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The Aquatic Component of Gap Analysis

Since the very beginning of Gap Analysis, there has been discussion on the need to apply the method to aquatic environments. The effort was officially launched in early September of 1994 with the formation of an advisory group. The group established the goal for the application of GAP methodology to aquatic environments as:

"To characterize aquatic biodiversity in the U.S. on a landscape scale for the effective management of land and water resources in ways that will preserve this biodiversity."

Dr. Patricia Heglund has been appointed as the coordinator for the aquatic GAP section. She recently moved to Moscow, Idaho from Alaska, where she had spent the past seven years as a research biologist (wetlands and waterfowl) for the U.S. Fish and Wildlife Service - Alaska Fish and Wildlife Research Center (now the National Biological Service - Alaska Science Center). Dr. Heglund currently holds affiliate faculty status in both the Department of Fish and Wildlife Resources and the Department of Biological Sciences at the University of Idaho.

Three prototype projects have been funded for 1995. These projects will be conducted in New York, Washington, and California. These pilot projects are predicated on the same fundamental tenets as the terrestrial component of GAP: 1) to identify places offering the best opportunities to conserve species while they are still common, through the identification of species and their habitats currently under-represented within our conservation network; 2) to provide a baseline for later biogeographic comparison; and 3) to provide landscape level spatial data useful for holistic resource management. These pilot projects will include lacustrine, palustrine, and riverine environments.

Our objectives for these prototype studies include:

1. Acquiring EPA River Reach File III data for use as base maps and catalogs of river basins at a scale of 1:100,000. Base maps will be registered with corresponding terrestrial GAP base maps and corrected for errors in River Reach data sets.
2. Mapping known distributions of fish, macroinvertebrates, amphibians, and reptiles (hereafter referred to as "elements") from museum collection records, agency records, published literature, and other sources.
3. Mapping general predicted ranges of each element from the published literature (e.g. Freshwater Fishes of Canada).
4. Mapping general habitat types, for example, aggregated from National Wetlands Inventory database.
5. Identifying habitat relations models for each element from existing literature.
6. Combining the steps listed above to generate maps for each water body or river reach of known or predicted occurrences of each element.
7. Reviewing predicted occurrences with experts and revising data layers as appropriate.
8. Developing attributes for each river reach, identifying its management status such as:
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   • county or state shoreline, or riparian management regulations,
   • state fisheries management practices (fishing regulations, stocking, pesticide use, motorized/non-motorized boating regulations, etc.),
   • state area-specific management designations (e.g., water quality, recreation, water withdrawals, aquatic vegetation management),
   • federal designation and regulations (e.g., Wild and Scenic Act, Clean Water Act, navigation considerations, other licenses and permits such as NPDES or FERC, federal structures).
9. Showing relations between, a) species distributions and in-stream management, and b) species distributions and terrestrial land cover between successive watershed sizes (fourth to second order watershed).
10. Determining where the best opportunities are to achieve long-term avoidance of threatened or endangered species status by both in-stream and watershed management.

Analyses will be conducted a second time when adjacent river basins are completed and their information is integrated, allowing for comparisons across larger biogeographic regions.

One of the most exciting aspects in developing the aquatic component of GAP is the construction of data sets compatible with the terrestrial data. Through the GAP process, we will integrate aquatic and terrestrial environments for a variety of analytical applications. For example, the data will show land cover for all second-order watersheds upstream of any given river reach. Although we expect others to find many uses for the data, our current goals are to: 1) conduct an initial screening of large areas from which more specific planning and management options can be developed within a bioregional context, and 2) provide a logical starting point at the landscape scale for conservation problem-solving.

In discussions about both the terrestrial and aquatic components of GAP, the question frequently arises, "What about riparian areas?" Our current position is that although riparian areas are of enormous importance, they cannot be adequately treated by our current level of funding. Adequate treatment of riparian areas requires a level of effort similar to the National Wetlands Inventory program, in that they should be mapped at a scale of at least 1:24,000. Given our funding constraints, we believe it is more productive to focus on landscape elements that can be adequately treated and continue to articulate the needs of those elements that are currently beyond our means.

As with terrestrial GAP, the aquatic component is starting with no generally accepted community- based habitat classification system. As with the land cover mapping effort, we hope the aquatic projects will spur a consensus about the structure and substance for a national classification system and how the system can be maintained over time.

Michael D. Jennings
National Coordinator, Gap Analysis Program

Patricia J. Heglund
Aquatic GAP Coordinator, Gap Analysis Program