U.S. Department of Agriculture: Animal and Plant Health Inspection Service


Date of this Version



Proceedings of the 10th Wildlife Damage Management Conference. (K.A. Fagerstone, G.W. Witmer, Eds). 2003.


Aquaculture in North America varies geographically with respect to species cultured, annual production, size, complexity, and spatial arrangement of facilities. Species assemblages of predacious birds using aquaculture facilities also vary with many of these industry characteristics. Wading birds are highly adaptable, relatively ubiquitous throughout the aquaculture industry, and often associated with fish depredation problems at aquaculture facilities. Suitability of information regarding the impacts of wading birds to aquaculture varies dramatically by depredating species and industry sector. Great blue herons (Ardea herodias) cause considerable depredation losses on trout aquaculture in the Northeast, and current research suggests that little blue herons (Egretta caerulea) negatively impact baitfish aquaculture. Early research provided similar findings with great blue heron depredations on catfish aquaculture. Recent research however, initiated a paradigm shift in management by demonstrating that some wading birds like the great blue heron and great egret (Casmerodius albus) largely eat diseased catfish and consumption of healthy catfish can be limited by specific management efforts. However, information is lacking on other wading bird species and their impacts to cultured species such as baitfish and crawfish. Issues regarding wading bird depredations are dynamic and evolve with changing demographics of both the aquaculture industry and wading bird populations. Emerging issues include great blue herons as possible vectors for whirling disease in Northeastern trout aquaculture and predation on catfish by wood storks (Mycteria americana). As local, regional, and continental populations of wading birds continue to change in number and geographic distribution, it is imperative that research identify where and how aquaculture production losses occur and guide science-based management plans to abate production loss. We discuss current population status and trends for selected wading birds and their potential impacts and management on major aquaculture industries in the United States.