Service biologists Jorge Buening and Ann Runstrom work to remove a bighead carp from a trammel net that was set in the Illinois River near Morris. Photo credit: Owen Johnson.

Service biologist Ann Runstrom has her hands full holding a bighead carp caught in the Illinois River. Photo credit: Owen Johnson.

Biologists use a combination of electrofishing and trammel nets to herd and capture Asian carp near an Illinois River gravel quarry. Photo credit: Owen Johnson.

Service biologist Eric Leis peers through a fish-shield, made of chicken-wire, to help protect him from collisions with leaping Asian carps while he pilots a survey boat on the Illinois River. Photo credit: Owen Johnson.

Treacherous currents, a flotilla of swift boats, periodic ‘missile’ attacks, deadly microbes, ultrasonic transmitters, personal protective equipment, and a lurking alligator … amidst this intriguing mix of seemingly unrelated subjects, what possible mission could an armada of Service biologists be out to accomplish in uncomfortably steamy surroundings that were often electrically charged?  The answer: working with partners and dedicated volunteers to safely conduct annual surveillance for round goby, Asian carps, and fish disease pathogens in the Illinois Waterway System.

Organized and outfitted with supplies by the La Crosse National Fish and Wildlife Conservation Office, a total of 40 individuals representing nine government (federal, state, and local) agencies, two educational institutions, and two private businesses participated in the 13^th Annual Goby Round-Up and the 7^th Annual Carp Corral, held 17-20 June 2008.  This year’s effort spanned a distance of nearly 100 miles from Alsip downstream to Peru and included portions of the Calumet-Sag Channel, the Chicago Sanitary and Ship Canal, the Des Plaines River, and the Illinois River.  Designed to estimate the downstream leading edge and relative abundance of round goby, as well as the upstream distribution and relative abundance of Asian carps, these and several other species of fish collected here were also tested by biologists from the La Crosse Fish Health Center for the presence of a variety of deadly fish disease pathogens as part of the Service’s nationwide Wild Fish Health Survey(http://www.fws.gov/wildfishsurvey/).

As in recent years, the numbers of round goby captured in minnow traps suggested a continued decline in the upstream relative abundance of this species since it peaked here nearly a decade ago.  Meanwhile flood conditions in the lower Illinois River forced the postponement of surveillance efforts for round goby at sites downstream of Peoria (the currently recognized extent of its dispersal in the Mississippi River Basin) until later this summer.  Results of all laboratory tests to detect fish disease pathogens remain pending, but because the often deadly viral hemorrhagic septicemia virus was identified earlier this year in round goby that washed ashore from Lake Michigan in Milwaukee (less than 100 miles from Chicago and the Great Lakes connection to the Mississippi River Basin), there is heightened interest in the outcome of these latest tests.

Surveillance activities this year did not detect Asian carps any farther upstream than the Des Plaines River location (river mile 281.5) where a bighead carp was collected in the Dresden Island Pool last year.  Two bighead carp were captured here this year and one was surgically implanted with an ultrasonic transmitter to closely monitor its movements. Thus far, the documented upstream range of bighead carp remains about 15 miles below an electrical fish barrier in Romeoville and 45 miles from Lake Michigan in Chicago.   Meanwhile the relative abundance of Asian carps increased markedly during the past year in adjoining navigation pools located downstream.  For example, a crew that surveyed the same portion of the Marseilles Pool with similar gears and levels of effort captured an annual total of five bighead carp while sampling here during June in both 2006 and 2007.  Under similar circumstances this year however, they caught a total of 41 bighead carp in this reach, as well as 9 silver carp.  Likewise, a single 150-ft trammel net set further downstream for just one night captured a surveillance record total of 57 Asian carps (32 silver, 17 grass, and 8 bighead) in the Starved Rock area of the Peoria Pool.  However the number of silver carp that leaped out of the water here, rocketing about the boat like slimy missiles meant to pummel the crew, was unexplainably (and fortunately) reduced this year.  This apparent lull in activity is not expected to persist though as flood waters this summer have increased the size of shallow water nursery habitats that are eventually expected to help produce a very large 2008 year class of Asian carps.

Surveillance findings were reported to the Asian Carp Rapid Response Team and the Chicago Barrier Advisory Task Force to help guide upcoming actions to limit the continued dispersal of these invasive fish and fish disease pathogens.  This information also attracted the interest of reporters and photographers from many electronic and print media outlets, due in no small part to outreach efforts coordinated by the Shedd Aquarium, a partner in this surveillance program for several years now.  Garnering other media attention at this time was the capture of a 5-foot-long alligator, thought to be a discarded pet, which was recovered by local authorities from the south branch of the Chicago River.  As a consequence of these surveillance efforts and media reports, the public is better informed about the current distribution of these aquatic nuisance species and the impacts they are having on the Great Lakes and Mississippi River ecosystems.