GOMESA Application Details

Internal Project Number: 271326
1. Title of Project: Developing model-based decision support tools and advancing understanding of tipping points in coastal wetlands
2. Location of Project: Grand Bay NERR with limited upland sediment input and managed with prescribed fires; Pascagoula Bay with abundant sediment from upland sources without prescribed fires; Graveline Bay, adjacent to urban development and influenced by local upland input.
3. Requesting Organization: The University of Southern Mississippi
4a. Name: Erica Kennedy
4b. Position
4c. Phone Number: 601-266-4119
4d. Fax Number
4e. Address Line 1: Office of Research Administration 118 College Drive #5157
4e. Address Line 2
4e. City, State Zip: Hattiesburg, Mississippi
4f. Email: ORA-PAM@usm.edu
5. FundingRequested: $342,715
Awarded Amount:
6. Other State or Federal Funding Sources: No
7a. Amount of Additional Funds
7b. Source of Additional Funds
8. Total Project Funds Amount: $342,715
9. Project Description/Overview: This proposed project aims to improve the conservation of coastal wetlands in Mississippi, which are essential to biodiversity, storm surge protection, and the livelihoods of coastal communities. It addresses four key questions: (1) how sea-level rise (SLR) and saltwater intrusion affect salt marsh vegetation and marsh landscapes; (2) what are the thresholds/tipping points of SLR and salinity stress for salt marshes; (3) how urban development impacts marsh migration; and (4) how restoration strategies (e.g., prescribed fire, living shorelines, thin-layer placement, land acquisition) improve resilience. We will test three hypotheses. H1: Landward migration cannot keep pace with salt marsh loss under SLR. H2: SLR and salinity thresholds are higher in salt marshes with abundance sediment input. H3: SLR and salinity thresholds are higher with restoration practices, demonstrating restorations help improve salt marsh resilience. We will study three representative estuarine systems—Grand Bay, Pascagoula Bay, and Graveline Bay—using integrated fieldwork, experiments, and modeling. Data from each estuary will help develop a modeling framework to predict salt marsh loss and landward migration under SLR, saltwater intrusion, urban development, and restoration scenarios. The framework builds on an existing landscape model developed in the PI’s lab, which currently focuses on salt marsh vegetation and inundation and erosion-driven marsh loss (Wu et al. 2020). We will expand it by incorporating salt marsh migration driven by geophysical factors such as SLR and saltwater intrusion and available suitable land, as well as biological factors like species tolerance and interspecific competition. This model will help identify salinity and inundation stress tipping points for salt marshes, accounting for landward migration rates. Prior studies often focus on migration potential but rarely address rate, which is critical for comparing with marsh loss rates to provide a fuller picture of future marsh area. We will then develop model-based decision support tools with user-friendly interfaces, guided by input from resource managers (see support letter). By incorporating tipping points, the research provides early warning of marsh changes and supports more informed conservation planning. The products will include model, tipping points, decision tools, predictive maps at 5-yr intervals through 2050 to guide conservation/restoration priorities under future SLR and development scenarios.
10. Project Goals/Objectives: The goal of this proposal is to advance our understanding of the resilience of coastal wetlands by examining both loss mechanisms driven by inundation and erosion, and landward migration processes. We also aim to evaluate how different restoration strategies can enhance coastal wetland resilience under future climate and development pressures. To support conservation and management, we will develop model-based decision support tools that allow resource managers and researchers to explore projected salt marsh landscapes under various scenarios, including SLR, urban expansion, and management practices such as land acquisition, prescribed fire, living shorelines, and thin-layer sediment placement. Salt marshes in Mississippi are primarily composed of Spartina alterniflora and Juncus roemerianus. While Spartina alterniflora is well studied due to its dominance across much of the Atlantic and northern Gulf coasts, Juncus roemerianus remains relatively under-researched. Our project addresses this critical knowledge gap by focusing on the vegetation dynamics of Juncus roemerianus, which is especially important for the unique marsh systems found in Mississippi and similar regions. Additionally, we will identify key salinity and inundation stress thresholds for salt marshes. These thresholds will serve not only as scientific benchmarks but also as tools to communicate resilience concepts in accessible terms for stakeholders and policymakers. They will function as early warning indicators of marsh vulnerability, helping guide timely and proactive conservation efforts. This proposed research has four primary objectives that support the overarching goals: (1) Model the impacts of sea-level rise and urban development on salt marsh vegetation and landscape dynamics, informed by field data on vegetation, soil, and water samples; (2) Derive sea-level rise and salinity stress thresholds for salt marsh ecosystems to serve as indicators of resilience and early warning signals; (3) Identify vulnerable areas that would benefit most from targeted conservation or restoration efforts, and evaluate the effectiveness of strategies such as prescribed fire, living shorelines, thin-layer placement, and upland land acquisition that supports landward marsh migration; (4) Develop decision support tools based on the modeling framework, featuring a user-friendly interface and customizable management scenarios, to help resource managers make informed planning and policy decisions.
11. Which of the following authorized uses set forth in the GOMESA Act does this project fall under?

(A) Projects and activities for the purpose of coastal protection, including conservation, coastal restoration, hurricane protection, and infrastructure directly affected by coastal wetlands losses: Yes: This project will provide research support for the long-term conservation and management of coastal wetlands in Mississippi’s Coastal Preserves, which are essential to biodiversity, fisheries, and the protection of coastal communities. By developing a robust, science-based modeling framework, the project will enable reliable predictions of salt marsh loss and migration under scenarios of sea-level rise, urban development, and restoration efforts. These insights will empower coastal resource managers and other stakeholders to make informed, forward-looking decisions that enhance ecosystem resilience. The project will deliver user-friendly, model-based decision support tools co-developed with resource managers, allowing them to prioritize actions.

(B) Mitigation of damage to fish, wildlife, or natural resources.: Yes: This project will support the conservation of fish and wildlife by protecting their critical habitats—coastal wetlands. More than 75% of commercial and 90% of recreational fish and shellfish harvested in the U.S. rely on coastal wetlands for food or habitat during some part of their life cycle (https://cfpub.epa.gov/watertrain/moduleFrame.cfm?parent_object_id=301&object_id=304). Enhancing the conservation of these wetlands will help sustain vital coastal natural resources, preserve biodiversity, and support the many species that depend on them.

(C) Implementation of a federally-approved marine, coastal, or conservation management plan.

(D) Mitigation of the impact of Outer Continental Shelf activities through funding of onshore infrastructure projects.

12. Project Timetable/Milestones: Despite their importance to human well-being, coastal wetlands have experienced significant loss and degradation in recent decades due to sea-level rise (SLR), more frequent and severe droughts, storms, hurricanes, oil spills, and increased subsidence from oil and gas exploration etc. To support their conservation, we will develop a modeling framework that captures the interactions, feedbacks, and landscape connectivity driving salt marsh loss and landward migration. This framework will enable projections of future marsh change, tipping points, and the evaluation of potential management strategies. Through engagement with coastal resource managers on the Mississippi Gulf Coast, we identified critical needs for 25-year projections of salt marsh change, a better understanding of urban development’s influence on marsh migration, and guidance on where and which restoration practices can enhance resilience to SLR. Our approach integrates modeling, field observations, and experimental work, leveraging existing data, models, and prior projects. We will collect field data along transects to improve an existing landscape model developed in the PI’s lab—currently focused on marsh loss—by expanding it to simulate landward migration. The enhanced model will account for accretion, erosion, upland availability, species tolerance, and interspecific competition. We will co-develop model-based decision support tools to predict the effects of SLR and management practices at the landscape scale and derive salinity stress and SLR tipping points. These tools will also incorporate the effects of nearby urban development to inform conservation and restoration priorities. Milestone 1: Field Campaign. We will establish five transects per estuary across salinity and elevation gradients, from salt marshes to pine savannas, with a focus on less studied ecotones (transition zones from marshes to uplands). Each transect, running perpendicular to the shoreline, will include eight ecotone sites, five salt marsh sites, and five coastal forest sites. At each site, we will measure elevation, vegetation productivity (biomass, DBH, height), density, and soil properties etc. Some transects will cover restoration projects or past prescribed fires,and some will account for canopy shading. Dominant vegetation will be identified, and a regression tree will be trained using Sentinel-2 imagery. Transects will be established in February 2026, with major field and lab work in 2026–2027 and auxiliary data collection (e.g., DBH) in 2028 for model refinement. Milestone 2: Model Development. We will model vegetation productivity as a function of competition (e.g., for light and nutrients) and geophysical factors like porewater salinity and elevation, a proxy for inundation. This will form the basis of an individual-based model for marsh migration, coupled with suitable uplands for marsh migration and our existing landscape model focused on marsh loss. Model development will begin in Fall 2026, complete in 2027, and be refined in 2028. Milestone 3: Threshold/tipping point Analysis. We will run the calibrated model under different SLR and salinity scenarios and compute marsh area and landscape metrics (Wu 2019). Sigmoidal regression curves will be fitted to landscape metrics vs. SLR/salinity to derive tipping points using inflection points (Wu et al. 2020). This work will conclude in 2028. Milestone 4: GIS & Scenario Analysis. We will identify vulnerable areas and simulate marsh changes under varying SLR, development, and restoration scenarios. This will help identify effective strategies for restoration, land use planning, and climate adaptation. This analysis will begin in late 2027 and continue into 2028. Milestone 5: Decision Support Tools. We will develop interactive, model-based decision tools using R-Shiny to support resource managers. Interface options (e.g., scenarios, years) will be guided by managers. A beta version will be tested in 2028. We will hold biannual meetings with managers in 2026–2027 and quarterly meetings in 2028. One M.S. student will graduate in 2027 and one Ph.D. student in 2028. Findings will be disseminated through conferences, workshops, and publications (2027–2028). References: 1) Wu, 2019. Ecological Indicators 103, 260–271. 2) Wu et al., 2020. Science of the Total Environment 718 (2020) 137181.
13. Project Timing: Short-term
14. Current status of architectural/engineering plans & specifications for this project (if applicable):: Other N/A Funds Not Budgeted

15. In what way does this project meet the goals and objectives of the Department of Marine Resources, which includes enhancing, protecting and conserving the marine interest of Mississippi for present and future generations?: This proposal focuses on the conservation of Mississippi’s coastal wetlands, which are critical to maintaining ecological integrity, sustaining fisheries productivity, and improving community resilience in the face of sea-level rise, hurricanes, and urban development. The study areas are located within the Mississippi Coastal Preserves, which are actively managed by Mississippi Department of Marine Resources (MDMR). By centering our efforts on salt marsh systems in these preserves, the project is designed to collaborate closely with coastal resource managers and stakeholders, and explicitly advances MDMR’s mission to “restore, enhance, protect, and manage Mississippi’s remaining coastal estuarine marsh ecosystems” through a combination of innovative modeling, stakeholder engagement, and decision-making tools. To accomplish this, the project will deliver three key products that support informed planning and proactive conservation: 1) A co-produced decision support tool, developed in collaboration with resource managers and iteratively tested to ensure usability and alignment with real-world management needs. This tool will allow exploration of future marsh conditions under different SLR, land use, and restoration scenarios. 2) Sea-level rise and salinity stress thresholds, derived from field data and modeling, that serve both as technical indicators of marsh vulnerability and as effective communication tools to translate resilience science into early warning signals and management triggers. 3) Spatially explicit maps projecting salt marsh distribution through 2050, updated at five-year intervals, to visually illustrate the impacts of sea-level rise, development, and restoration strategies on marsh landscapes. These maps will help guide conservation priorities and restoration planning over time. Furthermore, the strategic selection of study sites within representative Coastal Preserves ensures that the tools and findings will be scalable and transferable, with potential for application across broader regions along the Gulf Coast and beyond. Additionally, while Spartina alterniflora has been extensively studied due to its widespread dominance across the Atlantic and northern Gulf coasts, Juncus roemerianus, a species particularly prevalent in Mississippi, remains underrepresented in the literature. By addressing the knowledge gap in the vegetation dynamics of Juncus roemerianus, our project contributes new scientific insights that are directly relevant to the ecosystems MDMR is charged with protecting.

16. Estimated Years To Completion: 3
17. Estimated Completion Date: 12/31/2028

Budget:

Salaries,Wages, Fringe
Travel
Architecture & Engineering
Legal
Consulting
Construction
Site Work
Equipment
Indirects
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Application Submission Date: 06/20/2025
Fiscal Year: 2027
Project Status
Application Status: Submitted
Meets Criteria
Internal Notes:
Attachments:: https://gomesa_internal/attachments/GOMESA_1326_COMPLETE.pdf
Hyperlink:: Attachments

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