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PostPosted: September 25th, 2018, 6:43 pm 
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Creatures vs. climate: The lake trout. Published on Sep 24, 2018 TVO

https://tvo.org/article/current-affairs ... lake-trout

Warming temperatures are affecting thousands of lakes across the province and making life difficult for species that live beneath the waves — including the iconic lake trout, one of Ontario’s most popular sport fish.

“It’s water temperatures and oxygen that really limit lake trout,” says Sapna Sharma, associate professor of biology at York University and director of the Sharma Laboratory. “With climate change, water temperatures are generally becoming warmer and oxygen levels are becoming lower, and that can stress lake trout populations.”

According to a 2009 paper in Ecology authored by Sharma and two others, lake trout populations in more than 1,600 lakes in Ontario could be vulnerable by 2050, based on climate-change projections. By 2100, there could be as many as 9,700 vulnerable populations across Canada.

And warmer water isn’t the only issue that lake trout have to deal with — the effects of climate change have also made the province’s lakes more hospitable to smallmouth bass, which can out-eat the lake trout, leaving the struggling fish without enough food to survive.

Smallmouth bass are native to North America, but over the past 100 years, they’ve spread further north in Canada. While they lack the ability to jump from one lake to another, they can travel by river between bodies of water. “They’re moving northward at a pretty rapid rate,” Sharma says. “They’re voracious predators — they eat a lot of the minnows. They can eat a lot of things.”

One of the lake trout’s most important sources of food is the cisco, or lake herring, a coldwater species that’s also threatened by warming temperatures. Smallmouth bass consume cisco in large quantities, which means there are fewer available for lake trout to eat.

Lake trout are what researchers call a bellwether species — that is, when they’re in trouble, it’s an indication that the water quality of the lakes they live in is dipping, Sharma says.

The fish already occupy Ontario’s northernmost lakes, meaning that when warming temperatures push lake trout out of their habitats in the south, they have nowhere else to go. The lake trout’s range is rolling up like a carpet.

“There are very few populations left in the U.S., because it’s become too warm for them,” Sharma says. “Most of the lake trout populations are in Canada and a large portion of recreational fisheries and tourism. People come to Ontario and Canada to fish for lake trout. It contributes quite a lot socioeconomically.”


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PostPosted: September 25th, 2018, 8:35 pm 
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Location: Rattlesnake Pond ME
What?
We have plenty of lake trout. We even have derbies to try and control the population
Northern Pike are being a pest species and if caught are not to be put back.

The reason for this odd thinking is preservation of landlocked salmon.


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PostPosted: September 26th, 2018, 4:32 am 
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Location: Near Ottawa ON
Yeah, I could see spending my tourist dollars fishing Ouananiche in Maine. Pike, not so much.


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PostPosted: September 26th, 2018, 7:28 am 
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Location: Bancroft, Ontario Canada
The problem is longer summers will mean lake trout lakes that have low volumes of cold bottom waters (shallower lake basins) will deplete more oxygen over a longer period of time before the surface waters cool enough to become habitable again. Borderline lakes that hold barely enough oxygen down there over the course of a summer normally, will lose trout as summers become longer and longer.

Brook trout lakes in APP often cool enough by the end of the season, Sept 30 so that shallow water inshore catch is possible... wonder whether this year might be different if the inshore habitat hasn't cooled enough?

This year saw a sudden spike in Great Lakes water temps, up three degrees in some places:

https://www.cbc.ca/news/canada/hamilton ... -1.4817127

Somewhat OT in the news today... the Environmental Commissioner of Ontario slams Doug Ford's cancelling of the cap and trade climate change plan. Maybe buck-a-beer will make up for that? Long, hot summer ya know, ya need something for it.



Here's Joe Robinet catching monster lake trout in Great Slave lake, they're popular there.

https://www.youtube.com/watch?v=B4xEmAgwlbk

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PostPosted: September 26th, 2018, 10:58 am 
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Krusty wrote:
Yeah, I could see spending my tourist dollars fishing Ouananiche in Maine. Pike, not so much.


You might catch a few togue while you are at it!

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PostPosted: September 26th, 2018, 4:57 pm 
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Location: Rattlesnake Pond ME
No doubt water is warming. The Gulf of Maine is said to be the fastest warming ocean water in the world
Longnecked clams are fone . Lobster babies are hard to find though there nay be a drop in temperatures temporarily with massive icecap thawing
We are on the Labrador Current

Already fisheries are changing and oyster businesss is burgeoning
Thanks for green crabs Nova Scotia.
Enough trouble with the Asian invasive green crab

Bye bye cod


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