Keeping count of the number and kinds of invasive species deposited in the Great Lakes by ships coming from other bodies of water amounts to a statistical nightmare, says J. Rudi Strickler, UWM Shaw Distinguished Professor of Biological Sciences.
These aquatic organisms, which range from fish and mussels to tiny water fleas, are introduced by “hitching a ride” in the ballast water of oceangoing ships. Once released into the Great Lakes they often out-compete native species for food and habitat, threatening the lakes’ ecological health.
The U.S. Environmental Protection Agency has recently awarded Strickler nearly $400,000 from the Great Lakes Restoration Initiative to find a more efficient method of monitoring incoming invasives. A new non-native species is discovered on average once every 28 weeks.
“We don’t know what’s actually in that ballast water,” he says. “We don’t realize the magnitude of the situation. In order to measure more accurately, we have to create an instrument.”
Filling and emptying the ballast water is necessary to maintain a ship’s center of gravity as it loads and unloads cargo. Strickler is developing holograph-based technology and related software that will offer
3-D images of what’s in the ballast water as it flows past the mechanism.
The software stores only the images on which something appears, and then sends the data over the Internet for analysis.
Currently, harbor administrators take manual samples of ballast water and test them for live invasives. If the samples show more than 10 viable organisms per cubic meter (263 gallons), the treatment could include using a chemical that is toxic to many invasives before pumping the water out. Regulations currently require oceangoing ships to replace their ballast water with ocean water before entering the Great Lakes. But this saltwater flushing commonly leaves behind many invasives.
“You need to be able to sort it out on the spot,” says Strickler. “Like a smoke detector, it tells the skipper there’s a problem. Or it allows him to do nothing at all if he doesn’t have to.”
During the two-year grant, Strickler and his lab members will partner with Milwaukee Community Service Corps, offering paid training in cleaning the invasives from ships to Milwaukee’s unemployed youth. Outreach efforts also include teaming up with the Alliance for the Great Lakes to host webinars for the public and policymakers.