Optimization of Salt Marsh Management at the Bombay Hook National Wildlife Refuge, Delaware, Through Use of Structured Decision Making

Open-File Report 2018-1160
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 salt marsh management decisions at the Bombay Hook National Wildlife Refuge in Delaware. Refuge biologists, refuge managers, and research scientists identified multiple potential management actions to improve the ecological integrity of eight salt marsh units within the refuge 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 salt marsh 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 would increase consistently up to approximately \$300,000, but that further expenditures would yield diminishing return on investment. Management actions selected within optimal portfolios at total costs less than \$300,000 included hydrologic restoration, recontouring adjacent uplands to facilitate marsh migration, and burning the marsh. The prototype presented here provides a framework for decision making at the Bombay Hook National Wildlife Refuge that can be updated as new data and information become available.

Suggested Citation

Neckles, H.A., Lyons, J.E., Nagel, J.L., Adamowicz, S.C., Mikula, T., Guiteras, S.T., and Mitchell, L.R., 2018, Optimization of salt marsh management at the Bombay Hook National Wildlife Refuge, Delaware, through use of structured decision making: U.S. Geological Survey Open-File Report 2018–1160, 18 p., https://doi.org/10.3133/ofr20181160.

ISSN: 2331-1258 (online)

Study Area

Table of Contents

  • Acknowledgments
  • Abstract
  • Introduction
  • Regional Structured Decision-Making Framework
  • Application to the Bombay Hook National Wildlife Refuge
  • Results of Constrained Optimization
  • Considerations for Optimizing Salt Marsh Management
  • References Cited
  • Appendix 1. Utility Functions for the Bombay Hook National Wildlife Refuge

Additional publication details

Publication type Report
Publication Subtype USGS Numbered Series
Title Optimization of salt marsh management at the Bombay Hook National Wildlife Refuge, Delaware, through use of structured decision making
Series title Open-File Report
Series number 2018-1160
DOI 10.3133/ofr20181160
Year Published 2018
Language English
Publisher U.S. Geological Survey
Publisher location Reston, VA
Contributing office(s) Patuxent Wildlife Research Center
Description vi, 18 p.
Country United States
State Delaware
Other Geospatial Bombay Hook National Wildlife Refuge
Online Only (Y/N) Y
Additional Online Files (Y/N) N