7210

• UCREFRP Catalog Number: 7210
• Author: McMahon, T. E. and J. W. Terrell.
• Title: Habitat Suitability Index Models
• USFW Year: 1982.
• USFW - Doc Type: Channel Catfish.
• Copyright Material: NO

habitat size for channel catfish, although this species is most abundant in
larger water bodies.
Verification level. The acceptable output of these models .is an index
between 0 and 1 which the authors believe has a positive relationship to
carrying capacity. In order to verify that the model output was acceptable,
sample data sets were developed for calculating HSI's from the models.
The sample data sets and their relationship to model verification are
discussed in greater detail following the presentation of the models.
Model Description
It is assumed that channel catfish habitat quality is based primarily on
their food, cover, water quality, and reproduction requirements. Variables
that have been shown to have an impact on the growth, survival, distribution,
abundance, or other measure of well-being of channel catfish are placed in the
appropriate component and a component rating derived from the individual
variable suitability indices (Figs. 1 and 2). Variables that affect habitat
quality for channel catfish, but which do not easily fit into these four major
components, are combined under the "other component" heading. Levels of a
variable that are near lethal or result in no growth cannot be .offset by other
variables.
Model Description - Riverine
Food component. Percent cover (UZ) is assumed t.o `~e important for rating
the food component because if cover is available, fish would be more likely to
occupy an area and utilize the food resources. Substrate (b'4) is included
because stream. production po~ential of aquatic insects (consumed directly by
both channel catfish and their prey species) is related to airount and ,type of
substrate. _
f.
Cover component.- Percent pools (U1)-is included because channel catfish
utilize pools as cover: Percent cover (UZ) is van index of all types of~~
objects, including logs and debris, used for cover in rivers. Average current
velocity in cover areas (U18) is important because the usable habitat near a
cover object decreases if cover objects are surrounded by high velocities.
Water quality component. The water quality component is limited to
temperature, oxygen,.turbidity, and salinity measurements. These:,parameters
have been shown to effect growth or .survival, or have been correlated with
changes in standing crop. Variables related to temperature,~oxygen, and
salinity are assumed to be limiting when they approach lethal levels. Toxic
substances are not consfidered.
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