These non-native invaders have the potential to disrupt food chains and harm ecosystems and damage sport-fishing opportunities.

Fishing tips are common in this part of the state, but one of the best bits of angling advice is a message being heard with increasing frequency across Missouri and other states:

Don’t dump your bait.

Pitching unused minnows or the last couple of crawdads over the side of the boat into the water has long been one of the final acts of a day on the lake. However, the increasing appearances of unwanted invasive species in our reservoirs and streams indicate this seemingly inconsequential action does, indeed, have consequences that could spell trouble for our native aquatic species.

Missouri’s waterways are home to 200 species of native fish, 65 species of native mussels and more than 30 species of crayfish. However, invasive species are showing up in these same waterways with increasing frequency. These non-native invaders have the potential to disrupt food chains and harm ecosystems and damage sport-fishing opportunities.

There are a number of ways non-native species come to our waters but biologists recognize “bait bucket introductions” as one of the most common ways these species are introduced and spread to other locations. This occurs when anglers dump live bait into a water body from which that bait did not originate. Rusty crayfish and several species of Asian carp are among the harmful non-native species that are being spread throughout the Midwest’s streams and rivers in this fashion.

To illustrate the problems these species can cause, one needs look no further than the rusty crayfish. This aggressive aquatic invertebrate will out-compete many native crayfish species for food and damage aquatic plant beds. The damage they do to aquatic plant beds results in reduced cover for native fish – including popular sportfish species.

Ecosystem disruption is not the only problem non-native species can cause. Newcomers can also bring diseases that native species are not equipped to cope with.

Even anglers who seine their own bait from lakes and streams could be spreading unwanted species if they don’t release the fish back into the same body of water from which they were collected. The reason for this is that carp and other non-native fish species can resemble native minnows when they’re young and small. As a result, a few unwanted exotic fish could be netted along with native species and an angler who dumps these left-over bait fish in a new body of water may unknowingly spread an invasive species to a new area.

Disposing of bait on land, once you get out of the water, seems like a good idea, but in the case of crayfish, it isn’t. Crayfish can live for a period of time out of water and can be quite mobile, even on dry land, so the chances of them walking to a body of water are highly possible.

Alternatives for dumping include taking your bait home to use on future fishing trips or placing it in a sealed container in the trash.

It should be noted that the Wildlife Code of Missouri has established a list of prohibited species that may not be possessed in Missouri. This list includes rusty crayfish. For a complete list, see 3 CSR 10-4.117 of the Wildlife Code.

Information about proper bait disposal and other fishing information can be found at your nearest Missouri Department of Conservation office or at mdc.mo.gov.

Francis Skalicky is the media specialist for the Missouri Department of Conservation’s Southwest Region. For more information about conservation issues, call 417-895-6880.