By Don Davis
A new study shows it now appears large numbers of Asian carp are not in Minnesota.
A technique that found indications of tiny amounts of Asian carp DNA had appeared to indicate the invasive species could be in the state’s streams.
The new report released today, called the most rigorous Minnesota study of the issue, showed that silver carp likely are in Iowa, but it found no evidence the fish is in Minnesota. No bighead carp DNA was found in Iowa or Minnesota.
Bighead and silver carp are among species of Asian carp, fish that escaped southern United States ponds in the 1970s and are moving north. They weigh up to 100 pounds and eat so much food that native species may starve.
“These results support the conclusion that bighead and silver carp have not yet become established in Minnesota,” said Steve Hirsch of the Minnesota Department of Natural Resources.
However, Hirsch and other experts said Minnesotans need to remain vigilant.
“The threat of Asian carp is, nevertheless, an urgent issue for the state, requiring immediate action,” Hirsch said.
The study released today was coordinated by the Minnesota Aquatic Invasive Species Research Center at the University of Minnesota.
The center’s Peter Sorensen said the study still shows there are reasons to believe that Asian carp are entering Minnesota from the south, and they eventually could breed in the state.
A few Asian carp have been caught in the Mississippi and St. Croix rivers, but today’s study shows they likely are the exception.
Earlier tests used environmental DNA techniques, known as eDNA. Sorensen said eDNA results may be getting more accurate as technology evolves.
“This particular technique needs to be refined for detecting this species in open waters,” Sorensen said.
Asian carp experts say that before the fish arrive in large numbers they are difficult to detect. So water is filtered to find small DNA particles.