A Goby Invades the Kankakee River
By Aaron Swiercz / Reprinted with permission from The Outdoor Times
It was inevitable that the round goby, an aggressive little fish from the Black and Caspian seas, would someday appear in the Kankakee River. Biologists with the Illinois Department of Natural Resources were hoping it wouldn't arrive so soon. Twelve round gobies were trapped last month at the mouth of the Kankakee River, exposing the spread of the invader fish from Lake Michigan into the Illinois River watershed.
According to IDNR biologist Rob Miller, the round gobies were discovered in traps planted along riprap near the mouth of the Kankakee and Illinois rivers. "It is a cause for concern. Gobies are extremely aggressive species, known for their ability to quickly proliferate in an environment, and displace the local aquatic life."
A captive smallmouth bass and round goby
Biologists from 10 state, regional, and federal natural resource agencies sampled for the invasive round goby in a 100-mile stretch of the Illinois Waterway from the Chicago area downstream to La Salle/Peru. The purpose of the monitoring effort is to determine the relative abundance and downstream leading edge of this aquatic nuisance species. The gobies found at the confluence of the Kankakee/Illinois Rivers near the Dresden Lock and Dam indicate that the fish has traveled 13 miles further south than the biologists first expected.
The round goby was first discovered in North American waters in 1990 and has since spread to all of the Great Lakes. The invader species has been moving inland from Lake Michigan toward the Mississippi River basin via the Illinois Waterway System since 1993. The most downstream verified specimen of a round goby, to date, was the Brandon Road Lock and Dam at the Joliet Midwest Generation Power Plant where they were found as recently as April. This collection places the round goby almost 50 miles inland from Calumet Harbor on Lake Michigan and approximately 15 percent down the length of the Illinois Waterway on its way to the Mississippi River.
"In Calumet Harbor we estimate that the density of the gobies is in the neighborhood of 50 to 70 per square meter. To get the picture, think of 50 to 70 gobies in an area the size of your bathtub. It's getting so that the goby might replace the zebra-mussel as enemy number one," said Pam Thiel of the U.S. Fish and Wildlife service, to the Chicago Tribune. The exotic fish is a bottom-feeding species known for its defensive behavior and prolific reproductive rate. These traits make them a threat to native fish and a nuisance to anglers.
The round goby has received national attention since increasing populations could seriously impact sport fishing industries. This and all other invasive species have the potential to upset the natural balance of the ecosystem and cause long-term damage. As threatening as they are, Miller believes the species will be in for a surprise as it ventures up the Kankakee River. The biologist said the river's strong population of game fish--smallmouth bass, catfish, pike and walleye -- should prey upon the finger-size gobies. "The gobies may not be ready for what awaits them if they make it upstream into the Kankakee river system. There are more than enough fish who would be happy to feast on the goby if it wants to come down this way, commented Miller. "Smallmouth bass, walleye, bluegill and catfish would all find the gobies a sustaining food source and would not hesitate to feast on the new food supply. "The only way the gobies could pose a significant threat is to move so rapidly up the river that they effect all of the tributaries as well."
Miller said the goby is used to living in cooler water, so all of the lakes and streams that receive drainage water will provide an uncomfortable warmth for these fish. He suspects the gobies may congregate at dams where the water is cooler and pumped with oxygen. They better be good at hiding. On other bodies of water, the outlook is grim. The Illinois Waterway System in the Chicago area consists of several interconnecting channels and natural rivers that provide a direct link between the Great Lakes and the Mississippi River basins. The Mississippi River Basin is the largest in North America and the third largest in the world; and the Great Lakes Basin contains 20 percent of the Earth's fresh surface water; and together these huge basins encompass portions of 30 states and two provinces. Therefore, the potential economic and environmental impact of invasive species, such as round goby, could be wide-spread and significant.
The Illinois Waterway System currently provides an easy avenue for non-native species to travel in either direction between the Great Lakes and the Mississippi River basins. The zebra mussel is one of the most recent invaders to spread from the Great Lakes into the Illinois and Mississippi rivers on this pathway. The round goby is poised to follow the same route. Other non-indigenous species, like bighead carp, are traveling in the opposite direction and have established breeding populations in the Illinois and Mississippi rivers, and may soon disperse into Lake Michigan.
In order to prevent and slow gobies and other non-indigenous species from spreading throughout these basins, the Non-indigenous Species Act of 1996 authorized the U.S. Army Corps of Engineers to study and determine the feasibility of an aquatic nuisance species dispersal barrier as a demonstration project. An interagency advisory panel was assembled and recommended a full-water column electrical barrier as the most practical strategy for slowing the spread of round goby and preventing the movements of other non-indigenous fish between the Great Lakes and the Mississippi basin.
This non-lethal deterrent has been successfully tested in both the laboratory and the field. The Corps awarded a $1.3 million contract to Smith-Root, Inc. of Vancouver, Washington to build the electrical dispersal barrier. According to Beldon McPheron, the Army Corps' project manager, "Construction of the barrier, located in the Chicago Sanitary and Ship Canal near Romeoville, began this March and is expected to be completed by August."
Round gobies have been collected about 11 miles downstream from the barrier site. Thiel, project leader for the Service's La Crosse Fishery Resources Office and coordinator of the monitoring, said, "Even though gobies are past the barrier site, their population numbers are still relatively low. The barrier will help slow the downstream spread of the higher upstream goby concentrations. "The barrier will also deter other invasive fish like ruffe coming from the Great Lakes and bighead carp moving toward Lake Michigan. In addition, the technologies developed from this demonstration project can be transferred to other areas with similar problems."
Anglers should report goby catches. The IDNR wants to keep abreast of the spread of the round goby into Illinois. Fishermen who catch the invader fish species from area streams or even lakes, should report their catches to the DNR at Silver Springs State Park office: 630-553-6680.