Foreign ships like this one from Cypress are known as "Salties." They account for about 5% of ship traffic on the Great Lakes. If a salty dumps its ballast water in a Michigan port, they first have to show the state that they've sanitized the water. International shipping agencies have sued the state over this law. (Photo by Mark Brush)
The fight over foreign invasive pests in cargo ships is heating up. Mark Brush
reports environmental and conservation groups are going to court to defend
one of the toughest ballast water laws in the country:
Transcript
The fight over foreign invasive pests in cargo ships is heating up. Mark Brush
reports environmental and conservation groups are going to court to defend
one of the toughest ballast water laws in the country:
It’s been estimated that invasive species in the Great Lakes do billions of dollars in
damage every year. To stop foreign pests from getting into its waters, the state of
Michigan passed a law that affects all ocean-going ships stopping in
its ports. It requires them to sanitize their ballast to eliminate
invasive species that stow away in it.
International shipping agencies sued the state. They say Michigan’s
law will hurt interstate commerce.
Andy Buchsbaum is the director of the National Wildlife Federation’s
Great Lakes office. It’s one of the groups defending the ballast water
law. He says the international shipping industry might have opened
itself up to counter litigation:
“They fired the first shot – the ocean going shipping industry fired
the first shot, but it’s only the first shot. And I think you’re going
to see an awful lot of action that follows through on this. They’re
going to regret that they filed this lawsuit.”
A hearing on Michigan’s Ballast Water law is scheduled to take place
this May.
Peter H. Gleick, President and co-founder of the Pacific Institute, is concerned that without reducing greenhouse gas emissions, global warming will have dire impact on water resources. (Courtesy of the Pacific Institute)
With concern about climate change growing, some scientists are trying to determine how global warming will affect sources of water. Lester Graham spoke with the President of the Pacific Institute, Peter Gleick about what climate change might mean to weather patterns:
Transcript
With concern about climate change growing, some scientists are trying to determine how global warming will affect sources of water.
Lester Graham spoke with the President of the Pacific Institute, Peter Gleick about what climate change might mean to weather
patterns:
PG: Overall, the planet is gonna get wetter because as it gets hotter, we’ll see more
evaporation. The problem is, we aren’t always gonna get rain where we want it.
Sometimes we’re gonna get rain where we don’t want it. And at the moment it looks like
the biggest increases in rainfall will be in the northern regions where typically water is
less of a problem. Or at least water quantity is less of a problem. And we may actually get
less rainfall in the Southwest where we need it more.
LG: Let’s talk about some of the precious areas to North America. For instance, a lot of
people are worried about snow pack in the Rockies.
PG: Yes, well, one of the most certain impacts of global climate change is going to be
significant changes in snowfall and snowmelt patterns in the western United States as a
whole, actually in the United States as a whole because as it warms up, what falls out of
the atmosphere is going to be rain and not snow. Now that really matters in the Western
United States, in the Rocky Mountains and the Sierra Nevada where our snow pack really
forms the basis of our water supply system. Unfortunately, as the climate is changing,
we’re seeing rising temperatures and decreasing snow pack. More of what falls in the
mountains is falling as rain, less of it’s going to be snow. That’s going to wreck havoc on
our management system, the reservoirs that we’ve built to deal with these variations in
climate. Incidentally, it’s also going to ruin the ski season eventually.
LG: You mentioned that the farther north you go, according to some models, we’ll see
more rain or more precipitation. At the same time, with warmer temperatures, we’ll see
less ice covering some of the inland lakes, such as the Great Lakes, which means more
evaporation. So, what are we going to see as far as those surface waters sources across
the continent?
PG: Without a doubt, global climate is changing. And it’s going to get worse and worse
as humans put more and more greenhouse gases in the atmosphere. And as it gets
warmer, we’re going to see more evaporation off of the surface of all kinds of lakes,
including especially the Great Lakes. And interestingly, even though we don’t have a
great degree of confidence of what’s going to happen precisely with precipitation in the
Great Lakes, all of the models seem to agree that over time, the Great Lakes levels are
going to drop. And it looks like we’re going to lose more water out of the surface of the
Great Lakes from increased evaporation off the lakes than we’re likely to get from
precipitation, even if precipitation goes up somewhat. And I think that’s a great worry for
homeowners and industry around the margin of the lake. Ultimately for navigation,
ultimately for water supply.
LG: There’s a lot of talk about the gloom and doom scenarios of global warming, but
they’ll be longer growing seasons and we’re also going to be seeing, as the zones change,
more of this fertile ground in as northern US and Canada get longer growing seasons.
That’s not a bad thing.
PG: There are going to be winners and loser from global climate change. And
interestingly, there are going to be winners and losers at different times. Certainly, a
longer growing season is a possibility as it warms up. And I think that, in the short term,
could prove to be beneficial for certain agriculture in certain regions. Interestingly
though, and perhaps a little depressingly, over time, if the globe continues to warm up, if
the globe continues to warm up, evidence suggest that the short term improvements in
agriculture that we might see might ultimately be wiped out. As it gets hotter and hotter,
some crop yields will go down after they go up. We’re going to see an increase in pests
that we didn’t used to see because of warmer weather. Unfortunately, pests like warmer
weather. Furthermore, if we don’t really get a handle on greenhouse gas emissions, if we
don’t really start to cut the severity of the climate changes that we’re going to see, the
doom and gloom scenarios unfortunately get more likely. Over time, the temperatures go
up not just one or two or three degrees Celsius but four or five or eight degree Celsius.
And that truly is a catastrophe for the kind of systems we’ve set up around the planet.
HOST TAG: Peter Gleick is a water expert and President of the Pacific Institute for Studies in Development, Environment and Security, based in California.
Ballast holds can carry aquatic species from foreign ports to U.S. ports. Those species can cause severe damage to the ecological system of harbors, lakes and rivers. (Photo courtesy of NOAA Great Lakes Environmental Research Laboratory)
The Saint Lawrence Seaway is now open to international ship
traffic from the Atlantic Ocean to the Great Lakes. But as
Sarah Hulett reports, the start of this year’s Great Lakes
shipping season is raising questions about a new state law aimed
at protecting the lakes from invasive species:
Transcript
The Saint Lawrence Seaway is now open to international ship
traffic from the Atlantic Ocean to the Great Lakes. But as
Sarah Hulett reports, the start of this year’s Great Lakes
shipping season is raising questions about a new state law aimed
at protecting the lakes from invasive species:
The state of Michigan is now requiring ocean-going ships that
come into the state’s ports to get ballast water permits, and
agree not to discharge untreated ballast into the lakes.
Ballast water is pumped in and out of a ship to help keep it
level in the water, but ballast water is known to carry small
organisms from foreign waters that can wreak havoc on Great
Lakes’ ecosystems.
So far, only two shipping companies have applied for the
permits. John Jamian heads the Seaway Great Lakes Trade
Association:
“The joke is that the big players that represent over 98% of the
cargo that comes into Michigan ports have not filed for permits.”
Jamian’s organization and others are suing to get the law
overturned. They say it violates the Commerce Clause of the U.S.
Constitution.
Wildlife officials want to eliminate the European mute swan so it doesn't compete with native birds. (Photo by Christina Shockley)
Controversy over what to do about a non-native swan has taken an
unusual turn. One state that was going to kill all of its mute swans
will now give some of them a short lease on life. It’s going to let
people “adopt” the wild birds. Christina Shockley has the story:
Transcript
Controversy over what to do about a non-native swan has taken an
unusual turn. One state that was going to kill all of its mute swans
will now give some of them a short lease on life. It’s going to let
people “adopt” the wild birds. Christina Shockley has the story:
Mute swans are large, gorgeous, white birds. They were brought to the
U.S. from Europe in the 1800s to beautify parks and estates. The swans
were meant to be kept in captivity, but they escaped, and since, the
numbers have skyrocketed along the Great Lakes and Eastern seaboard.
So, like in other areas, the Wisconsin Department of Natural Resources
has come up with a plan. The state wants to shoot all the mute swans,
but this doesn’t sit well with a lot of people.
Pat Kujawa is one of them. Kujawa is sitting in her home on Phantom
Lake. The area is home to about 85% of Wisconsin’s mute swans. Each
summer for several years, Kujawa’s family has bonded with the mute
swans. She sees the birds as neighbors on the lake.
She holds a photo album full of pictures of the swans and her kids as
they grew up:
“We have pictures of our son Kyle swimming with them, and he’s probably
about I would say 8 or 9 years old, and again other pictures like that,
showing the parents standing back, and all of the babies coming up and
taking bread right out of Kyle’s hands. Sort of suggests that perhaps
the DNR characterization of them being aggressive is somewhat
misguided, or at least it’s what they want people to hear.”
Wildlife officials say the mute swans ARE aggressive, especially during
the nesting and breeding season. They say the mutes push native birds
out of their habitat and upset aquatic life by uprooting vegetation
along the shore.
Officials also say the mute swan was posing a problem as the state
worked to re-introduce the native trumpeter swan. Their numbers have
just recovered.
But because of protests from people like Kujawa, the state government
says it will temporarily modify its mute swan eradication plan. What
they’re doing might seem a little unusual. The state is going to let
people in three counties “adopt,” or sponsor, as many mute swans as they
want.
Erin Celello is from the Department of Natural Resources. She says
people won’t have to bring the birds in the house to live like a cat or
dog, but she says they will have to get the swans fixed:
“They will be able to apply for a permit, to capture a swan from the
wild, and they will be required to neuter that swan, and re-release
that swan into the wild.”
Celello says that will keep the birds from breeding, and the state
won’t shoot the birds when they see them:
“We felt that this is kind of a win-win for everyone. As an agency, we
are still upholding our share of what has become a national mute swan
control policy, while at the same time, allowing for citizens who have
formed emotional attachments to these birds, to keep those birds
around, and keep them on their landscape.”
Celello says the state’s goal is still to kill all of the mute swans. She
says officials will shoot the mutes that aren’t wearing neck tags that
show the birds have been spayed or neutered. And obviously the swans
that have the surgery won’t be having babies. One vet says the spaying
or neutering procedure could cost between 150 and 250 dollars per bird,
and Grace Graham says that might be difficult for her to afford.
Graham is Pat Kujawa’s neighbor on Phantom Lake.
The 70-year-old retired school teacher has been swimming with, and
feeding, the mute swans for years. She says the mute swans should just
be left alone and that it’s wrong to eliminate a species. But she
knows, ultimately, if it’s impossible for the birds to reproduce, the
swans will be gone at some point:
“I don’t want to even think about our lake not having any mute swans on
it. All this summer, the last time I swam with them before the water
got cold I thought, Grace, this is the last time you’re going to get to
do this. Last time you fed them, last time you do all of these things.
It’s kind of like a death thing.”
For the Environment Report, I’m Christina Shockley.
A commission that advises the US and
Canadian governments on the Great Lakes wants to
see more accountability from Washington and
Ottawa. Chuck Quirmbach reports:
Transcript
A commission that advises the US and
Canadian governments on the Great Lakes wants to
see more accountability from Washington and
Ottawa. Chuck Quirmbach reports:
The International Joint Commission is focusing its latest report on
getting the US and Canada to set up an accountability plan for
restoring and protecting the Great Lakes.
US Commissioner Allen Olson says one example of accountability is
getting Congress to approve money for an Asian Carp barrier near
Chicago to keep the foreign fish out of the lakes.
“There are a number of members of the United States Congress of both
parties that are immediately accountable to address that issue.”
Canadian Commissioner Jack Blaney says the governments also have to be
accountable to what citizens said at recent IJC hearings:
“They want to swim at their beaches, they want to be able to eat the
fish. They want to be able to take water out of the lakes that they
don’t have to spend enormous sums treating.”
The IJC wants a preliminary plan to be ready by the summer of next
year.
Federal restrictions have not stopped importation of invasive species. Now some states are passing laws that will stop some ocean-going ships from docking in their ports. (Photo by Lester Graham)
Ocean-going cargo ships are blamed for bringing in many aquatic invasive species that damage the environment, such as zebra mussels, quagga mussels and round gobies. These foreign species also cost the economy in lost fishing, clogged intake pipes, and in eradication efforts. (Photo by Lester Graham)
US ports receive more than imported cargo.
They often receive fish and other aquatic organisms
from foreign ports. They stow away in the ballast
water of cargo ships. Once in US waters, some of
the foreign species become invaders, damaging the
ecosystem. The federal government has done little
to stop these invasive species. Rick Pluta reports now some states have decided to take
things into their own hands:
Transcript
US ports receive more than imported cargo.
They often receive fish and other aquatic organisms
from foreign ports. They stow away in the ballast
water of cargo ships. Once in US waters, some of
the foreign species become invaders, damaging the
ecosystem. The federal government has done little
to stop these invasive species. Rick Pluta reports now some states have decided to take
things into their own hands:
The damage caused by invasive species carried to the US in
ballast water is not only harmful to the environment, but it
hurts the economy. The federal regulations have not stopped the
problem. So, states such as California and Michigan have passed
laws that require foreign ships to treat ballast water like
pollution. They have to clean it up before they can discharge it
into a port. The problem is, almost no ships have a way to treat
the ballast.
In Michigan, the Great Lakes shipping industry is trying to delay
the new Michigan rules. Shipping companies, port owners, and
dock workers say Michigan’s new rules are jeopardizing jobs
without actually stopping the introduction of new species into
the Great Lakes.
The damage caused by invasive species carried to the US in
ballast water is not only harmful to the environment, but it
hurts the economy. The federal regulations have not stopped the
problem. So, states such as California and Michigan have passed
laws that require foreign ships to treat ballast water like
pollution. They have to clean it up before they can discharge it
into a port. The problem is, almost no ships have a way to treat
the ballast.
In Michigan, the Great Lakes shipping industry is trying to delay
the new Michigan rules. Shipping companies, port owners, and
dock workers say Michigan’s new rules are jeopardizing jobs
without actually stopping the introduction of new species into
the Great Lakes.
People in the shipping business say the problem is Michigan is
the only state in the Great Lakes region that is requiring ocean-
going freighters to install expensive technology as a condition
of using one of its ports.
John Jamian is the president of the Seaway Great Lakes Trade
Association. He says requiring ocean-going freighters to install
expensive technology before they can dock in Michigan ports won’t
solve the problem. The ships will just go to other Great Lakes
ports.
If a ship goes to Windsor or Toledo that doesn’t have these rules
and regulations, they will discharge their cargo. If there were
any critters on those ships they could still swim or crawl into
Michigan waters, so you still haven’t solved anything.
Jamian represents the owners of ships that travel from the
Atlantic Ocean to the Great Lakes via the Saint Lawrence Seaway.
He says ship owners will very likely avoid Michigan ports, and
choose to unload at ports in other states and Canada:
“The fact of the matter is that they’re not going to put an
expensive piece of equipment just because Michigan calls for it
on their ship when in fact it may not be acceptable anywhere else
in the world and it might just be easier to take that cargo
across the river and unload it where they don’t have these
regulations.”
And for Michigan ports that are near other competing ports,
that’s a concern. Patrick Sutka is the treasurer for Nicholson
Terminal and Dock Company at the Port of Detroit:
“We fear these ships may be going to other ports, such as Windsor
right across the waterway, or other competitors of ours such as
Toledo or Cleveland.”
At the height of the shipping season, there might be three
freighters at a time moored to the docks, offloading steel and
other cargo. A hundred trucks a day will move in and out of the
docking area to get those commodities to factories.
On the dock right now are dozens of stacks of 20-ton slabs of
steel from France and Russia. That Russian steel was most likely
shipped from a port in the Caspian Sea or the Black Sea. The
freighters take on ballast water from those seas for the voyage
to the Great Lakes. That ballast water helps keep the ships low
and steady in the water.
The ships are required to exchange the water in deep ocean mid-
journey. The salt water is supposed to kill the fresh water
organisms. But, some organisms can survive the trip. That’s how
zebra mussels, quagga mussels and the round goby fish made their
way from the Balkans to the Great Lakes.
Those invasive species and others combine to cost the economy an
estimated 5 billion dollars a year. For example, zebra
mussels cost taxpayers and utility customers. It shows up in
your power bill because the utilities have to pay divers to
scrape the crustaceans off pipes carrying cooling water to power
plants.
Shipping companies, port owners, and dock workers’ unions are all
pressuring Michigan to hold off on enforcing its new law. What
they’d really like is for the federal government to step in,
negotiate with Canada, and create a regional set of rules for
combating aquatic invaders:
“…But the federal government has not had the guts or the
gumption to step up to the plate and get this done.”
Patti Birkholz chairs the Michigan Senate Environmental Affairs
Committee. She sponsored the law:
“So we’re going to do it on a state-by-state basis. Our eco-
system within the Great Lakes is what many scientists have termed
‘on the tipping point.’ We cannot deal with any more invasive
species in this system, and we know the majority of the invasive
species come through the ocean-going vessels. They know they’re
the cause. We know they’re the cause. We’ve got to deal with this
situation.”
Michigan’s new law is as much a political statement as anything
else and other states are starting to follow Michigan’s lead.
Birkholz says Wisconsin and New York could pass ballast standards
this year.
In the mean time, Michigan environmental officials say they
intend to enforce the state’s requirements when the Great Lakes
shipping season resumes in the spring. But, so far, no ocean
freighters have applied for a permit to dock at a Michigan Port.
The recent appearance of a new invasive species shows just how easily an even worse invader could make its way into the Great Lakes. Rebecca Williams reports the invaders are hitching a ride in the ballast water of foreign ships:
Transcript
The recent appearance of a new invasive species shows just how easily an
even worse invader could make its way into the Great Lakes. Rebecca
Williams reports the invaders are hitching a ride in the ballast water of
foreign ships:
The new shrimp that’s here is called the bloody red mysid. Scientists say
the shrimp eat tiny organisms at the bottom of the food web… and could
compete with fish for food.
Steve Pothoven is a fisheries biologist with the Great Lakes Environmental
Research Lab. He discovered thousands of the shrimp near Lake Michigan.
“They’re originally from the Ponto-Caspian region, which is the Black and
Caspian Seas. The Ponto-Caspian is the same region that zebra mussels,
quaggas mussels are from, gobies, so that’s the region we’ve got a lot of
the more recent well known invaders.”
Scientists have an eye out for another invader from that same region. It’s
called the killer shrimp. It’s known for biting and shredding its victims…
and doesn’t always eat what it kills. Some scientists are worried if it
gets in, the killer shrimp could cause even more devastation to the Great
Lakes food web.
A year ago, governors of all eight Great Lakes states endorsed a
multi-state compact to protect the lakes against plans to pump water out of
the basin. Bill Cohen reports… a full year later, not one state legislature
has actually approved the compact:
Transcript
A year ago, governors of all eight Great Lakes states endorsed a multi-state compact
to protect the
lakes against plans to pump water out of the basin. Bill Cohen reports… a full year
later, not one
state legislature has actually approved the compact:
Most states haven’t even gotten one of their legislative chambers to okay the
compact. Most
people think the compact is to protect against shipping millions of gallons of water
to foreign
countries, but the biggest roadblock has been the fear that each state would be
giving up the right
to allow water diversions for its own cities and industries.
Molly Flannagan with the National Wildlife Federation says environmental activists
are not giving
up. She says 2006 has been a year to educate lawmakers:
“We had four states that had legislation introduced this year. We’re expecting to
have more states
introducing legislation next year. I think this is the year really of building
momentum towards
getting the compact done, hopefully in 2007 or 2008.”
Backers of the plan are also seeking approval from Quebec and Ontario.
A close-up of the quagga mussel. Quaggas have spread in all of the Great Lakes except Lake Superior. (Photo courtesy of the Michigan Sea Grant
Archives)
The quagga (left) next to its close relative, the zebra mussel. (Photo courtesy of the Michigan Sea Grant Archives)
Whitefish is a main dish for everything from fish boils to fancy dinners all around the Great Lakes region. But in some areas of the Great Lakes, whitefish aren’t doing so well. Rebecca Williams reports on what’s happening to the fish many people love to eat:
Transcript
Whitefish is a main dish for everything from fish boils to fancy dinners all around the Great Lakes region. But in some areas of the Great Lakes, whitefish aren’t doing so well. Rebecca Williams reports on what’s happening to the fish many people love to eat:
(sound of knives getting sharpened and fish being filleted)
Mike Monahan sells fish from all over the world at his seafood market. But he says whitefish is a very popular seller.
“It’s been there forever, and everybody just expects it to be there, and it’s inexpensive. But really it’s a great fish, as far as a nice light delicate fish, I’d put it up against the soles and flounders.”
Monahan says he’s still getting good supplies of whitefish. So, for now, he’s happy.
But some of the people who catch whitefish are worried. Commercial fishers have been hauling in skinnier whitefish in some parts of the lakes. It’s taking whitefish longer to grow to a size worth selling. And in some cases, the fish aren’t fat enough to make a good fillet.
(sound of shorebirds)
Paul Jensen fishes for whitefish in Lake Michigan. He says lately, he’s had to move his boat to deeper waters. That’s because whitefish are hungry and they’re swimming out deeper. They aren’t finding their favorite food. It’s a little shrimp-like creature called Diporeia.
“Diporeia are probably like a Snickers bar to whitefish; they were high in fats, high in lipids and it was their main food – it was very nutritious for them and it affected their growth rate. Eating Diporeia a fish could reach maturity maybe in 18 months or 2 years. Now we’re looking at fish that may take 5 years to get there.”
Whitefish are not eating Diporeia because it’s vanishing. In some places, researchers used to find 10-thousand of the little critters in a square meter of sediment. Now there are very few, or none at all.
Tom Nalepa has been trying to figure out why. Nalepa is a biologist with the National Oceanic and Atmospheric Administration’s Great Lakes Environmental Research Lab.
“It’s a real scientific puzzle as to why Diporeia is declining. It’s definitely related to the spread of quagga mussels and zebra mussels but that exact negative relationship is kind of elusive at this point in time.”
But Nalepa says he’s sure the invasive mussels are to blame. The mussels got into the Lakes in the ballast tanks of foreign ships. And they’ve spread in all the lakes except Superior.
Tom Nalepa says he’s seen populations of Diporeia crash right around the time the mussels were booming. Nalepa says now, Diporeia’s gone from large areas in most of the Lakes.
That’s bad because Diporeia is an important food source for most of the fish in the Great Lakes.
But for whitefish it’s really crucial. Back in the good old days, Diporeia made up about 80% of their diet.
Tom Nalepa says whitefish are trying to find something else to eat. He’s seeing them switch to a snack food that could make them even skinnier.
They’re starting to eat quagga mussels.
“When whitefish feed on quagga mussels they have to deal with the shell which has no energy content at all and it has to pass the shells through its digestive system so basically the fish feels full when it’s not getting any energy source.”
Nalepa says to the fish, quagga mussels must seem like good food, because there are lots of them.
He says quagga mussels are booming, because they can live in harsher conditions than zebra mussels can. So biologists are predicting quaggas will be even worse for the lakes than zebra mussels.
“Where are things ultimately going to end up? People may just have to get used to fewer fish. Because basically now we’re trading the fish community for the mussel community. The lakes are loaded with mussels instead of fish now. It may be just the way it’s gonna be.”
Some fishermen are already seeing things change. One day last season, Paul Jensen pulled in some of his nets. He was expecting fish.
“It was kind of startling because the amount of quagga mussels that came up with those nets far exceeded the catch of fish. And we hadn’t really equipped the boat with a snow shovel to shovel quagga mussels out of the boat. The impacts are startling because you begin to wonder, if our little net caught these, how many are there and what are the impacts going to be down the road?”
Jensen says he wishes the invaders had never gotten into the lakes in the first place, because there’s no way to predict what effect they’ll have next.
But some scientists worry these changes at the bottom of the food chain will lead to a major collapse of the fish stocks that many people depend on.
A naturally reproduced wild lake trout fingerling. (Photo courtesy of MI DNR.)
Alewives held up in a net. Alewives are an invasive species on which introduced salmon and other predator fish feed. They are among the prey fish species that have declined severely in Lake Huron. (Photo courtesy of MI DNR.)
Alewives being pulled from the lake. (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.
Foreign ships like this one from Cypress are known as "Salties." They account for about 5% of ship traffic on the Great Lakes. If a salty dumps its ballast water in a Michigan port, they first have to show the state that they've sanitized the water. International shipping agencies have sued the state over this law. (Photo by Mark Brush)
