A Theory Of Mine

[fisher26]

OK I'm just tossing this theory our there. I have heard something similar to it before but I thought of this on my own.

 

My theory is about Cutthroat and Rainbow hybridization in the middle sections of rivers. What I have noticed quite a weird trend, as you go further downstream on a cold freestone stream the average size of the fish seems to go down... Think about an average Livingstone cutt, now is the average fish (excluding Bulls) from the middle section of the Oldman any bigger? Not really in my experience the reverse is actually true. As you move further upstream into the Livingstone the size of the fish goes up. However there is much more nutrients in the lower river so the reveres should be true. Now this is also true for the Castle too. After fishing the lower portion of the castle I noticed that the average fish (rainbow, or hybrids) were significantly smaller that the ones much further upstream. Wherever the cutts are predominate and then rainbows slowly take over the system the average size seems to go down.

 

 

My theory is that the cutts are more adapt to live in cooler water. The area were rainbows can scratch out a living, but are slowly spreading, have smaller fish simply because the rainbows don't do as well in the cold water. Have you ever caught a very large rainbow from the Livingstone? In my experience no.

 

 

In rivers like the elk or wigwam where the cutt populations are pure (essentially) the average size is quite high. Stock it with rainbows and the size of the fish would probably go down simply because the rainbows win genetically, but in term of growth rates the cutts do better in cold water conditions.

 

 

Any thoughts? Ideas? Contrary?

 

 

Note: The above is a sketchy and scatter thought hypothesis. It is based on no facts and only the observations of a lunatic fly fisherman.

[Guest bigbadbrent]

i think its more biomass. There are more fish downstream, then there are upstream..

 

10 fish that way 1 pound, or 5 fish that weigh 2 lb..etc etc

 

the rainbows bring in more fish, so their average size goes down

 

It's all about finding the middle ground, lotsa big fish

 

 

if you can find the big resident rainbows, they'll be over 20" (including high upstream)

[Tako]

You're close.

 

Edit. Helps to look before posting

 

Status of WCTR in AB

[DonAndersen]

fisher26,

 

There are 2 more things to consider:

 

1] nutrient load - there are many springs near the mountains that provide increased nutrient load - hence more bugs and larger fish. The lower Oldman has few of these springs whereas there are several located in Daisy, Vicary and Racehorse that provide higher water quality. Of course, springs are not the only answer. Sometimes it's sewage. Look @ the Crow & Bow.

 

2] Catch & keep vs C&R. Big ones are dead where folks can get to or where the regulations are poor.

 

catch ya'

 

 

Don

[fisher26]

Thanks for the replies. It's probably a combination of all the factors listed that cause this trend. I'm glad others noticed at too, I was thinking maybe I can't catch as many big fish in the lower sections!

 

 

Any other thoughts?

[bulltrout]

fishing pressure would be decreased the higher up you go as well...

[Harps]

There are certainly larger fish in the lower sections... there is also more water, it's harder to fish for them. And they aren't as easy to catch as the fish in higher elevations. Fish in higher elevations/less productive waters need to eat as much as they can through the shorter growing season. They are less selective, especially compared to the larger fish lower in the watershed that can afford to select the most energy efficient means of feeding (eating things with hooks isn't energy efficient).

[fisher26]

fishing pressure would be decreased the higher up you go as well...

 

 

 

IMO the opposite is true for the Oldman. The feeder streams are pounded like crazy and the lower sections don't have too many people on them.

 

I haven’t fished the Castle system tons, however I found the same to be true when I fished it.

[Guest bigbadbrent]

IMO the opposite is true for the Oldman. The feeder streams are pounded like crazy and the lower sections don't have too many people on them.

 

 

 

Have ya fished the Gap? find a day that you don't run into one person, and it will be the chance of a lifetime..never, ever happens anymore

 

 

I know most of the river from the gap to the end of the road (i think its km 29 or something that we've gotten to)...they certaintly get smaller once you're above the falls, and there is little pressure (or at least when i was last there 3 or 4 years ago, before the logging and stupid fishing and horse camps decided to make a complete mess of the place..)

[Taco]

One observation from an OFer; I find my biggest fish in the most heavily pounded sections of the retention fishery but it gets to be pretty technical fishin' for Cutties. Go small, go long or go elsewhere.

[Tako]

As a rule, the farther you walk, the better the fishing.

 

Cutties are just a trout. Their growth is limited by all the normal factors. Oxygen, temperature, nutrient availability, competition, habitat and other stress factors. Find an area with low to medium population density and suitable biological factors (cool water, good nutrient load, good cover etc) and you'll find hawg cutties. It's not rocket science.

[fisher26]

Have ya fished the Gap? find a day that you don't run into one person, and it will be the chance of a lifetime..never, ever happens anymore

 

Brent don't get me started on the Gap. I used to fish it a lot maybe 5 - 6 years ago and even between that short time the fishing pressure has sky rocketed. One of the reasons I started the Livingstone thread was to get people thinking about how we can better preserve our rivers to protect them from getting ruined. The Oldman Gap, upper Oldman and Livingstone are on the brink of not over fishing but environmental strain. The amount of sh*t that goes on there is ridiculous.

 

 

So many people fish that area but take no concern to the threats that are going to eventually ruin it. Random camping, poaching, rampant OHV use will eventually catch up too the amount of stress the ecosystem can take. Coupled with the major clear-cutting projects at the headwaters and oil and gas exploration the Oldman will eventually crumble.

 

 

IMO it's not the amount of fishermen rather the responsibility these people take. Due to it's proximity to a booming city of oil workers that is exceeding a million people it gets a lot of strain. The frank fact is that people don't give a damn and fish it thinking someone else will take care of the problems. Listen to the guys who have fished in Alberta for 50+ years and they will tell you something must be done.

 

As an Albertan all my life (although a younger one) I have seen this province go up and down but one thing is for sure the amount of people in Alberta will continue to grow. We must adapt to the provinces situation or lose what is valuable to us.

[Guest bigbadbrent]

I'm with you man, i fished the gap for the first time maybe 9 years ago, right when i was young. We didn't see a single soul for the week we were there, and the only company we had was a pair of bald eagles that followed us all day (I'll never forget that day..)

 

As soon as the crowsnest fires hit, thats when the oldman got beat up, and its getting worse then ever every year. I've timed it TWICE in two rows that im fishing, as the guys from lethbridge are doing their electrofishing. Both times midweek. And again i went this summer midweek, taking my vacation time off thinking i'd get it to myself, to find a bunch of guided groups running through it...pisses me off to no end. Guides should be kept on the bow (uhh ohh, i started something now..didn't i)

 

Hell, even when i went in october when it was an absolutely miserable day, raining and barely over 0, midweek i still ran into one guy.

 

I miss the gap i used to fish, i can tell you that.

[trailhead]

I agree with Tako, the less pressure the bigger the fish. There is a middle section of the Oldman that has some real nice cutts, (see avatar) I have seen very few anglers on this stretch, but it is rather unexciting looking and you gotta walk. The only time I have seen other anglers they were hanging around fishing at the access point. I also think that the "catch & release" mentality does increase the size of the fish, but they get wary. I have a story that illustrates this; in 1981 a few us were camped along the Oldman by the falls, and the average size of the fish was about 6 inches, I released every fish I caught, and I got one on just about every cast of my royal coachman. A whole family group of about 5 walked up and kept every fish they caught. It was all legal, because I believe at the time the limit was 5 or 10 fish. Anyway I did say something and their response was that they were having a fish fry. They did leave though, but I think that their mentality at the time kept the fish pretty small. I have been back to that spot and the fish aren't as big as down lower but the average size now has to be around 10 to 12 inches, but I don't catch as many. So maybe we have less fish but they are smarter & bigger?

[clarki]

another thing to keep in mind is the time of year you are fishing these streams. earlier in the season bigger fish will be farther upstream closer to spawning areas or tribs and then will drop back as the season progresses. also it is said that over time as fish grow bigger they usually move downstream to bigger, more nutrient rich waters.

 

trailhead: if you release all the 6 inch fish then they are competeing wiht each other for resources and therefore wont grow at the same rate as they would if there was less competition, if you remove a few then there will be more resources for the fish that are still there and not in the fry pan, which should lead to fewer but larger fish. i like this thread, makes a guy think about stuff a bit eh??

 

M

[Tako]

trailhead: if you release all the 6 inch fish then they are competeing wiht each other for resources and therefore wont grow at the same rate as they would if there was less competition, if you remove a few then there will be more resources for the fish that are still there and not in the fry pan, which should lead to fewer but larger fish. i like this thread, makes a guy think about stuff a bit eh??

 

M

 

I'd think that competition isn't a real big factor in a lot of these creeks. That certain area may have good juvenile rearing habitat, but not much suitable for larger fish. Off the top of my head??

[Harps]

I'd think that competition isn't a real big factor in a lot of these creeks. That certain area may have good juvenile rearing habitat, but not much suitable for larger fish. Off the top of my head??

Nah,

I'd say resources are limiting in these waterbodies... they are cold nutrient poor systems. Competition is very important... and it doesn't help when just the big fish get taken out.

The system needs to be balanced to produce big fish. Without space, resources, or a population limiter you'll get a stunted population... not all the fish can grow big and survive as residents.

Look at the adult size of reproducing brookies in small streams... high populations, few large fish to eat the little ones, lots of competition, resulting in a fight for all the food. Energy wasted that could be put into growth. Top that off with the cold temps and you have small adult fish.

They won't outgrow their habitat... they move as number increase past the carrying capacity, or they get smaller. its all about energy.

[trailhead]

Yeah all those are factors, but in the old days the human factor had a lot to do with fish size. People would keep everything they caught or just the bigger ones, and that was why the fish remained small. They never got past 6 inches in size before someone ate them. As for predation by larger fish, I can't recall ever catching a bull trout back in those days, well except on the Wildhay River upstream of the FTR.