Submitted to: Aquaculture
Publication Type: Peer reviewed journal
Publication Acceptance Date: 9/17/2003
Publication Date: 3/1/2004
Citation: Mischke, C.C., Zimba, P.V. 2004. Plankton Community Responses in Earthen Channel Catfish Nursery Ponds Under Various Fertilization Regimes. North American Journal of Aquaculture. 233:219-235. Interpretive Summary: Management recommendations for catfish fry ponds are generally lacking. Catfish fry depend on zooplankton as a natural forage base during early growth. Zooplankton feed on algae and the type of algae affects the nutritional quality of the zooplankton. We tested addition of cottonseed meal and inorganic fertilizer versus no additions on phytoplanktkon composition. Three methods were used to assess phytoplankton biomass; all three methods suggested additional nitrogen would increase phytoplankton biomass.
Technical Abstract: Fertilization recommendations for channel catfish nursery ponds are available, but are not based on systematic research. Current management recommendations for catfish fry production include pond fertilization with cottonseed meal and inorganic fertilizer. We assessed the effects of recommended fertilization practices using laboratory enrichment bioassays, changes in pigment signatures, and pulse-modulated fluorescence yield. All three methods of algal population assessment were applied to two 0.4 hectare experimental ponds. All three methods indicated nitrogen limitation of phytoplankton production, suggesting increased nitrogen fertilization was required for optimal production.