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Bill Silvert's comments should be viewed as a very valuable contribution
to a larger discussion of ecosystem based fishery management and the
present feasibility of jumping into a modelling mode for Gulf of Mexico
fisheries.
I urge everyone to look at the link
(http://bill.silvert.org/pdf/ECOPATH%20Report.pdf) on Bill's web page. It
should be required reading for all members of the Gulf Council (SSC and
Council members/staff). It is a very enlightening article. I think Bill
was being modest in the way he offhandedly referred to that work.
The discussion might also be enhanced if Carl Walters and Behzad Mahmoudi
would address some of the conclusions of the aforementioned article with
regard feasibility of modelling entire large fisheries using Ecopath
specifically, and using modelling in general. They may have some valuable
counterpoints to offer to the discussion. I, like most, am trying to keep
an open mind and can use as much enlightenment as can given.
However, many of the conclusions reservations in the Silvert article are
completely consistent with most reactions from fish ecologists to the idea
of developing and using models of large Gulf of Mexico fisheries for
fishery management purposes. So many of the ecological factors and
interactions are still unknown or poorly understood. Energetic models
that do not address demography and population structure and growth can
hardly be expected to be realistic. Models that do not assess spatial
considerations but instead lump all individuals of each species into a
common compartment are similarly unlikely to be more than of pedagogic
use.
The Gulf Council should be commended for moving forward into ecosystem
based fishery management, and ultimately that is where fishery management
must move, in my humble opinion. However, the Gulf Council might benefit
from taking a deep breath and getting broad and diversified opinions about
modeling and its present potential.
Probably the issue of most practical importance to the Gulf Council and US
marine fisheries in general with regard to ecosystem based fishery
management is the reauthorization of the Magnuson Stevens Act that in its
recently passed House and Senate versions has sidestepped ecosystem based
fishery management by "allowing" but not mandating it. Imagine how
effective the original Magnuson Act would have been if it had "allowed"
but not mandated the councils to stop overfishing.
I am not sure if there is any practical hope of improving the Senate
version (S. 2012) at this stage. Most observers are just hoping that the
Senate version prevails over Rep. Pombo's House bill (HR 5018). I have
been amazed at how little discussion of this important reauthorization has
come from fishery scientists and conservation organizations during the
last year. There has been a little "buzz" lately, but it is probably too
little too late and akin to closing the barn door after the horse has
escaped -- given that all that is left is to reconcile the two versions.
Oh well, we can get it right in ten more years.
Randy
Randy E. Edwards, Ph.D.
Research Associate Professor
University of South Florida
Department of Environmental Science, Policy, and Geography
USGS Center For Coastal & Watershed Studies
600 Fourth Street South
St. Petersburg, FL 33701-4846
Phone: 727/803-8747 (x3069)
FAX: 727/803-2031
[log in to unmask]
Do not tell fish stories where the people know you; but particularly,
don't
tell them where they know the fish. [Mark Twain]
Steven Atran <[log in to unmask]>
Sent by: Scientific forum on fish and fisheries <[log in to unmask]>
07/11/2006 02:12 PM
Please respond to
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To
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Subject
Re: Gulf Council seeks proposals for ecosystem modeling using Ecosism
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You are correct that there are other models available, and we did consider
other approaches. Going forward we may or may not stick with Ecosim.
However, we are in the early stages of developing an ecosystem approach to
fishery management in the Gulf of Mexico, and the primary purpose of our
workshop is to demonstrate to the Gulf Council whether ecosystem modeling
is a feasible way to approach some real world fishery issues. Ecosim was
selected is because, with a relatively short time frame involved until the
workshop this fall, we decided to build upon the expertise of our
Ecosystem SSC, which has several members who are familiar with Ecosim, and
base the demonstration models on extending a Gulf of Mexico Ecosim model
that Carl Walters has been working on. I'm not an ecosystem modeling
person myself, so we are focusing on the strengths of our Ecosystem SSC
members to assist the contractors and evaluate the results.
I'll take a look at your website. Up to now I haven't heard anybody say
anything negative Ecosim.
Steven Atran
Gulf of Mexico Fishery Management Council
---------- Original Message ----------------------------------
From: Bill Silvert <[log in to unmask]>
Reply-To: Scientific forum on fish and fisheries
<[log in to unmask]>
Date: Tue, 11 Jul 2006 14:37:25 +0100
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>
>Wow, they really have it backwards. They should start by looking at
>ecosystem modelling and then ask whether Ecosim fills the bill. I did
some
>investigations of the North Sea with Ecosim and it really produces
>ridiculous results (www.bill.silvert.org/pdf, go to the bottom of the
page
>for the Ecosim stuff).
>
>Bill Silvert
>
>
>----- Original Message -----
>From: "Steven Atran" <[log in to unmask]>
>To: <[log in to unmask]>
>Sent: Tuesday, July 11, 2006 2:15 PM
>Subject: Gulf Council seeks proposals for ecosystem modeling using
Ecosism
>
>
>> The Gulf of Mexico Fishery Management Council is seeking proposals from
>> qualified and experienced contractors to develop models based on Ecosim
to
>> demonstrate the feasibility of using ecosystem modeling as a tool to
>> address fishery management issues of interest in the Gulf of Mexico
>> fisheries. Issues of interest include:
>
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