New research shows that having ships dump their ballast water before entering the Great Lakes might not be enough to stop the growth of invasive species in the region. The Great Lakes Radio Consortium’s Lester Graham reports:
Transcript
New research shows that having ships dump their ballast water before entering the Great Lakes might not be enough to stop the growth of invasive species in the region. The Great Lakes Radio Consortium’s Lester Graham reports:
Freighter ships are now required to exchange their ballast water in the ocean before entering the Great Lakes to flush out aquatic nuisances that might have hitchhiked from foreign ports. But a biology student at the University of Windsor, Sarah Bandoni, has found that the slime and silt at the bottom of the ballast tanks carry lots of eggs. That silt isn’t all removed when the water is flushed. And, despite having been in dark and freezing conditions, when things become better, the eggs can hatch.
“In the most part, I’m finding quite a lot of them are viable, averaging probably 50 to 75-percent of the eggs have been able to hatch.”
Bandoni says that means there’s at least the potential for some of these eggs to escape into Great Lakes ports. About 160 invasive species, such as the zebra mussel have been imported by cargo ships, causing damage to native species, including fish.
For the Great Lakes Radio Consortium, this is Lester Graham.
A $5,000 reward is being offered to anyone who finds a tiny, parasitic worm in the U.S. that kills leaf-eating slugs. The gray garden slug is notorious for destroying crops and ornamental plants in the Midwest. Researchers at Ohio State University have been looking for the worm that eats the slugs. So far, they’ve examined thousands of slugs sent to them in the mail … but they haven’t been able to find the worm. The Great Lakes Radio Consortium’s Natalie Walston reports:
Transcript
A five thousand dollar reward is being offered to anyone who finds a tiny, parasitic worm in the United States that kills leaf-eating slugs. The gray garden slug is notorious for destroying crops and ornamental plants in the Midwest. Researchers at Ohio State University have been looking for the worm that eats the slugs. So far, they’ve examined thousands of slugs sent to them in the mail, but they haven’t been able to find the worm. The Great Lakes Radio Consortium’s Natalie Walston reports.
(Natural sound of guinea hens)
The Kingwood Center in Mansfield, Ohio is made up of 50 acres of well-tended English gardens. Paved trails lead through rows of perennials and peonies, around fountains and a duck pond. Hundreds of hostas grow beneath shade trees, but the plants leaves have holes chewed through them. John Makely is Kingwood’s head gardener. He says the conventional methods to kill the slugs eating his hostas are out of the question here.
“The problem that we have here with slug bait is that we do have birds roaming around, peacocks and guinea hens that roam around freely. They sort of grouse, browse I should say, the grounds and we would be afraid that they would pick up some of those pellets and poison them.”
Slug bait consists of a poison that can harm more than its intended target. But right now, it’s the only commercial method available to control slugs. So, now there’s a big push by large, commercial nurseries to find a chemical-free way to kill the gray garden slugs that eat ornamental plants. Ohio State University researcher, Pavinder Grewal says there’s a major economic reason to find a good control method.
“Last year we had a lot of rain here when the corn was emerging. And there have been several fields in Ohio that were totally wiped out by the slugs. Basically zero corn production in some fields.”
Grewal has found a natural slug killer. It’s a tiny parasitic worm, known as a nematode. It is native to England and parts of several countries in South America. Farmers and gardeners in those countries buy them in bulk in powder form and sprinkle the worms on their fields. Scientists think the worm will work in this country as well. But if the worm is imported, it must first undergo years of testing to make sure it will not harm native plants and animals.
“We don’t see any problem because some of the tests that we have performed with the nematode…we find it to be pretty safe to non-target organisms. And, we find that this nematode does not infect all slugs.”
To prove this to the federal government could be difficult. Grewal is looking for the worm, in the United States he took out an ad in various publications. He studies more than twenty thousand slugs, but has yet to find the worm he’s looking for. Now he’s sending people off to remote areas of the country to find it. He hopes to be successful because it could take years of testing before the worms can be brought into this country. For the Great Lakes Radio Consortium, I’m Natalie Walston.