Columbia Fish and Wildlife Conservation Office
It’s What We Do
BY COLUMBIA FWCO STAFF
The Columbia Fish and Wildlife Conservation Office (FWCO) serves Region 3 as a partner in fisheries management with State and Federal Agencies. Our work is diverse and currently involves the fight against invasive fish, monitoring protected streams of the Ozarks, providing fishery technical assistance, or informing the public about our precious big rivers.
lessons at local schools. Credit: USFWS
Invasive Asian Carp
The Columbia FWCO has been a leader in the development of new and innovative trawling gears designed to target invasive carp species at all life stages. These new gears have been instrumental in assessing the risk of young silver carp that may eventually challenge the electrical barrier that now protects Lake Michigan. Additional gear development promises to promote large–scale removal efforts of the fish occurring at high densities as they continue their spread throughout the Midwest.
The first trawl gear, and the one with the longest development history, is the Paupier Trawl. The Paupier is modeled after a butterfly-style shrimp skimmer commonly used in coastal waters of Louisiana. Columbia’s flagship vessel (Magna Carpa) is like these skimmers, but has the addition of electricity that delivers 80 amps of electricity in front of two 5-foot deep by 12-foot wide nets on each side of the boat. These large nets, high amperage electricity, and a fast moving boat (4 mph) enable us to sample large areas quickly and collect fish not detectable by standard sampling techniques. This gear has enabled biologists to increase capture efficiency of all sizes of silver carp in backwaters, large rivers, tributaries, and reservoirs at rates not observed in any other traditional sampling gears.
The second trawling gear is reminiscent of the push trawl gear used across the world, but the Columbia FWCO version (dubbed the “Dozer Trawl”) is electrified. This gear uses a 3-foot deep by 7-foot wide single framed trawl protruding from the front of a jet or shallow drive 16-foot boat. The net rises up and down much like the front blade on a bull dozer, allowing for varying fishing depths in the extremely shallow habitat favored by juvenile carp. The electrical array on this boat is mounted forward of the net mouth, and moves independently of the frame. In early testing, this gear worked remarkably well in our mission to detect the leading edge of the northern invasion of age-0 carp. Its utility is supplementary to the Paupier because it can be used in more hazardous flowing water conditions, far up the tributaries, amongst vegetation, or in very shallow backwaters. Like the Paupier, when sampling large bodies of water, it is important to use gears that are fast (4 mph) and catch all sizes of fish, not just those that can be viewed below the surface. An existing electrofishing boat can be modified to incorporate this gear for around $500, enabling it to be easily incorporated into an agency’s fleet.