2004 Annual Report 4.What were the most significant accomplishments this past year? D. Progress Report. This is a termination report for research conducted under specific cooperative agreement 6402-31000-006-01S, "Acoustic Technologies for Evaluating Catfish Production," with the National Center of Physical Acoustics, University of Mississippi. Additional details can be found in the report for the parent project 6402-31000-006-00D "Catfish Genetics, Breeding, and Physiology". This project terminated on 6/30/2004. Three prototype units of the Aquascanner catfish sonar have been built and parts have been assembled to build three more. The units have been tested at select ponds at the ARS-NWAC facility in Stoneville, MS, and Harvest Select Inc. in Inverness, MS. The units are providing good qualitative displays of the ponds and large-scale data collection is providing the necessary data to refine and improve an empirical model to correlate the acoustic data to population data. The population data is being collected from stocking records and seining records where available. The inclusion of wireless Ethernet has greatly improved the portability and ease of use of the system as bulky cables to shore for power and data transfer are no longer required. The unit fits easily into the back of a truck and can be deployed and operated by a two man crew with deployment and scan times of approximately 30 minutes per pond. In conjunction with the Aquascanner development an additional season of acoustic recordings from spawning catfish has been collected in the Spring of 2004 with the automated and user friendly data acquisition system developed by NCPA personnel described in previous reports. This data set adds to previously identified signals of interest from catfish during spawning which could be used to understand behavior during spawning. This understanding may be useful in improving spawning rates or possibly modifying behavior such as during seining operations. This project has been discontinued under the current CRIS but is being renewed under a new CRIS.