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United States Department of Agriculture

Agricultural Research Service

Title: Can Manipulating Pond Color Minimize Double-Crested Cormorant Depredation at Fishponds

Authors
item Radomski, Andrew
item Thomson, Steven

Submitted to: American Ornithologists' Union Annual Meeting
Publication Type: Abstract Only
Publication Acceptance Date: June 18, 2004
Publication Date: August 16, 2004
Citation: Radomski, A.A., Thomson, S.J. 2004. Can manipulating pond color minimize double-crested cormorant depredation at fishponds [abstract]. American Ornithologists' Union Annual Meeting. p. 69.

Technical Abstract: Recent advancements in studies on the acuity of avian visible spectrum and remote sensing have allowed ornithologists a unique opportunity to conduct field experiments within the birds' perceived environment. This study was an attempt to correlate cormorant use and avoidance with pond constituents (surface condition, secchi reading, depth, pH, temperature, salinity, dissolve oxygen, total phosphorus, TAN, nitrite, nitrate, hardness, and chlorophyll a) and digital values from pond images obtained using low-altitude aerial digital video. During this winter (2004), Double-crested Cormorants (Phalacrocorax auritus), a major predator at aquaculture farms in the southeastern USA, were quantified at 3 commercial fish farms in Arkansas (USA). These farms were typical of commercial production, in that the farms had >40 fishponds, ponds were 6 ha, and stocked with single- or multiple-age class channel catfish (Ictalurus punctatus). Cormorants were quantified for 2 months at each farm and then the ponds were classified as preferred or avoided. After classifying the ponds, the treatment (AquashadeTM, an approved dye for use in aquaculture) was applied to 4 ponds (2 preferred, 2 avoided) at each farm. Subsequently, cormorants were quantified for 2 months post-treatment. The primary objectives of this study were to determine if cormorants could be deterred from aquaculture ponds treated with this dye and quantify any deleterious water quality changes to the ponds.

Last Modified: 7/30/2014
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