[GRASS-user] Aquatic (Fish) Habitat Modeling with GRASS

[Rich Shepard]

On Thu, 29 Jul 2010, Rich Shepard wrote:

>  I've not found a module or integrated tool to model aquatic (primarily
> fish) habitats by stream/river or drainage basin. I've looked at the Wiki
> and searched fairly extensively with Google and have not found anything
> useful ... that runs on linux or the *BSDs.

Stephen/Brent:

   I've found nothing but a couple of references to simple models running on
ESRI's software and comments on the short-comings of the standard (at least
here in the US) IFIM/PHABSIM[1] models. There is an interesting report of
aquatic habitats from the perspective of adult walleye in Lake Erie that
demonstrated the lack of information and value when measurements are
averaged, another report that where stream/river transects are placed
(absolutely and relative to each other) influences the PHABSIM output of
'Weighted Usable Area,' and a third report that notes the disconnect between
hydraulic and morphometric models and the complexities and heterogeneities of
water chemistry and microhabitats that control where fish (and their food
organisms) are found.

   The IFIM/PHABSIM suite were originally developed as research tools by the
US Forest Service which makes them less than optimal for resource allocation
and permitting decisions.

   The numeric (and rare spatial) models also do not cover the habitat needs
of the complete life cycle of a species nor variations among co-habitating
species in the same stream/river system or reach.

   What this all suggests to me is that from an applied viewpoint (that is,
providing technical informations for well-informed policy or regulatory
decisions) there is nothing readily available.

   I know the approach that I would take, and I might just develop a model
that is more practical and appropriate if I have the time. No one's going to
fund my efforts so it may be quite a while until something is ready for use.

Rich

[1] Instream Flow Incremental Methodology and Physical Habitat Simulation.
The latter is a component of the former.