- [Narrator] Coming up on "Great Lakes Now."

A mutant invader that can clone itself.

- And those fertile eggs will all be females.

They will then continue laying eggs.

They don't need any males.

- [Narrator] Big changes on our biggest Great Lake.

- Last couple years, there's been virtually no ice whatsoever.

The sun's raised and energy are just going right into the water, so that's a significant impact.

- [Narrator] And news from around the lakes.

(upbeat music) - [Announcer] This program is brought to you by the Fred A. and Barbara M. Herb Family Foundation, the Charles Stewart Mott Foundation, Richard C. Devereaux Foundation for Energy and Environmental Programs at Detroit PBS, Polk Family Fund, DTE Foundation, and contributions to your PBS station from viewers like you.

Thank you.

(gentle music) (air whooshing) - Hi, I'm Anna Sysling.

Welcome to "Great Lakes Now."

The lakes are now home to more than 180 non-indigenous species, many native to rivers, lakes, and seas around the world, but one recent arrival has a different origin story.

From Burlington, Ontario, TVO field reporter Jayan Jeganathan brings us the story.

(air whooshing) (gentle music) - [Jayan Jeganathan] A creature that sheds its skin, lays 500 eggs at a time, and can clone itself.

Meet the marbled crayfish.

They may not look scary, but these little crustaceans have wildlife experts in Ontario on high alert.

- They're a big problem.

And in Europe, they're spread all over there, even in Israel and in Madagascar as well, in Africa.

- [Jayan Jeganathan] Meet Premek Hamr.

He's Ontario's leading expert on crayfish and dedicated over 40 years to researching them.

In fact, he's known as Dr. Crayfish.

A marbled crayfish is a crayfish that originated in the pet trade actually in Germany and we think around the late '90s, we're not quite sure.

There was a mutation and this crayfish became parthenogenetic, which means asexual, which means that it's all females and those females are all fertile.

So they'll lay fertile eggs, and those fertile eggs will all be females.

And they will then continue laying eggs.

They don't need any males.

- [Jayan Jeganathan] Marbled Crayfish range 10 to 12 centimeters in length, around four to five inches, and they look a lot like many of Ontario's native crayfish species.

- One big difference between the crayfish that you see in our streams here and them is the marbled pattern.

So, that's really characteristic marbled pattern on the side of the carapace and on top and even on the tail.

But also their claws are proportionately smaller to the body.

They have quite, kinda dainty longish claws.

- [Jayan Jeganathan]As of 2022, marbled crayfish are listed as a prohibited species, under Ontario's Invasive Species Act.

This means they cannot be bought, sold, traded, or kept in a home aquarium.

However, according to the Invading Species Awareness Program, that's still happening.

- It was a very popular species in the aquarium trade, primarily due to the way that it reproduces.

And so you had it in the aquarium trade both as a pet, but as well as food fish or fish food, I should say.

So because of the way it reproduces, you only need a few specimens.

They reproduce.

They create offspring.

So, you have a continuous supply of crayfishes to feed to your pet fishes, let's say.

- [Jayan Jeganathan] Brook Schryer is the assistant coordinator for Ontario's invading species awareness program.

For over 30 years, the program has acted as a frontline defense against invasive species in Ontario.

- So, we're an education program that was started in 1992 as a partnership program between the Ontario Ministry of Natural Resource and Forestry and the Ontario Federation of Anglers and Hunters.

So back in the early '90s, we had the introduction of the invasive zebra mussel to Lake St. Clair, and at that point the government said, "We need to address this.

We need to raise awareness in the province to try to mitigate its spread."

- [Jayan Jeganathan] From zebra mussels to newer threats like the marbled crayfish, the group's work is needed more than ever.

- Ontario is actually the most heavily invaded province out of any province in Canada, and that's primarily as a result of our history and the fact that we have the Great Lakes right there.

So, shipping was a big culprit for introducing invasive species, especially via the St. Lawrence.

And in Ontario today we have about 445 invasive terrestrial species.

- [Jayan Jeganathan] That includes bugs, plants, pathogens, and most recently wild pigs.

Wild pigs is a catch-all term that refers to escaped domestic pigs as well as wild boars, which were brought from Europe in the late 1980s to diversify Canada's livestock production.

Recently, wild pigs have been causing havoc in Canada's prairie provinces, but luckily there are no established populations in Ontario, at least for now.

If that changes, Brooks' team is sure to spot them.

- They receive a trail camera, a spy point, trail camera.

They receive all the necessary things to.

- Every year we have 50 volunteers who sign up, who receive kits, which then they deploy, the beat a location.

We kind of tell them what to look for in determining a site, and then they'll deploy their cameras to monitor those cameras, and then they'll make sure that they report any potential sightings to us.

- [Jayan Jeganathan] When it comes to Ontario's waterways, Brook says there are 185 non-natives species.

Of those, 10% are considered invasive, meaning they have extreme impacts on the environment and economy.

While the impact of marbled crayfish has not been felt yet, Hamr and Schryer are worried about the potential harm to local habitats.

- So, there'll be competition for resources.

They also will eat aquatic plants, so they could, you know, damage the ecosystem.

They will eat snails.

They'll eat insects.

So if they increase in large numbers in water bodies, they could basically cut off the bottom of the food chain.

- If they burrow en masse, that can lead to erosion, shoreline erosion, those types of infrastructural damages, particularly in urban environments.

- [Jayan Jeganathan]This is ground zero of the marbled crayfish invasion, City View Park in Burlington, Ontario.

These ponds are the first places in North America where these tiny creatures were found in the wild.

Back in late 2021, someone snapped a photo of a crayfish, and shared it to iNaturalist, a citizen science tool, in hopes of identifying it.

- In this case, the individual did not know what it was.

Had reported the photo.

It went for a few months without us finding it until Dr. Premek Hamr brought it to our attention.

The following summer I went to a world crayfish conference and I brought the picture with me and they identified it positively as a marbled crayfish.

- [Jayan Jeganathan] That same year, Hamr and Schryer conducted a search of the pond and set traps, but came up empty handed.

The team collected samples using environmental DNA technology to find them.

- We do a lot of environmental DNA in our job, where what we essentially do, just to break it down to its nuts and bolts, is collect water samples, put them through filters, then take those filters, send them to Trent University, where Chris Wilson has his eDNA lab, and he's able to process those samples to determine whether or not the DNA of that particular species is in that water.

So, there are limitations with eDNA because primarily what it's telling you is presence or absence.

Is that species there?

But if you do get a confirmed hit of DNA, you don't necessarily know what that specimen looks like.

Is it a dead specimen?

Is a living specimen?

Is it a bird that ate some of it and then defecated?

So there's no real way of knowing, but it's still a smoke alarm and it's telling us to keep looking.

- [Jayan Jeganathan] Despite positive eDNA tests, it would be another summer before the team finally saw an actual crayfish.

The group captured dozens of marbled crayfish at the site in the months that followed, however wiping out these rapidly self-cloning crustaceans would need a tougher approach.

Over the winter, city workers drained the ponds in an attempt to freeze out the invasive crayfish.

It's believed they can survive temperatures as low as 4 degrees Celsius, but any colder and they go dormant and painlessly freeze to death.

- So luckily, these ponds are self-contained.

They're stormwater ponds, so they're not connected to any stream or anything.

So, that's one of the good things about this whole thing.

By draining the ponds down to as low as possible, we were hoping that it would freeze the mud and the crayfish.

They burrow, they make burrows so they can make shallow burrows and escape.

That's how frogs and other things also survive our winters.

And so we were hoping if we lower the water, it would it would freeze them and they would die.

- [Jayan Jeganathan] The team has had good success so far, with dead crayfish carcasses littering the ponds' edge to prove it.

But warmer winter temperatures have been a challenge.

- You need to hope that when you do drain those ponds, that one, you're able to drain them low enough that you're gonna freeze those crayfish out of their burrows.

But then also, for a long enough period of time that they're actually exposed long enough to then, you know, cause death.

- [Jayan Jeganathan] It's not clear how the marbled crayfish ended up in Burlington, but it's suspected that someone illegally owned one or more and released them into the storm ponds.

Wildlife officials are aware that even though they are prohibited, the crayfish are still being sold and purchased in Ontario.

- We're still seeing sales online, whether it's Facebook Marketplace or if it's places like Kijiji.

Those are the areas where we're seeing those ads pop up, and each time we see one, what we're doing is our due diligence to make sure that we're contacting the authorities, the proper authorities, the Ministry of Natural Resource and Forestry, to inform them of these sales that are going on that are in contravention to the Invasive Species Act.

- [Jayan Jeganathan] The Ministry of Natural Resources and Forestry says it's taking an education-first approach and have not laid any charges so far.

- I think the level of knowledge around marble crayfish is kind of 50-50.

Some people know that it's a problem and unfortunately have continued to try to sell it, whereas others, just don't know it all.

And that's where, you know, organizations like mine come in where we're trying to elevate that education and outreach component.

- [Jayan Jeganathan] The team cannot be certain that the ponds in Burlington are the only place in the province where a population has been established.

That's why Hamr and Schryer plan to work with conservation authorities along the Great Lakes to defend Ontario's shorelines from these alien creatures.

(air whooshing) - For more about invasive species in the Great Lakes and the measures being taken to deal with them, visit greatlakesnow.org.

Famously-frigid Lake Superior is warming quickly, and a recent documentary explores the ways that change will affect people and natural systems.

(air whooshing) (gentle music) - [Laura Weber Davis] When describing Lake Superior, you really can't go overboard with superlatives.

It's spectacular, rugged, and powerful.

Some even describe it as an inland sea.

Yet despite its immense size, Lake Superior remains vulnerable.

In November 2023, filmmaker John Shepard of Hamline University's Center for Global Environmental Education released a documentary about the impacts of climate change on the lake.

- I think this story and what we were able to uncover about the warming of Lake Superior has really broad relevance.

So, our film, "A Sea Change for Superior: The Warming of the World's Largest Lake," examines the fact that Lake Superior, the largest lake in the world by surface area, is now among the fastest warming of the world's largest lakes.

(fun upbeat music) - [Laura Weber Davis] Bob Sterner is the director of the Large Lakes Observatory at University of Minnesota Duluth.

- Lake Superior's known as a cold lake, for good reason.

And most of the lake water, no matter what's going on with the atmosphere and the sun and everything, most of the lake water is deep and is roughly four degrees Celsius, so just over the freezing point.

One of the things, though, that is changing surprisingly rapidly in Lake Superior is the summer water temperature is going up really, really fast, faster than the overlying air.

- [Laura Weber Davis] To understand why, we need to examine the vanishing winter conditions around Lake Superior.

According to Deanna Erickson, director of Lake Superior National Estuarine Research Reserve, during winter, ice typically acts as an insulator, which keeps the lake cold.

- It's like a lid on top of the water.

And so when that lid is there, it's often white because it's got snow on it and it's reflecting light back out into the atmosphere.

And that white lid keeps the Great Lakes cooler underneath.

- [Laura Weber Davis] But global warming brings warmer winters, and that's changing traditional weather patterns in the region.

- The last couple of years, there's been virtually no ice whatsoever.

So when there are winters with very little ice cover, the sun is just, the sun's rays and energy are just going right into the water and warming the water through the winter.

So, that's a significant impact.

- [Narrator] To illuminate the dramatic warming of Lake Superior, Shepard's film features a record-setting open water swim by a team of six world-class marathon swimmers.

- So the days here, how are you feeling right now?

- I'm super excited.

The water is a great temperature.

It's I guess I didn't get a read on it.

I heard it was maybe 65 even.

- [Jayan Jeganathan] They swam nonstop from Split Rock lighthouse, which is 46 miles from Duluth.

They swam from there all the way to Duluth, nonstop over about a 24-hour period.

As it turned out, they were able to complete the swim, and the water the whole time they were swimming was never colder than 60 degrees, which is extraordinary.

- I also love the story of people swimming in the lake, because it really sticks a pin in the changes that we're seeing.

It marks it in this very tangible human way and I really appreciate that.

- [Laura Weber Davis] While warmer water might sound appealing, it actually creates challenges on the lake.

Experts worry that invasive species, which flourish in warm water, might become an issue.

And commercial fishermen, like Steven Dahl, who's been fishing herring in the lake for over 30 years, say the warm water creates rough currents that make their job increasingly dangerous.

(mellow music) - Cold is beautiful.

Uniformly cold water out there, no trouble.

The top water gets warm.

It'll get up to 60, 65 degrees.

You know, and it's 39 degrees down in the bottom.

So, you get some really weird currents.

And quite often we see it wind is one way and currents in other way.

So when the net comes up, it'll start spinning on you or the net will be way out there in front of the bow and the winds pushing you back the other way.

It's been frightening sometimes.

(gentle music) When the water's cold and uniformly cold, you don't get those problems.

You don't get the currents.

- [Laura Weber Davis] Experts also believe that climate change contributes to extreme weather around Lake Superior.

- There have been three, 500-year, or thousand-year storm events within a six-year period that impacted Duluth and the south shore of Lake Superior, Wisconsin and the Upper Peninsula of Michigan.

And the destruction of those storms was incredible.

- [Laura Weber Davis] On top of damage to infrastructure and homes, scientists believe these storms triggered a new issue in the region.

A few weeks after the first storm hit in 2012, scientists recorded the first ever algal bloom on Lake Superior.

- The attitude then was, wow, that was weird.

Maybe it has to do with the rainstorm and I hope we never see it again.

But what has happened is we have seen these blooms again since.

- [Laura Weber Davis] The appearance of blooms doesn't seem to be a coincidence.

Big storms produce large amounts of nutrient-rich flood water, which overflows into Lake Superior.

And when that happens during warm months, conditions are ripe for algal blooms.

Those blooms often happen in conditions where it's warmer and there's more nutrients.

So, we've got more nutrients from floods and we've got warmer conditions as the atmosphere is warming around us.

Algal blooms can spell trouble for the lake.

Although they only last for a short period of time, they produce a bright green scum that sits on the water's surface, and it can be harmful to humans and other creatures.

- Algal blooms are a big human health concern because often, not always, but often, algal blooms can carry concerning levels of toxins.

(gentle music) - It's important to understand the changes that are happening in Lake Superior as a whole, because of the impact those changes have on our lives.

I hope when audiences see this film that they feel lucky to know about Lake Superior.

That they experience a little bit of the awe and the beauty of the place, and the importance of the place on a global scale, but that they also feel motivated to support researchers, scientists, institutions, natural resource professionals, and others who are really working often on public funds to care for these places.

Because when we're doing that, we're trying to do it for all of us.

And not just all of us humans, all of us living things around the Great Lakes.

And we need people's support for that.

- Temperature is a kind of a master variable for many things.

And so if we're talking about warm versus cold, it has that has an impact on almost everything that's going on in the lake.

There's a lot more science that needs to be done here than we have available today.

(gentle music) (air whooshing) - For more about how the Great Lakes are changing, or to watch "A Sea Change For Superior," visit GreatLakesNow.org And now it's time for The Catch, where we bring you news stories and events from around the Great Lakes.

(air whooshing) - [Anna Sysling] In 2023, a record number of shipwrecks were found in Wisconsin's Lake Michigan waters.

Caitlin Looby covered the story for the Milwaukee Journal Sentinel.

- In 2023, there were a total of 13 shipwrecks that were found on the Wisconsin side of Lake Michigan.

There were some schooners.

There was a fishing vessel and even yachts.

And most of the ones found in 2023, sank in the late 1800s.

- [Anna Sysling] There are an estimated 6,000 shipwrecks in the Great Lakes.

According to the Wisconsin Historical Society, 780 of those are believed to be in Wisconsin's waters, with 248 identified so far.

This new record blows away the previous one set in 2016.

- So in 2016, four shipwrecks were found.

And usually in a typical year, they only find two or three.

- [Anna Sysling] No one is exactly sure why 2023 was such a big year for shipwreck discoveries in Wisconsin, but Caitlin says there are a couple of theories.

- Shorelines in the Great Lakes are really dynamic, and water levels fluctuate from year to year.

Sandbars can also drift depth depending on whether it's a high water year or a low water year.

From the record low water year in 2013 and the record high water year in 2020, and then now the water moving back down to near average today, it's possible that that caused the sandbars to shift dramatically, uncovering more shipwrecks in shallower waters.

- [Anna Sysling] Another reason for the new record could be that more people know how to report discovered shipwrecks than in years past.

Several of the 13 shipwrecks were not discovered by researchers or shipwreck hunters, but people enjoying the lake recreationally.

- All sorts of people were discovering shipwrecks.

I heard there was one man who runs a kayak company in Door County, Wisconsin.

There was also a four year old girl, who was out fishing with her dad, and then also some shipwreck hunters as well.

- [Anna Sysling] So, what should you do if you find a shipwreck?

Caitlin says that the best thing would be to find out what agency keeps tabs on shipwrecks in the area that you're in and report your discovery to them.

In regards to the Lake Michigan states, here in Wisconsin, you can report them to the Wisconsin Historical Society.

There's a state maritime archeologist with the Michigan DNR.

And both Indiana and Illinois, their Department of Natural Resources have divisions for historic preservation and archeology.

(air whooshing) Throughout the Great Lakes region, cities are dedicating resources to make their waterfronts more accessible to residents and tourists.

The transformation of Detroit's riverfront is the subject of a new documentary, "Ignore the Noise."

We spoke with Mark Wallace, the president, and CEO of the Detroit Riverfront Conservancy about their work.

- The Riverfront Conservancy was brought together to steward the transformation of the riverfront from a really neglected, industrial blighted area into a beautiful public space where everyone comes together, everyone feels welcome, and everyone feels a great sense of pride in the city of Detroit.

The primary focus of the Riverfront Conservancy has been to transform the public spaces and create a system of parks and green ways that allow people to experience the riverfront in different ways at different locations.

- [Anna Sysling] Historically, Detroit's riverfront was an industrial area without much public access to the water.

Mark says that opening up those spaces with an emphasis on nature is behind much of their work.

- Every project that we've touched has started with an environmental cleanup.

We've been one of the leading stewards of brownfield sites, and also restoration of the seawall and creation of new habitat along areas where we've been able to take down historic seawalls and turn them into a soft shoreline.

The riverfront is an amazing ecosystem - [Anna Sysling] The Detroit Riverfront Conservancy has looked for inspiration in waterfronts from around the country, including other Great Lakes cities.

- We've spent a lot of time looking at what other people have done around the country.

There's some great ideas in the Chicago riverfront area.

I love Toronto's waterfront, and we've learned a lot from watching that project.

- [Anna Sysling] But despite high praise for other waterfronts, Mark says that Detroit's is truly unique.

- Very few cities can say they have a southern facing waterfront, where the sun rises on one side, sets on the other.

Very few places can say they have an international waterfront, where you have Canada on one side of the water and Michigan on the other side of the other water.

So, it's a very special riverfront.

This is a place where we get inspired and our brains open up because we're spending time close to nature.

And it's also a place where everyone feels welcome and everyone congregates.

(air whooshing) - [Anna Sysling] And now, an excerpt from our digital series called Waves of Change, where we spotlight the diverse perspectives shaping the environmental justice movement throughout the Great Lakes.

This month we spoke with Gary Swick, educator and president of Friends of the Fox River.

The Fox River is a tributary of the Illinois River, and flows from southern Wisconsin to Ottawa, Illinois.

Gary has advocated for the river and used it as a classroom since joining the Friends in 1991.

- The Fox River was categorized as an impaired waterway in the early 2000s.

And that is synonymous to a plant or animal being, getting the status of an endangered species.

That means that it's a mandate to to save that and address that But we're educating and building a stewardship ethic with young people and hoping that they're gonna carry that forward.

I've had tens of thousands experiences, primarily with young people in streams.

The excitement, the wow, and the wonder that occurs can really drive a person.

being able to provide those connections that I think are especially thrilling for me.

(air whooshing) - Thanks for watching.

For the full interview with Gary Swick or for more about any of our stories, visit GreatLakesNow.org When you get there, you can follow us on social media or subscribe to our newsletter to get updates about our work.

See you out on the lakes!

(air whooshing) (upbeat music) (upbeat music continues) (air whooshing) - [Announcer] This program is brought to you by the Fred A. and Barbara M. Herb Family Foundation, the Charles Stewart Mott Foundation, Richard C. Devereaux Foundation for Energy and Environmental Programs at Detroit PBS, Polk Family Fund, DTE Foundation, and contributions to your PBS station from viewers like you.

Thank you.

(gentle music) (upbeat music)