Michigan's Legislature may weaken a policy requiring oceangoing cargo ships to treat ballast water against invasive species before dumping it.
A 2005 law prohibits saltwater vessels from discharging ballast water at Michigan ports unless they have systems to kill fish, mussels or other foreign organisms it may contain.
Scientists believe dozens of destructive species have reached the Great Lakes in ballast water.
A bill approved by the state House and awaiting a vote in the Senate would drop a requirement that ships use a state-approved technology to cleanse ballast or else refrain from discharging it in Michigan waters.
Instead, the state would adopt federal standards that environmental groups say are weaker.
Rep. Dan Lauwers of St. Clair County's Brockway Township says the existing policy makes Michigan's shipping industry less competitive.
