Zac Beussink works to free a blue catfish from a trammel net captured in Overton chute. - FWS photo by Joe McMullen

Mitigation crew members Joe McMullen and Zac Beussink prepare to push trawl Tadpole chute. - FWS photo by Rick Hansen

The 2007 Mitigation Program field season has come to an end on the lower Missouri River.  The Mitigation crew logged 2,320 field hours over the 180 field day period to conduct 980 sampling events.

Columbia NFWCO has completed the second formal season of collecting biological data on the fish communities from four selected side channels (chutes).  Lisbon chute, near Glasgow, MO was naturally created during the floods of 1993 and 1995. 

Overton and Tadpole chutes, near Rocheport, MO were engineered chutes opened by the U.S. Army Corps of Engineers (Corps) in 2001 and 2006 respectively. Lastly, Tate Island chute, near Portland, MO, is an older chute and one of the few that were never closed off. 

The Corps dug Overton and Tadpole chutes in order to provide shallow water habitat for fish and to mitigate for lost habitat. 

Approximately 1.2 million acres of aquatic habitat was lost during efforts to stabilize the Missouri River and provide a navigation channel.  Beginning in the early 1900’s seven Congressional acts have provided for the construction and maintenance of a navigation channel, seven dams and bank stabilization works. 

Our fish sampling season took place from April until the beginning of this October for several reasons.  First, when the Corps closes off navigation flows from upstream dams it makes access to the areas impossible.  Secondly, spawning of adult fishes has ceased by this time.  Lastly, juvenile fishes which feed in these areas have now sought over wintering habitats and the security of deeper water. 

New this season was the addition of push trawling as a standard gear.  The inclusion of this technique completes a full compliment of methods used to sample the wide range of fish found in these chutes.  The push trawl is designed to capture small bodied fish, in shallow water, making this method of sampling fish particularly important in the chutes.

Several species of concern were sampled this year including the state endangered lake sturgeon, and species of concern, blue suckers and sauger.  No Pallid Sturgeon were captured in 2007, however several hybrid sturgeon (Shovelnose x Pallid Sturgeon) were.

In the future, Jameson chute, just downstream from Lisbon, Baltimore Bend chute near Waverly and other chutes are likely to be opened in coming years.  These proposed secondary channels will continue to add to the diversity of habitats on the Missouri River, and hopefully aid in the successful recovery of threatened and endangered species.  Information gathered from this 3 year mitigation chute study will provide baseline information for rapid assessment and a biological scoring of future chute openings.

Joseph McMullen and Jeff Finley