Since 1915, nearly 40 million non-native fish and eggs have been released into Banff National Park's watersheds. They have significantly altered aquatic ecosystems. In 2002, a team of Aquatic Specialists began removing non-native Brook trout from Banff's Devon Lakes. They are trying to return that aquatic ecosystem to its original fishless state.
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Since 1915, nearly 40 million non-native fish and eggs have been released into Banff National Park's watersheds.
They have significantly altered aquatic ecosystems.
In 2002, a team of Aquatic Specialists began removing non-native Brook trout from Banff's Devon Lakes.
The Devon Lakes are in the most remote region of Banff National Park.
The fish were never supposed to be here.
Restoring to Zero
Barb Johnson:
All the parks in the mountains particularly had non-native fish stocked.
Charlie Pacas:
Fish in these lakes provided opportunities for people to come up to an incredible alpine environment and come fishing.
No one really realized the impact that the stocking would have.
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Art Laurenson - Resource Conservation Specialist, Banff National Park
Art Laurenson:
Putting trout in these lakes is like putting a pyrana in your fishtank.
Monika Vittnova:
It's weird that people would put fish into lakes where they don't belong.
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Monika Vittnova, Devon Lakes Restoration Field Technician
Charlie Pacas:
The Brook trout eventually outcompeted the cutthroat trout and became the only species of fish in the two lakes.
And what happens is that fish do end up swimming downstream and so these fish started moving all the way through the system, populating the Clearwater river system.
The last lakes that were stocked in Banff were in 1988 and they would have been roadside-type lakes. In about 1972, I think the warning signs were being read by many of the fisheries biologists at that time. They realized that it was time to stop.
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Charlie Pacas, Banff National Park Aquatic specialist
Barb Johnson:
It's like any landscape or ecosystem in the world that suffers from introduced species, it changes.
We've done restoration for years in parks and it just seems so much more natural on a terrestrial level because we as humans relate a lot better to that. But if you walked into one of these parks and you saw gazelles and zebras running around, you'd be alarmed.
And you walk in here and you look in the aquatic systems and it's pretty much what you've got. You've got top predators that aren't supposed to be there.
And it dramatcially changes the ecosystem. And because we're terrestrial beings, we don't really see that as a problem.
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Barb Johnson - Waterton Lakes National Park
Charlie Pacas:
We're hoping to try and restore a lot of the aquatic systems across the Mountain Parks - across parks in general - to their historically natural state.
We've had close to 2 km of gill nets in the lakes, fishing initially just through the summertimes in 2002 to 2005 and then we put nets in and they just stayed in the water continuously. I'm pretty confident that we've eradicated all of the fish in the lakes. We still have nets in there. We haven't caught a fish since September, 2006.
The thing about it is you look at these lakes and you think "nothing can be wrong" but it's actually within the lakes that you really start to see the change.
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1547 fish have been removed from the lakes since 2002.
There are only two ways that people say, if you look at the literature, that you can actually get rid of fish successfully. One of them is through piscicides - or fish toxins.
Our original plan at the Devon Lakes was to deploy a fish toxin called Rotenone into the headwaters of the Clearwater. By deploying this we would eliminate the last of the fish that were found in the river.
We decided not to use it even though the Rotenone is pretty much selective for fish, it does also impact the invertebrates that are found in the river and we were concerned that they may not return back to reference levels or back to their historical conditions in a short period of time.
Barb Johnson:
And the other way they say to be able to successfully get rid of fish is dewatering.
Charlie Pacas:
We're putting in aquadams at the outlets of the upper Devon Lake and the middle Devon Lake. The reason that we're doing that is that we're trying to stem the amount of water leaving theses lakes. With the dams going across, basically stopping the flows will reduce the amount of water in the Clearwater River which will give us an opportunity to get into about 4 km of river and electrofish the remaining Brook Trout out of the stream.
We ended up putting in an aquadam and initially we got it filled up to about the 5 foot level, which was max and then all of a sudden the aquadam deflated.
They provided us with another aquadam - they flew it in the next morning. And we got it filled up by quarter to 10 and…
It's hooped. It blew exactly around the same height as the other one.
Producer:
What do they think the problem was?
Charlie Pacas:
Well its plastic is just weak. Weakness in the plastic.
Producer:
That's all she wrote?
Charlie Pacas:
That's all she wrote. So today's going to be a cleanup day and we won't be continuing on with the dam.
Producer:
What's going to happen with the rest of the project?
Charlie Pacas:
It'll still continue. We'll do it no matter what, but this was supposed to be the thing that would help out at the other end of the electrofishing.
Group:
Adios. See ya Frank. Thanks Frank.
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Devon Lakes Tent Camp - 80 kilometers north of the Banff townsite
Charlie Pacas:
We've broken the river off into 100m reaches putting in block nets at every 100m. The fence essentially stops any kind of mevement or fish passage through or within the stream and the pvc is weighted down so there's no way that fish can actually swim underneath.
We've split our electrofishers into four groups of two. You electrofish a reach twice if you don't catch fish. If catch a fish, then you go back in and you electrofish until you do two successive passes without catching any fish.
At about the 4 km mark, there's a barrier waterfall, so fish can actually flow over the barrier waterfall but they can't make it back.
We'll be going right up to just below the barrier right at the outlet of the lower Devon Lake.
In about 9 or 10 days time we'll have removed all of the fish there.
Electrofishers:
Hey I'm Alex and I'm Jimmy: and together we're the Brook Trout task force. And we're going electrofishing. That's right!
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140 days of electro-fishing since 2002
3616 fish caught
Charlie Pacas:
There's always a halo over Charlie.
Radio:
…Devon Lakes portable
Charlie Pacas:
Devon Lakes, good morning.
Radio:
How are you folks today?
Charlie Pacas:
I think everybody's doing good. We've got a little bit of snow falling now. We're going to be working on the river and we're all back at the same location tonight.
We're kind of hoping for a little bit better weather.
So, lousy day. So we've had to rethink how we're going to get today done. I'm thinking that we'll use the weather day to help Art, Monika and Ray out initially in the morning to move block nets.
I think it's probably snowed almost every year that we've been here. In fact I can't recall a time where we haven't had snow. On some occassions we've had up to a metre of snow.
Having a good day?
Monika Vittnova:
Great day. Last day of summer, it's great. Best weather. Ever.
Charlie Pacas:
Well guess what? We're almost done. We've come up to the base of the Lower Devon Lake, so the outlet of the Lower Devon Lake is probably about 40 m up. We have a barrier waterfall here, so fish can't make it upstream from the barrier waterfall. We've fished right to this point. there's still 3 other teams on the river, but they're probably 10 or 15 minutes away from being done. So far [gestures zero with fingers], that's the number of brookies we have so far.
Producer:
How does it feel to be done?
Electrofishers:
Excellent. You know, satisfying, we're happy.
Charlie Pacas:
We're done!
Let's go have lunch.
Not everything worked out as well as we hoped, but we put in 130,000 seconds of electrofishing effort into the creek and we didn't catch any fish, so with last last year's capture of 1 fish and zero this year, I'm feeling pretty confident that we've taken care of all the fish in the upper Clearwater.
Barb Johnson:
One of the biggest concerns we have as biologists or people in general is climate change. That's going to be a huge stress on our natural systems. Any creatures that have evolved over eons to survive in a system with all the different parts. If there's somethig that can survive and adapt in time to still be able to be there with a stressor as strong as climate change - or others - it's probably the native community of plants and animals that was there originally.
Charlie Pacas:
I think visitors to this area probably would expect that this area is in a very pristine-type state. I'm not sure whether that's just a feeling that people have that you know, they feel "hey it feels pristine here, doesn't look like it's been touched" and we've been able to bring some of that back to that state.
Barb Johnson:
This isn't a quick fix. It's something that you have to learn the system intricately. Charlie's been here since 2001 and knows this place inside out. And if you do want to fix something you do need to know as much as you possibly can about the system before you go tinkering. that's one of the things I'll for sure take back: go and learn your systems and then decide what the best way to try and tackle the challenges are. And also that it can be done. I think that's a pretty important message to take back: don't give up. It is a huge challenge, especially when there is complexities like tributaries and more than one lake, when the systems are complex like this. but it still can be done.
We say that national parks is kind of the last bastion of wilderness and natural protected areas in Canada. If there's somewhere where things should be the way they were before we meddled them up, perhaps this is where that is. And this is one place where we said actually: "that's our policy. That's what we're going to do here, to the best of our ability."
Producer:
How does it feel to be leaving today and going away from this, probably never coming back in the same way that you've been coming here?
Charlie Pacas:
It feels a little sad. But I feel quite happy that we did it. So…
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The invertebrate population is slaready rebounding to a more natural state as a result of the brook trout removal.
Downstream of the restoration site, non-native fish species have mixed with native Bull trout.
In 2010, Charlie and his crew returned one last time and caught no fish. Downstream, they caught over 100 non-native fish in an afternoon.
To be continued…
Producer:
Okay, I want your head right in here. Right about there and that's where you go: "zero"
Group:
Zero. Zero fish!
No fish
I didn't see a fish, smell a fish or catch a fish. Zero fish
Been skunked. Haven't seen a fish all week. Zero.
No fish!
Zero fish.
Nar fish in the brook Raymond, nar fish.
Not something I usually brag about, but got skunked. No fish.
It's mighty poor fishing around here, I'll tell ya.
No fish, no kill. Go Vegetarians!
Zero fish.
