Intellectual Merit & Research Plan

WiCCED Salt advances understanding of the drivers and risks of saltwater intrusion (SWI) and develops evidence-based solutions across three interconnected areas: urban/suburban, rural, and natural systems. The project evaluates physical risks, studies how communities and decision-makers respond, and creates new mitigation and adaptation innovations—such as salinity-resistant crops, marsh-migration strategies, ecosystem-service incentives, and wetland-based carbon removal.

Through close collaboration across disciplines and institutions, WiCCED Salt strengthens Delaware’s capacity to protect natural resources and communities, builds new knowledge and partnerships, and catalyzes future solutions.

RESEARCH PLAN

Leads: Michael (UD) and Yue (DSU). Participants: Messer, Palm-Forster, Mondal, (UD), VAP-BS, VAP-EH (DSU), 7 grad students.

What risks does SWI impose on coastal environments and how can evidence-based decisions and innovations cost-effectively mitigate their effects?

Task D.1: Investigating Compound Stressors

How does the combination of stressors, salinization mechanisms, and land and water use affect the vulnerability of soil and water to salinization across various timescales, and how will the adoption of mitigation strategies reduce vulnerability?

This task examines the mechanisms and sources of salinization in complex systems.
It aims to quantify vulnerabilities and identify mitigation strategies for various land uses.
The research will utilize data from the DE Geological Survey and new airborne electromagnetic data.

USGS aerial electromagnetic survey. Top: flight lines. Bottom: sample resistivity line; cool colors show relatively fresh groundwater, and warm colors show relatively saline groundwater. Adapted from Ball et al. (2023).

Task D.2: Resource Use and Decision-Making

How is CPR extraction affected by heterogeneous risks of SWI in dynamic settings? How will the public respond to policies and programs aimed to mitigate and adapt to SWI?

(Palm-Forster, Michael, Messer, VAP-BS)

This task explores how SWI risks affect common-pool resource extraction behaviors.
It will analyze public responses to policies aimed at mitigating SWI impacts.
The research will employ economic lab experiments to understand groundwater pumping behavior under risk.

Urban and Suburban SWI Impacts

Leads: Voter (UD), Yue (DSU). Participants: Messer, Michael, Mondal, Palm-Forster (UD); VAP-EH, VAP-BS (DSU), 6 grad students.

SWI poses hidden threats to urban infrastructure, affecting wastewater and stormwater systems.
Prolonged saline contact can mobilize contaminants and impair infrastructure performance.
The project will map urban infrastructure exposure to SWI and assess vulnerabilities.

Task U.1: Urban Infrastructure Vulnerability Assessment

Where are urban infrastructures of all types (buildings, roads, pipes, septic tanks, contaminated sites) likely to be exposed to saline groundwater? How vulnerable are stormwater and wastewater infrastructures to future SWI?

This task will identify urban infrastructures exposed to saline groundwater.
It aims to quantify the vulnerability of stormwater and wastewater systems to future SWI.
The research will couple groundwater flow models with urban infrastructure models for comprehensive analysis.

Task U.2: Management and Planning for SWI

How is CPR extraction affected by heterogeneous risks of SWI in dynamic settings? How will the public respond to policies and programs aimed to mitigate and adapt to SWI?

This task examines how SWI risks influence stormwater and wastewater management decisions.
It will assess gaps between perceived and modeled risks and explore innovative management strategies.
The research aims to provide decision-makers with actionable insights for improving infrastructure resilience.

Stormwater Management and Infrastructure Adaptation

Methods for assessing stormwater management strategies and the perspectives of decision-makers in vulnerable areas of Delaware.

The Delphi method will be used to interview 10-15 decision-makers and managers involved in stormwater management.
Interviewees will include those responsible for MS4 permits, wastewater treatment plants, and septic systems.
Questions will focus on local barriers to adaptation, opportunities for implementation, and ideal policy responses.
Managers will assess local vulnerabilities, current mitigation efforts, and future goals for adaptation.
Public perceptions regarding the use of treated wastewater for aquifer replenishment will also be explored.

Homeowner Participation in SWI Adaptation

The willingness of coastal homeowners to engage in actions addressing stormwater intrusion (SWI) and their preferences for mitigation strategies.

Research questions focus on homeowners’ willingness to act against SWI and their preference for private versus public mitigation actions.
The study aims to understand coastal residents’ willingness to invest in SWI mitigation strategies that provide private benefits.
Economic field experiments and randomized controlled trials will be conducted with DE residents to assess their willingness to adopt solutions.
Focus groups will refine a survey to evaluate willingness to pay for mitigation activities.
Responses will be compared with those from upland communities facing little SWI threat.

Salinity Effects on Marine and Terrestrial Organisms

The physiological impacts of salinity on coastal ecosystems and the implications for agriculture and aquaculture.

Understanding salinity effects is crucial for predicting climate change impacts on coastal ecosystems.
Salinity variations can increase susceptibility to infections in benthic communities like oysters and blue crabs.
SWI can hinder plants’ nutrient uptake, leading to poor growth and reduced agricultural productivity.
Effective policies require knowledge of community perspectives on adaptation strategies to increase resilience.

Implications for Aquaculture and Benthic Fauna

How temperature and salinity changes affect the health of blue crabs and oysters, as well as consumer demand for seafood.

Research questions focus on the relationship between temperature, salinity, and pathogen susceptibility in blue crabs and oysters.
The study hypothesizes that variations in salinity increase the severity of infections and diminish consumer demand for affected seafood.
Molecular biology techniques will be used to investigate pathogen prevalence in DE salt marshes.
Consumer demand will be assessed through field experiments based on previous studies.

Development of Salinity-Resistant Crops

Identifying plant species that can adapt to excess salinity and their potential for agricultural production.

The task aims to evaluate salt-tolerant crops to mitigate negative impacts on agriculture due to salinization.
Molecular genetics will be used to analyze relationships between salinity and nutrient dynamics in crops.
Field trials will involve local farmers to assess the viability of salt-tolerant varieties.
Enterprise budgets will be developed to evaluate the profitability of incorporating these crops.

SWI Adaptation Strategies for Rural Areas

Explore farmer and landowner preferences for various strategies to adapt to SWI in rural landscapes.

The research question focuses on what strategies farmers are willing to adopt for SWI adaptation.
A discrete-choice experiment will measure preferences for land management strategies, including infrastructure investments and land use changes.
Behavioral characteristics affecting preferences will be examined, such as risk perception and social norms.
A survey will be conducted to increase sample size and refine expected outcomes.

Natural Systems and Ecosystem Services

Address the impacts of salinization on coastal ecosystems and the potential for marsh migration as a nature-based solution.

Coastal ecosystems are changing due to salinization, affecting marsh migration and ecosystem services.
The research will quantify marsh ecosystem services and the effects of salinity on these services.
The study will evaluate the potential for marsh migration to offset losses from sea-level rise.
Machine learning and remote sensing will be used to identify suitable areas for marsh migration.

Engineered Blue Carbon Storage

Investigate the relationship between coastal salinization and carbon sequestration in wetland soils.

Research questions focus on how salinization affects total alkalinity (TAlk) and dissolved inorganic carbon (DIC) exports from wetlands.
The study hypothesizes that coastal wetlands export more blue carbon than they store in soils.
Detailed analyses will be conducted at two salt marsh sites to measure DIC and TAlk exports.
The project aims to develop cost-effective carbon dioxide removal technologies using scrap concrete.

Water Quality Ecosystem Services from Marshlands

Examine the relationship between marshland characteristics and water quality in nearby aquatic systems.

The research will establish empirical relationships between marshland proximity and water quality indicators.
The study aims to simulate landscape-level outcomes of landowner participation in conservation programs.
Economic models will be developed to estimate the costs and benefits of strategic marsh migration.
The project will validate predictions using satellite-derived data and field measurements.

Saltmarsh Migration as a Nature-Based Solution

Focus on quantifying marsh migration rates and potential future migration under sea-level rise.

The research will use advanced data-science techniques to analyze marsh migration into farmlands.
The study hypothesizes that marsh migration has accelerated but is constrained by land management practices.
Machine learning and remote sensing will be employed to map wetlands and identify transition zones.
The project aims to develop conservation policies that facilitate marsh migration and enhance ecosystem services.

Workforce Development and Education Initiatives

Outline the strategies for preparing students and researchers for careers related to stormwater intrusion.

The project aims to grow future leaders through mentorship programs and structured research opportunities.
At least 25 undergraduate and nine graduate researchers will be supported across partner institutions.
Efforts will focus on broadening participation among underrepresented students in STEM fields.
An interactive online tool will be developed to guide students through career pathways related to SWI.

Jurisdictional Impact and Sustainability

The broader impacts of the project on Delaware’s water supply and ecosystems.

The project aims to address the challenges posed by salinization and its effects on coastal ecosystems.
It seeks to attract and retain talent to position Delaware as a leader in addressing coastal SWI challenges.
The initiative anticipates generating transformative outcomes that benefit Delaware and other coastal areas.
Engaging students in research will build workforce skills and enhance educational experiences.