Tag: salmon

Salmon Fishery on the Rocks

  • The Chinook salmon was initially introduced to the Great Lakes in the 1870s. Michigan, New York and Wisconsin reintroduced the Chinook salmon to the Great Lakes in 1966. (Photo courtesy of USFWS)

There’s a decision looming for Lake Huron that would have been unthinkable 10 years ago. The state must decide whether it should keep putting chinook salmon in the lake. The fish has been the driving force behind sport fishing in the Great Lakes. But the salmon’s future in the Upper Lakes is now questionable. Peter Payette reports:


It’s hard to overstate how drastically salmon transformed the Great Lakes after they were introduced more than 40 years ago.


Ed Retherford is a charter boat captain on Lake Huron.
He says in the old days on a weekend in Rockport he’d see cars with boat trailers backed up for a mile or two waiting to launch.
But that’s all gone now.


“You’d be lucky, except maybe for the brown trout festival, you’d be lucky to see twenty boats there on a weekend. It just decimated that area. You can imagine the economics involved.”


Chinook or king salmon practically disappeared from Lake Huron about seven years ago. Most of the charter boats are gone now because the kinds of fish that remain are just not as exciting to catch as salmon.


State officials figure little towns like Rockport lose upwards of a million dollars in tourism business every year without the fishery.

More about Chinook salmon from the DNR

A related Environment Report story

Ten Threats to the Great Lakes

Transcript

The salmon’s demise followed the disappearance of its favorite food, little fish called alewives. Scientists say there were too many salmon eating the alewives and problems lower down on the food chain caused by invasive mussels.


State fisheries biologist Jim Johnson says salmon would rather starve than eat something besides an alewife.


“So at first, the salmon went through a period of just being starved out. They didn’t have enough to eat. They wouldn’t switch to eating round gobies and they died of malnutrition.”


The changes in Lake Huron since have been significant.


Neither salmon nor alewives are native to the lake. And with them out of the way, native fish like walleye have come back.


The state continues to stock one and a half million Chinook salmon in Lake Huron every year.


But Jim Johnson says the walleye eat most of them. He says Lake Huron can’t support a big salmon fishery any more.


“It’s just not realistic. The lake doesn’t offer that and there’s nothing the DNR can do to change that.”


The question now is whether to stock any chinook salmon in Huron at all. Giving up on the most popular sport fish in the Great Lakes is hard to swallow but most people see the writing on the wall. So even if stocking continues, it will likely be a fraction of what it once was.


On the other side of the state, there are now worrying signs that the same fate might be in store for Lake Michigan.


There are lots of salmon in Lake Michigan today.


But charter boat captain Denny Grinold says something went wrong last fall. He says the big salmon, the four-year old fish that come up into the rivers to spawn in August, never showed up.


“You keep looking for ‘em. You keep looking for ‘em. You go out and you fish the patterns that you’ve fished in the past. Those large Chinook should be there and they just weren’t there.”


The warm water and lots of windy days last year might account for the missing fish. But research provides no comfort for the future.


The DNR has created a system of red flags to evaluate the conditions for salmon in Lake Michigan. These are based on things like how much food is available, the weight of the fish and how many are being caught.


Twenty of the 30 flags have been triggered.


The manager of Lake Michigan for the Department of Natural Resources, Jim Dexter, says the lake is not a happy place.


“The lake is very perturbed. It’s certainly not a stable, quality ecosystem. I mean it’s working right now. It’s producing a fishery. People are happy but it’s tenuous.”


There’s not much the state can do to change anything.


If the experience of Lake Huron is any guide, it’s the presence of those little feeder fish, alewives, that is critical.


At the moment, there are believed to be fewer alewives in Lake Michigan than at any time on record.


For the Environment Report, I’m Peter Payette.

Lake Huron’s Invasive Species

  • Filmmaker John Schmit says he wanted to make this film to show how even the smallest invader could mess up the delicate balance of life in the lake. (Photo courtesy of the NOAA GLERL)

You might call Lake Huron the forgotten Great Lake. There are no major cities on its shores. It doesn’t get the media attention the other four Great Lakes do. But its problems are just as bad or worse. Rebecca Williams reports a new documentary tells the story of Lake Huron’s struggle with dozens of alien invaders… and the biologists and fishermen who are trying to reclaim their lake:

Transcript

You might call Lake Huron the forgotten Great Lake. There are no major cities on its shores. It doesn’t get the media attention the other four Great Lakes do. But its problems are just as bad or worse. Rebecca Williams reports a new documentary tells the story of Lake Huron’s struggle with dozens of alien invaders… and the biologists and fishermen who are trying to reclaim their lake:

The documentary Lake Invaders is a cautionary tale about opening the door to strangers. It tells how Lake Huron was opened up to alien invasive species. The film paints fish biologists as the heroes rushing in.

“Seems like it always has to wait until it’s at a disaster level before you know, we can start fixing it… we’re constantly putting out these biological fires, running from fire to fire, to try to keep them under control. We have to find another way to approach this.”

More than 180 non-native species have gotten into the Lakes… and some of them have turned everything upside down. Long, slithering, blood-sucking parasites called sea lamprey were the first to get in. They slipped through a canal that connects the Atlantic Ocean and the Great Lakes. Lamprey killed off most of the big predator fish in the Lakes.

Then… came the alewife. Since the lamprey had taken out the top predators… there was nothing to eat the invading alewives. In the film… biologist Jeff Schaeffer explains how the small fish took over the lakes.

“At that time over 90% of the fish biomass of Lake Michigan and Lake Huron was probably dominated by the exotic alewife. One of my colleagues refers to the Great Lakes at that time as alewife soup.”

Suddenly… there was a major stinking mess. Each spring, hundreds of millions of dead alewives washed up on shore and rotted. Not the best thing for tourism.

Filmmaker John Schmit says he was surprised to learn what happened to the lakes next.

“The funny thing about the Great Lakes is there’s Pacific salmon in them.”

Schmit says biologists brought in millions of salmon from the Northwest to control the alewives. The crazy thing is… it worked. In the film we see how a 4 billion dollar sport fishing industry was born. And the native fish of Lake Huron were pretty much forgotten about.

The salmon fishery boomed for decades. Until the alewives crashed in 2003.

Fisher Doug Niergarth says then… the salmon started starving.

“Two years ago we saw some monster salmon heads that were sitting on little dwarfed bodies. And it was the ugliest thing and rather nasty. Just skinny and withered away. It was the nastiest thing you ever done seen.”

The fishing industry started slipping away. Marinas just scraped by. Tackle shops and motels closed. People finally realized there was something wrong with the lakes.

John Schmit says he wanted to make this film to show how even the smallest invader could mess up everything… both the delicate balance of life in the lake and the people who fish it and depend on money from tourism.

“Lake Huron has been the most impacted by the newest invaders. My personal concern, my investment in the Great Lakes and making this documentary is for people to be aware of the kind of damage invasive species can do to these huge lake systems.”

He says his film Lake Invaders is an example of what invasive creatures can do… not just to Lake Huron… but any ecosystem.

For The Environment Report, I’m Rebecca Williams.

Related Links

Salmon Spawning in Sewage Plant

  • Peter Baranyai directs Wastewater Operations for the Sanitary District of East Chicago, Indiana. The plant's effluent channel looks like a natural stream and has apparently fooled wilflide into thinking so, too. (Photo by Shawn Allee)

You might not expect much good
environmental news to come from
sewage plants, but, believe it or
not, there is some on occasion.
And in one case, that good news
even involves thriving salmon.
Shawn Allee has the story:

Transcript

You might not expect much good
environmental news to come from
sewage plants, but, believe it or
not, there is some on occasion.
And in one case, that good news
even involves thriving salmon.
Shawn Allee has the story:

Sewage plants are often out of sight, out of mind, and people usually like it that way. But people who work at the water treatment plant in East Chicago, Indiana, want everyone to know about an ecological come-back story there.

I’m game. So I meet the plant director Peter Baranyai.

Allee: “You’ve got this strange mix of some really striking natural areas, rivers and streams, but then everything’s kind of dotted by industry as well, and has been for a long time. What kind of industries are we talking about in this region?”

Baranyai: “Basic steel mills, oil refineries, chemical industries also.”

Allee: “So, when they’re talking ‘heavy industry’, they really mean it here?”

Baranyai: “Yes.”

Allee: “What are we looking at here?”

Baranyai: “We’re trying to look at our discharge channel. That’s the effluent from our treatment plant. This pipe here’s a 60-inch pipe.”

Allee: “You can see the water moving out of it pretty quickly.”

The treated wast water is from nearby homes and factories. And when it leaves the pipe, you’d swear it’s a natural stream. Apparently, it’s fooled plenty of critters, including Chinook salmon.

Each Fall, salmon swim from Lake Michigan, past shipping canals, steel mills and chemical factories – just to spawn in the treated waste water.

Baranyai: “They’re not being too cooperative today because I don’t see too much.”

The salmon spawned earlier than normal this year, so, I only find dead salmon on the banks.

Baranyai: “This was a, oh, almost 4-foot chinook salmon.”

Allee: “Or the evidence of it.”

Baranyai: “And he died.”

Allee: “Again, they’re kind of programmed to die after they spawn.”

Baranyai: “Yeah, he died on the rocks here.”

The government introduced Chinook salmon to Lake Michigan decades ago, but for a long time, salmon wouldn’t spawn here, and birds and nearly everything else shied away, too.

Baranyai says one problem was that they used to disinfect water with chlorine.

Baranyai: “It’s a very effective way of disinfecting, but it continues to disinfect downstream. It’s not selective, usually anyhthing that’s alive, it usually kills. It pretty much sterilizes everything. And that’s how most water treatment plants in our country do that, still.”


Baranyai says in the late 80s, things turned around. His plant added better filters, and now, when they disinfect water, they kill bacteria with ultraviolet light, not chlorine. In just a few years, salmon started spawning – right in the plant. Plus, fresh-water sponges grow in the plant, and herons showed up. Word got around.

Roger Klocek was a biologist at Chicago’s Shedd Aquarium at the time. He learned the news from a fellow scientist.

Klocek: “I thought he was nuts, literally. What are you talking about?”

Klocek says you have to understand, for a long time people ignored water treatment plants or they expected them to remove only the worst industrial pollutants.

Klocek: “I had no idea that waste water plants themselves could actually contribute to an improved ecology.”


Allee: “Maybe the opposite, they were putting chlorine in the water or bacteria, if they weren’t disinfecting.”

Klocek: “Absolutely, you know we hear constantly that technology is going to save us and I really don’t believe that. I think we put too much stock in that, but it sure is gratifying to see when there is some technology that makes a remarkable improvement.”

Klocek says, too often, people assume industrial areas like East Chicago will always be ecological basket cases.

He says, sure there’s room for improvement, but having one concrete example of something that works? That can give you hope about what nature can do if you give it a chance.

For The Environment Report, I’m Shawn Allee.

Related Links

Shrinking Salmon Populations

  • A close view of salmon eggs and developing salmon fry. (Photo courtesy of the US Fish and Wildlife Service)

A federal judge says the Obama
Administration soon has to come
up with a plan to restore endangered
salmon runs to the Pacific Northwest’s
biggest rivers. Ann Dornfeld went
gill net fishing on the Columbia
River to find out what’s at stake:

Transcript

A federal judge says the Obama
Administration soon has to come
up with a plan to restore endangered
salmon runs to the Pacific Northwest’s
biggest rivers. Ann Dornfeld went
gill net fishing on the Columbia
River to find out what’s at stake:

(sound of a boat moving through water)

Gary Soderstrom is a fourth-generation Columbia River salmon fisherman. Even though it’s his work, on a sunny summer day there are few places he’d rather be than casting a gill net on this tranquil bay near the mouth of the Columbia.

“Just being this far from the dock, it’s just a whole different world! All the nights and the days I’ve put out here, I still feel good when I get out here.” (laughs)

Soderstrom – or Suds, as he’s better known – says gillnetters today catch salmon pretty much the same way his great-great-grandfather caught them. The main difference today is motors help fishers lay out and reel in their nets.

(sound of reel squeaking as net is laid)

“See how he’s layin’ up the bank here, and then he’s gonna go across. That’ll create a trap for the fish if he leads ’em over to the beach, and they might get confused.”

The technique might not have changed much. But this river has. These days, a dozen species of salmon and steelhead on the Columbia are listed as endangered. One of the biggest factors is the hydroelectric dam system that provides most of the power to the Pacific Northwest. Those dams keep young salmon from making it to the ocean. Suds says that’s why his son won’t be a fifth generation fisherman.

“There used to be several thousand fishermen on the Columbia at one time. Now there’s a couple hundred of us that are still active. Most guys like my son and them have went and got other jobs to try and raise families on.”

Federal law requires the government to restore the endangered salmon runs. For years, fishers and environmental groups have been calling for the removal of four dams on the Snake River, a tributary of the Columbia.

But the Clinton and Bush Administrations backed other plans to restore salmon runs. Those plans ranged from spilling a small portion of water through the dams to trucking baby salmon around the dams. Federal courts rejected those plans as insufficient. Now a federal judge has told the Obama Administration it has until mid-September to come up with a plan that goes far beyond the scheme President Bush proposed last year.

Ann Dornfeld: “What do you think is the chance that they’re gonna take out the dams?”

Gary Soderstrom: “Well, about like me winnin’ the Powerball! (laughs) I mean, don’t think it’s ever gonna happen, but realistically, it’d work.”

Suds says he’d also like to see tougher restrictions put on farmers who irrigate their crops with water from the Columbia.

“Irrigation systems, a lot of them are still water hogs. I think they should be forced into using the least amount of water they can get by with.”

It’s been about 15 minutes, and it’s time to reel in the nets.

(sound of reeling in nets)

We’ve brought in one 17-pound coho.

(sound of salmon hitting the floor)

But like most of the other fish caught on the Columbia these days, it was raised in a hatchery upstream.

Suds says for years he’s been volunteering his time on advisory councils and boards throughout the state to try to restore the habitat that once brought millions of salmon down the river the natural way. But what he’d really like to do is meet with President Obama and explain the river’s history to him firsthand.

“But in my situation, being a peon fisherman, you’ll never get to talk to a guy like him. Y’know, if you could bring him out here and show him what I’ve shown you today, maybe he’d have a clearer understanding of what’s going on out here.”

Suds Soderstrom says he wants the president to make good on his promise to let science dictate his policies, rather than politics – which always seem to favor development.

“Sooner or later you’re either gonna have fish or people. And the people seem to be winning.”

The new Administration has until September 15th to propose its plan to save endangered salmon. The federal judge who’s been overseeing the process for years has made one requirement: this time, the plan has to work.

For The Environment Report, I’m Ann Dornfeld.

Related Links

Saving Salmon From Sea Lions

  • Bobby Begay has been patrolling the Columbia River below Bonneville Dam for the past three years, hazing sea lions. (Photo by Sadie Babits)

The Columbia River in the Pacific Northwest historically has been a super highway for salmon. But dams, development, and pollution have taken their toll on salmon. The fish have declined to the point that several species are endangered. Now the salmon face another threat, sea lions. As Sadie Babits reports wildlife managers are trying to get rid of the sea lions to protect the salmon:

Transcript

The Columbia River in the Pacific Northwest historically has been a super highway for salmon. But dams, development, and pollution have taken their toll on salmon. The fish have declined to the point that several species are endangered. Now the salmon face another threat, sea lions. As Sadie Babits reports wildlife managers are trying to get rid of the sea lions to protect the salmon:

Bobby Begay steers his small boat up the Columbia River. He knows this river, and he
knows the salmon. His ties to the salmon go back generations.

As a member of the Yakima Tribe, he comes out here to tribal fishing sites to catch
salmon. It’s something Indians along the Columbia River have been doing for thousands
of years. He says the salmon are considered sacred food.

“It’s part of our livelihood. It’s part of our health and well being.”

They use the salmon to feed everyone from the tribal elders to the children. Tribal
fishermen tell stories of seeing so many salmon in the Columbia River that you could
walk across their backs. Those days are gone.

A series of dams on the river make it hard for fish to get from the Pacific Ocean to fresh
water and back again. The salmon have fallen victim to over-fishing, agricultural
pollution, and habitat destruction. Pacific salmon are now listed as endangered. And they
face yet another threat on the Columbia River – sea lions.

“Sea lions have probably always been in the Columbia but not to this extent and have
done damage to salmon populations like it has and all of it is due because of a man-made
structure, which is Bonneville Dam.”

Sea lion numbers have exploded along the Pacific Coast. And more than a thousand of
them travel up the Columbia River looking for food. Some of them have figured out that
if they gather at the base of Bonneville Dam, they can easily catch salmon that are trying
to pass by.

Biologists estimate that every year sea lions eat some 13,000 salmon. This year, the
federal government gave state wildlife agencies in Oregon, Washington and Idaho, the go
ahead to kill up to 85 sea lions.

Begay won’t really talk about whether he thinks this is right. He’s torn.

“Well, ah, sea lion is a spiritual animal not only to us but to coastal tribes and we respect
the animal as it is, but also the salmon is a scared food to us as Columbia River Indians.”

So Begay works to protect the salmon without killing the sea lions. He works for the
Columbia River Inter-Tribal Fish Commission.

That’s why he’s out here in this boat. He patrols the river most days using fireworks to
scare sea lions away from the salmon.

Crew: “There he is 1 o’clock, 50 yards.”

(sound of gun shots and boat)

Begay’s crew shoots firecrackers over the sea lion.

“And hopefully we’ll get them into the main stem of the river and start hazing them down
stream.”

“The hazing really is not highly effective. The animals are really quick to learn.”

Robin Brown is a marine mammal researcher for the Oregon Department of Fish and
Wildlife.

Brown says they’ve euthanized seven sea lions this year. He says the decision to kill a sea
lion is made after everything else has failed.

“We have to have observed them killing salmon and steelhead, and they have to have
been exposed to all the non-lethal methods of harassment that you’ve observed here
today and shown that that isn’t detouring them from being here and feeding.”

The Humane Society opposes killing the sea lions. It’s asked the courts to put a stop to it.
While this legal battle plays out, Bobby Begay will keep hazing the sea lions until the end
of May.

That’s when the sea lions leave the dam and head back down the Columbia River to the
Pacific Coast to breed.

For The Environment Report, I’m Sadie Babits.

Related Links

Throwing the Big Fish Back

  • Fishing laws in Canada and US states often protect small fish and are less restrictive with big ones. (Photo courtesy of the US Fish and Wildlife Service)

People who love to fish spend plenty of money on gear, license fees and even gas for their boats. It’s enough to make anglers think, maybe they’re entitled to keeping the biggest fish for trophies or the frying pan, right? Shawn Allee met a researcher who wants you to throw back your biggest catch:

Transcript

People who love to fish spend plenty of money on gear, license fees and even gas for their boats. It’s enough to make anglers think, maybe they’re entitled to keeping the biggest fish for trophies or the frying pan, right? Shawn Allee met a researcher who wants you to throw back your biggest catch:

This is the guy who wants to change how a lot of people fish.

“My name is Paul Venturelli and I study fisheries biology at the University of Toronto.”

Venturelli’s disturbed by how many fish species are on the brink of collapse – either in oceans or in fresh water.

He hopes to grow fish stocks – with this fishing advice.

Toss the big ones back.

And what’s he got to back that up?

“I’ve got about ten pages of notes here. Nah, I’m kidding. I’m kidding.”

Actually, he says the idea is pretty simple.

“A ton of big, old fish will produce more new fish than a ton of smaller, younger fish. And this is because the bigger, older fish tend to produce offspring that have a higher chance of survival.”

Venturelli studies mostly ocean-species, but he says the principal should apply to North American freshwater fish like pike and walleye, too.

But Venturelli’s got a problem spreading this idea around.

Fishing laws in Canada and a lot of US states often protect small fish and are less restrictive with big ones.

I asked one of the head guys in Illinois fisheries, Joe Ferencak, why that is.

“Essentially what you’re doing with that minimum size limit is protecting one or two year classes of reproductive age fish so they can successfully spawn or reproduce.”

Ferencak says, fisheries science has stood behind the ‘protect the small fish’ theory for decades – with some exceptions.

He says to change laws, Venturelli would need to do more studies.

Plus, Ferencak says no state would want to completely keep people from big fish – that’s just not much fun.

“We want to maintain and enhance these fisheries for the benefit of the fishing public, the angler. And it’s kind of counter-intuitive to not allow them to take these larger fish.”

Well, I figure it wouldn’t be fair to talk about big fish without talking to outdoorsmen, so I spent some time in Griffith, Indiana.

It’s about ten miles from Lake Michigan.

Fishing and hunting outlets are all around – and there’s this place.

Allee: “So what’s the establishment.”

Leap: “American Natural Resources.”

Edward Leap Senior runs American Natural Resources – it’s a taxidermy shop – with stuffed deer, fox, and fish filling every nook and cranny.

I figure Leap would rush to the defense of catching big fish, but, you know what? He doesn’t bite.

Allee: “If you get a whole bunch of fish in your boat, I mean, you want to show off the big one. Most people do, right?”

Leap: “Yes and no, though. When you get talking about the conscientious outdoorsman, no, he’s not going to be thinking this way. He’s going to say, ‘I got this fifteen pound walleye, a super-trophy fish. It took a lot of years to grow this fish, I’m going to take a picture of it and I’m going to release it.'”

And, to prove the point, he reaches back and pulls a fish trophy off the shelf.

“For the trophy part of it, we’ll do a reproduction of it that you can’t tell from the real thing. And the fish now is out there spawning, and making eggs, and continuing its species.”

Leap says more and more fishermen are having him make fake fish – or, reproductions, as he calls them.

So, from his vantage, scientists like Paul Venturelli won’t have too much trouble with the advice to ‘throw back the big ones.’

Leap says you don’t have to keep fish you catch, and in his experience, smaller fish make better eating anyway.

For The Environment Report, I’m Shawn Allee.

Related Links

New Standards for Organic Fish

  • Farmed fish, such as salmon, eat a lot of wild fish that happen to swim into their pens. And that means they could be eating over-fished species. (Photo courtesy of the US Fish & Wildlife Service)

To be labeled organic, animals
have to be fed all organic food. But
under the new proposal that won’t be
the case for fish. Julie Grant reports
that in the recommendations for organic
fish, the standard is much lower:

Transcript

To be labeled organic, animals
have to be fed all organic food. But
under the new proposal that won’t be
the case for fish. Julie Grant reports
that in the recommendations for organic
fish, the standard is much lower:

Some fish is raised in huge net-pens in the ocean. Farmed
fish, such as salmon, eat a lot of wild fish that happen to
swim into their pens. And that means they could be eating
over-fished species.

New recommendations by the National Organic Standards
Board would go ahead and allow farmed fish to eat up to
25% wild food – as long as it’s not from endangered species.

George Leonard is director of aqua-culture with the Ocean
Conservancy. He says these standards would weaken the
organic label.

“You don’t change the organic standard to be consistent with
current practices, you hold the organic standard steady and
you allow or you incentive the industry to change their
practices to reach that standard.”

The new “organic fish” recommendations still need final
approval from the USDA.

For The Environment Report, I’m Julie Grant.

Related Links

Sushi Sustainability Guide

  • blueocean.org has created a guide that ranks sushi on how sustainable it is (Source: Hatago at Wikimedia Commons)

Some ocean conservation groups have
teamed up to make a color-coded guide that
ranks popular sushi. Lester Graham reports
the rankings are based on whether the fish
are caught or raised in sustainable ways:

Transcript

Some ocean conservation groups have
teamed up to make a color-coded guide that
ranks popular sushi. Lester Graham reports
the rankings are based on whether the fish
are caught or raised in sustainable ways:

You can download this sushi guide, print it out and carry it around with you if you
want, but Kate McLaughlin with the Blue Ocean Institute’s Seafood Program says
you could just look at it on your mobile device next time you go to a sushi bar.

“You can download a PDA formatted copy of the guide to your mobile device. Or
text the word ‘fish’ and then the name of the fish in question. Pretty much
immediately you get a response with the ranking.”

And it will tell you things like popular sushi such as bluefin tuna and farmed salmon
are on the “red” list, which means they’re either over-fished or farmed with
aquaculture methods that pollute the ocean.

You can get the guide at blueocean.org.

For The Environment Report, this is Lester Graham.

Related Links

Hatchery Fish Unprepared for Wild World

A new study finds if fish raised in captivity breed with fish in the
wild that might hurt the wild fish populations. Rebecca Williams
reports that’s because the captive fish are genetically weaker:

Transcript

A new study finds if fish raised in captivity breed with fish in the
wild that might hurt the wild fish populations. Rebecca Williams
reports that’s because the captive fish are genetically weaker:


Billions of fish are raised in hatcheries and released into lakes and
rivers.


But a new study in the journal Science says there could be
problems with that. The researchers found a type of salmon bred in
captivity quickly adapted to their less stressful life in the hatchery.
So they weren’t prepared for a cutthroat life in the wild.


Michael Blouin is an author of the study. He says the babies of
captive-bred fish have trouble finding food and aren’t very good at
escaping predators.


“If you have large numbers of hatchery fish mixing with wild
populations, the fear is they’ll be passing those genes to the wild
population and thereby dragging down the fitness of the wild
population.”


Blouin says this has not been proven outside of the laboratory yet, but he says the lab results raise some concerns about the widespread
use of captive fish to boost wild fish populations.


For the Environment Report, I’m Rebecca Williams.

Warming to Change Great Lakes Ecosystem?

Some researchers say global warming will impact fish habitat in the
Great Lakes. Chuck Quirmbach reports:

Transcript

Some researchers say global warming will impact fish habitat in the
Great Lakes. Chuck Quirmbach reports:


Some scientists have projected that more global warming will mean less
rain and snow falling into the Great Lakes and the continuation
of low water levels.


Researcher Brian Shuter is with the Ontario Ministry of Natural
Resources. He says if the projection comes true, there will be
more stress on the millions of Great Lakes fish:


“I mean the space for fish to live in is just gonna shrink and the less
space there is, the less fish there will be.”


Shuter also anticipates higher summertime water temperatures and less
ice cover in the lakes. That’s a change that could lead to more warm
water fish like bass and fewer of the cold water fish like salmon
and trout that people like to eat.


Shuter says the change could also promote the growth of invasive
species that favor warmer water temperatures. So, he encourages tighter
controls on invasives and more water conservation programs.


For the Environment Report, I’m Chuck Quirmbach.

Related Links