Making Gap Analysis Work for New York Waters: A State Perspective on Aquatic GAP

Mark B. Bain and Marcia S. Meixler

New York Cooperative Fish and Wildlife Research Unit, Cornell University, Ithaca

A review of the New York Aquatic GAP pilot project ("Making GAP Analysis Work for New York Waters" workshop) was held in December 1997 with natural resource agencies in New York. The workshop was attended by representatives of many bureaus and offices of the New York Department of Environmental Conservation (NYDEC): Hudson Valley region, marine resources, habitat protection, fisheries, bioassessment and monitoring, and water resources. Representatives of the New York offices of the U.S. Fish and Wildlife Service, The Nature Conservancy, and the U.S. Geological Survey also participated. Our aim was to present the methods developed in the pilot project for the aquatic component of GAP in New York to a select group of agency representatives, to recommend actions, and to obtain their thoughts and ideas for applying gap analysis to all New York waters. The event worked well because the attendees were interested in and enthusiastic about the application of GAP methods to aquatic environments. They readily contributed ideas on how to enhance the GIS models, enhance the pilot project to better meet their agency’s needs, and apply GAP to real management issues in New York. The workshop discussions also posed some challenges to making "aquatic" GAP a highly state-relevant technology.

An encompassing notion that emerged was that national programs and within-state perspectives often contrast. The National GAP Program seeks to develop standardized methods to be applied broadly and consistently across the nation for the purpose of identifying biodiversity conservation priorities-this purpose requires methods that are general, broad-scale, and oriented to diversity of species. NYDEC and other state agencies see the greatest gain in GIS efforts aimed at specific kinds of problems (e.g., streamside buffers, bank erosion, vegetation beds), fish species and life stages, and assessing threats of a site-specific nature. Further, it was noted that the GAP Program counts geographic coverage as a measure of accomplishment, and the workshop attendees recommended that the geographic scope of future work be either halted or reduced. The top priority of workshop attendees was to see the GAP models tested and perfected in a limited area using data that is already assembled and detailed, targeted field surveys. Consequently, some hard thinking by workshop attendees was needed to see a way to closely mesh state and federal interests in this program.

In the interest of integrating GAP technology with state needs and priorities, three general themes were raised in the many comments offered during the review. First, the GAP Program’s focus on high species diversity as a measure of management priority was not seen as central in the issues or approach of New York agencies. Agency representatives were largely interested in fish species and often just one life stage (e.g., spawning) of some species. This species-oriented perspective would call for model development aimed at very specific habitats, which differs from the GAP approach of mapping habitats associated with species and communities. Some means of addressing diversity and communities while retaining predictive power for species and life stages of economically important species will be needed to blend national and state-level needs.

A second issue was the scale of GAP technology development and application. The GAP Program aims at developing broad-scale habitat coverages for states or regions, but this does not match the scale of management issues on the agendas of state agencies. Some way is needed to use a GIS system to simultaneously provide broad spatial coverage and do fine-scale applications. Finally, the GAP Program’s development approach is to complete statewide habitat coverages and learn how to best use those for identifying conservation "gaps." The workshop attendees strongly favored model development, testing, and refinement in a limited area before moving to statewide coverages. Some sort of dual development approach is needed to balance model refinement and validation with expanding spatial coverage.

Despite the differences in perspectives, almost everyone at the workshop realized the utility and potential applications of predicting biota from remotely sensed data and mapped habitats. This is the basic philosophy of GAP, and no suggestions were made to abandon it. Also, there was no sentiment for the apparent alternative GIS development mode of consolidating aquatic biosurvey data to map known species distributions. New York agencies have extensive biological survey data, there are established programs maintaining this information, and most of it is in computer databases. The inconsistencies identified in the workshop dealt only with the level of biological predictions (diversity vs. species), the scale of development (statewide vs. limited area), and the initial development approach (statewide coverage construction vs. validated protocol refinement).

The leadership of the NYDEC is committed to seeing aquatic GAP continue in the state, and it has made a commitment to shared support of GAP. With the workshop results in mind, a joint USGS (NY Coop Unit) and NYDEC proposal was formed for the continued development of aquatic GAP in New York. Some changes in the methods of our pilot project were identified to make aquatic GAP serve a diversity of needs while retaining the basic attributes of the National GAP Program. Building greater prediction flexibility into the GAP protocol would bridge the need to address species diversity and species-specific mapping. Unlike terrestrial GAP that largely relies on satellite data, aquatic GAP used a variety of data that we mapped in categorical form, such as shaded or open canopy cover, high or low gradient, and stressful or suitable water quality. The use of continuous data (e.g., gradient in m/km rather than high and low slope) on a variety of parameters (canopy cover, water quality, channel structure, etc.) would greatly enhance the capability of GAP models to deal with varied prediction needs. We already developed GIS tools to automate the acquisition of continuous form data for GIS modeling. Prediction algorithms would differ for species and diversity, and a subset of variables with optimized weighting could be developed for each use. The workshop promoted a staged approach to developing GAP coverages in New York; that is, expand state-level coverage by developing coverages basin by basin across the state. This approach allows both expanded GAP coverage while working in watersheds with extensive data useful in model testing and refinement.

The proposed USGS/NYDEC Aquatic GAP Project would develop the GIS software and protocols for implementing an automated system and developing prediction equations. The national aquatic GAP methods, developed over time with experiences in several states, would include a set of GIS data layers to develop and how (the GIS structure), a set of classification equations for national-scale syntheses (National GAP classification rules), and a protocol for developing study and species-specific predictions (habitat classification optimization). If the mathematical formats were standardized, a wide variety of uses could be accommodated depending on user interests without separate development efforts. The "Making GAP Work for New York Waters" workshop raised tough questions about the basic aquatic GAP approach. The new ideas presented in the joint USGS/NYDEC proposal could not have been developed without the input of the New York agencies.