MANAGEMENT TECHNIQUES TO MINIMIZE DOUBLE-CRESTED CORMORANT AND OTHER FISH-EATING BIRDS AT AQUACULTURE FACILITIES.

Authors: Radomski, Andrew; Freeman, Donald

Submitted to: The Wildlife Society
Publication Type: Abstract Only
Publication Acceptance Date: 7/1/2002
Publication Date: 9/24/2002
Citation: RADOMSKI, A.A., FREEMAN, D.W. MANAGEMENT TECHNIQUES TO MINIMIZE DOUBLE-CRESTED CORMORANT AND OTHER FISH-EATING BIRDS AT AQUACULTURE FACILITIES.. THE WILDLIFE SOCIETY. 2002. p.202.

Interpretive Summary:

Technical Abstract: Bird depredation research at USDA, ARS, SNARC focuses on developing cost-efficient methods to minimize bird depredation within the aquaculture industry and to resolve piscivorous bird-human conflicts. Methods used to minimize double-crested cormorant (Phalacrocorax auritus) and other fish-eating birds at aquaculture facilities have limited success because birds acclimate or adjust to the technique. During 2000-2001, a technique using twine strung at 30 m intervals across 8 catfish ponds was tested. Observations were made from a 4 m tower during the winter months in 4 hour blocks. Over 100 hours of observations resulted in 4240 cormorant observations. Treatment ponds had 429 cormorant encounters (2.3 birds per hour) compared to 1017 cormorant encounters (10.6 birds per hour) on control ponds. During 2001-2002, 20 additional catfish ponds were utilized and an additional treatment of twine strung at 60 m was tested. Although this study is ongoing, preliminary findings are 646 cormorant encounters (4.3 birds per hour) on treatment ponds compared to 2350 cormorant encounters (15.6 birds per hour) on control ponds. Although not exclusive to all fish-eating birds, this technique offers a nonlethal, cost-efficient, easy to setup, and low maintenance method to minimize depredation at aquaculture facilities.