Population Control for Cormorants

  • Biologists Jim Farquhar and Mike Smith inspect the cormorant nests in the treetops. (Photo by Karen Kelly)

The pesticide DDT almost wiped
out the double-crested cormorant.
Now, the bird is thriving, and it’s
blamed for devouring fish in lakes,
rivers, and fish farms in many parts
of the country. Karen Kelly reports
on the struggle to share resources
with this unpopular bird:

Transcript

The pesticide DDT almost wiped
out the double-crested cormorant.
Now, the bird is thriving, and it’s
blamed for devouring fish in lakes,
rivers, and fish farms in many parts
of the country. Karen Kelly reports
on the struggle to share resources
with this unpopular bird:

(sound of clanking and birds)

Mike Smith eases a boat into the shallow water just off Little Murphy Island. It’s a tiny patch of sand and trees in the middle of the St. Lawrence River. It straddles the New York border with Canada.

Smith is a wildlife technician with New York’s department of environmental conservation. He specializes in cormorant management. That means he knocks down nests, breaks eggs, and – very occasionally – shoots them.

Before he even jumps off the boat, he starts counting the birds that are poking out of nests in the treetops.

“I see a few. I’m looking at their nests. We tried to have a zero percent successful reproduction rate.”

Smith counts maybe ten nests. They started with 150 or so in the spring.

There are tens of thousands of these birds. They spend their summers in the north. And in the winter, they go south where they raid fish farms.

Biologists estimate each bird eats a pound of fish a day. That can make a dent in the local fish population. The birds also strip trees of their leaves to create nests. And their guano ends up killing the trees’ root systems. That ends up driving out other animals that need vegetation.

Some people feel the birds should be eradicated. One group of anglers was even arrested for killing hundreds of them on Lake Ontario.

There are others, like the group Cormorant Defenders International. They feel they should be protected.

It’s up to biologists like Jim Farquhar of New York’s Department of Environmental Conservation to find the balance between human needs and cormorants.

Farquhar: “We have needs too, as people.”

Karen: “And we’re competing with them.”

Farquhar: “And we’re competing with them in some cases. Hopefully, if we can inject good science, we make good decisions as a result.”

The biologists’ biggest effort has been on Lake Ontario. They’ve been destroying nests there — and killing some adults – for ten years. Farquhar says they’re finally seeing results.

They’ve reduced the cormorant population on the lake by about two-thirds, and the fishing’s improved.

Now, the biologists are trying to have the same success on the St. Lawrence River. But they’ve only seen a 13% decrease in the number of cormorant nests and they’ve been doing it for four years.

Part of the challenge is that most of the birds live on Canadian soil where management is left to the landowner.

Local anglers like Steve Sharland of Ogdensburg, New York, are frustrated with the slow progress.

“They should eliminate them. They’re not a Northern New York bird and what they’re doing to our fisheries is a sin.”

That’s a common misconception. Actually, the cormorant is native to the region but few people have seen them in such large numbers.

Sharland says some people are so frustrated, they’ve been shooting the birds illegally. But Jim Farquhar believes those are isolated incidents.

“Mike just mentioned that we’ve got some black-crowned night herons nesting out here. It’s another species we’re concerned about, and one we’ve been trying to actively protect from the cormorants. So that’s a good sign.”

A good sign. But it’s another species trying to live on this small patch of land. And the biologists’ balancing act has become even more delicate.

For The Environment Report, I’m Karen Kelly

Related Links

Sport Fishing Drops on Great Lakes

  • Researchers are trying to figure out why fewer people are fishing the Great Lakes. (Photo by Lester Graham)

A national survey of anglers is trying to determine why
fewer people are fishing the Great Lakes. Peter Payette
reports:

Transcript

A national survey of anglers is trying to determine why
fewer people are fishing the Great Lakes. Peter Payette
reports:


The Great Lakes have seen a steep decline in sport fishing
in recent years. But Rob Southwick says there’s little or
no research to explain why.


His firm, Southwick Associates, conducts a national
survey every month on recreational fishing. In December
they asked anglers about the Great Lakes.


Southwick says despite advisories about contamination in
fish in the lakes, less than one percent of those surveyed
mentioned health warnings as the problem.


We think that was a major issue in the late eighties and
early nineties but people are not telling us that is a reason
why they are staying away from the Great Lakes anymore.


Southwick says people are finding other lakes and streams
to fish, even though no one is complaining about the
quality of fishing on the big lakes.


But he thinks the time and gear needed to fish in the deep
wide waters of the Great Lakes are part of the problem.


For the Environment Report, I’m Peter Payette.

Related Links

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.

Related Links

Carp Derby Brings in Foreign Fishers

A strange phenomenon has been occurring on a river in the Great Lakes basin. Anglers from Europe have been arriving in growing numbers to fish for something most of the locals won’t touch – the common carp. But that foreign interest is beginning to attract greater attention. The Great Lakes Radio Consortium’s Karen Kelly reports that some believe carp fishing will offer new hope for a struggling economy:

Transcript

A strange phenomenon has been occurring on a river in the Great Lakes basin. Anglers from
Europe have been arriving in growing numbers to fish for something most of the locals won’t
touch – the common carp. But that foreign interest is beginning to attract greater attention. The
Great Lakes Radio Consortium’s Karen Kelly reports that some believe carp fishing will offer
new hope for a struggling economy:


(sound by river)


Many call the St. Lawrence River an angler’s paradise. 750 miles long, it’s stocked with gamefish
like salmon, pike, bass and walleye.


But the area surrounding it is sparsely populated and a little rundown. It’s never caught on as
much of a tourist destination – until now.


(sound at registration)


It’s ten minutes before the start of the first international junior carp tournament – and the scene in
this Waddington, New York arena is one of organized chaos.


Clumps of teenagers are standing in line, impatient to register. Harried looking volunteers are
handing out instructions and bags of free bait as quickly as they can.


“Your pegs are at the customs house, okay?”


It’s the first time an international carp derby has been hosted on the St. Lawrence – and it’s one of
the largest ever held in the U.S. There are 92 registrants – and they’ve come from places such as
Britain, Italy, Canada, California and Chicago. Top prize is 10 thousand dollars.


Martin James is a fishing correspondent for the British Broadcasting Corporation and an avid carp
angler. He says in Britain, the carp reigns supreme.


“The attitude towards the carp in the United Kingdom, is it’s the number one sports fish. There’s
more people fish for carp than any other species of fish. It’s a billion dollar business.


(outdoors sound)


For people who grew up around here, that idea has taken some getting used to. Most locals go
after fish they can eat – like walleye and bass.


According to the New York health department, carp is loaded with toxins. And so they’ve come
to be known as trash fish, unsafe to eat.


There’s even a bow hunting season for carp in which the fish are killed and discarded.


Local angler Doug Sholette is one of the marshals for the fishing derby. But he admits he’s never
tried carp fishing.


“So even coming into the tournament, you were a little bit skeptical about…” “Actually about
touching it. I’m like it’s a carp, you know?” “And you’re the marshal!” “Yeah, I guess I…I
thought about wearing gloves. But they gave us a rundown and what the Europeans think of carp
changes your whole attitude.”


That’s what fishing guide Jerry Laramay has been waiting to hear.


For five years, he’s been leading carp fishing adventures on the St. Lawrence for anglers from all
over the world. He’s also been just about the only local to try it himself. Laramay helped
organize the tournament with the hope of convincing his neighbors that this so-called trash fish is
a valuable resource.


“Can we affect the economy in this area? Absolutely. In this general area, it’s an impoverished
area, as far as our economy goes. I mean, we have to use these resources. God gave us the St.
Lawrence River in front of us, if you’re not going to use it, you’re a fool.


(yelling – “There it is!”)


Kids come running down the beach as 13 year old Josh Schrader pulls in the first carp of the day.
It’s a moment of excitement but also a learning opportunity. British angler Phil Saunders quickly
hops into the water with a net and starts giving instructions.


“Okay, put him in the sling…”


Saunders carefully lays the fish on a padded mat and then lifts it up to be weighed.


(11 pounds 4 ounces. “Alright Josh!”)


Saunders checks the fish to see if it has any wounds that need treating. Then he gently releases it.
The Europeans never eat them. Before the tournament, both the adult volunteers and the kids in
the derby were given a crash course in so-called carp care. The reasoning is simple. Take care of
the fish, and the catches will grow even bigger.


But Jerry Laramay says, for him, the need for conservation goes beyond sport fishing. He says
he’s seen a lot of wildlife disappear.


“If we don’t start protecting our natural resources, we’re not going to have them anymore. And
one day the carp will be gone also.”


(We haven’t even caught any big fish yet…)


As the day wears on, a clear winner emerges. Warren Dolan of London, England pulls in one
carp after another, while most of the lines around him remain still. He’s come to the derby with
extra poles, bags of special bait imported from England and expert gear to deposit it over the
water. The kids who live here rely on borrowed equipment. But three of them still end up in the
top 10. And many more are going home after reeling in a 10 or 20 pound fish. Jerry Laramay
hopes the experience will create a new generation of St. Lawrence anglers – and new hope for the
communities where they live.


For the Great Lakes Radio Consortium, I’m Karen Kelly.

Related Links

Study: Anglers to Blame for Earthworm Invasion

Earthworms invading forests throughout the region are probably being introduced by anglers. That’s the conclusion of a new study. The Great Lakes Radio Consortium’s Stephanie Hemphill reports:

Transcript

Earthworms invading forests around the Great Lakes are probably
being introduced by anglers. That’s the conclusion of a new
study. The Great Lakes Radio Consortium’s Stephanie Hemphill
reports:


Earthworms are good for gardens. But in forests they eat up the
thick layer of leaves on the forest floor.


Lee Frehlich is with the University of Minnesota. He supervised
the study.

“Many of the tree seedlings and the wildflowers that live in the
forest are actually rooted in all of this leaf material. So when
the worms eat that, their rooting material is literally eaten out
from under them, so a lot of them die.”

The study found in some areas infested with worms, there were
half as many young sugar maples as in worm-free areas. Birds
that use leaves for nests on the ground could also decline.

Frelich says anglers should bring any unused earthworms back home
with them, rather than dumping them in the lake.

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

Dead Fish Are No Cause for Alarm

As trout fishing season opens up throughout the country this month
(April), many fisherman will be lining the banks of streams, lakes
and ponds. One thing that may startle these anglers is the large
amount of dead fish washing up on the shore. But as the Great Lakes
Radio Consortium’s Tom Scheck reports, conservation officials say
pollution and chemical spills may not be to blame: