An invasive insect that has hurt forests in eastern states for more than 50 years is spreading to northern forests. Richie Duchon reports officials think it came by way of out-of-state nurseries:
Transcript
An invasive insect that has hurt forests in eastern states for more than 50 years is spreading to
northern forests. Richie Duchon reports officials think it came by way of out of state nurseries:
The tiny bug kills hemlock trees. The Hemlock Wooly Adelgid makes the trees weak and
vulnerable to droughts. Most of them die within ten years.
Mike Phillip is with the Michigan Department of Agriculture. He says this is an important time
of year for finding the adelgid.
“It begins to become active and will develop a white cottony, fluffy surrounding for its body. It’s
called an ova sac. And that is where it gets its name Wooly Adelgid. And that is an important
stage for us, because that’s where it becomes visible to us, and we can really get an idea of the
size of an infestation and what we’re really facing.”
Hemlocks are an important tree in forests, because they make good habitat for birds and animals.
Commercial fishers and biologists are concerned
about the impact a viral disease will have on the Great Lakes fishery.
There have been some large fish kills. Live fish commerce has been
restricted to help prevent the spread of the disease.
A disease is spreading, causing large fish kills in the Great Lakes.
Biologists and fishery officials are working to prevent further spread of
the disease, but there’s a conflict between government agencies. Lester
Graham reports there’s also a cost to businesses that deal in live fish:
Transcript
A disease is spreading, causing large fish kills in the Great Lakes. Biologists and
fishery
officials are working to prevent further spread of the disease, but there’s a conflict
between government agencies. Lester Graham reports there’s also a cost to businesses
that deal in live fish:
The disease that’s killing fish is called Viral Hemorrhagic Septicemia — or VHS. Jim
Diana is a fish biologist at the University of Michigan who’s been looking into what
it
does to fish…
“So, it’s a virus that the fish pick up and the virus causes really kind of a
general systemic
deterioration. Most notable, sometimes they’ll develop sores or lesions on the
outside of
the body, but they often will die without really external evidence at all.”
Basically, the fish die from internal bleeding. For several years there have been
die-offs
in the St. Lawrence River, which connects the Great Lakes to the Atlantic Ocean. But
researchers weren’t able to confirm the cause was VHS. Then this past summer in Lake
Saint Clair — the lake near Detroit that lies between Lake Huron and Lake Erie —
Jim
Diana says fish die-offs were confirmed to be caused by VHS.
“And since then, they’ve found it in quite a few other species, something like 20
other
species, so it’s quite widespread.”
It’s not clear how the virus got here. But… it originated in Europe. Researchers
guess
that infected fish hitchhiked in the ballast tanks of a ship… or a live fish shipment
escaped into the St. Lawrence River and it’s spread from there by ship.
Biologists say the spread of VHS is not good. It’s not expected to wipe out fish in
the
Great Lakes. But it is causing some real concern.
“We’re not talking about a couple of fish here, we’re talking about large fish
kills. And
VHS is present in those and implicated in the deaths of those fish.”
Marc Gaden is with the Great Lakes Fishery Commission. Gaden says because stocking
fish is a big industry… there’s a lot of fish shipped between the U.S. and Canada and
between one state and another.
“So, in the Great Lakes basin there is a movement of fish, fish eggs and other fishery
related things like water that’s used in the fish stocking trucks, things like that.
There’s
aquaculture that occurs, fish farms in the Great Lakes basin. The Departments of
Natural Resources harvest fish eggs to use in their stocking programs and the fish
themselves are stocked. So, there’s movement of fish and fish eggs throughout the
Great
Lakes basin just as a normal part of fisheries management and commerce that occurs.”
So the chance that the virus can be spread by all those fish moving around is
significant.
The federal government thought it was such a risk that it banned all fish shipments.
The
states quickly appealed that. They said it was overkill. They persuaded the feds
that they
were doing enough testing that the chances that VHS would be spread were slim.
So, the feds backed off a bit. But restrictions are still causing some problems. For
example… live fish that are not going to be put back into the lakes… live fish that
are
headed for dinner plates at restaurants still have to be tested. And VHS poses no
risk to
human health.
Ted Batterson is the director of the North Central Regional Aquaculture Center at
Michigan State University. He says he knows one fish farmer whose business is
supplying rainbow trout to restaurants.
“Well, now to be able to do that, he has to have the certification that these are
VHS-free.
It takes him currently, with the laboratory he’s been sending these to, up to 90
days to
get the certification that these are disease free. Well, that is not timely because
these
people who want fish at the other end need them in essence like yesterday, not 90 days
down the road.”
Another business hit by the restrictions on moving live fish is the bait industry.
If the
bait industry has to test –for example—one out of every 50 fish… and the test costs
about
50-dollars… no one will be able to afford to sell bait fish.
The states and the feds are still trying to figure out how to prevent the spread of
VHS…
without hurting the businesses that rely on live fish shipments any more than
necessary.
But… some businesses are already feeling the squeeze.
For the Environment Report, this is Lester Graham.
A naturally reproduced wild lake trout fingerling. (Photo courtesy of MI DNR.)
Alewives held up in a net. Alewives are an invasive species on which introduced salmon and other predator fish feed. They are among the prey fish species that have declined severely in Lake Huron. (Photo courtesy of MI DNR.)
Alewives being pulled from the lake. (Photo courtesy of MI DNR.)
The fisheries in the Great Lakes are seeing dramatic changes. In one lake, an invasive species that has become part of the food chain has collapsed. But some native fish are doing better because of that collapse. Lester Graham reports some fishery managers are debating what to do next:
Transcript
The fisheries in the Great Lakes are seeing dramatic changes. In one lake, an invasive species that has become part of the food chain has collapsed. But, some native fish are doing better because of that collapse. Lester Graham reports some fishery managers are debating what to do next:
When we started digging canals, connecting the lakes to the Atlantic Ocean, things changed a lot for the fish in the Great Lakes.
First, the sea lamprey got into the lakes through the Welland canal that bypasses Niagara Falls.
The lamprey is an eel-like parasite that nearly wiped out the big fish in the Great Lakes by attaching to them and sucking the life out of them.
Also slipping through the canals was a smaller fish, the alewife. Since the lamprey wiped out most of the predator fish in the lakes, the alewife population exploded. They out-competed native fish for food. It got so bad, that by the mid 1960s, if you weighed all the fish in Lake Michigan, more than 80% of the weight would have been alewives.
So, once wildlife managers got the sea lamprey under control, they had to figure out what they could do to get alewives under control. The fish biologists decided to introduce new predators, trout and salmon, to prey on the alewives. These fish were not native to the Great Lakes. Expensive nurseries were built by federal and state game agencies to keep supplying new trout and salmon every year to prey on alewives.
Forty years later, in Lake Huron, the alewife population collapsed, and in Lake Michigan alewives are declining rapidly. Mission accomplished, right?
Well, in that 40 years, a whole recreational fishing industry has grown up around fishing for those introduced trout and salmon. Some fishery managers now say we have to find a balance of the right amount of alewives to sustain the introduced trout and salmon fishery. So, recently states have cut their trout and salmon stocking programs to give alewives a chance to recover.
Tom Trudeau [who] operates a fish nursery for the state of Illinois says it would cause trouble to try to take the Great Lakes back to native fish only.
“We do have this industry that we have pressure to keep. You know, you’re putting a lot of people out of business if you get rid of it.”
And Trudeau says because of ecological damage, many of the smaller native fish on which big predators used to feed have been wiped out.
“So, I mean, of the six or seven species in that category, we only have one. And a couple of them are extinct. So, I mean, we could talk about going back to the ideal situation of pure native species, but we’ve disrupted the habitat so much.”
So, the argument goes, the invasive alewives are now needed. But something unexpected happened when the alewives disappeared from Lake Huron. The native fish, walleye, yellow perch, and lake trout started doing better.
Dave Fielder is a fisheries research biologist with the Michigan Department of Natural Resources.
“We’ve long known that adult alewives were a predator and a competitor on newly hatched perch and walleye fry. We just didn’t realize how substantial that effect was until finally the adult alewives were removed from the system and now we’re enjoying some greatly increased reproductive success. Walleye, particularly in Saginaw bay, are at some of the highest levels that we’ve seen in a long time.”
But, after 40 years, people are used to fishing for those introduced trout and salmon. And some fisheries managers are wondering what will happen to all those expensive nurseries that provide their jobs.
What happens to all of those charter boat fishing operations, fishing tourism, if the government were to stop stocking those trout and salmon? Would they switch to fishing for native fish? And, can the native fish even survive in the long-run since so many of the smaller native prey-fish are no longer around?
Dave Fielder says it’s hard to say.
“So, we’re kind of in the middle of a change – it’s really a paradigm shift in many ways – and that’s always scary because nobody really knows how we’re going to end up, but I prefer to be optimistic. I think there are a lot of reasons to be hopeful in regards to the benefits that we’re seeing for our native species.”
But some fisheries managers say the debate of whether to go all native or to try to find the right mix of native and non-native fish is not over. Since invasive species, pollution, and habitat destruction have changed the Great Lakes so much, wildlife managers think they’ll still have to keep stocking one kind of fish or another to keep the recreational fishing industry going. If that’s the case, does it matter whether it’s native fish, or the introduced fish that anglers have grown to like so much?
For the Environment Report, this is Lester Graham.
Centaurea diffusa a.k.a. Spotted knapweed. Introduced in the late 1800's, knapweed can reduce diversity in the region's prairies. (Photo courtesy of the USDA)
Myriophyllum spicatum L. a.k.a. Eurasian watermilfoil. Introduced in the 1940's, dense mats of watermilfoil can rob water of oxygen, provide good habitat for mosquitoes, and impair swimming and boating. (Photo courtesy of the USDA)
Phragmites australis a.k.a. the common reed. A European strain was imported in the 1900's. It can quickly inhabit wet soils and create monocultures. Monocultures as big as 7000 acres have been documented. This plant also likes salty water, which is why it's often found in roadside ditches, where road salt accumulates. (Photo courtesy of Invasives.org )
Gardeners have been ordering new plants and digging in the dirt this spring, but if they’re not careful, they could be introducing plants that can cause havoc with forests, lakes, and other natural areas. Gardeners can’t count on their suppliers to warn them about plants that can damage the local ecosystems. In another report in the series, “Your Choice; Your Planet,” the Great Lakes Radio Consortium’s Lester Graham reports:
Transcript
Gardeners have been ordering new plants and digging in the dirt this spring, but, if
they’re not careful, they could be introducing plants that can cause havoc with forests,
lakes, and other natural areas. Gardeners can’t count on their suppliers to warn them
about plants that can damage the local ecosystems. In another report in the series “Your
Choice; Your Planet,” the Great Lakes Radio Consortium’s Lester Graham reports:
Gardening, especially flower gardening, seems to get more popular all the time. Maybe
it’s because the baby-boomers have all reached that age where they’re beginning to
appreciate stopping for a moment to smell the roses.
That’s fine. In fact if gardeners plant the right kinds of plants… it can be great for
wildlife. There are all kinds of guides for backyard natural areas.
But… in some cases… gardeners can unleash plant pests on the environment.
Katherine Kennedy is with the Center for Plant Conservation. She says almost all of the
problem plants that damage the native ecosystems were planted with good intentions…
“I don’t believe that any invasive species has ever been introduced into the United States
on purpose by someone who willingly said, ‘Oh yeah, this is going to be a problem, but I
don’t care.’ They’ve almost all been inadvertent problems that were introduced by
someone who thought they were doing something good or who thought they were
bringing in something beautiful.”
English ivy, a decorative ground cover, is now killing forests in the Pacific Northwest…
kudzu is doing the same in the southeast… and in the Great Lakes region and the
Midwest… pretty flowering plants such as purple loosestrife and water plants such as
Eurasian watermilfoil are causing damage to wetlands, crowding out native plants and
disturbing the habitat that many wildlife species need to survive.
Bob Wilson works in the Michigan Senate Majority policy office. Like many other
states, Michigan is looking at legislation to ban certain problem plants. Wilson agrees
that these plant pests are generally not intentional… but they do show that people seem to
unaware of the problems that they’re causing…
“The two most common vectors for bringing in these kinds of plants are typically
landscapers, who bring it in as a way of decorating yards and lawns, and then aquarium
dumpers, people who inadvertently dump their aquarium, thinking that there’s no
consequence to that. Before you know it, something that was contained is now spread.”
But stopping the import of pest plants is a lot harder than just passing laws that ban them.
With mail order and Internet orders from large nurseries so common, the plants can get
shipped to a local nursery, landscaper or local gardener without the government ever
knowing about it.
Recently, botanists, garden clubs, and plant nursery industry groups put together some
codes of conducts. Called the St. Louis Protocol or the St. Louis Declaration… the
document set out voluntary guidelines for the industry and gardeners to follow to avoid
sending plants to areas where they can cause damage.
Sarah Reichard is a botanist with the University of Washington. She helped put the St.
Louis Protocol together. She says if a nursery signs on to the protocol, it will help stop
invasive plant species from being shipped to the wrong places….
“And it’s up to each of the nursery owners, particularly those who sell mail order or
Internet, to go and find out which species are banned in each state.” LG: And is that
happening? “Uh, I think most nursery people are pretty responsible and are trying to
do the best that they can. I’m sure that they’re very frustrated and understandably so
because the tools aren’t really out there for them and it is very difficult to find the
information. So, it’s a frustrating situation for them.”
But in preparing this report, we found that some of the biggest mail-order nurseries had
never heard of the St. Louis protocol. And many of the smaller nurseries don’t have the
staff or resources to check out the potential damage of newly imported plants… or even
to check out each state to make sure that banned plants aren’t being sent inadvertently.
Sarah Reichard says that means gardeners… you… need to do some homework before
ordering that pretty flowering vine. Is it banned in your state? Is it a nuisance that could
cause damage? Reichard says if enough gardeners care, they can make a difference…
“You know, gardeners have tremendous power. We, you know, the people that are
buying the plants at the nurseries – that’s what it’s all about. I mean, the nurseries are
there to provide a service to provide plants to those people and if those people have
certain tastes and demands such as not wanting to buy and plant invasive species, the
nurseries are going to respond to it. So, we’re all part of one team.”
Reichard and others concerned about the problem say although agencies are working on
it… the federal government has not yet done enough to effectively stop invasives from
being imported and shipped to the wrong areas. They say it’s up to the nurseries, the
botanists, and the gardeners to stop them. If not, we’ll all pay in tax money as
government agencies react to invasives with expensive eradication programs to try to get
rid of the plants invading parks, preserves, and other natural areas.
For the Great Lakes Radio Consortium, this is Lester Graham.
Centaurea diffusa a.k.a. Spotted knapweed. Introduced in the late 1800's, knapweed can reduce diversity in the region's prairies. (Photo courtesy of the USDA)
Myriophyllum spicatum L. a.k.a. Eurasian watermilfoil. Introduced in the 1940's, dense mats of watermilfoil can rob water of oxygen, provide good habitat for mosquitoes, and impair swimming and boating. (Photo courtesy of the USDA)
Phragmites australis a.k.a. the common reed. A European strain was imported in the 1900's. It can quickly inhabit wet soils and create monocultures. Monocultures as big as 7000 acres have been documented. This plant also likes salty water, which is why it's often found in roadside ditches, where road salt accumulates. (Photo courtesy of )
Gardeners are being asked to be careful about what they plant. Invasive species that cause damage to natural areas often start as a pretty plant in someone’s yard. The Great Lakes Radio Consortium’s Lester Graham reports:
Transcript
Gardeners are being asked to be careful about what they plant. Invasive species that
cause damage to natural areas often start as a pretty plant in someone’s yard. The Great
Lakes Radio Consortium’s Lester Graham reports:
Botanists, plant nurseries and gardeners are all being asked to do a little more homework
before importing, selling, or planting new kinds of plants. Katherine Kennedy is with the
Center for Plant Conservation. She says some of the plants you mail order from the
nursery can end up being invasive kinds of plants that damage the local ecosystem…
“We are actually at a point where these invasions crowd out the native community, not
just a species or two, but the entire community. And the wildlife value falls and the
native plants are displaced. And, so, the destructive potential for a species that becomes
truly invasive is more immense than I think many people realize.”
Kennedy says you can’t count on the nursery to warn you when you order plants. She
says gardeners have to make sure the plants they’re ordering won’t hurt the surrounding
landscape.
For the Great Lakes Radio Consortium, this is Lester Graham.
Scientists are working to control a new non-native beetle that’s destroying hundreds of thousands of ash trees in the Midwest. The Great Lakes Radio Consortium’s Erin Toner reports:
Transcript
Scientists are working to control a new non-native beetle that’s destroying hundreds of
thousands of ash trees in the Great Lakes region. The Great Lakes Radio Consortium’s
Erin Toner reports:
The Emerald Ash Borer is native to Asia, and probably made its way to the United States
through wood packing materials. Therese Poland is an entomologist with the
USDA. She says so far, the beetles have destroyed 100 thousand ash trees in southeastern
Michigan and southern Ontario.
“We think it’s been here for at least five years and even with some of the other exotic
beetles that have been discovered in recent years, when they were first discovered they
weren’t as widespread as this.”
Poland says there’s a quarantine over the infested areas to keep the beetles from moving
to new areas. Officials are inspecting nurseries to make sure they’re not selling infested
trees. They’re also checking whether tree care companies are disposing of trees properly.
But officials admit they probably won’t be able to stop people who unknowingly transport
infested firewood or yard waste.
For the Great Lakes Radio Consortium, I’m Erin Toner.
