Bushkill C&R Study

afishinado

afishinado

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Interesting trout population data on the SR section of the Bushkill. The regulations of the section was to changed C&R in 1988 according to the article. Check out the chart of fish 7” > in the 80’s vs. the 90’s. Are C&R regulations a factor in the population increase in the 90’s?

The 2008 survey shows the population is down from its high the 90’s. Hopefully it’s because of recent floods as the article states, and the stream rebounds.

http://www.fish.state.pa.us/images/fisheries/afm/2009/5x03_04bushkill.htm
 

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Among a number of general rather than Bushkill specific things that these population data demonstrate are first, that natural variations in trout populations can and often do readily overide the effects of special regulations, even in limestoners. Although Bushkill is a limestone stream, this situation (substantial population variation due to natural factors) is typical in freestone trout streams, probably occurs (repeats) much more frequently in freestoners, and is one of most likely reasons why special regs have not been effective in the vast majority of Pa. freestoners. Of course, if angler harvest was not limiting the abundance of trout in those freestone streams in the first place (prior to SR implementation), then the regs would not be effective either. Note:Low angler harvest on wild trout streams has been readily demonstrated by the statewide wild trout creel survey.

Secondly, when one considers the substantial natural decline in the Bushkill fish population over the past nine years one wonders how some anglers would have interpreted the situation (the last 9 years) if special regs had not already been in place and the anglers had not had the information presented to them in the report about flooding. What would they have said if this were not the Bushkill, but instead was stream X, they did not have any data other than their own fishing experiences to go by, they had fished stream X for a decade, and stream X was managed under general statewide regs? Would they have (incorrectly) said "angler harvest is limiting the quality of the fishery; therefore, the PFBC should implement C&R regulations?" How many times have we heard such comments on this board about other streams? Food for thought.
 
Thanks for the info Mike. Here’s my take on the numbers. Since the surveys were not maintained in the decade of the 2000’s, 2008 is just a snapshot. An entire decade of info is a lot more valuable. It seems reasonable that the explanation that recent floods have contributed to the decline in the population seen in the 2008 survey. Looking at the graph, and comparing the 80’s survey as a decade, with general harvest regs, and the decade of the 90’s with C&R regs., some might conclude that the C&R reg.s were one contributing factor to a much higher average population, certainly not the only one. Extreme conditions such as floods or droughts always trump stream regulations. Since the regulations are the only constant, the highs and lows of the population due to extreme conditions tend to even out in a ten year period. Looking at a ten year average allows me to make a more accurate evaluation of the factors influencing the population. Just saying……..
 
I remember reading about a problem on the upper part of bushkill creek a few years ago. If I remember correctly, didn't it dry up somewhat, around Stockerton?

I fished it once about 6-7 years, and was quite impressed with the numbers, and size of the fish I caught , during the trico hatch
 
Afish: My point was not about the Bushkill, nor was it a discussion of the Bushkill. It was a general point about natural declines in trout populations as shown for the past nine years on the Bushkill. It was particularly instructive since the stream is already C&R and since the report points out the flooding problem that likely caused the decline over the past nine years. The Bushkill is appropriately managed.
 
Mike,

I agree that the Bushkill is properly managed. Further I understand and agree with your point that harvest regulations generally are not the largest factor, and maybe no factor at all in the density of a wild fish population. Every stream is different. Some streams would benefit from C&R, while others would not. I agree with all that.

I think if I had a point, it was that the only way to gauge the effectiveness of regulations and gauge the effects of extreme conditions (floods and droughts) are long term surveys. Looking at one year's data gives little insight. Further, I fully understand that these surveys are very expensive, and can only be done on a limited basis and with specific goals in mind.

Getting back to why I posted the survey in the first place. I think it demonstrates a likelyhood that the FBC change of regulations has had a postitive effect on this particular stream section and the 2008 survey results is just a blip on the radar screen. Further I applaud the FBC for committing to future studies to verify all is well with the Bushkill.
 
I wonder what happened to the data from 2003? I seem to remember Mike that you told me they survey that year and the numbers were similar to other years.
As to what the data are telling us, it pretty well matches what I've been saying about last year, the fishing pretty much sucked everywhere. Though I think the most devistating thing about flooding is that we had major floods, 3 or 4 within 18 months of Ivan. Those floods have driven trout populations down about as low as they can, and hopefully the habitat is good enough in most streams that trout populations will now rebound. At the end of last summer there seemed to be an abundance of small trout.
 
What year did the special regs go into effect on this stretch?
 
JackM wrote:
1988

Wasn't there some other "special" regulation on Bushkill Cr before the C&R regs?

Maybe Mike or a long-time Bushkill regular would know the history of management on this section.
 
Mike Please explain to me this statement: “Although Bushkill is a limestone stream, this situation (substantial population variation due to natural factors) is typical in freestone trout streams, probably occurs (repeats) much more frequently in freestoners, and is one of most likely reasons why special regs have not been effective in the vast majority of Pa. freestoners.”

Just what do you mean by the word “effective?” Does this mean trout populations in freestone streams that are being harvested on a regular basis do not show a decrease in the number of legal and larger size trout? If so, then how does this work - arithmetically?

Certainly the number of legal and larger sized trout is reduced by harvesting to whatever the extent of the harvest. Fish removed early in the season are unavailable to anglers, at least for the rest of the season. It seems to me that every trout removed, unless it perishes during the winter, is one less left in the stream to continue to grow. The 7-inch brook trout returned to the stream this year is the 8.5-inch brookie of next year and a 10 inch fish two years hence. Yes, natural losses are high, but one cannot discount the effect of harvest. At the end of the year, it is the total losses that matter (natural + angler). Neither is insignificant.

And, I might add, humans are the worst predators of all. We take from the gene pool the larger and most fit individuals that have stood the test of time. Natural causes take mostly the young, the old and the weak. Cropping off the larger individuals selects for early maturity and small size. There is no use in having the potential to live for 6 or 7 years if the odds are you aren’t going to live past the first week of trout season.
 
Two words, KenU: Compensatory Mortality. This is how it works, plus growth and rapid fish replacement in the best lies.

Additionally, at the population level it takes very high fishing mortality to override the effects of natural mortaliy.

Fish removed early in the season are rapidly replaced, and then some. Comparative electrofishing surveys at the same sites in the same year show that legal trout are more abundant (often much more abundant) in a given stretch of freestone stream in mid-summer than they are just before the preceding opening day, even in a well-publicized, Class A, "right along the road," suburban, wild brook trout stream, located on public land.

Where are these wild trout streams with such high harvest? The randomized statewide wild trout angler use and harvest study indicated that they must not be very common because harvest was very low....about 7 brook trout and one brown trout per mile. Exploitation rates for wild brook and brown trout were only 8% and less than 1%, respectively. With such low exploitation more conservative regulations or harvest practices than presently exist or occur would not be expected to have an impact on these populations.

As for the 7 inch (brook trout) returned to the stream becoming next year's 8.5 inch trout, that depends on the fish's growth rate, age, and population mortality rates. That is a low probability event on in a Pa. freestone stream where the average annual mortality rate is 60%, the vast majority of which is natural mortality based on the aforementioned creel survey.
 
Id like to say a few things.

Where are these wild trout streams with such high harvest? The randomized statewide wild trout angler use and harvest study indicated that they must not be very common because harvest was low.

I have even witnessed it, heard it and talked about it with first day anglers. They dont know that wild trout even exist and think the PFBC is stocking "little trout", which they think is a rip-off. Is it possible they are harvesting wild fish and dont know that they are?
Just a thought...

Fish removed early in the season are rapidly replaced, and then some.
How are they rapidly replaced when they dont spawn until the following fall? If you are saying that they are replaced in the best lies the following summer by another legal sized trout, then thats not really replacement at all. Its a re-distribution of fish. There isnt really another fish replacing the other.

I think using the wild trout survey is also comparing apples and oranges. The survey was done by talking to anglers that were on unstocked wild trout streams. The Bushkill is stocked. In the C&R area and out of the catch and release area. It is very possible that harvest of wild trout is greater than the projected 4 percent that the survey shows, at least for this stream.There are a lot of streams that fall into this category. Id say those high harvest wild trout streams are right under your nose, when the PFBC dumps buckets of fish into them.

Understand im not saying that harvest is a major limiting factor on many streams. Im not. Its ALL about habitat. I wonder if money spent doing other activities should go into restoring habitat. Then all these arguments would be moot.
 
Sal: I am not speaking about stocked trout streams sections. I am speaking about wild trout stream sections, although they may be wild trout stream sections into which some stocked fish have moved.

Sal, you'll have to read about territorial mosaics and the territorial behavior of trout to see that such replacement is exactly how the populations function whether an individual fish is lost due to natural or man caused mortality, or is pushed out of an ideal lie through territorial interaction with a more dominant fish. Even if KenU is correct, as an angler or a bioligist I don't find the loss of 7 legal trout per mile per year to be anything worth worrying about. Using a fishing rod, such a loss is not perceptable.
 
isnt this thread about a wild trout stream that is stocked?;-)

Sal, you'll have to read about territorial mosaics and the territorial behavior of trout to see that such replacement is exactly how the populations function whether an individual fish is lost due to natural or man caused mortality, or is pushed out of an ideal lie through territorial interaction with a more dominant fish. Even if KenU is correct, as an angler or a bioligist I don't find the loss of 7 legal trout per mile per year to be anything worth worrying about. Using a fishing rod, such a loss is not perceptable.

I understand all that, all im saying is that is not replaced but rather a function of re-distribution. Anotherwords,

If the total population of legal fish in stream X is 90 and 3 are harvested or pushed from prime lies the population is now 87.

The following summer the population of stream X is still 87, unless the growth rate is high. Since most wild trout streams are infertile and it takes longer than 4 months for the other fish to become legal size.i got 4 months(which is generous) given april to mid summer.
a 3 year old brook trout in an infertile stream is appox. 5 inches and grows 1.8 inches in a year. So in 4 months the fish would only be about 5.5 inches. Still not legal size. So the larger fish are just taking over the prime lies from another locale. The legal size fish have not yet been replaced. its still 87.
 
does what i am saying makes sense at all?
 
The dynamics of the Bush Kill are somewhat unique in that the upper end of the C & R area is a dam, there is another dambelow the C & R area, but it doesn't keep trout from moving in and out of the C & R area. Harvest below the lower boundary would be reflected in the population estimate. And it is stocked in the downstream section even though it is at or very close to Class A. There is NO DOUBT in my mind that the Bush Kill population is suppressed by harvest of wild fish from Tatamy on down to the river, give the population of fish shown in the photos last fall of the fish kill.
Take away the stocking and you will have a very good wild brown trout fishery, maybe one of the best in PA. Certainly in the 150 to 200KG/Ht range. Among all the fish that are harvested in the Bush Kill there are tons of wild fish harvested , even in the C & R section.
That doesn't mean that weather, particularly floods has a large impact, it does, but the natural mortality would easily be over estimated and the harvest under estimated, when anglers don't even know the difference between small wild fish tat are legal and stcokers. Most opening day anglers don't know the difference.
Before the current C & R area there was a FFO area up in Tatamy, don't know the limits there, never fished it.
 
It would if you and mike were using the word replacement in the same way. I believe he was referring to harvest of wilds and that other wilds will replace the harvested fish in the best lies and feeding lanes...He reluctantly mentioned that yes, stocked trout from non-class A sections of the same waters may migrate into class A sections, but he made no connection to his other points. I'm sure he'll correct me if I misunderstood.
 
Mike,

First of all, you haven’t said anything about size. Size matters! The biggest complaint I hear from the average angler is that brookies never get big enough to be very interesting. And that is true, if the streams they are fishing are being harvested to any extent. A typical small freestone stream only holds 10 to 40 legal sized brookies per mile. Two skilled anglers can crop off a significant proportion of these legal sized trout in a few trips (2 to 4) to the stream under the current regulations: 5/day - 7 inches and over. This is fine if you feel that catching a few limits of barely-legal-sized brook trout every year is what trout fishing is all about. I don’t!

Sure, there are always lots of sub-legal brook trout left at the end of the season to grow to barely legal size by the next season. But, a 6- to 6.5-inch brook trout is only going to grow another 1 to 2 inches by the next opening day and again be subject to harvesting. This is why any native brook trout angler worth his salt parks at the last access point and walks about 20 minutes in before starting. 8- to 10-inch brookies are not that unusual when one gets away from the road. Even an 11-incher pops up every once in a while.

Brookies (and brown trout) in small, infertile freestone streams with good habitat (i.e., sufficient pools for winter and summer refuge) regularly reach 8 to 10 inches and in sufficient numbers to provide a quality angling experience. But, in most accessible stream reaches, few ever reach this size, simply because they are being harvested almost as fast as they reach legal size. If you don’t believe this, spend some time on any brook trout stream along the road (especially one that is being stocked regularly) after the first couple weeks of trout season. Brookies of 8 to 10 inches in these waters are rare indeed.
 
You told it like is is. I couldn't agree more. Let them go and they will grow! I have NEVER kept a native brookie in 30 years of fishing for them. I have however, kept/killed exactly three wild browns in that same span of time. Two of them are on my wall. I ate the other one.
 
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