The Mitigation crew at Columbia NFWCO shows off a nice sturgeon haul from a trawl at Lisbon Bottom chute.

The Mitigation team at Columbia National Fish and Wildlife Conservation Office (NFWCO) recently completed the first two months of sampling. The Mitigation project’s purpose is to document fish communities and habitats present within four side-channels, or chutes, on the lower Missouri River near Columbia, Mo. Lisbon Bottom and Tate Island are two side-channels that were naturally created by river processes.  North Overton Bottoms and Tadpole Island are chutes that were created by the US Army Corps of Engineers to mitigate for lost side-channel, and shallow water habitat.

Shallow water habitat, provided by side-channels, is an important component of many fishes home range.  These side-channels serve as productive foraging areas, spawning grounds, and provides refuge for fish during high water events. Sturgeons are some of the many species that use side-channels, and this year their presence within these habitats was especially pronounced. During April and May of this year a total of 274 shovelnose sturgeon, one lake sturgeon, and one pallid sturgeon were captured within the four chutes involved in the project. During the 2007 sampling season (April to September) only 275 shovelnose sturgeon were captured during the entire season.

Lisbon Chute produced the greatest number of shovelnose sturgeon compared to the other three chutes, accounting for nearly 50 percent of the fish captured. The lone pallid sturgeon caught was from Lisbon chute as well; this fish represents the first of its kind captured during Mitigation sampling at Columbia NFWCO which began in 2005. Tadpole Chute had the second highest shovelnose sturgeon numbers accounting for around 27 percent of April and May’s total catch. A lake sturgeon was also captured in Tadpole chute this spring, the only representative of its species in 2008 so far. Tate and Overton chutes held the lowest numbers of shovelnose sturgeon, each of which contributed around 10 percent of the total catch for this spring.

Finding sturgeon in these side-channels is an interesting pattern of habitat use that biologists at Columbia NFWCO will investigate in the near future. The data collected this spring, as well as that collected in previous years, will serve as a means by which to better understand these fish and the habitats they require. Eventually patterns in sturgeon behavior and population numbers can be used to make sound, science based decisions concerning the management of these species. As a “natural” side-channel, Lisbon chute serves as an example of what shallow water habitat on the Missouri River can be. Lisbon offers productivity and diversity to the system, which aids in restoring natural river conditions. Encouraging, though, is the presence of sturgeon in Tadpole chute. This engineered side-channel is supporting significant numbers of sturgeon, and may in the future become as productive as Lisbon chute. By studying these chutes, biologists will have the information they need to make suggestions on how to create more suitable side-channel habitats for all river species, and aide in the recovery of endangered Missouri river fish such as the pallid sturgeon.