Invasive Die-Off Stirs Fishery Debate

  • A naturally reproduced wild lake trout fingerling. (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.

Related Links

Ten Threats: Canals Past and Present

  • This is an ocean vessel in the Soo Locks, Sault Ste. Marie, Michigan. The Soo Locks connect Lake Superior and Lake Huron, allowing for ships to travel back and forth. (Photo courtesy of EPA)

One of the Ten Threats to the Great Lakes identified by experts across the region is the possible
expansion of canals to allow larger ocean-going ships into the lakes. Some see the expansion of
shipping channels as a threat to the environment; others see it as great economic opportunity.
Just like in the early days of settlement, they see the shipping channels on the Great Lakes as
a way to make trade opportunities better.

Transcript

In our next report from the series, “Ten Threats to the Great Lakes,”
Lester Graham brings us a look at shipping on the lakes. Some people think
bigger ships could bring more trade to the region:


One of the Ten Threats to the Great Lakes identified by experts across the region is the possible
expansion of canals to allow larger ocean-going ships into the lakes. Some see the expansion of
shipping channels as a threat to the environment; others see it as great economic opportunity.
Just like in the early days of settlement, they see the shipping channels on the Great Lakes as
a way to make trade opportunities better.


Native Americans had canoe trade routes on the Great Lakes long before the Europeans appeared
on the scene. When French fur traders arrived, they copied what they saw. They built birch-bark
canoes to travel the lakes and to haul back fur pelts.


(Sound of Saginaw Voyageurs paddling and singing “Alouette, gentile Alouette…”)


Chuck Hoover is with the Saginaw Voyageurs, a group of re-enactors who re-trace the French
Voyageurs routes. Hoover says the large canoes were great until you ran into rapids on the rivers
connecting the lakes.


“What you had to do was pick up everything, including the boat, and carry it across the dry land to
the next place that you could put in water that was navigable.”


Those portages could be as long as seven miles. Carrying a canoe big enough to haul more than a
dozen men and the heavy bundles of fur pelts was a tough job and it slowed trade. So, some small
canals were dug to make passage easier. As the region developed even more valuable natural
resources were discovered. Bigger canals were needed.


Stanley Jacek is an Area Engineer with the U.S. Army Corps of Engineers at the canal and locks
at Sault Ste. Marie, Michigan. He says by the middle of the 1800s mining around Lake Superior
had become big business.


“Back in those days they discovered iron ore and copper in the upper end of the lakes here. So,
they had to get all that commerce down to the heartland of the country, so locks had to be
built.”


With a canal and locks to help ships negotiate the drop from one lake level to the next, the ore
could be transported to the big steel mills in industrial cities such as Cleveland and Gary, Indiana.


Christopher Gilchrist is with the Great Lakes Historical Society. He says you can’t underestimate
the value of those canals.


“The water-borne transportation was critical for the creation of the industrial age in U.S. history.
There’s a reason why the steel mills are located right on the banks of these Great Lakes. All the major
steel mills were located right by the water so that they could get their raw materials cost
effectively.”


At the other end of the Great Lakes the St. Lawrence Seaway opened in the 1950s to make it
possible for ships on the Atlantic Ocean to enter the lakes, and another big canal and set of
several locks overcame another obstacle to shipping on the Great Lakes – The Niagara Falls.


The Welland canal allows ships to go around Niagara. Since it first opened in the 19th century the
Welland canal and its locks have been enlarged four times. Each time the Welland canal locks
and the St. Lawrence Seaway have been made wider and deeper, the shipping industry builds
bigger and bigger ships to the point that they literally just squeak through…


(Sound of ship squeaking against timbers)


…Often rubbing up against the timbers that act as bumpers on the locks’ concrete walls.


Throughout the history of the canals, there’s been pressure to make them bigger and bigger.
Many feel the amount of shipping through the canals is tied directly to the economic well being
of the nation. The more the canals can handle the better the economy.


(Sound of buzzing, roar of compressor)


Back at Sault Ste. Marie, the locks open to allow another big ship through.


Stanley Jacek, the engineer at the Soo Locks connecting Lakes Superior and Huron says the
economic impact is pretty easy to track.


“What we do here in the way of passing of commerce mimics what’s happening in the country. You
can actually see spikes in the economy by looking at our traffic here.”


But some say the canals could do more than just reflect the health of the economy. They could
spur the economy if even bigger ships could come into the lakes. The ships, the kind carrying
containers ready to be pulled by trucks or loaded on rail cars, could go directly to Great Lakes
ports instead of ports on the East or West coasts. More direct shipping might improve the
region’s economy.


But environmentalists are worried. They say bigger ships from all over the world might mean
more alien invasive species damaging the Great Lakes. The wider, deeper channels might
damage the environment along scenic rivers connecting the lakes, and some believe expanding
the channels will let too much water flow out of the lakes that could worsen the problem of lower
lake levels seen in recent years.


The plans for bigger ships are on hold for right now. But, given the history of the canals, many
believe expansion is only a matter of time.


For the GLRC, this is Lester Graham.

Related Links

Ten Threats: The Earliest Invader

  • A bridge for a river... this portion of the Erie Canal crossed the Genesee River via an aqueduct in Rochester, NY. This photo was taken around 1914. (From the collection of the Rochester Public Library Local History Division)

The Ten Threats to the Great Lakes” is looking first at alien invasive species. There are more than 160 non-native species in the Great Lakes basin. If they do environmental or economic harm, they’re called invasive species. There are estimates that invasive species cost the region billions of dollars a year. Different species got here different ways. David Sommerstein tells us how some of the region’s earliest invaders got into the Lakes:

Transcript

We’re bringing you an extensive series on Ten Threats to the Great Lakes. The Great Lakes Radio Consortium’s Lester Graham is guiding us through the reports:


“The Ten Threats to the Great Lakes” is looking first at alien invasive species. There are more than 160 non-native species in the Great Lakes basin. If they do environmental or economic harm, they’re called invasive species. There are estimates that invasive species cost the region billions of dollars a year. Different species got here different ways. David Sommerstein tells us how some of the region’s earliest invaders got into the Lakes:


If the history of invasive species were a movie, it would open like this:


(Sound of banjo)


It’s 1825. Politicians have just ridden the first ship across the newly dug Erie Canal from Buffalo to New York.


(Sound of “The Erie Canal”)


“I’ve got an old mule, and her name is Sal. Fifteen miles on the Erie Canal…”


Chuck O’Neill is an invasive species expert with New York Sea Grant.


“At the canal’s formal opening, Governor DeWitt Clinton dumped a cask of Lake Erie water; he dumped that water into New York Harbor.”


Meanwhile, in Buffalo, a cask of Hudson River water was triumphantly poured into Lake Erie.


“In a movie, that would be the flashback with the impending doom-type music in the background.”


(Sound of ominous music)


It was an engineering and economic milestone, but a danger lurked. For the first time since glaciers carved the landscape twelve thousand years ago, water from the Hudson and water from the Great Lakes mixed.


(Sound of “Dragnet” theme)


Enter the villain: the sea lamprey. It’s a slimy, snake-like parasite in the Atlantic Ocean. It sucks the blood of host fish.


Within a decade after the Erie Canal and its network of feeders opened, the sea lamprey uses the waterways to swim into Lake Ontario. By the 1920’s and 30’s, it squirms into the upper Lakes, bypassing Niagara Falls through the Welland Canal.


What happens next is among the most notorious examples of damage done by an invasive species in the Great Lakes. By the 1950’s, the sea lamprey devastates Lake trout populations in Lake Superior. Mark Gaden is with the Great Lakes Fishery Commission.


“They changed a way of life in the Great Lakes basin, the lampreys. They preyed directly on fish, they drove commercial fisheries out of business, the communities in the areas that were built around the fisheries were impacted severely.”


The sea lamprey wasn’t the only invader that used the canals. Canal barges carried stowaway plants and animals in their hulls and ballast. In the mid-1800’s, the European faucet snail clogged water intakes across the region. The European pea clam, purple loosestrife, marsh foxtail, flowering rush – all used the canal system to enter the Great Lakes.


Chuck O’Neill says the spread of invasive species also tells the tale of human transportation.


“If you look at a map, you can pretty much say there was some kind of a right-of-way – railroad, canal, stageline – that was in those areas just by the vegetation patterns.”


Almost one hundred invasive species came to the Great Lakes this way before 1960. O’Neill says every new arrival had a cascading effect.


“Each time you add in to an ecosystem another organism that can out-compete the native organisms that evolved there, you’re gradually making that ecosystem more and more artificial, less and less stable, much more likely to be invaded by the next invader that comes along.”


(Sound of “Dragnet” theme)


The next one in the Great Lakes just might be the Asian Carp. It’s swimming up the Illinois River, headed toward Lake Michigan. Cameron Davis directs the Alliance for the Great Lakes.


“If this thing gets in, it can cause catastrophic damage to the Great Lakes, ‘cause it eats thirty, forty percent of its body weight in plankton every day, and plankton are the base of the food chain in the Great Lakes.”


The U.S. Army Corps of Engineers has installed an electric barrier in the Chicago Sanitary and Ship Canal that might stop the carp. But as long as the canals around the region remain open for shipping and recreation, it’s likely more invaders may hitch a ride or simply swim into the Great Lakes.


For the GLRC, I’m David Sommerstein.

Related Links

Epa Declares Love Canal Clean

Its discovery 25 years ago led to the creation of the EPA Superfund Program for the cleanup of toxic waste sites. Now, the Environmental Protection Agency says cleanup work is finished at the infamous Love Canal dumpsite in Niagara Falls, New York. The Great Lakes Radio Consortium’s Bud Lowell has more:

Transcript

Its discovery 25 years ago led to the creation of the EPA Superfund Program for the cleanup of
toxic waste sites. Now the Environmental Protection Agency says cleanup work is finished at the
infamous Love Canal dumpsite in Niagara Falls, New York. The Great Lakes Radio
Consortium’s Bud Lowell has more:


The Love Canal neighborhood became a national symbol for the problems of toxic waste in 1978.
Nine hundred families were evacuated. An elementary school and two streets of homes were
bulldozed. The remaining landfill was sealed off.


Today, EPA says the 70-acre site can come off the Superfund List but Mike Schade with a
Buffalo-based group called the Citizens Environmental Coalition isn’t so sure. He says about 22-
thousand tons of World War II era chemical byproducts remain buried at the Love Canal site.


“Now, while the EPA and Occidental are monitoring the landfill, time will prove that landfill will
eventually leak. It’s really, inevitable.”


Schade believes the EPA announcement seeks to defuse criticism of a recent U.S. Senate vote.
That vote blocked reauthorizing a law taxing oil and chemical companies to support the
Superfund program.


For the Great Lakes Radio Consortium, I’m Bud Lowell.

Related Links

Saving Niagara’s Natural Beauty

A historian believes one of the world’s most visited natural sites is
being ruined by tourist development. The Great Lakes Radio Consortium’s
Lester Graham reports that instead of new hotels and casinos…one man is
pushing for an appreciation of the natural beauty of Niagara Falls: