JEFFERSON CITY—The Department of Conservation continues to gather information to make an informed scientific decision on invasive crayfish. The Department has listened and consulted with bait producers and dealers on invasive crayfish. Education efforts have worked to inform anglers and bait sellers about how to prevent invasive crayfish from damaging the state’s sport-fishing industry.
A proposed course of action would prohibit the importation, purchase or sale of live crayfish, commonly called crawdads, for use as fish bait. It would not prevent anglers from catching crayfish and using them as bait. This action is intended to prevent damage to stream and lake ecology, species losses and protect recreational and economic values associated with fishing. More than 1.1 million Missourians enjoy sport fishing, which generates more than $2 billion in economic activity in the state annually.
Surveys conducted in 2010 and 2011 showed crayfish sales were minor for most Missouri bait shops, pet shops and aquaculture operations, typically representing only about 1 percent of their income. Nevertheless, Deputy Director Tom Draper, who chairs MDC’s Regulations Committee, says the decision to consider banning commercial crayfish sales was not taken lightly.
“The Conservation Department is responsible to the citizens of Missouri for protecting fish and wildlife and the economic and recreational benefits that go with them,” says Draper. “Other states already are seeing declines in the quality of fishing because of invasive crayfish. We don’t want to get 20 or 30 years down the road and wish we had done something to protect our fishing when we had the chance. Knowing what we do, it would be irresponsible not to take some type of action to protect Missouri’s aquatic resources.”
MDC Resource Scientist Bob DiStefano says crayfish are unlike many invasive species, because they don’t have to be far from their native areas to cause trouble. A crayfish species whose population is in balance with other species in its native waters can cause ecological problems when introduced to a neighboring watershed.
“Many crayfish species can become invasive if moved into the wrong setting,” says DiStefano. Imported crayfish also can carry diseases with the potential of decimating native crayfish populations. Crayfish are a staple food for black bass, sunfish and many other sport fish.
What MDC knows about invasive crayfish comes from dozens of studies in Missouri and other states. DiStefano says those studies show that the danger posed by commercial trade in crayfish is real and serious.
For example, spot checks conducted by MDC before passage of the crayfish sales ban showed that more than one-quarter of bait shops were selling crayfish species that already were illegal under previous regulations. In most cases, these were not willful violations. Bait shop owners simply did not know the difference between crayfish species including the invasive species. Even if dealers could tell the difference, they could not be expected to detect a few individuals of an invasive species mixed in with a shipment of thousands of less-destructive crayfish.
MDC inspections also found that many bait shops were selling crayfish obtained from outside of Missouri and that some shops were illegally selling crayfish collected from the wild.
Invasive crayfish already are impacting Missouri waters. DiStefano said field studies have documented 25 instances of crayfish invasions in Missouri. Those invasions have caused declines of six native species.
DiStefano says invasive crayfish have been shown to out-compete native crayfish, compete with game fish for food, destroy aquatic plant beds used as spawning grounds and nurseries for game fish, and are known to also eat fish eggs. This combined with reduced spawning habitat and food means fewer and smaller fish. A study of lakes in Vilas County, Wisc., documented resource damage from invasions of rusty crayfish of more than $1 million annually.
Draper noted that Missouri anglers would still be allowed to catch crayfish and use them for bait if the Department implemented a regulation. A ban would only prohibit commercial trade in live crayfish bait. Bait shops would still be permitted to sell dead or preserved crayfish for bait. He says delaying implementation of a ban would give MDC time to inform anglers about the risks associated with moving crayfish from one place to another.
“The Department needs anglers’ help to protect Missouri’s lake and stream fishing,” says Draper. “It is critical for anglers to know the danger posed by moving crayfish and other bait from one place to another. How well we do our job of educating the public will make a huge difference for the future of fishing in Missouri.”
A recent survey of anglers showed that 40 percent of Missouri anglers release live bait into fishing waters. DiStefano urges anglers to use crayfish for bait only if they are caught in the same body of water where they will be used. He also asks anglers not to release commercially purchased live bait, including minnows and worms, at the end of a fishing trip. He says this has serious potential consequences, because both commercially sold live bait and bait caught by anglers often is transported across natural or state borders.
“The world is a lot smaller today than it was even a few decades ago,” says DiStefano. “In the past, we didn’t have to worry as much about introduction of exotic species, but those days are gone. We have to change our habits if we want to protect Missouri’s fisheries and other aquatic resources.”
Besides allowing anglers to use crayfish that they catch themselves, a crayfish ban would include two exceptions for commercial sales. One is for human consumption. The other is for crayfish used for scientific research or for food for confined animals held by authorized representatives of universities, colleges, schools, incorporated city, state or federal agencies, publicly-owned zoo or other qualified individuals. Anyone who imports, sells or buys crayfish under these exceptions must meet certain record-keeping requirements. Buying or selling live crayfish taken from waters of the state already was prohibited.
For more information about invasive crayfish, visit:
• malibu.patch.com/articles/invasion-of-the-crayfish-pest-threatens-wildlife-in-local-streams-bdcd674a or