phytoplankton growth (i.e., increased algal assimilation) than to a direct effect of bacterial inoculation. The mechanism by which bioaugmentation may have enhanced phytoplankton growth is unknown and contradicts several past studies. Net fish production and feed conversion ratios were not affected by bacterial treatment in either year (P > 0.05); accordingly, there is no economic incentive to use Bacillus bacterial bioaugmentation products in channel catfish ponds.

Last Modified: 10/1/2014
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