Flathead Lake: Lake trout & Mysis shrimp

This video I want to discuss what happened when Lake trout and mysis shrimp were introduced into Flathead Lake.

References:

[electrofisheratmt]

Hey guys so here we go with this one, . The lake trout are native to MT as you say, the fish I deal with are the fish on the Beaverhead. These guys live in Elk Lake and Twin Lake. We think it was from the movements of glaciers and possibly with mixing of water flowing both ways over the continental divide for the past 40, 000 years. The fish in these lakes have probably been there for at least 10, 000 years. The fish in Elk have been stable and not many fish. The fish from Twin are monitored by FWP and seem to be doing better in the past few years. In fact last year the large fish was over 10lbs. OK here we go for the bull trout, Westslope Cutthroat, lake trout and kokanee. The native fishery in Flathead was dominated by cutthroat and bull trout. Cutthroat are interesting in that they can filter feed and pick out zooplankton. Bull trout were the top of the food chain and ate all the other fish species in the lake. If you look at the old pictures, before FWP got involved, or the Fisher Management service the lake was producing huge cutthroat and bull trout. The native Americans can be seen with cutthroat up to 10lbs and bull trout well over 20. Westslopes are strange creatures they never switch over and become piscivorous. Only swimming around eating plankton to get large. The addition of kokanee changed the entire interaction of the lake fish. The cutthroat began to be out competed by these non-natives and the size of the westslopes and the number began to decrease. The migrations of the kokanee up the Flathead was epic. I got to see some of the last runs back in the 1970's. The lake trout just kind of hung around for the time not really taking over biomass of the bull trout. Again people were catching large bull trout and lake trout were incidental. Here comes with FWP and their idea of what they had seen in BC, especially in Kamloops lake. They had moved mysids into Kamloops and the fish went wild. Huge rainbows giant kokanee. The problem no one looked at their life cycle. You place them in shallow lakes where the fish have access to them, the get eaten. You stick them in deep lakes and you find they have something called nocturnal migration. They sink to the bottom during the day and float up the water column to feed at night. So you have cutthroat being bombed by kokanee and now you have mysids. Now we get to a spot were we have actual tropic cascading effect. Where the mysids were eating all the zooplankton, the kokanee are really good at eating what is left, and the cutthroat are now on a decline where they cannot recover. Bull trout are now losing their food source, they mostly feed near the shores or up in the water column where the westslopes would be. The lake trout who lived at the bottom of the lake all of a sudden had an ample food source of large zooplankton that they were the only ones eating. Replacement came quick, fish that had dominated that ecosystem for 10, 000 years were not out competed and placed on a scale of incidental populations within in the lake. This took only about 20 years. It blows my mind even trying to understand how fast that was. The kicker, FWP also placed them in all our other deep lakes around Flathead and Lincoln county. This again was the end of a lot of our larger fish in the area. After we lost these fish, we know that the perciformies started to become dominate fish in many of our larger lakes. What we know about the life cycles of bull trout is that the issue is more complex than what was thought 20 years ago. When the fish were listed in 1998 we all got together and talked about why they were on a decline. 98% of the fish bio's said it was due to land management ie logging and road building there were a few of us who raised our hands and said wait a minute you cannot build your models on 5-10 years of data, we dont know what these numbers where a 100 years ago. Do you think there may be something with non-native, do you think that we have lost our migratory competent from dams in the large rivers, do you think maybe there are things we are not looking at besides spawning habitat? I can tell you being stuck in the mud on this one, I have replaced or removed 100's of culverts, removed over 1000 miles of road, reconstructed stream channels and built great fish habitat. What do we have, declining numbers of fish in all the large watersheds. Not only is it bad, but we think we have lost over 70% of our bull trout in the past 20 years. What has changed? Non-natives and poor management where we have these fish. The movement of the fish up to Grace Lake was from USGS and it was Clint Mofiled. Again when you are thinking about lakes dont forget our lesson about stratification., Just because the surface water is above 60 has nothing to do with the other two levels with the hypolimnion being much cooler up to 20 degrees. Hungary horse was so far and away from everything that FWP never added the big non-native group to the SF. Which is one of the better things they did, left shit alone. It was an amazing time back around the turn of the century in MT. We had all sorts of Europeans showing up here and they wanted the fish they were used to catching back home. We had 100's of millions of non-native fish being moved into the area via railroad. The local road and gun clubs would move these non-natives into lakes all around by horse back and hiking. The old milk jug stocking was a real thing. It was just lack of thinking since we had national forests and national parks coming on line. Where these guys were looking at maybe natives species have intrinsic value. Not with fish it was the non-native should rule the water ways. The best example I can always give, do you know why there are carp in the all the major river system in the US. Carp are native to Asia. Well it was thought that a hungry nation needed a food source. The last little tid-bit I will leave you with, is that the native people had fish weirs and nets in the lakes and rivers of Flathead lake. They were talking out 100, 000 of fish a year, it was thought that the cutthroat runs into the upper rivers systems was in the millions of fish, all adult fish that were probably over 5lbs on average. The rivers teamed with these fish and bull trout which were following them in the spring to eat them, and in the fall they were making spawning runs in the 100, 000's. I think the idea of the state giving us 6in salmon was a good trade off for 10lb westslopes and 20lb bull trout. Sorry about this long one here. This has been one of those issues that I have had to deal with and seen my whole life being from Libby.

[slefler]

Awesome to hear some of the fish history of our region, really diggin these info videos.

[smokey]

Very informative and well done, Thanks for that and the links,

[Klamath]

Lake Kintla in Glacier has huge Lake Trout as well as small Cutthroat and Bull Trout. I have caught Lake Trout as big a 10 lbs. in there. Upper Lake Kintla has only Bull Trout and you are not allowed to fish there. It was saved from lake trout by Kintla Falls. Nice videos. Keep it up.

[patlippincott]

Very informative as to what is happening in flathead lake i wonder if what is going On there has any similarities to what is happening in Lake Chelan, Wa. Where they introduced lake trout in the 70s & that population has exploded

[shignig]

My dad talks about the eagles from when he was younger when I was I kid one of the biggest mistakes the fish and game talked about was the shrimp and how they basically killed off the salmon which was a main food source as the bull trout and far as planting the salmon they won't reproduce naturally because it's not there native water that's why they plant mcgregor Bitterroot Ashley tobacco River what I'm not impressed with is them killing off all the mountain streams for brook trout making it impossible to fish for food when all you catch is cuttys

[RushVoorhisOutdoors]

cool video man, didn't know about the lakers!!! wanna get on one soon

[shignig]

I could also go down to old steel Bridge with a can of salmon eggs and catch bull trout tell my arms were tired but it's against the law now