‘Why not try to return what was there?’

Sudbury Star

Accent: Lake Nepahwin used to be called Trout Lake, before they died off. Laurentian researchers working to restore trout to this urban lake

Laurentian University fishery technician Melissa Godfrey pulls a net containing various fish species from Nepahwin Lake in Sudbury, Ont. on Thursday September 12, 2019. The fish collection is part of a study being conducted at the Vale Living with Lakes Centre at Laurentian University in Sudbury, Ont. John Lappa/Sudbury Star

Lake Nepahwin used to be called Trout Lake.

Like many lakes in the Sudbury area, however, it lost the fish for which it had become famous.

Its new name, chosen in 1949, is said to derive from an Ojibwe term meaning “sleeping lake.”

Might it awake, and host lake trout once more?

John Gunn, director with the Living With Lakes Centre, believes it’s certainly worth a shot — especially since other lakes in the Sudbury area have been able to regain their trout populations.

John Gunn, director of the Vale Living with Lakes Centre at Laurentian University in Sudbury, Ont., holds a fish caught from Nepahwin Lake that is part of a fish study. John Lappa/Sudbury Star/Postmedia Network John Lappa / John Lappa/Sudbury Star

“We don’t have any in Nepahwin now, but the positive news elsewhere might be enough to encourage our city fathers and mothers to look more seriously at our downtown lakes,” he said. “How much work would it take to protect the lake to the point that it could be restored? And wouldn’t that be a good, symbolic thing to do?”

This past week a team of researchers was busy netting fish from Nepahwin as part of a broader study of the lakes that were previously decimated by acidification.

For Gunn, who is nearing retirement, it’s a fitting way to cap off a career. “When I started here, one of my first assignments was what are we going to do about these lost lake-trout lakes in the Sudbury area,” he noted.

The fish is iconic, he said, since it can only survive in cold, oxygenated water, and “only one per cent of Ontario lakes contain lake trout.”

Laurentian University graduate student Jasmine Louste-Fillion weighs a fish at the Vale Living with Lakes Centre at Laurentian University in Sudbury, Ont. John Lappa/Sudbury Star/Postmedia Network John Lappa / John Lappa/Sudbury Star

Sudbury has an unusual share of those lakes, yet by 1980 they were compromised “to the point that the lake trout were either entirely extinct, or had just a few remnant populations,” said Gunn.

Over the next couple of decades, biologists would periodically go back to these big lakes — like Chiniguchi and Kukagami to the northeast of Sudbury, or George and Johnny to the southwest in Killarney Park — to see what improvements had occurred in water quality and fish numbers.

Gunn felt it was high time to take another look, so was thrilled when enough funding and in-kind support came together this year to begin a fresh survey of all 60 damaged lake-trout lakes.

The collaborative project between the Ministry of Natural Resources and Forestry, the Ministry of Environment, Conservation and Parks and Laurentian University, with contributions from Vale, will continue beyond this year.

Laurentian University graduate student Jasmine Louste-Fillion takes a tissue sample from a fish at the Vale Living with Lakes Centre at Laurentian University in Sudbury, Ont. Tissue samples will be sent away for analysis. John Lappa/Sudbury Star/Postmedia Network John Lappa / John Lappa/Sudbury Star

“We have completed 26 out of the 60 so far, sampling a good portion of them, and hope to have them all done in the next couple of years,” Gunn said.

The news, so far, has been encouraging. Lake trout are reproducing in quite a few of the more remote lakes, he said, and other species are coming back, too, or establishing a new presence.

“We’ve found wonderful surprises everywhere,” said Gunn. “Even with some of the species we had called dead or extinct, we found some remnants. In George Lake, we found an ancient whitefish that might be 40 years old that survived that whole period of acidification.”

Many lakes have been stocked by natural resources staff over the years, he said, but it’s been a while since any work was put into tracking how those fish have fared. The current study will help to provide a picture of reproductive success.

Laurentian University fishery technician Melissa Godfrey pulls a net containing various fish species from Nepahwin Lake in Sudbury, Ont. on Thursday September 12, 2019. The fish collection is part of a study being conducted at the Vale Living with Lakes Centre at Laurentian University in Sudbury, Ont. John Lappa/Sudbury Star/Postmedia Network John Lappa / John Lappa/Sudbury Star

A few lakes received special strains of trout. Two Killarney Lakes, for instance, were stocked with Iroquois Bay trout, “which are remnants of the Great Lakes fishery,” he said, while one lake south of Sudbury “received some of the fish that had survived the collapse from sea lamprey in Big Sound, in Parry Sound. So they were like organ donors, if you will, and once lost lakes became the home lakes for endangered stocks.”

The research team, operating under the project title Community Restoration of Acid Damaged Lakes, or CRADL, is now wrapping up Year One of its ambitious study.

“Nepahwin was our second to last for this year, and we will be doing Bell Lake in Killarney as our final lake,” said Gunn. “Nepahwin was good to do at the end of the series because there are a whole bunch of other problems to look at simultaneously.”

The lake has always been deep enough, at 22 metres (72 feet), to host lakers, he said, but loading from phosphorous and salt has depleted the oxygen in the lower strata where trout need to swim.

Laurentian University fishery technicians Adam Maiangowi, left, and Melissa Godfrey collect a net containing various fish species from Nepahwin Lake in Sudbury, Ont. on Thursday September 12, 2019. The fish collection is part of a study being conducted at the Vale Living with Lakes Centre at Laurentian University in Sudbury, Ont. John Lappa/Sudbury Star/Postmedia Network John Lappa / John Lappa/Sudbury Star

Some trout were planted in the 1990s as an experiment, he said, and splake (which don’t reproduce) have also been tried out in Nepahwin. The latter “survived and grew,” he said, but neither splake nor trout were turning up in the nets of the researchers this past week.

“There were 11 to 12 species, but mostly what we’re seeing is pike, walleye and bass,” he said.

Nepahwin also has a population of smelt, likely imported when an angler “washed a bucket full of fertilized eggs,” theorized Gunn. There’s even a little smelt run in the spring in a creek near Loach’s Road, noted the scientist.

Bass have perhaps taken over some of the trout habitat, he said, but since  the former “can find their way to shallow water,” it’s possible trout could still stake out the lower depths.

Laurentian University graduate student Jasmine Louste-Fillion, right, takes a tissue sample from a fish at the Vale Living with Lakes Centre at Laurentian University in Sudbury, Ont., as Lee Haslam, senior technician with the Ministry of Natural Resources and Forestry, prepares to bag the sample, which will be sent away for analysis. John Lappa/Sudbury Star/Postmedia Network John Lappa / John Lappa/Sudbury Star

It’s heartening, too, that temperatures are cooling at those deeper levels compared to earlier decades, when the clarifying impact of acid rain allowed the sun to penetrate and warm the depths.

“Even though the climate is warming, many lakes are now colder on the bottom, because the clarity has changed,” said Gunn. “When you get shading to the bottom water, that allows the lake trout to return. So here, in a strange little way, the climate impacts are at least delayed through these thermal changes.”

Still, it will be a challenge to bring Nepahwin back to a state that would justify its original name. Too much soil is being flushed into the lake from construction projects, said Gunn, and stormwater management is not nearly as strict as it needs to be.

The public also needs to be better informed about the extent of the watershed and recognize the impacts that are being felt from seemingly distant or unrelated activities.

“People don’t think the Walmart parking lot is part of their lake, but every bit of salt spread there makes its way to Nepahwin,” said Gunn. “People empty their oil pans in a drain, and don’t realize it’s going in the lake. That sheen on the water could be coming from a kilometre away.”

Long shot or not, Gunn thinks it’s worth trying to re-establish a trout fishery in this urban water body.

“It’s a wish and a prayer that you could get them to succeed,” he admitted. “But if you look at Lake Simcoe, they had all the same problems — algal blooms, oxygen depletion, invasive species — and they got an act through parliament and created such rigorous development standards that a healthy lake trout population is reproducing there.”

If Barrie can do it, then surely Sudbury, in his view, could do the same, even if it’s on a slightly smaller scale.

“It’s a hard challenge,” he said. “But why not try to return what was there?”

jmoodie@postmedia.com

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