Arguably, the entire field of diadromous fish passage could be considered an 
example of assisted migration.  Fishways are structures designed to assist 
migration; sometimes this amounts to mechanical transport, including 
trapping animals and transporting them above or below dams.  This is a 
controversial method, but it can also be considered part of a continuum that 
includes technical fishways, even the new 'nature-like' designs (which are 
supposed to simulate natural rivers).

In truth, none of these fish passage structures can be considered 
natural...Jim's point about the evolutionary context is a good one which is 
generally ignored in fishway design.  Still, the need for assisted migration 
is clear and work continues on improving their functionality.  To be clear: 
most fishways work poorly except for a limited number of species, and there 
is ample room for skepticism along the lines of Jim's remarks.  Anyone 
advocating assisted migration as a mitigation measure would do well to 
consider the history of fish passage to gain some perspective.

Ted

---------------------------------------------------------------------------------------------------------
Theodore Castro-Santos, Ph.D.
Ecologist
S.O. Conte Anadromous Fish Research Center, USGS-BRD
P.O. Box 796, One Migratory Way
Turners Falls, MA  01376
[EMAIL PROTECTED]
Ph:   (413)863-3838
FAX: (413)863-9810







----- Original Message ----- 
From: "James J. Roper" <[EMAIL PROTECTED]>
To: <[email protected]>
Sent: Wednesday, July 18, 2007 9:06 PM
Subject: Re: assisted migration


> Interesting concept - if you take my sarcasm.  Let's imagine that 
> migration
> took eons to evolve - do we have such hubris that we think we can predict
> evolution?  With global warming, will animals need to migrate anymore, or
> will migration be even more important?  And, if we translocated some
> animals, are they going to know that the idea was for them to migrate? 
> Are
> we going to net populations of birds, turtles and wildebeest and move them
> to another place, hoping that they will figure it out?
>
> But, that is just my humble opinion....
>
> Cheers,
>
> Jim
>
> On 7/18/07, David Inouye <[EMAIL PROTECTED]> wrote:
>>
>> John Nielsen, a Correspondent on the Science Desk at NPR News in
>> Washington DC is working on a story about "assisted migration" as it
>> relates to global climate change. "I have heard that while there are no
>> "official" translocations taking place at the moment, there's a lively
>> scientific debate going on about whether there will or should be."
>>
>> "I'd like to hear what the folks who subscribe to the ECOLOG listserve
>> think of "assisted migration.""
>>
>
>
>
> --=20
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> James J. Roper, Ph.D.
> Ecologia e Din=E2micas Populacionais
> de Vertebrados Terrestres
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