New alarm sounded about Asian carp threat to Great Lakes

By Jerry Zremski Buffalo NewsJuly 13, 2012

WASHINGTON – Asian carp would likely thrive in all five Great Lakes, and the introduction of fewer than 20 of the invasive fish could be enough to set off a spawning spree that could forever change the region’s ecosystem.

Those are the main conclusions of a report released Thursday by Fisheries and Oceans Canada, which portrayed the potential for a fish invasion as much more far-reaching than previously predicted.

Other research had indicated that the huge and hungry invader fish would most likely thrive in the warmer, shallower waters of Lake Erie. And while the Canadian report confirmed that Lake Erie is in grave danger, it also said the Asian carp would likely find suitable living conditions and plenty to eat throughout the Great Lakes.

“Bigheaded carps would find suitable food, and thermal and spawning habitats in the Great Lakes basin that would allow them to survive and become established,” the report said. “The areas that would be attractive and favorable are Lake Erie, including Lake St. Clair, and high-productivity embayments (indentations on the shoreline) of Lakes Superior, Michigan, Huron and Ontario.”

The Chicago waterway system leading into Lake Michigan remains the most likely entry point for the invading fish, the report said. And once they enter, they are expected to spread to lakes Erie and Huron within a decade. It would take longer for the fish to become established in Lake Ontario, which is farther from the Chicago waterway system than the other lakes.

What’s more, it wouldn’t take many Asian carp to produce a lot of Asian carp. Fewer than 10 males, paired with fewer than 10 females in any one of the lakes, would likely be enough to establish a fast-growing population, the report said.

“Suitable spawning tributaries are found in all the lakes,” the report said, while acknowledging that it’s not yet known whether the fish would reproduce directly in the lakes.

Even given that uncertainty, the scientists who prepared the Canadian report warned of dire consequences if the Asian carp were to reproduce in great numbers.

“Bigheaded carps have the potential to become a dominant biomass in favorable locations,” the report said.

The report was cautious, however, about the invading fish’s potential impact on existing fish species in the lakes.

Environmentalists and sport fishermen have expressed concern that the Asian carp could swallow the food supply and essentially drive out the existing sport fish in the lakes. But the authors of the Canadian report said that impact on fisheries is difficult to predict and beyond the scope of their work.

Still, the report drew a quick and fervent response from the National Wildlife Federation, which has been among the most vocal groups in urging action to stop the Asian carp before it reaches the lakes.

“The report underscores the severity of the Asian carp threat and the need for leadership so that we can solve the problem once and for all,” said Andy Buchsbaum, director of the group’s Great Lakes office. “… his report shows that the cost of inaction will be devastating.”

Buchsbaum called on President Obama and his Republican rival in the current presidential race, Mitt Romney, to commit to building “an effective physical barrier to keep the Asian carp out of the Great Lakes.”

The authors of the Canadian report did not offer specific recommendations on how to prevent the carp invasion. But they said that the fish are so close to invading the lakes that government authorities should be looking both to preventing the invasion and controlling the Asian carp population if prevention measures fail.

Environmentalists and New York’s senators remain focused on separating the Chicago waterway system from Lake Michigan, an expensive engineering task that’s strongly opposed by Chicago-area business interests.

But the senators said the Canadian report was one more argument for action.

“We cannot afford to wait, and I will continue to push the Army Corps of Engineers to finalize the Great Lakes – Mississippi River Interbasin Study as soon as possible and look at all options available, including hydrological separation, to keep Asian carp from migrating into the Great Lakes,” said Sen. Kirsten E. Gillibrand, D-N.Y.

Asian carp report must lead to action   

A well-deserved pat on the back