Fishing
Article Minnesota's Cormorant Population Explosion. Are We Sitting On A
Cormorant Time Bomb?
Keeping An Eye On Cormorants
In Minnesota? Check this page for Articles and updates about bird management
strategies and regulations as they unfold. Lots of useful links to research,
articles and updates concerning Cormorant populations and their influence on
fishing in Minnesota and North America.
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Minnesota’s Cormorant Time Bomb - Jeff Sundin - January
2005 |
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The comeback of the Double Crested Cormorant has
been phenomenal.
Formerly treated as a pest, the once threatened Cormorant
enjoyed consideration as a species of special concern during the late 1960’s
when persistent use of pesticides caused the decline of this and many other
birds. Over the past 30 years, Cormorant populations have rebounded all over
North America and throughout Europe. With no natural predators and continued
federal protections, populations have continued to rise. Wherever
significant populations of Cormorants exist, controversy about their impact
on sport and commercial fishing is sure to surface. Northern Minnesota’s
Cormorant population is one that has steadily increased and evidence of
their presence is being felt by area anglers and resort owners. The question
is whether we’re sitting on a fisheries management time bomb? Or if we can
learn from the experiences of others and get a handle on this threat before
we face another crisis?
Take a close look at the Cormorant in the
center, that's a filleting size fish it's guzzling down. Although they
prefer smaller size fish, they'll eat whatever gets in front of 'em. Click
for larger view. Photo courtesy of Sharon's Page, Birding on Cross Lake.
Large Cormorant populations exist "under the radar" on
a variety of popular waters in Minnesota. Seemingly un-noticed by wildlife
and fisheries management officials, anecdotal reports by anglers, guides and
resort owners suggest that there are sure to be more Cormorant stories to
come. Although there are several areas in Minnesota and throughout the
Midwest where evidence of Cormorant overpopulation is staring us in the
face, Leech Lake has been one of the earliest to reach the boiling point and
draw attention from anglers and fisheries management officials. For now,
here’s one of Minnesota’s highest profile cases.
Northern Minnesota’s Leech Lake like many other large
lake fisheries, has enjoyed a reputation for great Walleye fishing over the
years. But the habitat of Leech Lake has proven to be attractive not only
for fish, but also to the Cormorant. With rocky islands that provide ideal
nesting structure for the birds and plenty of shallow water feeding areas,
Cormorant populations have risen to the level of around 2500 nesting pairs.
After a half dozen years of steadily declining Walleye and Perch fishing,
it’s become known that before you mention Cormorants to a lot of folks
around Leech Lake these days, you better pack a lunch because you’re going
to be there for a while. As a result of speculation about the severity of
the problems associated with high Cormorant populations, Leech Lake
Fisheries Managers were forced to take a close look at the impact of these
birds on fish populations in Leech Lake.
As a result of the preliminary research, The Minnesota
Department of Natural Resources has undertaken a multi-faceted management
approach that combines a highly restrictive protected Walleye slot limit,
Cormorant reduction, Walleye stocking research and habitat management. It is
hoped that the plan will achieve the goal of facilitating a natural recovery
over the next several years. Most folks agree that reducing Cormorant
populations dramatically will be the key to allowing any other part of the
program work correctly.
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The problem is that Cormorants are highly efficient
predatory fishing birds that can dive to depths of 30 feet or more and eat
for about an hour each day. With each bird consuming around a pound of fish
every day, even seemingly small populations of birds are consuming lots of
fish. Just a few hundred Cormorants living on a lake will eat around 50,000
pounds of fish every open water season. On a lake like Leech where you have
already Over 5,000 resident birds, it’s easy to figure out where the small
fish are going. That’s 900,000 pounds of fish every single season! The most
damning evidence, is the fact that Leech Lake still contains a fairly good
population of larger "breeding size Walleye" but has virtually no population
of small fish outside of the deeper waters of Walker Bay. It makes sense, in
certain areas where the water is too deep for Cormorants to reach, these
small fish still exist. In areas where shallower water makes fish easier to
reach, small fish have virtually disappeared. Cormorants can’t eat the
larger fish, so they remain in the system for a while. These larger fish are
the key to facilitate a future recovery and therefore are the subject of a
new protected slot limit to be implemented in 2005.
Since Cormorants aren’t very selective about what kind
of fish they’ll eat, it’s not accurate to assume that every single
disappearing fish is a Walleye, Perch or any other particular game fish.
They will eat any small fish that lives within their key feeding areas, so
all fish from Minnows to Perch to Muskies are affected in some way by their
presence. In the results of a study comparing the angler harvest versus
Cormorant consumption on Lake Oneida – New York, Perch populations suffer
more than do the Walleyes. In fact according to the study, Cormorants
consumed an estimated 58 percent of Yellow Perch before age 10. Cormorants
have affected Smallmouth Bass in Lake Ontario, Catfish in Southern
commercial fish farms and Trout in Bavaria.
The impact of the Cormorant is felt most in that they
stand in the way of the lake’s natural ability to regenerate fish
populations. The larger spawning age fish go to the shallows and spawn like
they always have. But before the young fish can reach adult size, these
birds that prefer the smaller size and larger concentrations of the smallest
fish consume them. So before counting on any real chance of the lake
recovering on it’s own, the necessary reductions in Cormorant populations
must first be addressed. An article by Environment Canada, "winning the war
against Cormorants", says; "the Double-crested Cormorant clearly
demonstrates the "population explosion" phenomenon. This can be expected in
any species occupying a large new habitat". In other words, we should expect
populations to continue to rise much in the same way other exotic species
expand to take over systems as they move in. As the birds in one system
consume food supplies, they branch out to find newer un-tapped resources and
the cycle begins all over again.
The good news is that getting a handle on the problem
is possible and has been accomplished in other areas. After a ten-year
struggle against declining Walleye and perch populations, anglers on New
York’s Lake Oneida are finally reporting that Walleye fishing is rebounding.
One of the secrets was reducing the resident Cormorant population to about
100 breeding birds. In 2001 there was a strong year class of Walleyes and by
2004 catch rates had already risen from .24 to .81 Walleye per hour. That’s
about on par with most of Minnesota’s well known Walleye lakes and
demonstrates the effectiveness of the program. The Cormorant project
undertaken as a joint program of the US Fish and Wildlife Service, New York
State Department of Environmental Conservation and The US Department of
Agriculture, plans to continue the effort to maintain the breeding
population at 100 birds. Providing that the lake continues to produce a
decent year class in at least one out of every few years, fishing should
remain fairly stable for the next several years.
So we know the problem exists and we can point to
examples of where it’s been overcome. For us, it all boils down to whether
our management officials are willing to go the distance in solving the
overpopulation problems as they pop up. Let’s hope that Minnesota’s
reputation for tackling projects head on will win out in the end and we’ll
be able to maintain a balance that makes sense for all of us. With evidence
pouring in from all over the world, we shouldn’t have to wait until each
situation reaches crisis level before taking action. |
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Minnesota DNR To Focus on Restoring
Leech Lake Walleye Fishery 12-12-04 - Jeff Sundin |
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Leech Lake has long been one of my favorite
Walleye Fishing lakes. Unfortunately, Walleye
fishing has been extremely tough during the past few years and my visits have
become increasingly less frequent. Walleye reproduction in the lake appears
to be in trouble and almost all of the Walleyes that are caught by anglers are
older, adult fish considered to be prime spawning size females. Young of the
year Walleyes seem to disappear every year and it's been several years since
there's been a year class adequate to generate a comeback. Opinions vary about the causes and the severity of the problems, but most
folks are beginning to agree about one thing; The large population of
Cormorants on Leech Lake has contributed to the decline and threatens to
prevent a recovery from taking place. Since Cormorants target smaller fish,
protecting brood stock now by initiating a protected slot size limit is
unlikely to help because at this point, producing more young of the year
fish is probably just going to provide the birds with more food and serve to
perpetuate the problem. |
I've been trying to learn as much as I can about Cormorants during the past few months and
after reading some of the studies, it doesn't take long to realize that this problem
is not limited to Leech Lake, Minnesota or even North America. European
anglers face the same problem, as evidenced by the articles, studies and
links you'll find on this page. You be the judge, how can you control a
population of predators that have no natural enemy?
There are a lot of folks who depend on the health of this
great lake for their livelihoods and we ought to do whatever we can to help
Leech Lake and the folks who depend on it make a comeback. Even though Leech
Lake is the focus of attention right now, it's just a matter of time before
the over-population of Cormorants will be affecting many other lakes in our
region. So in my view, getting a handle on the Leech Lake problem is going
to give us a leg up on the problem throughout the area. Public comments are
being accepted right now by the DNR, see the notice below. |
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Doesn't look like too many birds in this
flock does it? Try counting them and remember you're only looking at the
ones on the waters surface. Each bird is eating as much as one pound of fish
each day. This flock alone can take 50,000 pounds of fish in an average
Minnesota summer. |
Here's a list of places to go for more information about
Cormorants Use the information to learn for yourself. Two of the better sources
are Rudstam study on Lake Oneida and The Canadian Wildlife Service Information
from Lake Ontario. I'll provide additional links as they become available.
Lake Oneida, New York - American Fisheries Society study of the comparison of
fish harvests between anglers and Cormorants. PDF read only file. Click on this
link and I can provide you a copy, but I do not have permission to re-print.
American Fisheries Society - Follow this
link to their home page.
The Canadian Wildlife Service, Ontario Region Calls it "A War" with Cormorants on the Great Lakes.
Read this excellent article that describes how the Cormorant population is at
the highest level in recorded history. This is a lengthy article. You'll have to copy and paste the
following link into your address bar because direct linking is not permitted.
http://www.on.ec.gc.ca/wildlife/factsheets/fs_cormorants-e.html
This link takes you to the following ARTICLE published
in the "Tribune-Review". The town is not specified, but presumably in the
Syracuse, NY area. The article has a "pro Cormorant slant", but includes some
interesting statistics. Click on the link to go directly to the site that
contains the article.
http://www.westol.com/~towhee/alerts.htm
Here is a follow-up newspaper article on a story from the
summer of 1998. From the Tribune-Review, Saturday, April 10, 1999: 10 admit killing up to 2,000 birds
Syracuse, NY (AP) - Ten men - three Lake Ontario fishing guides and seven
avid anglers - pleaded guilty in the slaughter of as many as 2,000
cormorants, a federally protected bird with a voracious appetite for fish. In federal court Thursday, nine of the men admitted shooting the birds
last summer. The 10th man admitted hiding the weapons. Sport fishermen and guides on eastern Lake Ontario have long complained
that the cormorants are ruining the fishing and threatening their
livelihoods. The birds were shot on Little Galloo Island, an uninhabited 52 acres five
miles offshore that is the cormorant's principal colony in eastern Lake
Ontario, with an estimated 7,500 nesting pairs. Hundreds of the birds were
wounded and left to die; many of the hatchlings were left to starve to
death. "There is no excuse for the inhumane way in which these birds were
slaughtered and left to die," said Ron Lambertson, regional director for the
U.S. Fish and Wildlife Service. The defendants could get up to six months of home confinement and fines
of up to $2,500 at sentencing Aug. 11. They will also have to donate
collectively a tax-deductible $27,500 to the National Fish and Wildlfie
Foundation.
The double-crested cormorant is protected under the Migratory Bird Treaty
Act. In December, a state study reported that the cormorant consumed an
estimated 87.5 million fish from eastern Lake Ontario in 1998, including 1.3
million small-mouth bass, the lake's most popular sport species. Last month, state officials unveiled a plan to reduce the Little Galloo
colony to 1,500 nests within five years by killing adult birds and spraying
eggs with oil to suffocate the embryos. But the defendants couldn't wait and instead "acted as vigilantes," said
John Cahill, state commissioner of environmental conservation. Defense attorney James McGraw said his clients, Ronald Ditch and his
three sons, were pushed by the state's inaction. Ditch has been a fishing guide on the lake for more than 30 years ans saw
the birds "cutting into his livelihood, ruining the health of the lake and
destroying the local economy'" the attorney said. "They waited and waited and watched the destruction of the fishery.
Finally, they did something about it," McGraw said.
My thoughts: (refers to the author of this article)
The Little Galloo Island cormorant colony is going to be reduced either
by the illegal actions of vigilantes (gunning) or by the legal actions of
state officials (oiling of eggs). The vigilantes killed an estimated 2,000
cormorants in the summer of 1998. NY state officials, according to the
newspaper article, plan on reducing a colony estimated at 7,500 nesting
pairs (15,000 individuals) to 1,500 nesting pairs (3,000 individuals) in
five years, akin to killing 2,400 individual birds per year. So the
vigilante fishermen were not far off the mark of the state's official plan.
The cormorants have been found guilty of competing with humans for natural
resources, and we all know who wins such competitions in the wars and
battles of voracious appetites.
The anglers vs the
cormorants Bitish Anglers vs Cormorants
By Paul Brown Article found in the Hindu, India's National
Newspaper
LONDON, SEPT. 17. Thousands of cormorants are to be shot
because British anglers complained that they were eating the fish they wanted to
catch. This has enraged the Royal Society for the Protection of Birds (RSPB),
which says the species is protected and it will take court action to save them.
Ben Bradshaw, the British Minister for Nature Conservation,
did not consult the RSPB before announcing yesterday that 3,000 birds a year
could be slaughtered. Over six years this would wipe out the British cormorant
population, even though the European Union Birds Directive protects the species.
The rules permit the culling of up to 300 birds a year if all
other methods to scare them away or protect the fish have failed. Now there will
be a presumption that the presence of cormorants is leading to fish losses.
Growth in
numbers There are an estimated 17,000 resident cormorants and 6,000
winter visitors; a big increase from the 1980s, when cormorants were a relative
rarity inland, being mostly confined to coasts and estuaries. Heavily stocked
trout lakes have provided easy pickings, and the improved quality of rivers and
lakes has let cormorants breed.
Mr. Bradshaw said his ruling was not intended to wipe out the
cormorant but to reduce the number. ``We have accepted for some time that
cormorants can and do cause damage to certain habitats.''
No
justification Mark Avery, Director of Conservation at the RSPB, said:
``The Minister has never consulted us about this. There is no scientific
justification for this, and we believe it is against the law.
``This is the thin edge of a very thick wedge. Next anglers
will be complaining that otters and ospreys are eating fish. Gamekeepers will
say merlins are wiping out grouse and farmers complain geese are damaging their
crops.
He asked: ``Is all wildlife vulnerable to some special
interest group pleading with the minister that their financial interests are
being damaged? There is no scientific or legal justification for killing on this
scale. We are consulting our lawyers and have already sent a warning letter to
ministers saying we believe they are in breach of E.U. law. We will take any
action we can to get this decision overturned.''
Decision
hailed The Moran Committee, which represents anglers, was delighted with
the decision. Terry Mansbridge, the chairman of its bird group, said: ``This
will significantly improve the ability of fishery managers to protect their fish
stocks whilst not affecting the conservation status of the birds.''
The killing season for cormorants will be August 31 to April
15, but this may be extended to May 1 in fish spawning sites.
The British Association for Shooting and Conservation also
welcomed the decision. Its director of conservation, Tim Russell, said: ``Many
people who shoot are also keen anglers and have seen at first hand the
devastation which a colony of cormorants can caused to inland fisheries and
waterways.''
Industrial
fishing On another issue the RSPB released a report yesterday on
industrial fishing for sand eels in the northeast Atlantic. They are turned into
animal feed and pellets for farmed fish.
Many seabird species, which rely on young fish and sand eels
to feed their young, are in steep decline in that area. The RSPB has been
campaigning for curbs on industrial fishing which it believes will lead to
further crashes in fish stocks. - Guardian Newspapers Limited 2004
