Open-water whitefish may be the last frontier of Canadian angling. Here’s how to find this underrated gamefish

We have hundreds, indeed, thousands of lakes scattered across the country where huge numbers of delectable whitefish—in the four, five, and six pound class—prowl without ever seeing a hook. In fact, I’ve long considered open-water angling for whitefish to be one of the last fishing frontiers available to us.

We recently sat down on our Doc Talks Fishing podcast with good friend and whitefish biologist, Becca Perry, an instructor at the Saskatchewan Polytechnic, to talk about whitefish habits and habitats. Becca agreed that we have almost unlimited opportunities to catch whitefish, but in order to successfully catch them during the open-water season, we need a special focus on where to find them.

So today, let’s take a look at what Becca has to say about the locational side of the summer whitefish puzzle.

• Anytime you have a species focusing on slow-moving benthic invertebrate-type prey—things that rest on the bottom—they’re not (the usual) prey.

• If you’ve ever seen whitefish hunt it’s really cool. They look like little sharks. Almost like the scene from Planet Earth where you see the fish picking prey out of the coral reefs. They’re just like that, but it’s just on a different scale.

• Whitefish are pretty opportunistic. They can eat a lot of things. That overhanging mouth and bulbous-type nose is designed to pick creatures off the bottom, and sort through sediment.

• They can filter feed when they’re eating plankton, for example, really small creatures, even though the plankton is so small the whitefish can’t see them. They take in water, and their gill rakers—they’re the bony part of their gills, not the red part—act like a comb and stop prey of a certain size from exiting. That’s filter feeding.

• But whitefish are good little hunters, too and visually hunt benthic invertebrates. That includes aquatic insects and crustaceans that might be a centimetre or two centimetres long, like caddis fly larvae, crayfish, mayfly larvae, nymphs. They grab them similar to a trout. So we have to give them a little bit more credit for their hunting ability. They can feed in all sorts of ways, filter feed or target individual prey items.

• When I studied whitefish, I  looked at their stomach contents. Their diet varied from lake to lake, based on what’s available. But typically they eat small benthic invertebrates that don’t have a backbone and live on the bottom, like worms, leeches, mayfly larvae, caddisfly larvae.

• Those little insects are very nutritious, and I found that whitefish focused on them a lot. Chironomids larvae, which are those little red worm-looking insects were also common, as well as freshwater shrimp

• I also found whitefish ate mussels and clams. Whether they’re targeting them or just inhaling them while they’re eating other insects I’m not sure. It’s not the most nutritional item for them. It’s pretty difficult to digest that shell. And occasionally we’d find baitfish.

When we asked Becca if she thought whitefish had a favourite food item, here is what she said:

• What’s the most important is hard to say. I think anything that looks tasty, that’s crawling along the bottom, that looks vulnerable, that’s visible to them, they’re going to target that. So, a small crayfish might be something that we can mimic pretty easily.

• So there was no favorite item. Inevitably there’s going to be something that comes out on top, but it’s rare that you see one thing in 90-percent of their guts. It tends to be a diversity of things.

• There are the times they’re going to switch to be opportunistic and feed on fish. It might not last forever. And then they’re going to switch to something else. That’s super important because the behavior of switching from bottom feeding to offshore feeding or pelagic feeding, as we call it, makes them a good habitat coupler.

• What that means is whitefish are a link between two different habitats. So you can have that nearshore, littoral area, offshore, open water area, and the whitefish will link that. So that’s one of the important ecosystem services that makes them so important.

 

What types of lake bottoms/substrates should we be looking for to contact whitefish? Do they prefer muddy bottoms, rocky bottoms, cobbly bottoms, steep drop-offs or gentle drop-offs?

• They’re quite dynamic. I’ve seen them making a living in lakes where I would never guess that they could survive, where we see other fish decline or even winter kill. We don’t see it with whitefish. So they must find a way to persist in some of these environments that are outside of their textbook range

• I see them as nomadic fish that are always moving. They’re very migrational. They make huge migrations in search of food. They’re constantly looking for food. They’re moving in big schools and so they’re not going to be in the same place twice necessarily. They might be gone the next day because they’re constantly moving. They’re like a continuous swimmer.

• If you look at their flesh when you fillet them you’ll see there’s a lot of red muscle. We don’t see that as much in something like a walleye, which has has that sandy-colored white flesh. That’s because that red muscle is different than the white muscle and has myoglobin in it, similar to hemoglobin. Myoglobin is a protein that binds oxygen.

• When you see a fish that has a lot of red muscle, it tells you that they’re a long-distance, continuous, migrational-type fish because they need a supply of oxygen all the time. It’s kind of like a marathon runner. They’re not going to be sedentary and hang out in a honey hole for a week. They’re grazing.

• In my experience, they like hard-bottom areas, so cobble, gravel, rocky substrate. The reason is those complex habitats are where benthic invertebrates grow. Most benthic invertebrates need somewhere to crawl and hide from being predated upon. So that’s where the whitefish are going to hone in.

• There are benthic invertebrates that can live on sand or mud bottoms, but they tend to burrow,  so it’s harder for whitefish to get them. They still can. They’re excellent at rooting out things. But when hunting for an easy meal, they’re going to cruise these hard bottom areas.

• So, if you can find a rocky shoal or similar in cool water, and it’s got some vegetation growing on it, that’s where they’re going to be.

Well that is enough to keep us busy for one week. Next week we’ll team up with Becca and look at fishing presentations and strategies to catch whitefish. In the meantime, if you’d like to listen to the fascinating podcast we had with Becca, just click on this link.