Underwater guns, traps, aim to shake up Great Lakes invaders

By BRIAN BIENKOWSKI
Capital News Service
LANSING — Nestled in the northwest corner of the Lower Peninsula, the Grand Traverse Bay has experienced declining native fish populations for decades. And all-too-common perpetrators are largely to blame – aquatic invaders.
But a new federal and state partnership seeks to bolster the bay’s native fish populations. Officials will use traps and seismic guns to clear rusty crayfish and round gobies from spawning reefs, where they hang out and eat fish eggs.
“We are trying to give the native species a helping hand,” said Lindsay Chadderton, the Great Lakes aquatic species director for the Nature Conservancy. Chadderton is based at the Biology Department at Notre Dame University.
The conservancy is partnering with the Department of Natural Resources, Central Michigan University, the U.S. Geological Survey and the Grand Traverse Band of Ottawa and Chippewa Indians on the project. The Environmental Protection Agency’s Great Lakes Restoration Initiative is funding the project with about $661,000, according to Melissa Soule, marketing manager for the Nature Conservancy.
Because trapping often doesn’t work on the mobile round gobies, thus the use of seismic guns. While the underwater cannons sound Star-Trekky, they’re pretty simple. They use sound frequencies and water jets to blast away invaders.
The U.S. Geological Survey is also testing the guns on Asian carp in the Chicago-area waterway.
“The use of seismic technology for this purpose has never been attempted,” said Jackson Gross, a U.S. Geological Survey scientist at the Northern Rocky Mountain Science Center in Bozeman, Mont.
“We have had success using these technologies as a sound or acoustic barrier, clearing fish from other areas, so the potential to move goby off spawning grounds is an idea worth testing,” Gross said. “Hopefully we will be annoying enough and make those gobies pack up and leave the neighborhood.”
The seismic guns represent a new way of thinking in the fight to stem the challenges of aquatic invaders – controlling them instead of trying to eliminate them.
While the egg-munching invaders are hurting native fish populations, they’re not the bay’s only problem. Matt Herbert, a Nature Conservancy aquatic ecologist, said that docks and other development near spawning reefs also hurt egg survival. A portion of the funding will go towards restoring the reefs to give the fish eggs cover and protection.
The initial phase – clearing invaders and restoring the reefs – will be completed by 2015, officials estimate.
Brian Bienkowski writes for Great Lakes Echo.
© 2012, Capital News Service, Michigan State University School of Journalism. Nonmembers cannot reproduce CNS articles without written permission.