Tag: cormorant

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

Fish-Eating Bird Disrupting Food Chain?

The once near-extinct double-crested cormorant has made a dramatic comeback in the past few decades, and sport fisherman say the fish-eating birds are hurting their business. But as states move to limit their cormorant populations, there’s still no solid research that the birds are really to blame. The GLRC’s Gregory Warner reports:

Transcript

The once near-extinct double-crested cormorant has made a dramatic
comeback in the past few decades, and sport fisherman say the
fish-eating birds are hurting their business. But as states move to
limit their cormorant populations, there’s still no solid research that
the birds are really to blame. The GLRC’s Gregory Warner reports:


More states are joining the war on cormorants: oiling eggs to prevent
them from hatching, or shooting the birds. More than 11,000 of the
federally-protected birds were shot last year.


But there’s still no scientific proof saying birds compete with sports
fisheries. Jim Farquar is a biologist with the New York Department of
Conservation:


“We’ve not been able to detect declines in the fisheries at this point
in time. But that doesn’t mean that with a larger cormorant population
it won’t happen.”


At issue is diet. Cormorants eat whatever small fish are available,
leaving big game fish alone. In some regions, the birds eat almost
exclusively round gobies, an invasive species. Anglers believe that
cormorants disrupt the food chain, causing the numbers of larger fish to
decline.


For the GLRC, I’m Gregory Warner.

Related Links

Cormorant-Killing Policy Ruffles Feathers

  • Cormorant populations have risen exponentially from their previously dismal numbers. (Photo courtesy of the NOAA)

Across the Great Lakes region, the recovery of the cormorant
is booming. But some anglers and resort owners think the cormorants are eating too many of the fish that people like to eat. In some areas, wildlife managers have resorted to killing cormorants on popular fishing lakes. In one case, critics say there’s not enough evidence to justify the killing. The Great Lakes Radio Consortium’s Stephanie Hemphill reports:

Transcript

Across the Great Lakes region the recovery of the cormorant is booming. But some anglers and resort owners think the cormorants are eating too many of the fish that people like to eat. In some areas, wildlife managers have resorted to killing cormorants on popular fishing lakes. In one case, critics say there’s not enough evidence to justify the killing. The Great Lakes Radio Consortium’s Stephanie Hemphill reports:


Larry Jacobson is the third generation in his family to run the Hiawatha Beach Resort on Leech Lake, about two hundred miles north of Minneapolis. Three years ago, on fishing opener weekend, all of his twenty-one cabins were full. This year, he had no guests. Jacobson says the word has spread that fishing is down on Leech Lake. He blames the cormorants. The birds nest on a small island in the south end of the lake. Eight years ago, there were fifty nests; last year, there were two thousand five hundred.


“The cormorants eat about a pound fish a day. The way the population was just exploding out there, you could see writing was on the wall, that this was really going to make dramatic impact.”


Jacobson says his guests are still catching big walleye, but the smaller, pan-sized walleye are getting hard to find.


There are several reasons why the walleye population might be down, but Jacobson and other business owners blame it on the cormorants, and they’ve asked the Department of Natural Resources to do something about the birds.


“Leech needs to be maintained as high quality fishery. There’s such an economic impact to the area from walleyes, that if you don’t maintain it that way, everyone’s going to be suffering.”


(Sound of boat motor)


Resource officials are responding to the resort owners’ concerns. The Leech Lake Band of Ojibwe owns the island. John Ringle is wildlife manager for the tribe.


“Okay we’re headed right at Little Pelican Island right now.”


Little Pelican Island is about three acres of sand and scruffy shrubs. Hundreds of cormorants cover the shore. Ringle says they fish out here in the open waters of Leech Lake.


“They’re omnivorous so they’re eating all sorts of different varieties of fish. Right now they’re probably eating large numbers of perch.”


Ringle is working with state and federal agencies to reduce the number of cormorants nesting here, eating fish, and crowding out other birds, such as the endangered common tern.


Normally, cormorants are a federally protected bird, just like eagles. That’s because they were almost wiped out by the insecticide DDT before it was banned in 1973. But a new rule allows resource officials to harass and even kill cormorants where they’re damaging other wildlife.


This summer, workers are sitting in hunting blinds on Little Pelican Island, shooting cormorants. They use air rifles to make as little noise as possible, so the other cormorants aren’t spooked away.


So far, they’ve killed more than two thousand birds. They plan to leave about five hundred nesting pairs alive. Ringle says nobody’s happy about shooting cormorants, but he says he thinks it’s necessary.


RINGLE: “My philosophy is that as mankind utilizes the resource, we have to manage them, we’re not in finite supply.”


HEMPHILL: “Do you think we know enough to manage them?”


RINGLE: “Not really. I think the public is demanding action prior to any conclusive study being conducted.”


And that’s a big problem for Francie Cuthbert. She’s a professor and cormorant researcher at the University of Minnesota. Cuthbert says the agencies that want to cut down the cormorant population skipped an important part of the management process: finding out what’s actually happening on Leech Lake.


“They’re really being driven by complaints from citizens and resort owners who are concerned about local economics, and who just don’t like the birds; they’re afraid of the numbers. If we responded to all natural resources conflicts this way, we’d be in a state of chaos.”


Cuthbert says even with the cormorants’ dramatic comeback since the days of DDT, there still aren’t as many as there were a hundred years ago. She says rather than kill cormorants, wildlife officials should try to boost the number of fish.


The state of Minnesota is working on that. It’s stocking Leech Lake with walleye for the first time this year. Conservation officials are studying some of the birds they killed to find out what they’re eating. And the state is also limiting what size of walleye anglers can catch so the fish can recover.


That makes resort owners like Larry Jacobson nervous, because he says a lot of anglers don’t like the limits. But at least he’s glad someone’s doing something.


“The fishery is a business, there’s no question about that. If you want to sustain our economy in this area, you’ve got to manage the lake.”


Workers will continue shooting cormorants occasionally through the summer. And the control effort could continue. Experts say it’ll take several years for the fish to recover enough to draw anglers back to the lake.


For the GLRC, I’m Stephanie Hemphill.

Related Links

Cormorant Control Begins in Earnest (Part 1)

In many ways, the double-crested cormorant is a wildlife success story. The
birds were almost wiped out by pesticide exposure in the 1960’s. But in
recent years, they’ve returned in large numbers to prime fishing areas in
the Great Lakes and elsewhere. In fact, they’re so good at catching fish,
commercial fishermen have been affected. In the first of a two part series,
the Great Lakes Radio Consortium’s Karen Kelly found that the biologists who
protect these birds are also looking for ways to get rid of them:

Legacy Left by Cormorant Slaughter (Part 2)

The double-crested cormorant has been an enemy of fishermen for centuries.
They’ve eaten salmon on the Atlantic coast, catfish in Missouri and game
fish in the Great Lakes. Fishermen complain the cormorants are bad for
business. And last summer, fishing guides on Lake Ontario made their point
by killing more than two thousand birds. A year later, they’ve been caught
and arrested. In the second of a two part series, the Great Lakes Radio
Consortium’s Karen Kelly reports the effect of those killings is still being
felt:

Cormorant Control

In April, the U-S Fish and Wildlife Service denied a permit request
from New York State to kill three-hundred cormorants on eastern Lake
Ontario. The proposed management plan as well as previous killings by
individual sportsmen has Great Lakes Radio Consortium commentator Don
Ogden reflecting:

Cormorant Control

Federal fish and wildlife officials will most likely let New York state
reduce the number of double breasted cormorants on Lake Ontario… but
not by euthanizing the birds. The Great Lakes Radio Consortium’s
Elizabeth Christensen reports: