On Mar 12, 7:40 pm, Willi wrote:
Halfordian Golfer wrote:
Do you have any studies that show that harvest increases the quality of
a trout fishery?

Willi

Yes.

I love to flyfish every place that allows it but can hardly stomach
the places that don't allow it.

Think about it. Would you rather fish:
the X Fork of the You Know....or the Frying Pan?
The Roaring Fork, or the Frying Pan?
The Elk or the Taylor Reservior Tail Water?
A Wyoming Beaver pond or Cheesman Canyon?

I say that tongue in cheek but, it's also intended to ring somewhat
true, but you must define quality for it to make any sense at all and
quality for me includes isolation and fish that act wild.

Don't take it from me, though, take it from John Gierach who talks
about when the St. Vrain became famous for a short period of time when
it became C&R. The parking lot filled up with cars but the fishing
was, more or less, as it always had been. When it was made normal
again, the cars left and it stayed the fair to middling creek that it
is.

This is with a 4 fish limit now: the fishing can be excellent. If it
were to get crummy, or if we wanted to tweak it, we could make it 2.
This is with no size restrictions, we could add one. Also, these are
browns. Very wary.

Your pal,

Halfordian Golfer

I agree that in Colorado, the designation of C&R (or most special regs
INCLUDING your "selective" harvest with its slot limits) often leads to
over crowding and I tend not to fish those waters for that reason.

But that DOESN'T answer my question. In some of your posts you assert or
at least imply that "selective" harvest will improve the quality of a
fishery (those large fish eaters etc). Can you show ANY study that
showed that harvest of any type improved the quality of a self
sustaining trout fishery? I can show you study after study that
demonstrate that reducing harvest can improve a fishery.

Willi

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.

In practice the latest trend is to look beyond maximum sustainable
yield to whole ecosystems management and adaptive management
strategies.

For example, Whales and other 'top predators' consume more ocean fish
than man. Managing the top predators and consuming the lower trophic
species becomes the management strategy while the high trophic species
recovers.

This is what I meant by 'whole pond management'.

So, I need to see a study of what you refer to, or have considerable
more detail in your question to discuss it.

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.

Your pal,

Halfordian Golfer
A cash flow runs through it.