Development and use of an acoustic device to estimate size distribution of catfish in commercial ponds.

Abstract

With increasing seafood demand, aquaculture remains a major industry in the United States. Channel catfish pond management strategies are compromised by high fish densities with large size distributions that result from years of continuous culture without a total harvest. Recent work has been presented on the Aquascanner SONAR system, which evaluates the total population of a pond but is less effective in determining the size distribution. One method to provide the size distribution is to pull a sub sample seine net across a pond to obtain a sample of the fish and manually weigh them in a time-consuming process. The work presented here attempts to use acoustic backscatter to determine the size distribution of the fish in lieu of the manual weight measurements. After being collected by the sub sample net, the fish are allowed to swim back into the pond through a restrictive pipe and are pinged acoustically to determine their target strength and thus size. The design of the system, size estimation method and results from several pond studies will be discussed. [Work supported by the USDA, SRAC.]