Habitat Modeling
The RACE Division Habitat Research Project is developing quantitative models that explain the distribution and abundance of fish on the continental shelf of the eastern Bering Sea (EBS). The overall effort addresses a Congressional mandate to describe and identify essential fish habitat (EFH) for federally managed species. EFH refers to those waters and substrate necessary to fish for spawning, breeding, feeding, or growth to maturity. In general, we must describe and map the location of physical, biological, and chemical characteristics required by each life history stage of these commercially important species.
We are using an iterative process to develop and refine our EFH habitat models. In practice, systematic trawl survey data are being used to identify EFH as those areas supporting the highest relative abundance. (This approach assumes that the best habitats support the highest densities of animals.) When combined with existing environmental data, preliminary models can be developed to explain the observed patterns of abundance. Subsequently, new sampling tools and new environmental data sources are developed to improve the quality of the models. By this method, habitat quality is judged by the fish themselves, and not by the scientist.
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