Environmentalists Cheered by Dam Removals

60 dams are scheduled for removal this year across the country. 40 of them are currently located in the eight Great Lakes states. Environmentalists say the removal of these dams will improve water quality and help restore fisheries. The Great Lakes Radio Consortium’s Celeste Headlee reports:

Transcript

60 dams are scheduled for removal this year across the country, 40 of them
are currently located in the eight Great Lakes states. Environmentalists
say the removal of these dams will improve water quality and help restore fisheries.
The Great Lakes Radio Consortium’s Celeste Headlee reports:


A survey by the environmental group American Rivers shows
that more than 145 dams have been removed nationwide since 1999. Serena
McClain is a conservation associate for American Rivers. She says there are
two good reasons why these dams are coming down. First, there’s a growing
concern for the ecological health of rivers and streams. But there is also
an economic benefit to removing some dams.


“It’s an infrastructure that requires constant maintenance and improvement. And a lot of
these dams, too… they’ve outlived their purpose. When they were first built, a lot of them
powered old grist mills, but now they’re just sitting there, kind of rotting away.”


McClain says migratory species like salmon and trout are negatively impacted by dams,
and new evidence shows even fish that don’t travel as far benefit when the structures are
pulled down. About 65 percent of the dams scheduled for removal this year are located
in the eight Great Lakes states.


For the Great Lakes Radio Consortium, I’m Celeste Headlee.

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Anglers Competing With Cormorants

  • The cormorant population is booming in the region, and some anglers say they're competing too hard with the birds for fish. (Photo courtesy of Steve Mortensen, Leech Lake Band of Ojibwe)

Anglers around the Great Lakes are eager for a summer of fishing. Everyone wants to catch the big one. But they’re getting some competition. It comes in the form of the double-crested cormorant. The big black birds with long necks are fish eaters. Cormorants were nearly wiped out by the now-banned pesticide, DDT, in the 1970’s. But now cormorants are back in big numbers. Some anglers feel there are too many cormorants now. And they say the birds are eating too many fish. The Great Lakes Radio Consortium’s Stephanie Hemphill reports on one experimental effort to control cormorants:

Transcript

Anglers around the Great Lakes are eager for a summer of fishing. Everyone wants to
catch the big one, but they’re getting some competition. It comes in the form of the
double-crested cormorant. The big black birds with long necks are fish eaters.
Cormorants were nearly wiped out by the now-banned pesticide, DDT, in the 1970’s. But
now cormorants are back in big numbers. Some anglers feel there are too many
cormorants now, and they say the birds are eating too many fish. The Great Lakes Radio
Consortium’s Stephanie Hemphill reports on one experimental effort to control
cormorants:


(sound of waves)


Robin Whaley often fishes here on Knife River. It’s the biggest spawning ground for
rainbow trout on the north shore of Lake Superior. But today she’s watching the
cormorants on Knife Island, a quarter-mile offshore.


The cormorant population is booming. About a hundred cormorants lived on the island
last year.


“I guess they’re just coming up into this area in the last few years and becoming a
problem, for degrading habitat and for eating little fish.”


Cormorants are native to this area, but they haven’t been around much in the last few
decades, because of poisoning from the pesticide DDT.


The Minnesota Department of Natural Resources stocks rainbow trout here. This year
they put 40,000 young fish into the river. Anglers like Robin Whaley hope the little fish
will grow big enough for them to catch someday.


The little fish face a lot of predators and hazards and the cormorants are one more threat.
Some people would like to reduce that threat. It’s illegal to kill cormorants. They’re
protected by law because they’re a migratory bird.


But a new federal rule says if they’re threatening a resource, people can fight back in a
different way.


Bill Paul runs the Agriculture Department’s Wildlife Services Program in Minnesota. He
sent workers onto Knife Island to try to keep the cormorants from nesting. Their methods
are experimental – but they’re pretty basic.


“We put up some flapping tarps in wind, a couple of yellow raincoat scarecrows, we also
put up ten flashing highway barricade lights, we also have a light siren device out there
that goes during the night.”


The workers also used special firecrackers shot by guns at passing birds to scare them
away.


They did this for two weeks during the cormorants’ nesting season. Bill Paul says even
with all that noise and commotion it wasn’t easy to scare them away.


“They seem to be fairly smart birds and real persistent at coming back to Knife Island.
So we’re uncertain yet whether our activities are actually going to keep them off there
long-term.”


As part of their study, researchers had permission to kill 25 cormorants to find out what
they’d been eating. They wanted to see how much of a threat the birds were to game fish
like the rainbow trout.


They found fish in the cormorants’ stomachs all right. But not the kind most people like
to catch and eat.


Don Schreiner supervises the Lake Superior fishery for the Minnesota DNR. He says
he’d need more than just a few samples to really know what the birds are eating.


“My guess is that cormorants are opportunists and if there’s a small silver fish out there
and he’s just hanging out and the cormorant has that available to eat, he’ll eat it. The
question becomes, is this a significant part of the population that they’re consuming, or
isn’t it?”


Despite the concerns of some anglers, researchers have been studying cormorants for
years, and so far they haven’t been able to prove the birds are harming wild fish
populations.


John Pastor is an ecologist at the University of Minnesota Duluth. He says the study at
Knife River won’t prove anything useful either.


He says it ignores the bigger picture. Pastor says you can’t just look at one predator and
come to any firm conclusions. There could be lots of reasons why there aren’t many
steelhead, or rainbow trout.


“Changes in land use. All the adult steelhead out there eating the young of the year
steelhead. Maybe it’s some pollutant in the lake. You never know. But it’s easy to fix on
the predator as the problem, because people see a cormorant dive down and come up with
a fish, and they say to themselves, I could have caught that fish.”


Pastor says even if the cormorants are eating lots of young rainbow trout, it doesn’t
necessarily mean the birds are hurting the overall trout population.


And even for an angler like Robin Whaley, the concern about the trout is mixed with a
feeling of respect for the cormorant.


“I admire the bird very much, but human beings, we’re in the business of controlling
habitats and populations, and this is just another case of that.”


For many anglers, the ultimate question in this competition between predators is simple.
It’s about who gets the trout – cormorants or humans.


For the Great Lakes Radio Consortium, I’m Stephanie Hemphill.

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Gobies Send Toxins Up the Food Chain

New research is showing that a foreign fish might be aiding the transfer of toxic substances into sportfish populations. The Great Lakes Radio Consortium’s Mark Brush has more:

Transcript

New research is showing that a foreign fish might be aiding the transfer
of toxic substances into sportfish populations. The Great Lakes Radio
Consortium’s Mark Brush has more:


Fish such as bass, trout, and walleye normally eat small native fish.
Now, these large sportfish have learned how to eat a new foreign fish – round
gobies. The gobies can contain toxic pollutants because they feed on
zebra mussels. And because of the way zebra mussels feed they can take up
a lot of pollutants like PCBs.


David Jude is a research scientist at the University of Michigan. He’s
been studying fish living near polluted areas.


“Yes, a lot of sportfish are eating round gobies, we found them in a lot of
predators we looked at in the St. Clair River – perch, brown trout,
walleyes – so the possibility of transferring PCBs into a
lot of the sportfish that people catch is certainly real.”


Jude says he hopes his research will determine ways to control goby
populations where they’ve become a problem.


For the Great Lakes Radio Consortium, I’m Mark Brush.

Tracking Long-Term Zebra Mussel Changes

Zebra mussels have been colonizing North American lakes and rivers since 1991. Scientists have looked at many of the ways mussels affect those ecosystems. But a new study underway shows how those effects are moving up the food web…and are having two very different results. The Great Lakes Radio Consortium’s Mark Brodie reports:

Transcript

Zebra mussels have been colonizing North American lakes and rivers since 1991. Scientists have looked at many of the ways mussels affect those ecosystems. But a new study underway shows how those effects are moving up the food web…and are having two very different results. The Great Lakes Radio Consortium’s Mark Brodie reports:


Between 50 and 5-hundred billion zebra mussels now live in New York’s Hudson River. That’s a lot of hungry mouths to feed on the river’s zooplankton and phytoplankton. The problem is the mussels are not the only ones that like to dine on the microscopic plants and animals. A new report suggests the mussels are stealing food from some of the river’s fish.


That’s forcing those fish to look elsewhere for their meals. Sandra Nierzwicki-Bauer is the director of the Darrin Freshwater Institute, and a biology professor at Rensselaer Polytechnic Institute in Troy, New York. She says the zebra mussels can dramatically alter an ecosystem.


“They’re very rapid filter feeders, and as such, they’re able to remove tremendous amounts of phytoplankton, algae, bacteria in the water column. As such, the phytoplankton serves as food sources for other organisms so you really are impacting the entire food web.”


Nierzwicki-Bauer says those impacts go all the way up to fish. David Strayer is a freshwater ecologist at the Institute of Ecosystem Studies, and a lead author of the report on the Hudson River. He says his team studied fish populations in the Hudson both before and since zebra mussels colonized there.


“In open water fish species, we saw a decline in abundance, we saw declines in growth rates, and we saw that the populations of those fish tended to shift downriver compared to the period before the zebra mussel invasion.”


That means some of the most common and popular fish in the Hudson are no longer where they used to be…among them American shad, herring, and white perch. That’s because the zebra mussels are eating those fish’s food…forcing the fish to go elsewhere.


But Strayer says while some fish have had to move away from the mussels…some species have welcomed their new neighbors.


“In the same period of time, we saw populations of fish that live in the weed beds…we saw those populations increase, we saw growth rates of those fish increase, and we saw the populations of those weed bed fish shift upriver into the area where the zebra mussels lived.”


These forage fish have more to eat because the plants at the river’s bottom are growing more. That’s because the zebra mussels clear up the water, which allows more sunlight to reach the plants. Strayer says the zebra mussels have changed almost everything about the Hudson’s ecology.


But he says some of those changes have been difficult to predict, and the changes may not apply to all bodies of water where the mussels have colonized. This is one of the first studies using long term data that looks at the zebra mussels’ affect on fish populations…but there is some evidence that other bodies of water are dealing with similar situations. There have been reports that zebra mussels may be affecting smelt and chub in Lake Michigan…these smaller fish are food for larger species, such as trout and salmon. But while the results are comparable, David Strayer says the changes in the Hudson River are more pronounced than changes elsewhere.


“This isn’t because we have more zebra mussels in the Hudson than in the other places, but it’s because there are differences in the structure of the ecosystem between the Hudson River and the Great Lakes and other places that have been invaded. So, you have to be a little cautious extrapolating from one body of water to the next.”


That sentiment is shared by Andy Kahnly. He’s a fishery scientist with the Hudson River fishery unit of the New York State Department of Environmental Conservation. He also worked on the new study. Kahnly warns for now, the results only apply to young fish…and not adults. That’s because fish can live up to 30 years, and the data don’t go that far back.


“Quite often, changes in early lifestages will take some time to translate into changes in fish populations and then to changes in fish communities. So it takes a lot of data, a lot of years of data to see a change.”


Kahnly says that means anglers in the Hudson might begin to notice some changes over the next few years… and he says the study did find a dramatic decrease in many of the species that people catch.


“If these changes in production of young persist into the future, then definitely there will be a decrease in the abundance of the adults which people are fishing for.”


But that depends on what you’re fishing for. The Institute of Ecosystem Studies’ David Strayer says your perspective might change depending on that you’re trying to catch.


“If you’re concerned about shad populations, if you’re a shad fisherman, then you might be concerned with the zebra mussel invasion and think it’s a bad thing. If you like the weed beds, if you’re a duck hunter or a large mouth bass fisherman this might be regarded as a positive thing.”


Strayer says the study shows zebra mussels are capable of having a tremendous impact on an ecosystem. He says it also shows the importance of being careful to prevent the introduction of invasive species…like zebra mussels…into an ecosystem.


For the Great Lakes Radio Consortium, I’m Mark Brodie.

Reward for Tagged Fish

Great Lakes scientists are using new technology to track certain kinds of fish. The Great Lakes Radio Consortium’s Jonathan Ahl reports:

Transcript

Great Lakes scientists are using new technology to track certain kinds of fish. The Great Lakes Radio Consortium’s Jonathan Ahl reports:


Researchers on lakes Huron and Superior are using a new computerized tagging system to track fish including trout and sturgeon. The new tag measures the water depth and temperature of the areas fish prefer to be. Henry Quinlin is a biologist with the U.S. Fish and Wildlife Service in Ashland, Wisconsin:


“Upon learning the habitat preferences, habitat could be enhanced or created to benefit lake sturgeon or the other species that are being studied.”


Quinlin hopes the data can be used to design better habitat protection and restoration projects. He also says the program’s success is dependent on sport fisherman returning the tagged fish. That’s why his office is paying one hundred dollars a piece for fish with the special tags. For the Great Lakes Radio Consortium, I’m Jonathan Ahl.

Will Trout Coast to Recovery?

A sport fish native to the Great Lakes region is famous for its looks and its size, but overfishing and habitat loss have driven its numbers down. Now, some fish experts are helping the coaster brook trout make a comeback. The Great Lakes Radio Consortium’s Rebecca Williams reports:

Transcript

A sport fish native to the Great Lakes region is famous for its looks and its size… but over fishing and habitat loss have driven its numbers down. Now, some fish experts are helping the coaster brook trout make a comeback. The Great Lakes Radio Consortium’s Rebecca Williams reports:


Coaster brook trout, or coasters, cruise the near shore waters of Lake Superior most of their lives, and only swim into rivers to spawn. Male coasters turn vibrant red when they’re spawning. And the trout grow much larger than their inland relatives… an 8 pound fish is a trophy.


But coasters are rare, so Trout Unlimited is working with other scientists to boost their numbers. In the last 2 years, biologists have released baby coasters in 4 rivers in the Upper Peninsula.


Bill Deephouse is president of Trout Unlimited’s Copper Country chapter.


“You can’t protect all of these little creatures. So you put… and this certainly isn’t exact… but you put 10,000 fish in, you hope a few thousand of them make it. Maybe a few hundred make it to adulthood.”


The biologists say it may be some time before fishermen will feel one of the reintroduced coasters on the end of their lines. For the Great Lakes Radio Consortium, I’m Rebecca Williams.

The Business of Fish Management

  • Similar scenes can be found up and down the eastern shore of Lake Michigan.

Now that summer’s officially here, beaches around the region are packed with
tourists and locals. But this year many beaches have been plagued with
unwanted visitors: tens of thousands of dead fish in the water and on the
sand. It’s a revolting sight-and smell – but in fact, the fish play an
important role in the lakes…and present an ongoing management challenge to
biologists. The Great Lakes Radio Consortium’s Wendy Nelson explains:

Dairy Farm Endangers Trout Stream

In the tiny town of Martell in western Wisconsin, residents are trying
to stop a big new dairy farm they fear will pollute one of the best
trout streams in the Midwest — the Rush River, about an hour’s drive
east of the Twin Cities. Its the same kind of battle small towns and
rural residents are fighting across the Midwest, as large-scale
livestock operations continue to expand. The Great Lakes Radio
Consortium’s Mary Losure reports:

Gender Disparity Endangers Yellow Perch

Scientists in Wisconsin say among yellow perch, males in Lake Michigan outnumber females by 9-to-1. Such a gender disparity may be detrimental to the food chain. The Great Lakes Radio Consortium’s Lisa Labuz has more: