Catch and Release Hurts our Quality of Life

Halfordian Golfer wrote:


Hi Willi,

I haven't seen any of the study URL's that I'd asked about to help
clarify your question, which, I'm sorry but is not specific enough to
be useful.

Here is a specific study on optimal partial harvesting:
http://tiny.cc/2g3hKhttp://tiny.cc/2g3hK (download the pdf).

Abstract When growth is density dependent, partial harvest of the
standing
stock of cultured species (fish or shrimp) over the course of the
growing season
(i.e., partial harvesting) would decrease competition and thereby
increase indi-
vidual growth rates and total yield.

Now, this is the basic fisheries management theory. Not 'exactly' what
you asked but it demonstrates the concepts clearly.



Your URL didn't work for me. However, from abstract, it was based on
cultured, not wild populations.

Like I tried to explain to you, I have no trouble with you
philosophical/religious position on C&R fishing. Like religion, that's a
personal choice based on an individual's own values.

However, I do object to, what I see as, your pseudo biological
explanations for
C&R which is why I changed the subject to fishery management. I was hoping
that you could discuss this in a more "scientific" vein. This is an area
that interests me and I've done considerable reading on it. You make
statements about how a C&R or any fishery can be "improved" by harvest.
There
are many studies done on the effects of different of regulations on fish
populations,
but I've NEVER seen a study based on a self sustaining trout population
that
shows what you claim. I asked you to cite one study.

Below are three examples of statements you have made concerning harvest
"improving" a fishery:

" Willi you just said that reducing harvest can improve a fishery. So
can increasing harvest. This is as old as the hills. Don't make me
spell out "S-T-U-N-T-E-D" again. There is no question about it.

I am interested in culling the fish that makes the
most sense for the given situation and large fish are good candidates
because they start to create negative yield from a fishery. Slots on
both sides with restricted bags and restricted fishing, instead of C&R
and watch the quality of the fishery soar.

It is undeniable and unequivocal. Partial Harvest increases individual
growth rate and total yield, at the very least in some situations, of
recruitment, available forage, size and nature of habitat, etc."


I asked (and still ask) you to show me ONE study done with a self
sustaining
population of trout in a stream or river that the supports any one of
the above
statements you made. There are tons of studies showing that reducing
harvest improves a fishery
in this manner. If you like I'd be glad to cite some (in addition to the
one YOU cited). I also cited two studies (and there are more) that showed
that "culling" large fish leads to a decrease in size of the
populations, which I felt you
discounted because it didn't agree with your position.


When I asked this in a past post, the study YOU cited was:

http://www.wnrmag.com/stories/2007/oct07/fishery.htm

The study didn't show that harvest improved the fishery rather that
REDUCING the harvest increased the number of "catchable" and large
trout as well as increasing the total trout biomass in a stream.

I'll try again.

1. Show me ONE study where a self sustaining stream based trout fishery
with C&R regulations was "improved" (use the article YOU cited as an
example of "improved") when harvesting was again allowed.

or

2. Show me ONE study where a self sustaining stream based trout fishery was
"improved" when harvesting was increased.

If you answer this post, please address question 1 and 2. "Improved"
needs to be
based on fish population statistics, not aesthetic opinions.


Willi

On Mar 22, 11:46 am, Willi wrote:
Halfordian Golfer wrote:

Hi Willi,

I haven't seen any of the study URL's that I'd asked about to help
clarify your question, which, I'm sorry but is not specific enough to
be useful.

Here is a specific study on optimal partial harvesting:
http://tiny.cc/2g3hKhttp://tiny.cc/2g3hK(download the pdf).

Abstract When growth is density dependent, partial harvest of the
standing
stock of cultured species (fish or shrimp) over the course of the
growing season
(i.e., partial harvesting) would decrease competition and thereby
increase indi-
vidual growth rates and total yield.

Now, this is the basic fisheries management theory. Not 'exactly' what
you asked but it demonstrates the concepts clearly.

Your URL didn't work for me. However, from abstract, it was based on
cultured, not wild populations.

Like I tried to explain to you, I have no trouble with you
philosophical/religious position on C&R fishing. Like religion, that's a
personal choice based on an individual's own values.

However, I do object to, what I see as, your pseudo biological
explanations for
C&R which is why I changed the subject to fishery management. I was hoping
that you could discuss this in a more "scientific" vein. This is an area
that interests me and I've done considerable reading on it. You make
statements about how a C&R or any fishery can be "improved" by harvest.
There
are many studies done on the effects of different of regulations on fish
populations,
but I've NEVER seen a study based on a self sustaining trout population
that
shows what you claim. I asked you to cite one study.

Below are three examples of statements you have made concerning harvest
"improving" a fishery:

" Willi you just said that reducing harvest can improve a fishery. So

can increasing harvest. This is as old as the hills. Don't make me
spell out "S-T-U-N-T-E-D" again. There is no question about it.

I am interested in culling the fish that makes the
most sense for the given situation and large fish are good candidates
because they start to create negative yield from a fishery. Slots on
both sides with restricted bags and restricted fishing, instead of C&R
and watch the quality of the fishery soar.

It is undeniable and unequivocal. Partial Harvest increases individual
growth rate and total yield, at the very least in some situations, of
recruitment, available forage, size and nature of habitat, etc."

I asked (and still ask) you to show me ONE study done with a self
sustaining
population of trout in a stream or river that the supports any one of
the above
statements you made. There are tons of studies showing that reducing
harvest improves a fishery
in this manner. If you like I'd be glad to cite some (in addition to the
one YOU cited). I also cited two studies (and there are more) that showed
that "culling" large fish leads to a decrease in size of the
populations, which I felt you
discounted because it didn't agree with your position.

When I asked this in a past post, the study YOU cited was:

http://www.wnrmag.com/stories/2007/oct07/fishery.htm

The study didn't show that harvest improved the fishery rather that
REDUCING the harvest increased the number of "catchable" and large
trout as well as increasing the total trout biomass in a stream.

I'll try again.

1. Show me ONE study where a self sustaining stream based trout fishery
with C&R regulations was "improved" (use the article YOU cited as an
example of "improved") when harvesting was again allowed.

or

2. Show me ONE study where a self sustaining stream based trout fishery was
"improved" when harvesting was increased.

If you answer this post, please address question 1 and 2. "Improved"
needs to be
based on fish population statistics, not aesthetic opinions.

Willi

Willi,

I have tried my best but can not satisfy your question for because it
is too nebulous to be taken serious. I've tried as politely as I can
to show you why. I've given you all the data you need to extrapolate
my essential points. I gave you a study that shows the ultimate
control a set of circumstances that could occur naturally in a myriad
of situations of 'self-sustaining' populations. I've written the CDOW
about the stunted brookies that could only benefit from optimal
partial harvesting and in practice by the plus 10 bag limit on brook
trout in colorado. You continue to hurl personal attacks, and this is
not fair.

I've asked you know for the study you report to have many of, because
I want to see how you have defined the following real world
constraints that can not be ignored in your gross oversimplification
of the basic fisheries management equation. Honestly, if that last
study wasn't conclusive, I'm not sure what would be.

I'm not being flippant in the least.

If you are to even begin to understand maximum sustainable harvest or
optimal partial harvest you have to address a lot of variables.

Improved in what way? If it's simply biomass as you suggested, pounds
per acre, the last study I gave you was conclusive. Any aquarist will
tell you this. It's simple math that is expressed in a variety of well
known management formulas.

What is the species? Brook trout in Colorado? This is clearly a
species that would benefit from harvest, as the CDOW has shown in its
increased bag limit.

Harvesting was increased from what to what?

What was the original population?

How stable is the recruitment each year?

How stable is the food source each year?

What year classes are present?

What species is being managed for?

Is there another species in the ecosystem?

How has natural predation changed?

Is there supplemental fertilizer/

Seriously, what "specifically" is your question Willi? If it's can I
produce a study that meets your narrow definition of success, no.

TBone

Halfordian Golfer wrote:
If it's can I
produce a study that meets your narrow definition of success, no.


THANKS!!

After all that, you finally answered the question. A simple "no" was fine.


Willi

Halfordian Golfer wrote:

What is the species? Brook trout in Colorado? This is clearly a
species that would benefit from harvest, as the CDOW has shown in its
increased bag limit.




Actually according to the CDOW, the increased bag limits in these
situations has been ineffective in having any significant impact on
these "stunted" populations or in reducing the number of Brook
Trout in streams where they are trying to reduce their numbers.
(Although it also hasn't hurt)



Willi

Halfordian Golfer wrote:

Willi,

I have tried my best but can not satisfy your question for because it
is too nebulous to be taken serious. I've tried as politely as I can
to show you why. I've given you all the data you need to extrapolate
my essential points. I gave you a study that shows the ultimate
control a set of circumstances that could occur naturally in a myriad
of situations of 'self-sustaining' populations.

I've asked you know for the study you report to have many of, because
I want to see how you have defined the following real world
constraints that can not be ignored in your gross oversimplification
of the basic fisheries management equation. Honestly, if that last
study wasn't conclusive, I'm not sure what would be.

I'm not being flippant in the least.



The study you cited is based on the aquaculture of shrimp and fish. You
can't use a study conducted in the closed, man made system of an
aquaculture environment containing a fixed population of age specific
animals and extrapolate the results to the dynamic system of a stream or
river with a self sustaining trout population.


Willi

Willi wrote:
Halfordian Golfer wrote:

What is the species? Brook trout in Colorado? This is clearly a
species that would benefit from harvest, as the CDOW has shown in its
increased bag limit.




Actually according to the CDOW, the increased bag limits in these
situations has been ineffective in having any significant impact on
these "stunted" populations or in reducing the number of Brook
Trout in streams where they are trying to reduce their numbers.
(Although it also hasn't hurt)



Willi


Not to answer my own question, but what the Colorado DOW found was what
has been found in most places where this was tried. Brook Trout are VERY
prolific breeders in these streams. However, I did find a situation in a
stream in Canada where this strategy had some limited success. In Quirk
Creek they had a concerted effort between Fish and Wildlife and TUC to
target Brook Trout in order to increase the number of native Cutt and
Bull trout. TUC sponsored supervised outings for angler removal of Brook
Trout. In the small area with easy road access, the angling effort over
6? years did reduce the number of big Brook Trout which resulted in some
increase in Cutts and Bull trout. Electroshock removal was also used in
the areas where there wasn't easy road access. It took artificially high
angler hours over 15 times "normal" to have this impact.

Willi

On Mar 24, 8:53 am, Willi wrote:
Willi wrote:
Halfordian Golfer wrote:

What is the species? Brook trout in Colorado? This is clearly a
species that would benefit from harvest, as the CDOW has shown in its
increased bag limit.

Actually according to the CDOW, the increased bag limits in these
situations has been ineffective in having any significant impact on
these "stunted" populations or in reducing the number of Brook
Trout in streams where they are trying to reduce their numbers.
(Although it also hasn't hurt)

Willi

Not to answer my own question, but what the Colorado DOW found was what
has been found in most places where this was tried. Brook Trout are VERY
prolific breeders in these streams. However, I did find a situation in a
stream in Canada where this strategy had some limited success. In Quirk
Creek they had a concerted effort between Fish and Wildlife and TUC to
target Brook Trout in order to increase the number of native Cutt and
Bull trout. TUC sponsored supervised outings for angler removal of Brook
Trout. In the small area with easy road access, the angling effort over
6? years did reduce the number of big Brook Trout which resulted in some
increase in Cutts and Bull trout. Electroshock removal was also used in
the areas where there wasn't easy road access. It took artificially high
angler hours over 15 times "normal" to have this impact.

Willi

What is normal? Pure C&R --- No bag limits?

Tim

On 2008-03-07, Ken Fortenberry wrote:

You don't have to resort to curse words to deliver an attack.

nb ....jaw on floor