PNAMP/NOAA Intrinsic Potential Workshop

Intrinsic landscape features that are not easily modified by anthropogenic influences can be helpful in evaluating the suitability of habitat for aquatic vertebrates. Datasets on such spatial features are broadly available or easy to estimate through spatial analyses. Analyses based upon characteristics that are associated with species’ preferences could form the foundation of a consistent approach on which to base management decisions for a suite of aquatic species (resident and anadromous fishes, amphibians), with respect to natural or historical habitat potential.

Intrinsic Potential (IP) models use geospatial data on such features to identify stream reaches with high or low potential for fish or other species, and provide a method for estimating potential habitat quantity and quality across local or regional scales. They are spatial analyses that use intrinsic physical stream habitat variables to rate the habitat potential of stream reaches for aquatic species. Typically, IP models use a set of index curves or biological envelopes to relate each variable to fish preference, then combine indices to estimate an intrinsic reach score. Intrinsic Potential analyses for ESA-listed salmon and steelhead have been incorporated into recovery planning activities for populations in the Pacific Northwest. However, currently, there is no standard methodology for developing geospatial datasets needed for IP analyses nor are there peer-reviewed habitat suitability curves for many resident and anadromous species in the Pacific Northwest.

The Pacific Northwest Aquatic Monitoring Partnership (PNAMP) and NOAA Fisheries hosted a workshop to improve the state of the knowledge on and consistency for Intrinsic Potential (IP) analyses used in the Pacific Northwest and California for salmon and resident salmonids. The workshop was held in November, 2008, to focus on the habitat data and suitability curves that underlie IP calculations as well as to meet the need for coordination in IP applications and research, and to facilitate sharing IP-related datasets. The primary goal of this workshop was to enhance the working relationship between state, tribal, private and federal fisheries biologists, spatial analysts and managers involved in intrinsic potential-type analyses. The workshop was divided into two topical days: one was devoted to the development and maintenance of spatial datasets, and the second was devoted to biological considerations.

The workshop was very successful in meeting our goals, has led to a series of manuscripts (in preparation) on related subjects, and resulted in an increase in regional knowledge, awareness, and input on this new paradigm for aquatic habitat potential. We brought together scientists, GIS analysts, and resource managers, and were able to facilitate a greater understanding of the importance of data quality, scale, sources, and data gaps, in the context of designing biological models. Participants contributed greatly to knowledge on all topics addressed in the workshop; their caveats, suggestions, and study ideas are included in this report. These perspectives will be incorporated into upcoming peer-reviewed manuscripts.

Spatial analysts and biologists gained a needed perspective on the accuracy and precision in hydrogeomorphic variables versus the accuracy and precision in species-specific thresholds and biological curves of those same variables, from field observations. The species-level workgroups made great progress in designing and contributing to a hierarchical approach for reach-based habitat potential models, and provided valuable expert opinion on habitat curves and thresholds for salmonid species, considering regional, ecological, and life history difference. A report containing background reference material compiled for the workshop, summaries of the sessions held, contributions from participants, and a synthesis of the major guidelines for conducting IP analyses will be published in 2009. It is intended to provide general guidance and scientific and technical perspectives for reach-based habitat potential analyses. Workshop organizers and collaborators are in the process of developing related papers on conducting IP analyses, modeling IP for an individual species, and integrating biological information into spatial stream networks.