---- — Asian carp have hogged the invasive species spotlight in recent years. But Michigan cannot afford to let one potential invader, dangerous as it is, distract from the fact that the fight also has to continue for better ballast water treatment to stop overseas arrivals such as the zebra mussel.
Unfortunately, at least four state senators want to take a step backward. Their legislation would void Michigan's singular, but still rather weak, attempt to require ballast water treatment for any ocean-going ship discharging in a Michigan port. That gives ships plenty of leeway to dump untreated ballast water before they reach port, so it's not even particularly strict. In any event, Michigan ports don't have a whole lot of commerce with ocean-going freighters.
What Michigan does have is nearly three-fifths of the Great Lakes shoreline on the U.S. side and the responsibility to keep pushing for better policies throughout the basin. Sometimes that means going out on a limb, and ballast water treatment is perhaps the premier issue on which the state should stay strong.
The bill would allow ships to discharge here if they have flushed their ballast tanks while at sea, a cleaning method that is considered only partially effective, since ballast tanks have nooks where sediment can build and continue to harbor the eggs and larvae of many species. Fully loaded ships often have no ballast water to exchange with ocean water while at sea, making it more difficult to flush their tanks.
Many researchers believe the biggest danger to the lakes comes from those ships that arrive fully loaded, then take on fresh water for stability as they unload their cargo. Then they head for another destination on the lakes, and dump the water — which may now be mixed with biological material from the bottom of their tanks — as they take on a new load for their return trip.
Zebra mussels, which undoubtedly arrived this way, were first discovered in Lake St. Clair in 1988. In the nearly 25 years since, Michigan and its Great Lakes neighbors have witnessed nothing but foot-dragging and whining from shipping industry interests that by now could and should be fully invested in ballast water treatment.
The problem is, shippers don't pay the costs for the harm they do. The results — the disruption to native species, the clogged intake pipes and the stringy buildup of algae throughout the lakes — don't always show up in ways everyone can see, but they do cost money. Although this isn't visible pollution, it's no less vile than if a ship's ballast water discharge was black, smelly and laced with dangerous chemicals.
No one, least of all anyone in Michigan, should back down from insisting that ocean-going shippers clean up their act.
Detroit Free Press