Sampling turns up eDNA from Asian carp in the Ohio River
Harrisburg, Pa. — The Pennsylvania Fish & Boat Commission has confirmed that environmental DNA from the invasive Asian silver carp and bighead carp has been found in six water samples collected from the Ohio River last year.
Sampling has been performed in Pennsylvania in response to the documented spread of Asian carp in the middle and lower Ohio River.
As part of a cooperative effort, biologists from the commission, Pennsylvania Department of Environmental Protection, and the U.S. Fish and Wildlife Service collected 595 water samples from the Ohio River basin in July 2014.
The tests found one positive result for silver carp eDNA in each of the Montgomery and New Cumberland pools of the Ohio River’s locks and dams systems. Each pool also showed two positive results for bighead carp eDNA. A total of 92 water samples were taken from each pool.
Researchers use eDNA analysis as a tool for the early detection of Asian carp. The findings indicate the presence of genetic material left behind by the species, such as scales, excrement, or mucous. But eDNA does not provide physical proof of the presence of live or dead Asian carp.
No Asian carp, alive or dead, have been reported from Pennsylvania’s portion of the Ohio River.
“Unfortunately, the 2014 test results provide a little more evidence that this invasive species could be in the upper Ohio River in Pennsylvania,” said John Arway, executive director of the commission.
“This is an early warning sign, since we don’t know for certain the origin of the genetic material. We don’t know if the eDNA came from live or dead fish or if it was transported from other sources, like bilge water or storm sewers, or even waterfowl visiting the basin.”
None of the 175 water samples from the Ohio River’s Dashfields and Emsworth pools, Beaver River, Little Beaver Creek, Raccoon Creek, Chartiers Creek, Monongahela River, or Allegheny River tested positive for silver or bighead carp eDNA.
This marks the second year that eDNA was found. In 2013, the Fish & Wildlife Service tested 184 water samples collected from the upper Ohio River between Wheeling, W.Va., and Pittsburgh and found eDNA in one sample from the Montgomery Pool near Aliquippa, Beaver County, and one sample from the backchannel of Babbs Island near East Liverpool, Ohio.
Asian carp are an invasive species that pose a serious threat because of their voracious appetite and ability to quickly reproduce.
Once in a waterway, they devour much of the microscopic algae and animals that other species rely on for food, effectively decimating other species and disrupting the aquatic ecosystem.
This, in turn, can harm local economies that rely on the revenue generated from sport fishing and boating.
Because of the destructive nature of the Asian carp species, officials urge anglers and boaters to help slow the spread.