Location: Warmwater Aquaculture Research UnitTitle: Bacterial Bioaugmentation of Channel Catfish Ponds Author
Submitted to: North American Journal of Aquaculture
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/10/2008
Publication Date: 7/9/2009
Publication URL: http://handle.nal.usda.gov/10113/55537
Citation: Tucker, C.S., Mischke, C.C., Kingsbury, S. 2009. Bacterial Bioaugmentation of Channel Catfish Ponds. North American Journal of Aquaculture. 71:315-319. Interpretive Summary: Industrial culture of bacteria are sometimes added to wastewaters to increase rates of decomposition in the pocress called bioaugmentation. A commercial bacterial bioaugmentation product was tested for 2 years in a double-blind study to determine if bioaugmention could improve water quality and growing conditions in catfish ponds The bacterial treatment did not affect algal biomass, nitrite, or ammonia in the first year. However, algal biomass was higher and nitrite and total ammonia were lower in the second year in bacterial-treated ponds. Although these unexplained differences did occur in treated ponds in year 2, fish production and feed conversions were not affected by bacterial treatment in either year; therefore, there is no economic incentive to use bioaugmentation products.
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.