If they gain entrance, Asian carp could find enough food and breeding areas to infest all five Great Lakes within 20 years, according to a recent risk analysis by scientists from the United States and Canada.
Additionally, authors of the report released by Canada’s Fisheries and Oceans Ministry suggested that just 10 mature females and even fewer males would be enough to establish a population within the Great Lakes. Previously, many theorized that at least hundreds of fish would be required.
“Ever since these non-native fish first escaped and began to breed prolifically in the rivers of the Midwest, the questions everyone has been asking are: ‘Can a breeding population survive in the Great Lakes and would it be a significant problem if they did?” Marcia McNutt, director of the U.S. Geological Survey (USGS), said in a released statement.
“Now we know the answers and, unfortunately, they are ‘yes’ and ‘yes.’”
No surprisingly, scientists still believe that the manmade connection between Lake Michigan and the Illinois River watershed is the most likely pathway for entry, an electric barrier notwithstanding.
But state and federal researchers recently reported that they have found DNA from Asian carp in Lake Erie, suggesting that rivers and wetlands connected to that fishery might provide entrance as well.
Four samples from Sandusky Bay in Ohio waters tested positive for bighead carp, while two samples from north Maumee Bay in Michigan waters were positive for silver carp.
“The results from these water samples are certainly concerning, as this marks the first time Asian carp DNA has been detected in water samples from Lake Erie or any of the Michigan waters intensively surveyed for the presence of invasive carp,” said Jim Dexter, fisheries chief for the Michigan Department of Natural Resources.
“Protecting the Great Lakes from the threat of Asian carp is critical to the health of our sport and commercial fisheries and to the quality of life in Michigan.”
The international analysis, meanwhile, projects carp would find Erie, Huron, and Michigan most to their liking, while infestation of Ontario and Superior would take longer.
(Reprinted from B.A.S.S. Times)