Why streams with no harvest?

[jifigz]

FrankTroutAngler wrote:

On June 12, 2019 I fished the Little Juniata River for 8.75 hours and caught 111 trout. Eight of the trout were stocked trout as best I could tell, so I will exclude them in this discussion. One hundred and three were wild brown trout.

So you caught a trout every 4.73 minutes and took accurate, detailed notes about their length........

Just so people know, this wasn't started to say "harvest fish to create more big fish." I was implying why not harvest fish if the stream can obviously handle it and we may get the boon of larger trout.

 

[jifigz]

acristickid wrote:
My favorite streams are polluted with no harvest- and they are terrific.

Okay, and this proves what I'm trying to say. I, too, know of streams that have very little fishing pressure, are polluted, and have huge trout. And plenty of them. Once again, I'm saying in high productive fisheries that produce a ton of fish I see ZERO benefit from bring closed to harvest. I don't think Spring Creek will ever grow as many big trout as many other streams that I know of and fish. So, if pollution and health of the consumer wasn't an issue, why not allow harvest? The same holds true for the Little J. Spring just doesn't have enough fantastic habitat to grow an abundance of large trout.

I personally would rather fish a steam that is less productive, warms more in the summer, and has different structure types than Spring Creek does. They generally still have a tremendous population of wild brown trout and have more large fish..just my .02.

 

[silverfox]

larkmark wrote:
Spring Creek and Penns had good numbers of fish in the 12-15" range years back. You would catch them in the same places and ways as you now catch those little ones that are as long as your hand. You could also catch some 18' fish fairly often. I'm talking on dry flies during sulpher and olive and caddis hatches. Also on tricos.

Can anyone give an explanation of what changed on those streams in the last 25 years?

I have a pretty good idea but let's hear what you think.

In my opinion, it's a year class and habitat thing. A 14" fish has to be 3 to 4 years old, and an 8" fish is no older than 2 or 3 years old. I could be wrong, but as far as I'm aware, you're not going to find 5 year old wild fish that are 12" long (I'm talking about brown trout).

IMO, if there is an absence of 14" to 18" fish, they're either being consumed by something or they're leaving. On spring, in the mainstem, I don't believe it has the habitat to hold big fish, so they leave (I'm saying generally). Again, trout move great distances to find food, habitat and temperature. I don't believe that all the 14" fish are being consumed from spring's mainstem. They just discover the bread feeding spot and never leave again. j/k

I read a study a while back that found that wild fish would move between thermal refuge and feeding areas. Sometimes staying in water that was outside their thermal comfort zone for long periods of time to feed, and then return to the thermal refuge to recover. Point is, if there is something they're lacking from a stretch of water, they'll move to find what they need.

I think the "leaving" (or traveling) thing plays a huge role in what we encounter on streams or stream sections.

 

[gulfgreyhound]

Natural Selection is pretty cool. Unnatural selection where man interferes isn't cool. Genetic manipulation is interesting,but may not help total species vigor. GG

 

[Mike]

With the substantial reduction in abundance, growth rates increased to the extent that initially the fish were up to a year ahead of their former “normal” growth rates. Survival rates also improved for certain age classes according to the individual who worked through the calculations. I would have expected these metrics to have adjusted downward again as the population density improved over time.

 

[OldLefty]

Here's something to consider for Spring Creek.
First, it is true that we caught a fair number of fish in the 16" to 20" class in years gone by. That means something has changed.
Now, let's consider this as a possibility. There was a study conducted that determined a brown trout in Spring Creek was caught around 6.3 times in a year. If we take average mortality for all angling methods to be approximately 5% how long would a brown trout survive only looking at angling mortality as a factor?
While I may be a bit off in my speculation I would imagine it takes about 4 years for a trout to grow to 14" to 15" in Spring Creek. When you do the math it doesn't bode well for a Spring Creek brown trout.
Oh, and by the way, the study was several years ago. Angling pressure likely increased from then 'til now.

 

[KenU]

Growth of trout living in streams has been studied extensively over the years. Trout living in lakes and ponds can and do become stunted from overcrowding. This does not seem to be the case in streams. Density has little effect on average or ultimate size. In moving waters trout establish energy efficient lies and will hold these positions until a larger fish comes along and drives them away (or eats them).

Once trout grow to a size where growth cannot continue – typically about 10 inches - they must move in order to find stream positions where they can continue to put on weight. Troutbert has it right: The bigger fish simply eat the smaller fish, even their own siblings. They aren’t fussy.

Typically once trout reach about ten inches they switch feeding activity to larger prey, typically minnows and crayfish, unless the available insect life is large, very abundant and readily available. The bigger trout get the more energy it takes to capture food. This is why big brown trout tend to lay low until a hatch occurs and prey is readily available. No use swimming around consuming more energy to catch the food than it contains. Fly anglers who use big minnow imitations and spin guys like the Nale brothers are much more likely to catch larger fish than those of us who concentrate on fishing dry flies and nymphs.

 

[larkmark]

I believe Old Lefty is right on target.

 

[silverfox]

I know there is angler mortality, but I just can't imagine there is enough of it to be "the cause". It may very well be a factor though, along with the other things.

I think about several other streams I fish that have the same "problem" in that there are a TON of wild browns, but they're almost all sub 12 inches. Almost all of them are the same general size. These streams hardly get fished as they're either a lot of private property or just not as famous. One stream in particular is very similar in makeup to Spring, just a tad smaller. There are some bigger fish in the stream, but very few. Another stream nearby has a ton of big fish, but very few small fish. The main difference I see is the big fish stream is full of log jams and tons of cover with some deep pools. The other neighboring stream with small fish is mostly open canopy with very little deep cover.

I know this is an issue with the Big Horn and always has been. Supposedly, recently, the fish size shot up again after a bunch of years of smaller fish. There have been all kinds of theories on why. Everything from higher water washing more shiners through the yellowtail dam/afterbay to the bigger fish themselves being flushed down due to high water. One thing is for sure, there hasn't been a decrease in angling pressure there!

Regardless, I personally don't believe changing harvest to reduce the smaller fish is going to result in tank heaven.

 

[tomgamber]

silverfox wrote:

... I personally don't believe changing harvest to reduce the smaller fish is going to result in tank heaven.

Correct me if I misunderstood but lefty wasn't talking about harvest, just CATCH mortality. That 5% of fish caught do not survive even if released. No? And the same fish being caught more often due to greater fishing pressure, multiplied by that % of catch mortality increases that percentage. I don't think he was even talking about harvested fish.

I also that believe that two separate streams can exhibit the same over population of small fish for different reasons. Every stream that has an abundance of smallish fish is that way for the same reason. If you are looking for single answer you will not find it.

I'm not saying I know what those reasons are. I just see a lot of data being attacked with anecdotal evidence.

 

[troutbert]

OldLefty wrote:
Here's something to consider for Spring Creek.
First, it is true that we caught a fair number of fish in the 16" to 20" class in years gone by. That means something has changed.
Now, let's consider this as a possibility. There was a study conducted that determined a brown trout in Spring Creek was caught around 6.3 times in a year. If we take average mortality for all angling methods to be approximately 5% how long would a brown trout survive only looking at angling mortality as a factor?
While I may be a bit off in my speculation I would imagine it takes about 4 years for a trout to grow to 14" to 15" in Spring Creek. When you do the math it doesn't bode well for a Spring Creek brown trout.
Oh, and by the way, the study was several years ago. Angling pressure likely increased from then 'til now.

Agreed. I wrote the same analysis in post 15.

If people disagree with this explanation, what specifically do you think it is wrong about it?

 

[troutbert]

sarce wrote:
I don't think you'd have an abundance of larger fish on Spring if harvest was allowed, due to limited big fish habitat.

The habitat has not changed significantly on Spring Creek since the time when 14 inchers were run-of-the-mill.

(With the exception of the stretches between Bellefonte and Milesburg affected by the removal of West Penn Power Dam and McCoy Dam.)

From Bellefonte upstream for miles the habitat hasn't changed much. But the size distribution of the trout has changed a lot.

 

[larkmark]

troutbert and old lefty sound like they remember the same things I do. For some reason the idea the handling fish a lot might be a possible cause is not too popular.

 

[krayfish2]

For years, I'd catch my big fish of the season from Spring. As things changed, I just stop going there. Where I might have fished it 15-20 times a year, I have probably been there twice in the past 10 years. Small fish + big crowds = me going anywhere else to fish for anything else

 

[Fly-Swatter]

Yep, same. I really enjoyed fishing Spring from '89 through '93. After an 8 year hiatus while living in South Carolina, I was disappointed with the crowds and fishing.

 

[larkmark]

I suspect you will see this same trend on Penns. More guides and year round pounding every time I go. Years ago there were nice big wild fish all the way up above Coburn. Something happened there too. You know something is off when a good sulpher hatch doesn't bring a few nicer ones up.

 

[silverfox]

tomgamber wrote:


Correct me if I misunderstood but lefty wasn't talking about harvest, just CATCH mortality. That 5% of fish caught do not survive even if released. No? And the same fish being caught more often due to greater fishing pressure, multiplied by that % of catch mortality increases that percentage. I don't think he was even talking about harvested fish.

I also that believe that two separate streams can exhibit the same over population of small fish for different reasons. Every stream that has an abundance of smallish fish is that way for the same reason. If you are looking for single answer you will not find it.

I'm not saying I know what those reasons are. I just see a lot of data being attacked with anecdotal evidence.

Isn't the subject of this thread about harvest and why we have streams with no harvest? I wasn't specifically replying to anyone.

 

[rrt]

I echo the posts of OL, t/b, and kray. Spring Creek was once a very special place for nice trout. I guess we really do love places to death.

 

[troutbert]

How old were the 14 inchers that were once very common in Spring Creek?

And how old are the 10 inchers that are now very common in Spring Creek?

The same age, with the difference in size caused by changes in growth rate?

Or were the 14 inchers larger because they were OLDER?

 

[gulfgreyhound]

When was the last stream survey done in Spring Creek? GG