2007 Annual Report 1a.Objectives (from AD-416) Determine the effects on fish production, water quality and economics of various aeration strategies. 1b.Approach (from AD-416) Ten commercial ponds will be selected for use in this demonstration project. The ponds will be managed using a single-batch system, and thus will be completely harvested and restocked whenever the fish reach market size. Since this will occur year-round, the study will be established with paired ponds. After clean-seining the ponds, they will be re-stocked with 4500/acre of similar-sized stocker catfish (0.2-0.4 lb. average weight). The first two ponds to be stocked will be operated for the next production cycle as control (current aerator placement) and test (new aerator placement) ponds. All ponds will be similarly brought into the study in pairs. Aerators in the control ponds will be placed adjacent to each other on the narrow end of the pond. Aerators in the test ponds will be placed according to Attachment 1. Dissolved oxygen will be checked on both ends of each pond on the farm's normal night schedule (approximately 2 hours per round during the growing season). The three aerators in all ponds will be turned on/off sequentially according to the farm's normal practices; when the dissolved oxygen concentration falls to below (or increases to) 4.5 ppm, 3.5 ppm and 2.5 ppm. Hour meters will be installed in-line with each aerator so total hours of electrical aerator operation will be known. Additional PTO-powered aerators will be used as necessary and run times recorded. Fish in all ponds will be fed according to normal farm practices, with the feeding rate determined by "Fishy" pond management software and limited to 120 lbs/acre/day. Individual ponds will be clean harvested as soon as the fish reach market size and are on-flavor. Water samples wil be collected at bi-weekly intervals and determinations made for pH, temperature, total ammonia nitrogen, unionized ammonia nitrogen, nitrite nitrogen, chlorophyll, suspended solids (total, fixed and volatile), and secchi disc visibility. It is the intention of the parties to this agreement that this demonstration shall be for the benefit of the aquaculture industry of Mississippi and elsewhere in the United States and for the general benefit of the people of the United States. 3.Progress Report This report serves to document research conducted under Non-Funded Cooperative Agreement between ARS and Dillard & Company, Inc. Additional details can be found in the report for the in-house project 6402-13320-003-00D, “Optimizing Catfish/Water Quality Interactions to Increase Catfish Production.” The purpose of this agreement was to determine the effects on fish production, water quality and economics of concentrating paddlewheel aeration in large commercial ponds, compared to the current method of placing aerators to maximize total pond aeration and circulation. Ten 11.5-23 acre ponds were selected for use in the study and were brought into the study in pairs as they were stocked for the 2007 growing season. Each pair was stocked near the same date with a single batch of graded, similarly-sized catfish. One pond of each pair was aerated with the new aerator placement, and the other was aerated using the existing system. Ponds will be “clean harvested” by multiple seining as the fish reached market size. Water quality, feed input and aeration are being monitored. The study is planned to run into 2008 when all ponds will be clean harvested by seining. The ADODR monitors this project through telephone calls and e-mails to the collaborator, and through bi-weekly site visits to collect water samples and to discuss operations on-site with the farm manager.