Michigan ought to show the nation exactly how ships should treat their ballast water and prevent the spread of invasive species.

U.S. Rep. Dale E. Kildee, D-Flint, saw to it that the Great Lakes State's strict ballast water standards become the nation's new rule for ships that use water as ballast.

We applaud his work to turn the U.S. Coast Guard reauthorization bill toward greater protection of our coastal waters.

In Michigan, we know too well the damage caused by foreign, imported species, likely carried here in the water ballast of salties - ocean-going ships. Zebra and quagga mussels litter our Great Lakes and may be partly responsible for the muck fouling our beaches. In all, more than 168 alien species have invaded the Great Lakes.

Our state's concern over untreated ballast water resulted in Michigan becoming the first to enact regulations for ship ballast discharges.

Knowledge of the problem also is why the U.S. Great Lakes Shipping Association supports a strict, nationwide - and uniform - ballast water treatment regimen. Shippers have long opposed a scatter-gun approach, with differing regulations in each state.

Now that the Coast Guard bill has passed the House, it's up to senators to keep this vital ballast water plan in place.

The goal, with increasingly strict standards eventually surpassing even Michigan's, is zero discharge in all U.S. ports of alien species from the ballast water of ships.

Any weaker target is unacceptable.

Those who doubt that are welcome to visit Michigan this summer.

They can kick at gobies, ruffes and those sharp little zebra-striped shells along mucky shores, and learn why untreated ballast water discharges are outlawed here.