Researchers argue several Asian carp taken from an Ohio river last year were spawned within the Lake Erie basin — a potential sign they could cause problems in the Great Lakes.
The four grass carp were caught by commercial fisherman last October in the Sandusky River, and scientists estimate they were at least one year old at the time. Grass carp are among the species of invasive Asian carp posing a major threat to the Great Lakes region.
“These findings are significant because they confirm recent U.S. Geological Survey research indicating the shorter rivers, like the Sandusky, are potential spawning sites for grass carp and other Asian carp as well,” said Duane Chapman, a Geological Survey scientist. “The study may also provide resource managers an opportunity to address the spread of grass carp before it becomes problematic.”
Decades after they were first introduced to Southern fish farms, Asian carp have slowly made their way north through the Mississippi River system. They are believed to be on the doorstep of Lake Michigan — separated only by an electric barrier in the Chicago Sanitary and Ship Canal.
While that area is considered the most likely pathway for the voracious carp to enter the Great Lakes, other routes are constantly monitored and tested. Once established in the lakes, experts believe Asian carp represent a major threat to the region’s $7 billion fishing industry.
By analyzing bones in the heads of the fish, researchers believe they have established the four grass carp spent their entire year of life in the Sandusky watershed. And if grass carp can reproduce there, then the more problematic Asian carp species — silver and bighead — could likely thrive there as well.
The biggest of the carp can grow to enormous sizes and eat the food sources of native fish populations. In some areas of the Illinois River, where Asian carp are firmly established, native fish are now scarce.