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2005 Striped Bass Stock Assessment is finally available

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The document is mostly "nifty" tables and graphs.

Trying to read it on the computer by scrolling and wearing bifocals has me blurry eyed. Need to go buy a ream of paper and print it out.

But from what I did read looks interestng. biggrin.gif

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As I expected, I didn't make it through half of the first page before I wanted to punch myself in the face mad.gif

 

The 2003 value of F from this year's VPA is 0.29, which is substantially lower than the terminal year F from last years VPA run of 0.62. This is due not only to the addition of another years worth of data but also due to the modified suite of tuning indices used in the this years VPA

 

I mean, I know they mention that they changed the "tuning indices" in the VPA - but how can they possibly compare the original mortality from 2003 with the updated mortality from 2003? mad.gifThey changed the math! When you change the math you are invalidating any and all prior results.

 

You cannot change the math and then say "Look how much lower the mortality is." Unbelievable. Very disappointed and I'm only a few sentences into it cwm13.gif

 

TimS

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Amen to that Tim ... it's like a lot of other data spewed onto us by media ... most of which you don't realize is invalidated due to such changes in the data sampling.

 

Some of the misleading data out there is intentional, and some is not. In cases like this there are no apples to compare to the apples, so they use the pears instead, and expect us to "buy it"!

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In cases like this there are no apples to compare to the apples, so they use the pears instead, and expect us to "buy it"!

 

Comparing the apples to the pears would be bad enough, but in this case they made up the pears and then compared them to the apples cwm27.gif

 

It's incredible - the first half of the report is all about how the Technical committee doesn't agree with the way the math has been changed. It's full of reservations and hesitations. All the while they are explaining how many dozens of difference assumptions and "tuning indices" - of which any one of being wrong or incorrect would have implications in the resultant mortality numbers - may be wrong or incorrect or out of whack.

 

Yet when the mortality comes in at .01 (2%) below the level that would require emergency action - everything is considered wonderful and we are welcome to continue killing bass at the same rate for the next 24 months or more mad.gif

 

It's unbelievable to me. How can this be considered management? Taking a bunch of numbers that are known to be just this side of wild guesses - crunching them into the VPA formula...and changing the formula and indices used until everything "fits" below the mortality threshold - and then passing it off as accurate to within .01? It just seems to get worse every single year.

 

What would it take for the ASMFC to actually reduce the mortality enough so that we can at least pretend that the target mortality is really the target? cwm13.gif Seems like when mortality gets too high we just change the way we do the math. That can go on forever.

 

TimS

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Taking a bunch of numbers that are known to be just this side of wild guesses - crunching them into the VPA formula...and changing the formula and indices used until everything "fits" below the mortality threshold - and then passing it off as accurate to within .01? It just seems to get worse every single year.

 

Tim,

That's not entirely true. They didn't change the math to keep things under the threshold. The TC held workshops with other scientists to see if they could fix the problems inherent in this particular approach.

 

One thing to note is to look at the 2003 values using the old and new method of weighting the tuning indices. Even using the "old" method, the 2003 mortality dropped a lot. That's because of the addition of that one year of data. It's a problem with the way things were done using the old way. The numbers are better, but this still is a problem with this type of method

 

And they have to compare both the "old" and the "new" ways of weighting the tuning indices....if they didn't everyone would have wanted to know what the "old" way said. So they had to put it in...and had to say something on why things had changed. They are sorta "damned if you do....damn if you don't"

 

But I'll agree with you that the precision is not accurate to 0.01. And had the number been 0.01 over the threshold....well I'm sure you would have heard a lot more about the lack of precision. wink.gif from many groups

 

What would it take for the ASMFC to actually reduce the mortality enough so that we can at least pretend that the target mortality is really the target? Seems like when mortality gets too high we just change the way we do the math. That can go on forever.

 

To answer; that would mean an amendment. Something ASMFC can do if there was support for it.

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They didn't change the math to keep things under the threshold. The TC held workshops with other scientists to see if they could fix the problems inherent in this particular approach.

 

One question for yah - these workshops - did they involve any industry representation from either "side"?

 

TimS

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To my knowledge....nope. These were all independent surveys so they only folks involved were other assessment scientists and the folks that run those state surveys. Everything is open to the public....but who in their right mind would wanna sit through that kind of a workshop. eek.gif

 

BTW they had no idea what the results were going to mean for the VPA; until they finalized the inputs and ran the model. it could have gone the other way...

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