There's a new rule to stop invasive species from entering the Great Lakes. It requires shippers to kill foreign organisms by treating their ballast water. But Michigan officials and environmental groups say the new rule doesn't go far enough.
When ships take on cargo they also may pump water into ballast tanks to balance the load. When they off-load they sometimes pump out their ballast tanks. That water, from foreign ports, may release fish and other aquatic species not found in the Great Lakes.
Because those new species have no natural enemies, their populations can get out of control and disrupt the entire food web. It's happened dozens of times over the last couple of decades, first with zebra mussels.
Up to now, foreign vessels just had to exchange their ballast water before they entered the lakes, and the U.S. Coast Guard has really clamped down in recent years, making sure that happens, according to Spokesman Lorne Thomas.
He says ships must either exchange tanks in salt water or the shipper has to certify that it won't release any ballast while in Great Lakes ports.
"We would go on board and just make sure they exchanged the ballast water," Thomas says. "But we really didn't have a good feel on how many organisms were being released into the environment.
"With the discharge standards there's a lot more certainty. And it certainly helps our enforcement picture."
The Coast Guard has studied this issue for more than decade.
Now, for the first time, it's requiring shippers to install technologies to treat ballast water. The rule says the treatment has to meet the existing International Maritime Standard or IMO.
Thomas says that's the only standard that can reliably be met.
"When you get beyond that, be it ten times or a hundred times, it gets very difficult to measure down to that level," he says. "And that's part of the argument that we have. That we don't have the capability to enforce a standard higher than the IMO standard."
Michigan Wanted a Stricter Rule
Michigan regulators aren't convinced that's the best approach. They say a tougher standard would push development of better technology.
"It may not be achievable now, but we think it's very important to set the final number so the technology treatments move in that direction to achieve a hundred times IMO," says Bill Creal, head of the water division for the state Department of Environmental Quality.
The DEQ insists a tougher standard would insure that more organisms would be removed from ballast water. This argument has gone back and forth over more than a decade. Wisconsin tried a stricter rule but backed off a few years ago saying the technology couldn't meet it.
Michigan hasn't backed off. For six years it's required ships to use an on-board treatment such as chemicals or ultraviolet light to kill organisms. But Creal says no foreign shippers have met the rule. They just promise not to dump ballast in state waters.
Now they'll have to install the new technology that applies in all U.S. waters.
Creal says this change would have been a perfect opportunity to up the standard and he thinks on-board treatment could have been geared to meet a stricter target in the future. Without that target, he doesn't see any stronger protection for the Lakes.
"The ships don't want to invest once and then have to invest again. There's going to be a tremendous resistance against that," he says. "If you could invest once to meet both standards you'd be all set."
DEQ says an EPA study last year shows a 30 percent chance of a new invasive getting into the lakes under the IMO standard.
But the Coast Guard argues the science isn't there yet to prove that a stronger standard will keep invaders out.