New Swarm Project

[glen e. p. ropella]

To the Swarm,

I just wanted to mention a project I've been helping with that has
been started at Humboldt State University.  It's a model of the lives
of Trout and their babies in streams.  I'm acting as a short-time
code-slinger (and slinging *is* the proper term [grin]) for the 
principals on the project, who are Dr. Rollie Lamberson (HSU), Steve
Railsback (Lang, Railsback & Assoc.), and Steve Jackson (HSU).

Hopefully, these guys will provide a good complement of fish biology
expertise to the Swarm community.

Here is a more thorough description of the project.  Much more will
come later.

glen

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The California Individual-based Fish Simulation System is a framework
for building, testing, and using models of how fish populations respond
to environmental change. The initial modeling work was funded by
California electric utilities and models how hydroelectric plants affect
stream trout populations. Hydropower has major global benefits
(providing over 95% of our renewable energy) but also can adversely
affect local fish populations by altering stream flow rates and
temperatures. Our modeling system is designed to help find good
tradeoffs between these global benefits and local impacts.

The fish simulation system imports habitat data (depths and velocities
in rectangular cells, temperatures) from external models or
observations. On a daily time step, it models how fish (a) select
habitat to improve growth and reduce mortality risks; (b) feed and grow;
(c) suffer mortality from predation, starvation, or habitat extremes;
and (d) spawn. The model also simulates survival of fish eggs from the
time of spawning until emergence as new fish. Fish are assumed to be
territorial, competing with each other for feeding sites. The
simulations are stochastic and use a number of parameters with uncertain
values, so the simulation system is designed to facilitate sensitivity
analysis and calibration. This formulation lets us predict how habitat
alterations (especially, changes in flow and temperature) and fish
behavior interact to determine populations.

Swarm was chosen for this modeling system after an extensive review of
alternative software platforms. Swarm provides an organizational
framework for the models, reduces code development via its existing
agent-based libraries, easily provides graphics that are essential for
calibration, facilitates (with the Experiment Swarm) model analysis and
calibration, and gives us access to a talented and stimulating user
community.

The Principal Investigator is Dr. Roland Lamberson of the Department of
Mathematics and the Environmental Systems Graduate Program, Humboldt
State University (address@hidden). Modeling support is provided
by Steve Railsback (address@hidden). The Swarm prototype was
developed by Glen Ropella, Swarm Corp. (address@hidden) and the code is
being maintained by Steve Jackson (address@hidden).

-- 
address@hidden
Lang, Railsback & Assoc.
Margaret Lang & Steve Railsback 
250 California Ave., Arcata CA 95521
707-822-0453; Fax 822-1868
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