|
Great Lakes
Article:
Empty Net is Good News in Search for
Asian Carp
By James Janega
Chicago Tribune
Published June 15, 2006
Wildlife managers dreading the spread of the Asian carp
breathed a sigh of relief Wednesday when they could find
none of the voracious fish closer to Chicago and the Great
Lakes than Joliet.
The spot where the fish were found, south of the Brandon
Road Lock and Dam--about 50 miles from the mouth of the
Chicago River and the Great Lakes--still gives the carp
access to the Kankakee River, however. Survey teams will
continue their annual search for the carp and other invasive
species until Friday.
While crews Wednesday were finding the oily, fat carp
in familiar spots on the Illinois River near Morris, they
have so far failed to find it north of the Brandon Road
lock.
"No news is good news, I guess," U.S. Fish
and Wildlife Service project leader Pamella A. Thiel said
Wednesday aboard a johnboat on the Calumet Sag Channel,
a tub full of common carp flopping at her feet.
While searching for Asian carp, the crews also are sampling
the health of fish they do catch, looking for a host of
waterborne parasites, pathogens and viruses.
Among the things they are looking for is evidence of
carp virus, considered among the possibilities for an
Asian carp die-off noticed May 30 between Havana and Spring
Valley. Definitive word on what caused the die-off will
come with lab results next month, Thiel said.
The annual scouring of Illinois waterways started in
1996, when wildlife managers began gauging the spread
of the invasive round goby, a ship ballast-tank stowaway
from the Black Sea now working its way from the Great
Lakes toward the Mississippi River.
The goby was bad enough--in some parts of Lake Michigan,
40 to 70 of the finger-size eating machines crowd areas
the size of a bathtub. Then the wildlife managers found
the Asian carp working its way north and added the much
larger fish to their list of concerns.
Since 2000, they've charted the carp's progress up the
Illinois River from Hennepin to Morris to Channahon. By
2002, the fish had slipped through the Dresden locks.
They have lingered there since.
This year, Fish and Wildlife workers, with 13 partner
organizations that include government agencies, the Shedd
Aquarium and Joliet Community College, are hoping the
carp will have inched no farther north than the Brandon
Road lock and dam, just south of Joliet.
Beyond that, two electrical fish barriers--one not yet
working, the other badly corroding--have been strung in
the carp's path to the Chicago and Calumet Rivers.
A barrier was sunk into the Sanitary and Ship Canal near
Romeoville in 2002 to stop the gobies from marching southward,
but was placed uselessly behind them. Since then, the
barrier has become a last line of defense against the
northward advance of the Asian carp. A new barrier three
times as big--and much sturdier--was put in next to it
recently, but it has not yet been switched on.
----------
jjanega@tribune.com
Copyright © 2006, Chicago Tribune
|
