On the Fish’n Canada episode previous to this one, we talked about Nagagami Lake being the perfect spot to showcase the advanced electronics now available in underwater sonar products. After all, Nagagami is a glacial lake that formed about 10,000 years ago by the retreat of a massive ice sheet called the Lauren-tide Glacier, meaning all kinds of underwater structure. It extended as far west as central Manitoba, as far south as the Great Lakes, and as far east as central Quebec and the St. Lawrence River.
In fact, many of the hundreds of thousands of lakes across this vast area were formed during this glacial retreat. They were so impacted by the sheer weight of this ice sheet that the surrounding earth is still rebounding. In fact, the surface area of many of these lakes is getting smaller as the earth tries to bounce back to its pre-glacial shape.
This explains the rough, multi-layered bottom of Nagagami Lake.
The extensive inflows and outflows provide nutrients and great water circulation, this is walleye heaven!
On that previous episode ‘hot as a pistol’ Pete ran a clinic on how to catch these walleye. Well, we didn’t know it at the time, but he was fishing on the cusp of a pre-frontal low, and despite the sophisticated electronics he was using, Mother Nature was giving him a huge leg up. Let’s talk about what she was actually doing.
MOTHER NATURE IS IN POWER
We’ve all heard the stories: “not one bite all day, cold front came through” or “we’re into a cold front, don’t bother goin’ out”, or most famously, “ya shoulda been here yesterday”.
So what’s really happening?
It’s about changes in barometric pressure, in the air and water, and the effect these changes have on an ecosystem.
Before a front, the pressure drops, and after a front, the pressure rises. Fishing is typically amazing during the pre-frontal low and a disaster during the post frontal high. The explanation lies at the very bottom of the food chain with microscopic sized animals called zoo-plankton and phyto-plankton.
Normal barometric pressure is considered to be about 30 inches of mercury or 762 mm.
A slight preliminary drop in pressure, as little as a millimeter or two is negligible to us or even the larger predator fish, but it can affect the buoyancy of these tiny creatures.
It pushes them out of their comfort zone, making them slightly unstable and vulnerable to predation.
So when tiny bait-fish gather to start feeding on them, it starts a chain reaction. A feeding frenzy. Once that party starts, it’s all over but the catching, because the fishing is typically amazing.
Like a domino effect, each level of predator starts to gorge and congregate in these areas.
This usually lasts about 12 hours. As the pressure and temperature continues to drop however things go from really good fishing to really bad really quick! Here’s why.
As the microscopic life continues to become unstable so does their reproductive cycle, resulting in the deterioration of the primary food source in that body of water.
In other words, the shelves in the grocery are now near empty and it doesn’t take long for the shoppers to stop coming in.
This is where Mother Nature performs her magic. Instinctively each level of predatory fish starts shutting down in anticipation of this temporary food shortage.
It’s important to note that shutting down does not mean they won’t eat, it means that their energy consumption meter has been dialed down to C for “conserve”.
During this period, which can last anywhere between 24 and 72 hours, the feeding zone of a mid-range predator like a large-mouth bass can go from several hundred feet to as little as 6 inches in just a matter of hours.
WHERE ARE ALL THE FISH
A good angler can take advantage of this by understanding what’s happening down there.
There’s a common misconception that when a front moves in, the fish disperse and go into the deepest part of the lake and become impossible to catch.
Nothing could be further from the truth. All they do is go to their comfort zone and stay put.
That could be deep water, shallow water, weed beds, break-lines, under cut banks to name a few. They tend to look for places that offer shelter from other predators but still have the potential of ambushing a quick meal.
Remember energy conservation is in effect, so they will NOT chase baits. Vertical presentations into good cover or deep structure will usually result in some of the best fishing days you will ever have.
“So, knowing what a great day Pete had at that spot”, says Ang, “I naturally used the waypoints he put into the Garmin and made my way there; but, this day was different: much cloudier and stiller water. I knew a front had moved in, and given the clouds, it was a low-pressure front”.
Sure enough, the small area Pete had such success in was empty. Nothing on the Garmin and no hits casting. Where did Pete’s fish go… something Ang had to figure out?
We talked about Nagagami having tons of structure, so with a quick look at a contour map on the Garmin, Ang could see changes in depth very close to Pete’s hunting ground.
All he did was move the boat a little, over a deeper trough and there they were.
Ang: “The fish had just slid over and dropped down a few feet. I know that when this happens, they’re not going to be actively feeding. I’m gonna have to drop my bait right on their noses, and with the Garmin it shouldn’t be that difficult”.
With the walleye being lazy and lethargic, the bait will have to be close and enticing, so minnows are the preferred bait.
And preferred they were. By that simple move deeper Ang had found Pete’s school “or” maybe even a completely other group of fish and saved the day.
The takeaway from this experience is, don’t get depressed when the weather changes on you. Learn about the water you’re going to fish. Find the structure and you’ll find the fish!
GETTIN’ THERE with RAM TRUCKS
To get to today’s awesome Walleye fishing we first took Hwy 400 north to Hwy 69. We took HWY 17 north west to White River. We then turned right onto 631 which took us to the Ford Air Base near Hornepayne Ontario. From there it was a short flight to Timberwolf Lodge.