Plant Kokanee into spray lake ?

aulrich · #1 06-08-2016, 12:43 PM

So I heard something new today that got me thinking, and that is in some lake trout reservoirs south of the border they plant kokanee to be food for the lake trout.

Supposedly the kokanee feed on a different part of the food chain and unlike the rockies, lakers will eat them, which should grow bigger lakers

Could this be viable to spray lake, I expect that the population would not be self sustaining but given the short lifespan of kokanee a yearly stocking could produce a interesting put and take fishery

though it would take 20 years to produce any big lakers but it beats what is happening now.

Obviously invasiveness should be considered and IDK if there is anything like viable spawning habitat.

Thoughts?

DiabeticKripple · #2 06-08-2016, 12:50 PM

Since spray is part of the bow River drainage, there would be the potential for them to spread all the way down the river into the SSR

Okotokian · #3 06-08-2016, 01:11 PM

Man, plans like that make me nervous. Kokanee stocks collapsed in Lake Okanagan when authorities decided to play God and introduce "food". As with most human-inspired introductions, I say leave well enough alone.

"The primary cause of this reduction was hypothesized
to be the introduction of the opossum shrimp, Mysis
relicta (Shepherd 1996). Ironically, the introduction of
Mysis into Okanagan Lake in 1966 was done with the intention
of boosting the size of kokanee, based on a decade of experience
with the introduction of Mysis into Kootenay Lake.
As it turned out, Mysis were able to avoid predation by kokanee
in the main basins of both lakes by sounding into the
dark depths during the day. By virtue of their sheer numbers,
together with their habit of coming up to feed all through the
night on the same zooplankton species preferred by kokanee,
Mysis instead became a formidable competitor."

http://www.env.gov.bc.ca/wld/documents/fr07shepard.pdf

huntsfurfish · #4 06-08-2016, 03:33 PM

Quote:

Originally Posted by Okotokian

Man, plans like that make me nervous. Kokanee stocks collapsed in Lake Okanagan when authorities decided to play God and introduce "food". As with most human-inspired introductions, I say leave well enough alone.

"The primary cause of this reduction was hypothesized
to be the introduction of the opossum shrimp, Mysis
relicta (Shepherd 1996). Ironically, the introduction of
Mysis into Okanagan Lake in 1966 was done with the intention
of boosting the size of kokanee, based on a decade of experience
with the introduction of Mysis into Kootenay Lake.
As it turned out, Mysis were able to avoid predation by kokanee
in the main basins of both lakes by sounding into the
dark depths during the day. By virtue of their sheer numbers,
together with their habit of coming up to feed all through the
night on the same zooplankton species preferred by kokanee,
Mysis instead became a formidable competitor."

http://www.env.gov.bc.ca/wld/documents/fr07shepard.pdf

This ^^^^^^^^^^^^^^^^^^^^^^^^^^

aulrich · #5 06-08-2016, 03:45 PM

When spray was first created they stocked whitefish (there is a U of C paper somewhere where I read this) they never took and after they grew past forage size and subsequently died out, the lakers got small since basically a bug feeder only gets so big. So I guess if you were going to stock un viable fish food you could just toss in whitefish again and since they did not take in the first place and most every lake downstream already has them there will be no net new impact .but As I understand it Kokanee have the same life span salmon so if they don’t spawn they will be gone in 4 years regardless, and even at full size they are still viable prey for a big laker. Also if they don’t spawn making a new put and take fishing opportunity has more chance of getting budget vs stocking fish food.

Not that there would be any budget for this.

If they can make a living in a river they will stop basically where the trout stop though I sort of doubt that they could make a living in a river or tolerate water warmer than trout can.

But realistically if they did have spawning habitat I would think they would end up in the reservoirs up stream of Calgary but downstream how many reservoirs are fed by the Bow and how many have catchable populations of trout? And about where does the Bow stop being a trout river Brooks ish ?

But taking a look at the impact at those other places this has happened is something to consider.

Oko you are right we have a viable small fish laker fishery and a change is a risk and it’s in how you manage that risk.

3blade · #6 06-08-2016, 04:18 PM

Biggest problem I can see is they could get downstream, start spawning and taking up food that small trout/whites eat. The laker fishery in spray isn't really worth messing with things that much.

Also, in the current political climate, you won't likely get any support for a non-native fish introduction. I was very surprised the tiger trout thing went ahead, my guess is that's the last we'll see of it.

EZM · #7 06-08-2016, 04:37 PM

I agree with the need to be careful and consider what we do and the potential unwanted consequences. All too often, what seems like a good idea initially, comes back to bite us later when we least expect it.

I have no issue stocking native species in native watersheds to reestablish populations.

I have no issue stocking reproducing species in isolated watersheds OR 3N (sterile triploids) in isolated watersheds.

But Spray is a high risk watershed with potential impacts throughout the bow valley watershed.

Not a good idea in my mind.

aulrich · #8 06-08-2016, 04:38 PM

Oh this is not happening in the current climate regardless so this is purely a "What if" thing

Jet - yes the one by Canmore and yes there are Rocky Mountain whitefish in spray oddly the only native fish there. But according to that report that talks about the lake whitefish dying off they are not a big prey item for the lake trout.

It's a pitty for so may years if you googled "Spray lake depth chart" that report was on the first page. I'll have to see if a link is somewhere deep in AO history

And since the Bow is already screwed up with invasive rainbow and brown trout it's unlikely to get any more screwed up

PerchBuster · #9 06-08-2016, 05:31 PM

I say no to the Kokanee but sounds like if there is whitefish in there Cisco's should do ok and Lakers do very well on Cisco's and Smelt. You've got the right kind of idea though in my opinion. More attention needs to be placed on establishing prolific forage bases in most lakes and waterways across the province in order to help boost populations and size of gamefish for sport fishing. If we help take care of their food sources, the gamefish will flourish in my opinion. You know they will put on the feed bag. When forage is sparse they go on to energy conservation mode, grow slowly, get skinny as the live partially on their body reserves and then the fishery starts to collapse or is just weak at best with low population count. We don't need a silver bullet like Kokanee I don't think to fix those issues. Improving the populations of the native forage species, case by case, lake by lake etc I think would go a long way to making a better fishery. Just my thoughts, I'm no expert. Good topic!

Flieguy · #10 06-09-2016, 10:31 PM

I don't think it would work. Spray is just not a super productive fishery and I doubt it really will be in the near future. I believe there was also a program which introduced freshwater shrimp there and that fell flat as well.

maybe sculpin or suckers? but I doubt they'd have enough to eat either