Submitted to: Book of Abstracts Aquaculture America
Publication Type: Abstract only
Publication Acceptance Date: 1/26/2007
Publication Date: 2/26/2007
Citation: Radomski, A.A., Ludwig, G.M., Hobbs, M.S., Perschbacher, P., Thomson, S.J. 2007. Commercial catfish pond water color and fish-eating birds: What is the connection [abstract]? Book of Abstracts Aquaculture America. p. 62. Interpretive Summary:
Technical Abstract: This study was designed to test and predict fish-eating bird use and avoidance at catfish production ponds during 2 winters in Arkansas. We measured (1) physical (size, length, width, depth, surface condition, secchi depth), (2) biological (fish size and stocking density, algal species composition and density, and chlorophyll a), and (3) physiochemical (pH, temperature, salinity, dissolve oxygen, total phosphorus, TAN, nitrite, nitrate, and hardness) variables within catfish ponds every 10 days to determine pond dynamics. In conjunction, fish-eating birds (namely, double-crested cormorants, great blue herons, and great egrets) were quantified over the duration of the study. Preassessment of pond use by birds were classified as 'preferred' or 'avoided'. Assessment of pond color was conducted using pond images obtained by low-altitude aerial digital video. Computer software programs generated digital numbers to classify each pond based on the red, green, and blue wavelengths. Cormorant and other fish-eating bird numbers and activity were quantified from observation towers at each farm throughout the over-wintering months. The treatment groups received AquashadeTM, a U.S. Environmental Protection Agency approved dye for use in aquaculture. The treatment was applied to 4 ponds at 3 spatially isolated catfish farms and replicated over 2 years. Results from this study indicate that no single variable was able to predict >60% of bird use of the pond. However, some pond attributes were slightly better at predicting those fish ponds with greater bird use.