Optimization of Tidal Marsh Management at the Cape May and Supawna Meadows National Wildlife Refuges, New Jersey, Through Use of Structured Decision Making

Open-File Report 2020-1055
Prepared in cooperation with the U.S. Fish and Wildlife Service
By: , and 

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Abstract

Structured decision making is a systematic, transparent process for improving the quality of complex decisions by identifying measurable management objectives and feasible management actions; predicting the potential consequences of management actions relative to the stated objectives; and selecting a course of action that maximizes the total benefit achieved and balances tradeoffs among objectives. The U.S. Geological Survey, in cooperation with the U.S. Fish and Wildlife Service, applied an existing, regional framework for structured decision making to develop a prototype tool for optimizing tidal marsh management decisions at the Cape May and Supawna Meadows National Wildlife Refuges in New Jersey. Refuge biologists, refuge managers, and research scientists identified multiple potential management actions to improve the ecological integrity of 13 marsh management units within the refuges and estimated the outcomes of each action in terms of performance metrics associated with each management objective. Value functions previously developed at the regional level were used to transform metric scores to a common utility scale, and utilities were summed to produce a single score representing the total management benefit that would be accrued from each potential management action. Constrained optimization was used to identify the set of management actions, one per marsh management unit, that would maximize total management benefits at different cost constraints at the refuge scale. Results indicated that, for the objectives and actions considered here, total management benefits may increase consistently up to approximately $785,000, but that further expenditures may yield diminishing return on investment. Management actions in optimal portfolios at total costs less than $785,000 included applying sediment to the marsh surface (thin layer deposition) in seven marsh management units, controlling the invasive reed Phragmites australis in four marsh management units, remediating hydrologic alterations in two marsh management units, and planting native vegetation in one marsh management unit. The management benefits were derived from expected improvements in the capacity for marsh elevation to keep pace with sea-level rise, increases in numbers of spiders (as an indicator of trophic health) and tidal marsh obligate birds, and increased cover of native vegetation. The prototype presented here provides a framework for decision making at the Cape May and Supawna Meadows National Wildlife Refuges that can be updated as new data and information become available. Insights from this process may also be useful to inform future habitat management planning at the refuges.

Suggested Citation

Neckles, H.A., Lyons, J.E., Nagel, J.L., Adamowicz, S.C., Mikula, T., Braudis, B., and Hanlon, H., 2020, Optimization of tidal marsh management at the Cape May and Supawna Meadows National Wildlife Refuges, New Jersey, through use of structured decision making: U.S. Geological Survey Open-File Report 2020–1055, 41 p., https://doi.org/10.3133/ofr20201055.

ISSN: 2331-1258 (online)

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Table of Contents

  • Acknowledgments
  • Abstract
  • Introduction
  • Regional Structured Decision-Making Framework
  • Application to the Cape May and Supawna Meadows National Wildlife Refuges
  • Results of Constrained Optimization
  • Considerations for Optimizing Salt Marsh Management
  • References Cited
  • Appendix 1. Regional Influence Diagrams
  • Appendix 2. Utility Functions for the Cape May and Supawna Meadows National Wildlife Refuges

Additional publication details

Publication type Report
Publication Subtype USGS Numbered Series
Title Optimization of tidal marsh management at the Cape May and Supawna Meadows National Wildlife Refuges, New Jersey, through use of structured decision making
Series title Open-File Report
Series number 2020-1055
DOI 10.3133/ofr20201055
Year Published 2020
Language English
Publisher U.S. Geological Survey
Publisher location Reston, VA
Contributing office(s) Patuxent Wildlife Research Center
Description vii, 41 p.
Country United States
State New Jersey
Other Geospatial Cape May, Supawna Meadows National Wildlife Refuges
Online Only (Y/N) Y
Additional Online Files (Y/N) N
Google Analytic Metrics Metrics page