Another invasive critter, this one with the apparent ability to decimate our Lake Superior, has moved frightfully closer. The Great Lakes are now considered in “imminent danger,” as the Detroit Free Press wrote this week, reporting that, for the first time, DNA from two types of invasive Asian carp have been found off the Chicago River’s south fork — just two and a half miles or so from Lake Michigan.

“We need executive leadership to protect the Great Lakes now,” the nonprofit Alliance for the Great Lakes (greatlakes.org) said in an urgent plea to the News Tribune Opinion page following the news report. “Otherwise we risk losing our region’s most precious asset, part of our local identity, and a key component of our way of life.”

We stand to lose a lot more than that should Asian carp make it to Lake Michigan and then the rest of the Great Lakes.

“Once they make their home in a body of water, it’s already too late,” the alliance said. “They are voracious filter feeders, capable of eating between 20% and 40% of their body weight in one day. They also spawn multiple times per year, making them a threat to the Great Lakes region’s $7 billion per year fishing industry and the recreational boating industry that adds $16 billion per year as well as 100,000 jobs to our communities.”

Encouragingly, a strategy has been devised to head off the tragedy. The U.S. Army Corps of Engineers is poised to fortify a lock and dam in Joliet, Ill., about 50 miles downstream of Chicago. The spot is considered “a critical choke-point for (the) invasive Asian carp,” according to the alliance.

An engineered channel there, with an acoustic fish deterrent, an air bubble curtain, an electric barrier, and other technologies, can keep the aggressive carp from moving into the Great Lakes basin from the Mississippi River basin via the Chicago Area Waterway System.

“(The) invasive Asian carp (can be stopped) before they crash the economy and environment of the Great Lakes region,” the alliance said.

Holding up action is Illinois Gov. J.B. Pritzker, who needs to sign off on an agreement with the Army Corps before its work can begin. The alliance and 39 other nonprofit environmental and conservation groups, including Minnesota’s Save Our Sky Blue Waters (sosbluewaters.org) delivered a letter urging Gov. Pritzker to “show (his) commitment to protecting the Great Lakes” in the face of what could become an “unstoppable crisis.”

Taking action has plenty of support. A 2018 survey found that nine in 10 Great Lakes-area residents support protections to block the Asian carp’s spread. In recent weeks, more than 4,000 from the Great Lakes region signed an alliance petition urging Gov. Pritzker to sign the letter of agreement. Nearly 40 businesses signed another letter urging the same. And in July, Great Lakes governors, including Minnesota Gov. Tim Walz, joined the premiers of Ontario and Quebec in pledging financial support for the Army Corps’ plan.

Illinois’ Gov. Pritzker is “considering” signing the agreement, the Detroit newspaper reported. He can do more than that before this threat moves any closer to the Great Lakes — and to our Lake Superior.