Invasive Flathead Catfish Threaten Native North Carolina Fish Species

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According to the N.C. Wildlife Resources Commission, snail bullheads and flat bullheads, also known as mudcats or yellow cats, have declined significantly throughout the upper Yadkin River, due to the introduction of the non-native flathead catfish.

Flathead catfish are the dominant predator in waters they inhabit. They prey heavily on bullheads, other catfishes, shad sunfishes. They also devour carp, crayfish, and other aquatic life.

In North Carolina, flathead catfish commonly reach weights of 20 to 30 pounds. The current state record, caught in 2005 in the Cape Fear River, tipped the scales at a whopping 78 pounds.

Snail bullheads and flat bullheads, on the other hand, are much smaller catfishes that typically weigh a pound or less. Until flathead catfish were introduced into the Yadkin River, bullheads were the primary catfish species in the river and a favorite target of anglers because they were plentiful, easy to catch and good to eat.

Fisheries biologists with the N.C.Wildlife Resources Commission recently completed a series of electro-fishing surveys in Surry, Yadkin and Wilkes counties and found that bullhead catch rates near Elkin had declined sharply between 2005 and 2012.

These latest survey results from the upper portion of the river confirm what biologists have long suspected; when flathead catfish are introduced in a river system, other fish populations decline significantly, either through direct predation by flathead catfish or through indirect competition for food. Bullhead catfishes, especially, seem to be susceptible to flathead catfish predation.

North Carolina Wildlife Resources Commission fisheries biologist Kin Hodges recently commented on the decline, stating:

“Sharp declines in bullhead abundance have been documented in other river systems in North Carolina and throughout the southeast where flatheads have been introduced.”

Flathead catfish are not native to North Carolina waters east of the Blue Ridge Mountains. Biologists speculate that they have been introduced mainly by anglers who want to increase fishing opportunities for the species.

In 2005, North Carolina Wildlife Resources Commission passed a regulation that required anyone interested in stocking a public, inland fishing water to obtain a stocking permit first.

The requirement protects native or legally established aquatic species from the potentially damaging effects of unauthorized stockings by allowing the Commission to assess, on a case-by-case basis, the impacts a proposed stocking may have on an established fishery.

For more information, visit the North Carolina Wildlife Resources Commission website.

source: North Carolina Wildlife Resources Commission