HabRate: a literature and stream survey based habitat rating model
Jennifer L. Burke, Kim K. Jones, and Jeffrey M. Dambacher
Oregon Department of Fish and Wildlife, Natural Production Section, Aquatic
Inventory Project
28655 Highway 34, Corvallis, OR 97333
(541) 757-4263
Abstract
To provide a habitat based potential for smolt production to the PASRAS model1,
we undertook a review of literature to describe critical habitat for chinook
salmon, steelhead, and kokanee salmon. Habitat ratings of high, medium, and low
were created for each stream survey variable, for each stream rearing life
stage. Variable scores were combined to provide a rating for each life stage at
the micro and meso scale. For instance, substrate ratings for fines, gravel and
cobble, were combined to create an overall rating for substrate. Similarly
habitat unit level information such as pools, depth, large boulders, and large
woody debris were combined into an overall rating for habitat complexity. These
overall ratings were then combined, based on a limiting factor approach to
create a single rating for that life stage. Five separate life stages were
included: spawning/emergence (for kokanee, chinook, and steelhead), 0+ summer
and winter (for chinook and steelhead), and 1+ summer and winter (for steelhead
only). Total smolt capacity was estimated based on function of total wetted area
and habitat quality. Model output is designed to be incorporated into the PASRAS
model through a CSV file format.
Design criteria for the model were 1) simplicity and 2) flexibility. It attempts
to work only from published literature, and rating values for high, medium, and
low can be easily changed. Information not found in standard stream surveys,
such as seasonal flow or temperature limitations can be included based on
professional judgment.
1: Gretchen Oosterhout, Ph.D., Decision Matrix, Inc., 23252 South
Central Point Road, Canby,
OR 97013 / (503) 266-8692