Native to China, Asian carp are something of a weed when it comes to preserving the country's fragile freshwater ecosystems. They grow fast, multiply at amazing rates and hog the resources where they are found. And now, researchers are saying they are a bigger threat than previously thought possible.
Published in the journal Freshwater Biology, the study warns that Asian carp can spawn in waters once considered to be too narrow or slow moving. What's more, the spawning season may actually last much longer and tolerate colder waters than previously thought.
Reuben Goforth is an assistant professor of forestry and natural resources at Purdue University and one of the researchers who oversaw in the study. In a press release published on the school's website, Gorforth attempts to offer comfort in the fact that more research must be done in order to discover whether the eggs they found will even survive.
"While the presence of eggs indicates successful spawning by these fishes in new areas, it's not known yet whether those eggs would be successful in surviving to adulthood," he said.
What the study does show, however, is that previous models built to predict the growth of Asian carp needs some updates, as Goforth puts it.
"The reason truly invasive species are successful is because they overcome obstacles," he said. "When you base their limitations on what happens in their native ecosystems, it's a good start. But it may be a good idea to go back and take this new data to recalculate more precise limits based on these new understandings."
Asian carp were first imported into the U.S. in the 1970s to filter pond water in fish farms in Arkansas, but they escaped when their habitats flooded and began reproducing in the wild during the early 1980s. Thirty years later, Asian carp represent over 97 percent of the biomass in portions of the Illinois and Mississippi Rivers and are headed toward the Great Lakes, according to the National Wildlife Federation.