Fish Population And Runnoff

[gentlemang]

I happened to be talking to a very experienced Alberta fly fisherman the other day and he mentioned that there have been a couple of high runnoffs in the past 20 years or so that have devestated the spawn for that year.

I was wonderng if we are going to have one of those years this year with all of this rain and snow still in the mountatins, or has the start to the runnoff been slow enough that the spawning will not be effected?

Just interested.

Greg

 

[SanJuanWorm]

Run off has been happening for 1000's of years. The fish survive just fine.

[Guest 420FLYFISHIN]

we should be far more concerned with the bank erosion of jet boats during high water! If the water is up and then a jet goes be you will erode stuff that would never get wet......yes its all a joke.

 

that and im still catching the small dinks that always plague my line lol

[Guest Grinr]

we should be far more concerned with the bank erosion of jet boats during high water! If the water is up and then a jet goes be you will erode stuff that would never get wet.....

Absolutely!!

I'm pretty sure there must have been a jetboat waaayyyy up FC above 37 St. SW today eroding banks cuz when I drove by the water was all muddy?

 

[DiabeticKripple]

Absolutely!!

I'm pretty sure there must have been a jetboat waaayyyy up FC above 37 St. SW today eroding banks cuz when I drove by the water was all muddy?

 

ummmm that would be the rain+runoff starting. the water levels are wayyy high now taking everything on the banks with them

[dube]

 

 

Sorry couldn't resist.

 

Yes, rivers are high, run off is happening.

[AlpineJames]

Can we get tee-shirts with that printed on them?

[AdamJ]

In all seriousness, run-off is one of the main reasons bio's are worried about brook trout. They are pre-adapted to our climate and weather patterns. In the spring, the rainbows spawn and run-off happens about the same time. A crapload of the eggs get killed off by the increasing silt in the water. In the fall however, there is no run off and this is when the brookies spawn. Turns out that a much larger proportion of brook trout eggs survive. In the end, the more brook trout there are, the more competition for food.......

[Hawgstoppah]

On a side note... I am no biologist but.... I think these big run offs are great for the fish. They clean out the smaller spawning streams, clean the silt out of the larger rivers too, and provide higher cooler water almost all year. All that silt from the spray lakes issues last year should theoretically be blown out this runoff as well. Hopefully our summer hatches (evening caddis) will be better on the Bow. Never saw a whole lot of good evening action all last year myself.

 

Another huge flood in 1995 changed the way the south fished. After the 1995 floods the crow fished fantastic in 1997-2002 or so. The best I have ever seen it fish.

 

After 2005 the Bow itself has fished extremely well starting in about 2008 up to now. These big floods take their toll for a few years, but when the rebound comes it fishes lights out. Rivers and fish populations are a cyclical thing. IMHO the crow could use a good "washout" right now, it's been sluggish for a couple years compared to what we got spoiled with.

 

Another river I fish quite often was the highest I have ever witnesses it ever being. But last fall it fished very, very well. The fish should be OK, they know where to go and hide.. crazy as it sounds but if you know the places the trout go and hide during runoff, you can do better on a day out now than you can when the masses think the river is back to "fishable" conditions.

[SanJuanWorm]

Can we get tee-shirts with that printed on them?

 

Just to to cafepress.com and order em up.

[Guest 420FLYFISHIN]

the only fish that can not work with high water in alberta went extinct long ago! As said before these fish have evolved to survive highwater or they would spawn in the fall like the others.

[gentlemang]

So now that the water levels hit a high and the river is being run clean of silt, didy and small trees. I see that some members feel it is a good thing for the fish population in a couple of years. Will this actually improve the fishing later this year? Or is it going to take a year or 2 to bounce back? Or is it just going to be another year on the river?

I don't remember the water this high last year even with the city ban on the river.

If there is a biologist lurking I wouldn't mind hearing an opinion from them.

Just to clarify, the purpose of this thread is to make conversation for a few days to let the river calm down a bit.

Weather looks like we are going to get a lot more rain early next week.

[Guest Grinr]

 

 

Sorry couldn't resist.

 

Yes, rivers are high, run off is happening.

Lmao.

[McLeod]

In all seriousness, run-off is one of the main reasons bio's are worried about brook trout. They are pre-adapted to our climate and weather patterns. In the spring, the rainbows spawn and run-off happens about the same time. A crapload of the eggs get killed off by the increasing silt in the water. In the fall however, there is no run off and this is when the brookies spawn. Turns out that a much larger proportion of brook trout eggs survive. In the end, the more brook trout there are, the more competition for food.......

 

 

 

Be interested to find out who or where you heard this from. Only in the Athabasca River System would one even consider that possibility.

Anywhere south the Rainbows are just as Non native as the Brookies so there is no validity to that statement that bio's are worried about it. Maybe your thinking of Cutties ?

[troutfriend]

Floods are good for fish.

1. Removes silt, excess nutrients like nitrogen and phosphates and deposits this in the active flood plains (unless they are dyked or developed with houses.

2. Scours plant/weed growth from river beds exposing new spawning habitat (more important for broadcast spawning species like the Mountain Whitefish). Anyone who visited Southland Dog Park following the flood of 2005 has seen the 2-3 inches of silt that were deposited on the park and has seen the great regeneration of grasses since the event.

3. Populations rise following flood events- increased recruitment is often observed in subsequent years (Call ASRD on this for the numbers).

4. Brook trout have an advantage as fall spawners over Cutthroat and Rainbow Trout, but Bull Trout and Mountain Whitefish are also fall spawners, the difference is:

a. Brook Trout can spawn in a wider range of temperatures and habitats.

b. Brook Trout can spawn when they are 2 or 3 years old, while bull mature at 6 or 7.

c. Brook Trout are harder to catch than Bull or Cutthroat Trout.

d. Weed/Algae growth reduces Mountain Whitefish spawning success.

5. Cottonwood Trees require floods to regenerate, during floods the small fish move in the floodplain and seek cover behind these trees. The river may be dark brown, but find a spring seep, backwater or little creek flowing fresh water into the Bow River this week and you will find lots of little fish just waiting this little flow event out.

 

Rivers need floods as they are living ecosystems,

[ironfly]

Probably of no interest to you Bow River Boys, but I'm sure happy to see a healthy runoff on the NSR. For one, the fish pack into the backwaters; I call it the Edmonton Duffer's Fortnight. For another, Goldeye spawn during runoff. Their eggs are neutrally-buoyant, and drift downstream mid-current, under cover of dirty water. It seems if there's no runoff, the fish go elsewhere, possibly trying to find good spawning conditions; makes for a lousy dryfly season. Good runoff on the NSR= great dryfly action all summer.

[Guest Grinr]

c. Brook Trout are harder to catch than Bull or Cutthroat Trout.

Ummmmm....according to who?

I'll admit to not having much experience with bulls and cutts,but I've caught thousands of brookies.IMHO they are opportunistic feeders (much like cutts that can't afford to be picky?)and it's extremely rare to find selective brookies that won't smash anything that resembles food.Generally speaking,if I can't pull a brookie out of a typical small stream pool with a wooly bugger,there's probably none there to catch?

[troutfriend]

Good question,

Here is one published local paper to support this:

http://www.tandfonline.com/doi/abs/10.1577...AO%3E2.0.CO%3B2

full document - http://www.bio.ucalgary.ca/contact/faculty...003%20NAJFM.pdf

 

Here is another related paper on the issue:

http://classes.uleth.ca/200901/biol4500a/R...gs/Stelfox2.pdf

 

[gentlemang]

Hey troutfriend, great post.

Thank you.