Why streams with no harvest?

[FrankTroutAngler]

Frank,
I've been standing in the Tully and watched a heron eat 4 fish in the 11" - 15" range in a single feeding. He had to work a little extra to get airborne but did it easily. If they feed like that every other day, that's a ton of trout that go missing and there might be 15-20 resident birds below the lake. Kind of amazing there's even fish in there with the amount of damage they do

I once saw a GBH eat a trout that was probably 15" long from the Little Juniata River. After catching the trout it flipped it up in the air and caught it head first and gulped it down in one gulp. Then it had the audacity to wash it down with a sip of water.

I was trying to be extremely conservative in my estimates about GBH's to avoid getting pummeled on here. I'm not at all surprised to hear that you saw one eat four nice trout for dinner.

In all honesty I believe that there are more than 15 GBH's on Spring Creek in the summer, too.

One thing I think a lot of people don't know is that GBH's congregate along Spring Creek each autumn before migration. They congregate in the posted section above the sewage treatment plant that's upstream from where Spring Creek is along Rock Road. (The STP is more or less along Trout Road.) I recall being there around Thanksgiving one year before it was posted and I flushed approximately 75 GBH's from the willow trees. It was quite a sight. Just imagine 75 GBH's flying down to Spring Creek for breakfast and what that would do to the trout population.

 

[Mike]

I agree with Frank. I would only comment that 11 inch hatchery trout weigh about a half pound each, so based on Frank’s source, consuming two trout of that size per day would not be out of the question. I would add, however, that during nesting season the predation rate is probably higher. It is also logical that gbh are opportunistic and probably not size selective except that they will occasionally pierce and drop prey that are larger or more active than they can handle. I have seen evidence of this with perhaps 14 or 15 inch white suckers. Either that or they bit off more than they could chew during a sucker run. It is also not unusual to see live, electrofished adult trout with substantial heron puncture wounds. Obviously, these fish got away wounded, but not consumed.

 

[JeffP]

I thought numbers were the problem. Now we are talking about all the fish being eaten by herons on Spring.

 

[Swattie87]

Not to shoot a hole in the Heron theory...I hate those things too, and would love to pin on it them. I hate having to give up a 1/4 mile of primo water on a small stream to bypass one to keep it from repeatedly flushing upstream and spooking everything as I work up.

But...There's no question there's a ton of fish in Spring (and Penns). The PFBC surveys document that they have among the highest total wild BT biomass of any streams in the state. Remember, biomass is total fish weight per unit of surface area. So it takes into account all sizes of fish...Sure big fish add up much quicker than small ones, but you can have very high biomass numbers from lots of small fish. I know a few small Poconos freestoners where this is very much the case...Super high biomass numbers...I've had many 50+ fish days on them and I've never caught a fish bigger than 10 or 11" from them.

The anecdotal account of anglers (both fly and spin, I might add) on Spring and Penns is that although good numbers of fish remain and are being caught, the average size is smaller. Two problems with the Heron theory as the cause of this:

1. Can it be shown that there are more Herons now than in the past glory days of bigger fish? If not, then the Herons are a relative constant. Frank recounts observing many Herons on Spring over many years. Given his propensity to accuracy, I tend to think this recollection is also accurate.

2. It seems like the consensus is that Heron feeding behavior doesn't necessarily target a preferred size range of fish. Meaning they'll try to kill fish without a distinct preference in size. It seems plausible that larger fish are harder for them to successfully kill, and escape at a higher rate however. Despite the Heron killings, Spring and Penns both have enough 10" fish that in theory, some should still survive to grow into larger fish, and the larger fish should be harder to be preyed on by the Herons.

Back to square one?

 

[PennKev]

JeffP wrote:
I thought numbers were the problem. Now we are talking about all the fish being eaten by herons on Spring.

High mortality offset by high reproduction??? The heron theory attempts to explain the lack of larger fish as it is another obstacle in their way to surviving to a large size. I think the only real takeaway is that there are numerous herons and that trout can be killed by them at almost any size.

I tend to think that the problem on Dpring, if it is real, may be a compound one. Changes in water quality, angler use, and predation all occurring over a given time span. Thats several changing variables.

 

[Swattie87]

I wonder if there’s been a shift in genetics. In favor of fish maturing faster, and being able to reproduce at a smaller size, but not growing to as large of a size. Think headwater Brook Trout theory, versus Brookies found in larger water.

 

[krayfish2]

I'm not saying that the herons are the reason for only smaller fish in the stream...just stating that they eat a lot of fish and could put a big dent in the numbers.

First hand experience:
Mergansers eat young trout on the Delaware system. I've heard stories of people shooting one and finding 20 trout 2"-4" in the birds stomach. They are EVERYWHERE up there. The other year PA and NY increased the harvest numbers due to complaints from the guides. Many guys started running cast and blast trips. Does it really matter? Well, this year I saw 1/10 of the mergansers I normally do AND I caught more 4" - 7" browns in late May 2019 than I had in the previous 10 years combined. I think it did make a big difference in survival rate for the little fellas.

 

[rrt]

Well, I still think it's the combination that several guys mentioned earlier. Man's influence cannot be underestimated. Let's say that the percentage of released fish that die is only 3% per guy. Let's say a fisherman catches 500 trout in a year. That puts his unintentional kill at 15 trout. Multiply that by 10 c/r fishermen. If my math is right, that comes out to 150 dead fish of the 5000 that were released. If the unintentional kill is 5%, then the numbers would be even more significant. No wonder the average size of the fish decreases in Spring Creek or other heavily fished streams.

Add the mergansers and the herons, and the numbers of dead trout increase even more, though to be fair, I'm sure the herons eat suckers and other fish they can capture.

Though it is not pleasant to consider, we anglers who practice catch-and-release fishing probably have more of an impact on trout size and populations than we care to admit. But, if we continue to fish -- and most of us will -- then we must acknowledge our influence on the fish that we pursue.

 

[Acristickid]

Catch and release as conservation-

Orvis Podcast

https://podcasts.apple.com/us/podcast/the-orvis-fly-fishing-podcast/id278930814#episodeGuid=2b033bbf-bcd1-4cb7-9c95-deaa90335e56

 

[larkmark]

rrt I think is right. It is good to acknowledge our impact for better or worse and make informed choices. When I started flyfishing it was just something I did as a past time/hobby. I went a few times a year, usually when I knew I could find hatches and rising fish. Like a lot of things these days people seem to pursue them in an obsessive way. Everyone is doing it like a job and piling up the numbers etc. That mentality is bound to create certain negative consequences when it comes to trout sizes on a heavily fished creek. Just my take.

 

[marcq]

I think it’s purely genetics. Explain the Lackawanna. I would say a marginal stream. Much of it not stocked, yet it has large fishing in it. They just look different. Big head, big mouth, sharp teeth, meat eaters. Also your are allowed to harvest fish. Not saying that helps grow larger fish.
I think this stream kills the fish that are not fit to survive in a non perfect condition like spring creek. They either die do to water temperature getting to warm in the summer or get eating by its big brother. Then your left with the strongest genes to spawn and create more big fish.

Everyone has heard stories about big spring having monster Brookies back in the day. There might be a handful still I’m not sure. That fish was perfect suited to that stream. Now you go to the ditch and all you is in dink’s. The hatchery fish bread the strong genes out of the original fish.

I think stocking has a lot to do with it as well. I listen to a lot of west coast steelhead podcast and they are pretty dead set on hatchery fish being detrimental to wild populations. Pretty sure the same goes with browns. Pfbc stock the hell out of a lot of waters that don’t need to be stocked and it probably hinders the genetic make up of true wild fish.

I would rather see a study done where they take two large fish from the upper Delaware, Lackawanna, any stream with true large wild fish and breed them and stick the eggs, fry fingerling in a stream like valley and see the results a few years later.

 

[krayfish2]

But.... spring had big fish and I'm not convinced that all were hatchery escapees.

The fish of the Lackawanna look the way they do because of their environment. Limited insect life causes them to transition to meat eaters at an earlier stage than you typically see on other streams. I guess some fish 'breeds' may have abnormally large heads but that's something I usually think of when I see fish that are malnourished because the body growth can't match the head size...which may not be the case since that system hold a lot of good sized fish.

I'd like to see some research where the pluck a scale from a half dozen fish in Spring, Penns, Lackawanna, Valley, Big Spring, Letort and others. Use the scales to document the age and size of the fish. The data could end this discussion pretty quickly.

If a 2 yr old fish in Spring is 10" and a 4 yr old averages 12"... something is wrong. You might also find out that a beastly Lackawanna brown might only be 3 yrs old or it might be 12 yrs old. Could be some interesting data.

 

[jifigz]

Has anyone here actually read the 88 page report on spring creek published by the PFBC? There is a ton of good information in there. Much of it relates to what we are talking about and also makes clear that only a very small percentage of fish in Spring were ever over 11 inches. I'm sure that is true for most all fisheries, however. But there is a lot of pertinent info in there.

 

[DaveS]

I’ll add one other little fact about Spring Creek that has changed. There is a lot more water that you can fish. I think some of these areas which saw not a lot of fishing pressure, acted as a refuge.

There is many things that have changed and they all play a part in Spring Creeks make up.
My .02

 

[salmonoid]

Maybe, since fluvial systems are dynamic and the ecology of hydrologic systems is dynamic, there are too many variables to boil this down to the One Thing that will fix all the ills of having [too many, too few, too big, too little, too skinny, too fat] fish in the stream.... There is no one great regulation that will rule them all, and in the darkness create great big fish..

There are certainly variables that can be identified that may have a weak or a strong correlation with fish size/growth/density/whatever. And that's the challenge of fisheries management - to identify those variables and the extent of the effect those variables have on fish in a stream. And then to somehow get consensus from people on which end-result to manage for...

Some of the observances of fish in streams (I'm thinking Spring Creek, because it is mentioned here numerous times and I just finished reading Harvey's discussion of Spring Creek in his Memories, Patterns, and Tactics) have occurred in a different day and time and so what we're really pondering is, what has changed? The large fish that Harvey describes are not there in the quantity now that they were then. The abundance of brook trout that he describes are also now not present. A lot has changed with the environment (think of how much more developed State College is now than then and what happens when a hatch, like the Green Drakes, disappears - thats a lot of tasty morsels for trout growth that is now gone), a lot has changed with angling pressure, and a lot has even changed with regulations. With the abundance of fish that were stocked in the Paradise, who knows how many of the larger fish that were in the stream got a head start over the stream bred fish, because they were stocked at a point in their life when they were already 12"?

 

[larkmark]

The larger fish we were catching there were not all that long ago. I'm talking 10 or 15 yrs and even more recently. The larger fish (13 and up) were there in good numbers and were readily caught during any good hatch. The change I observed happened in a fairly short time frame. The most obvious change was the number pf year round anglers so that is why some of us have suspected for a while now that the problem is related to repeated handling of fish. I think the last time I caught a true 18" fish on a dry there was about 5 yrs ago. I suspect you will start to see the same loss of numbers of larger fish even in bigger waters like Penns and the Delaware. Some of those big fish in the Delaware are looking like hideous pincushions by June, missing mandibles etc. It is kind of a shame.

 

[Swattie87]

So we’re back to closing these prized big fish waters for the Spring hatch season right? Might as well keep them closed over the Summer thermal season, and the Fall spawn, like I said before.

Open Jan 1 - April 15.

Wait...When do the fry hatch out?

 

[rrt]

I think Lark is right on target. I am afraid I do not know what the solution is. Perhaps part of Swattie's sarcastic post 98 would actually be helpful. Who knows?

I have seen similar things occurring on other streams as well -- but not quite to the extent it has occurred on Spring Creek.

 

[TroutTracker]

I agree with rrt, troutbert, larmark and others who say they notice increased angling pressure leading to changes in the size structure of the trout population in some heavily fished streams. I have noticed the same thing on Spring Creek.

To me, the two most important factors in growing big trout is the right habitat for them and lack angling pressure. Some streams (such as big spring) have such exceptional conditions for growing big fish that they continue to do so despite heavy angling pressure. Despite this reputation (and the still exiting great habitat) I would include Big Spring in the list of streams beginning to show reduced trout size.

Aside from a couple well known streams with reputations for producing larger than average trout, the vast majority of my largest trout every year come from streams that are not heavily fished and rarely talked about on the internet/in guide books. IMO large fish survive in these places because of lack of angler pressure. Harvest might help grow large trout in select situations, but even those situations it’s the harvest of small trout that helps grow large trout… Harvest of 18”+ trout certainly isn’t good for growing big trout. And guess which trout people like to keep, the big ones.

Like others, I don’t plan on fishing less so I’m not sure what the solution is... I will say, I’m starting to come around on seasonal closures. Not half the year like some states, but at this point I might support a closure on targeting wild trout during the month of November. And maybe even longer closures on the most heavily fished waters.

 

[ryansheehan]

Swattie87 wrote:
So we’re back to closing these prized big fish waters for the Spring hatch season right? Might as well keep them closed over the Summer thermal season, and the Fall spawn, like I said before.

Open Jan 1 - April 15.

Wait...When do the fry hatch out?

You can't fish in January and February the fish will freeze to death!