Symposium Summary: Blue Catfish: Lessons from a Large Riverine Opportunistic Catfish

41-kg Blue Catfish captured for feeding study from Rappahannock River, Virginia. Photo credit: Jason Emmel

41-kg Blue Catfish captured for feeding study from Rappahannock River, Virginia. Photo credit: Jason Emmel

This symposium session provided a current synthesis on the distribution, movement, biology, and life history of Blue Catfish (Ictalurus furcatus) inside and outside its native range. Blue Catfish are widely introduced outside their native range and have been stocked into many large reservoirs. They are growing in popularity with recreational and commercial fishers, and in particular, the trophy anglers. In Atlantic slope rivers, Blue Catfish are highly opportunistic omnivores, feeding on a wide diversity of plants and invertebrates before shifting to piscivory at sizes targeted by recreational anglers. In tributaries of the Chesapeake Bay, the expansion of Blue Catfish coincided with a decline of native White Catfish Ameiurus catus. Innovative approaches are used to identify diverse components of Blue Catfish diets with DNA barcodes, which revealed that many fish species of management concern are part of their diet. In the Mississippi River where Asian carp (Hypopthalmichthys sp.) are abundant, large Blue Catfish eat adult-size Asian carp. In one Missouri reservoir, concerns over overharvest led to special regulations to protect trophy-size Blue Catfish. Studies of movements of this mobile catfish revealed the locations and timing of active aggregations, explorations, and sedentary aggregations. Consequently, the spatial heterogeneity of productivity and physical features are important drivers of movement and distributions as well growth rates. Given the only recent interest in Blue Catfish, few systems have been examined by traditional stock assessment models. The symposium brought together investigators who investigated Blue Catfish in very different environments, yet the findings all point to a greater importance of focused study and management of Blue Catfish in the future. Read the abstracts here.

—D.J. Orth, M. E. Mather, J.D. Schmitt, and J.A. Emmel