Monday, June 16, 2008

Agencies Conduct 13th Annual “Carp Corral/Goby Roundup”

Jun 10: The U.S. Fish and Wildlife Service (FWS) and its Federal, state and regional partners, including Chicago’s Shedd Aquarium, will resume annual search efforts June 18 and 19, in the Illinois Waterway from the Chicago suburbs to near Havana, IL, for three species of invasive fish, as well as for lethal fish pathogens. During the 13th annual “Carp Corral/Goby Roundup,” biologists will estimate the relative abundance and upstream distribution of bighead carp and silver carp -- two types of Asian carps -- and chart the downstream range of the round goby.

This year the U.S. Army Corp of Engineers (USACE) will also be working with the U.S. Fish and Wildlife Service to expand an existing monitoring study of Asian carp movements to an upstream portion of the Illinois Waterway. Bighead and silver carp captured here will be implanted with ultrasonic transmitter tags and then released in order to detect the proximity of these fish to the Aquatic Nuisance Species Dispersal Barrier in Romeoville. The USACE will use information from this tagging study to develop a long-term monitoring plan that will evaluate the effectiveness of the electric barrier. Interconnected man-made channels and natural rivers of the Illinois Waterway System in metropolitan Chicago provide a direct link for water-borne movement of non-native aquatic nuisance species between the Great Lakes and Mississippi River basins. Together these watersheds encompass parts of 31 states and four Canadian provinces.

Sampling will cover nearly 200 miles, more than half the length of the Illinois Waterway, from Alsip downstream to Havana. Round goby are most abundant and likely to be seen at upstream sample sites like Alsip and Lockport while bighead and leaping silver carp are more common and likely to be encountered at a downstream area like LaSalle-Peru, Morris or Havana. Biologists will also collect tissue samples from captured fish to test for disease pathogens such as the non-native spring viremia of carp virus and the viral hemorrhagic septicemia virus, which can be lethal to a number of native fish species.

Viral hemorrhagic septicemia, or VHS, is one of the most feared fish diseases in the world, and has made its way into Lake Michigan. The virus was recently found (May 2008) in the southern basin of this lake for the first time where it killed thousands of round goby that later washed up along the Milwaukee shoreline, less than 100 miles from the Illinois Waterway. Biologists are now more concerned than ever before that the VHS virus could spread from Lake Michigan to the Mississippi and Ohio River basins via the Illinois Waterway.

The “Carp Corral/Goby Roundup” surveillance effort is critical in determining whether Asian carp have moved upstream of an electrical barrier near Romeoville, Ill., toward Lake Michigan, and whether round goby have made their way farther downstream toward the Mississippi River. An electrical fish barrier near Romeoville in the Chicago Sanitary and Ship Canal -- designed to prevent and slow the spread of nonindigenous aquatic species -- has been operational since 2002. This experimental prototype consists of a single array of 14 electrodes. One of the electrodes failed soon after installation. The 13 remaining electrodes are still functional but are wearing out due to corrosion.

Construction of a permanent barrier is complete just downstream from the prototype. University of Wisconsin Sea Grant Institute’s Dr. Phil Moy, co-chair of the Dispersal Barrier Advisory Panel said, “The new barrier has 46 electrodes, has the capability to operate at higher voltage to more effectively repel small fish, and has five- by five-inch steel bar electrodes with a design life of 20 years.” It is hoped that the new barrier will become fully operational later in 2008. Biologists found one bighead carp 15 miles below the electrical barrier in 2007, about 50 miles from Lake Michigan. To date no bighead or silver carp have been collected above the barrier. However, reproducing populations of bighead and silver carp have expanded from lower portions of the Illinois River to as far upstream as the Starved Rock Lock and Dam near Utica.

Access a lengthy release from FWS with further details and links to additional information(click here).