Columbia Missouri Biologist Chris Eggleston with 2 white crappie captured during scour sampling at Overton unit of Big Muddy National Fish and Wildlife Refuge - FWS photo by Cliff Wilson

Columbia Missouri FRO Biologist Jennifer Johnson setting mini-fyke net during scour sampling at Overton unit of Big Muddy national Fish and Wildlife Refuge - FWS photo by Cliff Wilson

Service biologist Wedge Watkins and Cliff Wilson carry stock channel catfish from a hatchery truck to a refuge scour at the Overton unit of the Big Muddy National Fish and wildlife Refuge - FWS photo by Cliff Wilson

Bundles of cedar trees are submerged in scours at Overton unit of the Big Muddy National Fish and Wildlife Refuge to provide recruitment and spawning habitat - FWS photo by Cliff Wilson

Columbia FRO worked with staff from the Big Muddy National Fish and Wildlife Refuge and the Missouri Department of Conservation (MDC) to improve and increase recreational fishing opportunities on scours at the Overton Bottoms unit of the Big Muddy National Fish and Wildlife Refuge.

The flood of 1993 created three scour basins ranging from six to thirty acres in size that have since served as a home for a variety of fish species. Resource users have expressed an interest in establishing healthy recreational fisheries in these scours. Therefore the Columbia FRO has led a collaborative effort to improve this fishery by first sampling the Diana Bend, I-70, and NC4 scours at Big Muddy NFWR, then using the results of the sampling to determine what could be done for the fishery. 

Initial plans for improving the fishery included both the creation of habitat for recruitment and reproduction and the stocking of channel catfish.

The scour sampling targeted the entire fish community by using a variety of gear types. Mentionable catches included silver and bighead carp, walleye, smallmouth bass, and paddlefish. The sampling indicated little recruitment was occurring in the scours due to a severe lack of available habitat. In other words small fish were not growing big and replenishing the larger adult portion of the population harvested by anglers.

After young fish hatch they have no place to hide, making them vulnerable to predation. In addition, the scours lack suitable spawning habitat limiting the amount of reproduction, causing recruitment to be hampered even more.

In order to improve the available habitat in the scours basins the Columbia FRO and Big Muddy Refuge staff placed reefs of cedar trees and cottonwood logs into them. This new habitat will increase areas for recruitment of crappie, sunfish and other young of the year fish and aggregate fish for anglers. Future surveys will show how well the new habitat has benefited the fish populations.

Refuge anglers have indicated a desire to catch riverine species such as buffalo and catfish. Our survey revealed both an abundance of smallmouth and bigmouth buffalo and a shortage of channel catfish. As part of a Cost Share Challenge Grant, the MDC stocked fingerling (ten to twelve inches) catfish to boost the population. These collaborative catfish stockings will be continued annually to increase angler satisfaction at the refuge.

Future plans for the refuge scours include holding a kid’s fishing clinic, creating additional access, creating more habitat for spawning and recruitment, and the additional stocking of channel catfish. Columbia FRO will sample these scours annually to monitor the condition and population of the fishery.

Collective efforts with the Big Muddy NFWR and MDC to identify and implement ways to increase recreational fishing supports the Partnerships and Accountability and Public Use goals of the Fisheries Programs Vision for the Future.