http://worldcat.org/entity/work/id/930943822

Defensible methods of assessing fish habitat lacustrine habitats in the Great Lakes Basin - conceptual basis and approach using a habitat suitability matrix (HSM) method

This report presents a detailed description of the structure and application of a quantitative fish habitat assessment tool for use in evaluating development proposals affecting lacustrine fish habitats in the Great Lakes and beyond. The scientific and regulatory context for the development of the tool are introduced along with a formal quantitative framework developed by Minns (1997) as a basis for assessing net change of productive capacity of fish habitats. Suitability indices are used as practical and pragmatic measures of habitat productivity and weighted suitable areas (area times suitability) are derived as surrogate measure of total productivity of the habitats affected at a development site. A habitat suitability matrix (HSM) model is described for estimating habitat suitability indices along with the rules and criteria that must be applied to allow evaluation of fish habitats. The HSM model uses pooled matrices representing the aggregate habitat preferences of many species by life stage to ensure that the needs of all fishes occurring in an ecosystem or ecoregion are considered. Species requirements are grouped by life stage and ecological groupings according to trophic level and thermal preference. Habitat scenario data sets describe the pre- and post-development conditions at a proposed site as series of habitat patches with characteristics of depth range, substrate type, and cover type. The HSM model generates suitability values for specific combinations of depth, substrate and cover that can be assigned to individual habitat patches. The rules and criteria for preparing the habitat scenario data sets and computing suitability matrices are described in detail with examples. The basis for using this approach in a regulatory context is described as the HSM approach to defensible methods of assessing fish habitat and is intended as an aid to the existing decision process, not as a replacement. Case studies are described as an aid for potential users of this approach. The whole approach has been implemented as an internet website for use by consultants working for developers and by regulatory agents. The scope for application of the approach is outlined along with a discussion of the limits for wise use of the approach. Implementation of the HSM model as a basis for assessing fish habitat represents a first step away from subjective and toward objective assessment tools. It is expected that further research will provide the basis for iterative improvements and enhancements.

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