Regarding Malcom McCallum's observation: Yep, culverts are de-facto fishways and often act as barriers to movements. New standards in Massachusetts and the Northwest reflect this (Also the US Army Corps of Engineers has adopted these standards), and new culverts are supposed to meet criteria to facilitate movements of a broad range of organisms (not just fish!).
The same thinking could apply to greenways and other means of connecting fragmented habitats. We are trying to mitigate for fragmentation using the best available science. Assisted migration is just a subset of the broader management goal of facilitated movement and promoting connectivity. There is a spectrum of degree of effort and of effectiveness associated with the various methods, although effectiveness is rarely quantified. Ted ----- Original Message ----- From: "Malcolm McCallum" <[EMAIL PROTECTED]> To: "Ted Castro-Santos" <[EMAIL PROTECTED]> Cc: <[email protected]> Sent: Thursday, July 19, 2007 10:11 AM Subject: Re: assisted migration > In this case, the tunnels that they put under roads back east for > amphibians to migrate to breeding ponds fits the mold. > > On Thu, July 19, 2007 7:59 am, Ted Castro-Santos wrote: >> 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 >>> -- >>> James J. Roper, Ph.D. >>> Ecologia e Din=E2micas Populacionais >>> de Vertebrados Terrestres >>> ------------------------------ >>> >>> Caixa Postal 19034 >>> 81531-990 Curitiba, Paran=E1, Brasil >>> ------------------------------ >>> >>> E-mail: [EMAIL PROTECTED] >>> Telefone: 55 41 33857249 >>> Mobile: 55 41 99870543 >>> ------------------------------ >>> >>> Ecologia e Conserva=E7=E3o na UFPR <http://www.bio.ufpr.br/ecologia/> >>> Econci=EAncia - Consultoria e Tradu=E7=F5es >>> <http://jjroper.googlespages.co= >>> m> >>> >> > > > Malcolm L. McCallum > Assistant Professor of Biology > Editor Herpetological Conservationa and Biology > [EMAIL PROTECTED] > [EMAIL PROTECTED] > >
