|
Round
Goby Q&A
Where
is the round goby from?
The round goby is native to several marine and freshwater
ecosystems of Eurasia including the Black Sea, Caspian
Sea, and Sea of Azov, and their tributaries (Miller
1986). The goby prefers nearshore gravel habitats, but
will also migrate to deep water sites especially in
winter.
What
does the round goby look like?
The round goby, Neogobius melanostomus, can be
identified from similar looking native fishes by it
fused pectoral fin. Here is the identification key gob1.jpg
(picture), gob2.jpg
(description)
What
native species of fish does the round goby resemble?
The round goby resemble the sculpin and can be identified
by the fused pelvic fins. The pelvic fins of round goby
are fused together while they are separate in the sculpin.
The round goby can actually use its fused pelvic fins
to cling to rocks.
When
was the round goby brought to the U.S.?
The round goby was introduced to the United States in
ballast water discharged from transoceanic ships operating
in the Great Lakes. The first record of a round goby
in North America was in St. Clair River near the Michigan-Ontario
border in 1990. Here is a map
that shows the advance of the round goby.
Where
are round goby found in the United States?
The first record of a round goby was in St. Clair River
near the Michigan-Ontario border. Since then, the round
goby has been spread by ships to all five of the Great
Lakes. Round Goby are now moving into Great Lakes tributaries
including the Shiawasse and Flint Rivers in Michigan,
the Grand Calumet River in Indiana, the Grand River
in Ohio, and the Illinois Waterway System in Illinois.
As of 2003, round goby were also reported to occur in
portions of Minnesota, Wisconsin, Illinois, Michigan,
Indiana, Ohio, Pennsylvania, and New York.
In 2003,
the round goby was distributed over a nearly 55-mile
reach of inland waters in Illinois that include much
of the Calumet and Little Calumet Rivers, the entire
Calumet Sag Channel, the Chicago Sanitary and Ship Canal,
the lower reaches of the Des Plaines River, and as far
downstream as Joliet near the Interstate 55 bridge over
the Illinois River (River Mile 278). This means that
the round goby is now 18 miles downstream of the site
where an electrical fish barrier was activated in April
2002 on the Chicago Sanitary and Ship Canal, near Romeoville,
Illinois. This electrical
fish barrier was activated to slow the spread of
all invasive fish between the Great Lakes and Mississippi
River basins.
How
can the round goby get to the Mississippi River from
Lake Michigan?
Round goby and other aquatic nuisance species can pass
freely between the Great Lakes and Mississippi River
basins via a series of interconnected rivers and man-made
canals in Chicago that continuously transmit water from
Lake Michigan to the Illinois River, a major tributary
of the Mississippi River. The electrical fish barrier,
brought online in April of 2002, will hopefully slow,
if not stop, the spread through this route.
Where
is the round goby headed?
The round goby has spread to all of the Great Lakes
and has entered the Mississippi River watershed near
Chicago. Round goby are now distributed over a nearly
55-mile reach of inland waters that include much of
the Calumet and Little Calumet Rivers, the Calumet Sag
Channel, the Chicago Sanitary and Ship Canal, the lower
reaches of the Des Plaines River, and the Illinois River.
This means that the round goby is now 18 miles downstream
of the site where an electrical fish barrier was activated
(April 2002) in the Chicago Sanitary and Ship Canal
near Romeoville, IL.
What
are the negative impacts of round goby in North America?
Round goby are thriving at the expense of some native
fishes in portions of the Great Lakes because of their
aggressive behavior, prolific reproductive abilities
(spawning 5,000 eggs as frequently as every 20 days
in warm water), and ability to feed voraciously in total
darkness. Round goby often eat eggs and young of native
fishes. The delicate ecological balance of the Great
Lakes ecosystem is thus being altered by the round goby
and the Mississippi River ecosystem may be next.
Continued
downstream movements of the pugnacious round goby and
the upstream movements of the Asian carp species may
soon threaten members of the diverse native fish community
that inhabit some of the more pristine tributary streams
of the Illinois Waterway and Mississippi River watershed.
What
makes the round goby an effective invader?
They are very aggressive and defend prime spawning sites
that native fish prefer. The round goby has a voracious
appetite and feeds on eggs and fry of native fish.
The goby
has a well developed sensory system and an ability to
detect water movement so it is able to feed in complete
darkness unlike other fish.
Round
goby are physiologically robust and able to survive
in poor water quality conditions.
The spawning
ability of a round goby is amazing. Females mature at
1-2 years and males at 3-4 years. Goby can spawn from
April to September and can produce 300 - 5,000 eggs
during each spawn.
How
big does the round goby get?
They can reach a maximum length of about 12 in, but
most commonly are observed in the U.S. at about 7 in
or less. Get an idea of the size here.
What
does the round goby eat?
Round goby eat aquatic insects (invertebrates), mussels
such as zebra mussels, clams, snails, eggs and juveniles
of native fishes such as sculpins, darters, lake trout,
and logperch, and bait such as nightcrawlers. Simply,
if it is alive and will fit into it's mouth it eats
it.
What
fish feed on round goby?
Smallmouth bass, rock bass, walleye, yellow perch and
brown trout have all been known to feed on goby.
Can
I catch the round goby if I go fishing?
Yes, the round goby can be caught by angling. Live goby
cannot be kept if caught while fishing. If you catch
a round goby goby downstream from Joliet, IL, in the
Illinois River kill it, freeze it, and call the La Crosse
FRO (608) 783-8434. Live goby cannot be transported.
What
has been done to control the spread of the round goby?
Since 1996, the La Crosse Fishery Resources Office (FRO)
has conducted annual surveys in the Illinois Waterway
System near Chicago, to determine the distribution of
the round goby in this portion of the Mississippi River
basin. A variety of gear including bottom
trawls, set lines, baited minnow traps, and angling
have been used here to capture round goby. Thus far,
minnow
traps appear to be the most effective and efficient
survey gear.
An electrical
fish barrier was activated in April 2002 in the
Chicago Sanitary and Ship Canal near Romeoville, IL.
This is a full-water column barrier that acts like an
electric fence and is designed to slow the movements
of the goby and other nonindigenous fish (e.g., ruffe,
and Asian carp species
such as the bighead carp, and silver carp) between the
Great Lakes and Mississippi River basins. This barrier
is expected to be effective for only a three year period.
Therefore, a second electrical barrier is being planned
for placement 1,000 feet downstream of the first barrier
in the summer of 2004.
The La
Crosse FRO will continue its periodic surveys to determine
the range and relative abundance of round goby in the
Illinois Waterway System in order to evaluate the effectiveness
of the barrier and to identify areas where other management
strategies may be needed to help limit the spread of
this exotic nuisance species in the Mississippi River
basin. The annual "Goby Round-Up", as it has
come to be known, is an excellent example of government
agencies and non-government organizations with different
missions working cooperatively on a common environmental
problem. Past and present participants include the U.S.
Fish and Wildlife Service, U.S. Army Corps of Engineers,
U.S. Environmental Protection Agency, Illinois Department
of Natural Resources, Illinois Environmental Protection
Agency, Illinois-Indiana Sea Grant, Metropolitan Water
Reclamation District of Greater Chicago, Cook County
Forest Preserve, U.S. Army, Friends of the Chicago River,
Equistar, Material Service Corporation, Perch America,
and interested volunteers.
What can I do to help
control the spread of nuisance fish like the round goby?
The public can prevent spread of the round goby and
other nuisance fish by: (1.) disposing of unused or
unwanted bait on land because there may be exotic species
of fish mixed in with the bait; (2.) washing and cleaning
boats, live wells, and bilges to remove weeds and debris
that come from infested waters; (3.) anglers should
never dip their bait bucket into a lake or river if
it has water in it from another; (4.) anglers should
never release live fish from one body of water into
another. If you catch a round goby downstream from Joliet,
IL, in the Illinois River kill it, freeze it, and call
the La Crosse FRO (608) 783-8434, or your local Natural
Resorces Agency.
|
