The Baltimore Social-Environmental Collaborative Integrated Field Laboratory
Lead PI: Ben Zaitchik, Johns Hopkins University
Collaborative co-PIs: C. Welty, UMBC; Ken Davis; Penn State; Michael Waring, Drexel University; James Hunter, Morgan State; Lawrence Band, University of Virginia; Jiazhen Ling, DOE NREL; Peter Groffman, CARY/CUNY; Morgan Grove, USFS
The Baltimore Social-Environmental Collaborative (BSEC) is a DOE Integrated Field Laboratory centered on the Baltimore, MD metropolitan area. BSEC’s goal is to develop a model for community-oriented urban climate science that can be applied in other metropolitan areas. We are working with community partners to establish measurement and modeling platforms that address environment, health, and development priorities of the city and its neighborhoods, and that provide accessible and flexible entry points to engage with scientific results. We are leveraging our vast existing modeling and observational resources to build the BSEC. Our approach will include (1) placing environmental justice at the center of IFL designs; (2) adopting a participatory, multi-objective framework to identify just and sustainable pathways under climate change; (3) addressing the complexities of the built environment, including indoor-outdoor environmental interactions, to connect the IFL to residents’ lived experience; and (4) recognizing that a city is a coupled natural-human ecosystem in which human well-being and ecosystem processes are intertwined.
Urban Critical Zone Cluster (National Science Foundation)
Lead PI: C. Welty
Collaborative PIs: J. Moore, D. Bain, P. Groffman, J. Duncan, A. Berkowitz, K. Prestegaard, L. Toran
This project will advance knowledge of urban critical zone processes through a Critical Zone (CZ) Cluster spanning four cities on the U.S. East Coast: Philadelphia, Baltimore, Washington, DC, and Raleigh. These cities were developed along the Fall Zone, a region of steep rivers incised into crystalline Piedmont bedrock upstream of the Atlantic Coastal Plain. The north-south gradient of this urban cluster is associated with climatic trends and with a gradient in age from older and denser development in Philadelphia and Baltimore to newer and sparser development in Raleigh.
We aim to address the following questions: (1) How does urbanization in a temperate, Eastern seaboard landscape result in a shift from a supply-limited to a transport-limited regime governing solute export? (2) How does the underlying structure of the CZ along the Piedmont-Coastal Plain transition interact with urbanization to affect export fluxes? (3) How do chemical and hydrological dynamics associated with urbanization affect material export along the latitudinal gradient from Philadelphia to Raleigh?
Research methods include development of a watershed-scale geochemical-hydrological model as a framework for data collection, assimilation, and prediction; geophysics for subsurface mapping; land cover/land use data analysis; soil and rock core chemical analysis; soil gas sampling; stream and well sampling for solutes; and analysis of sediment concentrations and yields. We will construct a new conceptual model of solute movement from the land surface through the subsurface to streams, constrained by geologic and geomorphic architecture and the overprinting of urban development. This project will train 7 undergraduates per year, 7 graduate students, and 1 post-doctoral associate.
Project participants will work with high school science teachers to identify topics for a CZ instructional module and a teacher professional development program. A regional CZ Citizen Science Interest Group will be convened to identify opportunities to adopt CZ project protocols in local programs and to contribute to CZ project research. The project engagement plan includes hosting open quarterly science meetings and establishing a visiting scholar fund to support scientific exchange with other CZ cluster sites.
Evaluation of watershed-scale impacts of stormwater management facilities on thermal loads to a Maryland Class IV stream using a high-frequency sensor network (Chesapeake Bay Trust)
PI: C. Welty
co-PI: A.J. MIller
We are deploying a high-density, high-frequency network of blue-tooth enabled temperature sensors throughout 16 km of a Use Class IV stream (Dead Run) in suburban Baltimore to address CBT 2021 RFP Question 5(a) on emerging pollutants: What best management practice design and siting methods will reduce thermal impacts to Maryland’s Use III and IV streams? At the watershed scale, we are collecting high-frequency (5-minute) temperature data from sensors secured to the streambed every 100 m, over all flow regimes (base flow to storm flow), for 2.25 years. Based on watershed-scale observations, we plan to collect stream temperature data downstream of ~30 BMP outfalls (spanning at least four BMP types) at a finer spatial scale (2 m – 50 m), and a higher frequency (1 minute). We will use this data set to quantify thermal inputs to the stream system from (1) surface and subsurface stormwater management facilities; (2) direct connections to land cover including impervious surface area during runoff events; and (3) effects of air temperature and tree canopy on stream temperature throughout the drainage network. This work will advance scientific knowledge by separating impacts from stormwater BMPs vs. other environmental factors on stream temperature at the watershed scale; the results can be used to inform regulatory policy for setting Total Maximum Daily Loads (TMDLs) for stream temperature.
Baltimore Ecosystem Study (National Science Foundation and USDA Forest Service)
PI/PD: Chris Swan
Field headquarters host: C. Welty
The Baltimore Ecosystem Study (BES) seeks to:
• Pursue excellence in social-ecological research in an urban system;
• Maintain positive engagement with communities, environmental institutions, and government agencies;
• Educate and inform the public, students, and organizations that have need of scientific knowledge; and,
• Assemble and nurture a diverse and inclusive community of researchers, educators, and participants.
Baltimore Ecosystem Study Phase III: Adaptive Processes in the Baltimore Socio-Ecological System from the Sanitary to the Sustainable City
PI: S. Pickett; co-PIs: P. Groffman; M. Cadenasso; C. Welty; J.M Grove
Project Web Site: http://beslter.org
The Baltimore Ecosystem Study (BES) was initiated as an LTER project in 1997, designed to understand the controls and interactions of urban ecosystem structure and function. This project will continue that long-term line of research and will expand it to address 3 fundamental issues: 1) The spatial and temporal relationships of socio-economic, ecological, and physical features of an urban area; 2) The fluxes of energy, matter, capital, and population in an urban area, and the development and relationships of these over time; and, 3) The ways in which people develop an understanding of the metropolis and use such understanding to reduce air and water pollution. The research integrates ecological, hydrologic, and social perspectives and research techniques to understand the human ecosystem and provide knowledge of relevance and utility for management of urban ecosystems and their neighboring environments. This project contributes to understanding of the structure, function, and dynamics of a metropolitan area, and includes development of techniques for better understanding socio-ecological and urban ecosystems in general. It assembles and integrates valuable long-term data sets from paleoecological, historical, and contemporary time-frames. The project has broad societal value through its contributions to improved management of urban ecosystems and its focus on techniques for reducing environmental pollution and degradation. Its broader values also include extensive research-based training, educational program development, and public outreach programs.
Regional Climate Variability and Patterns of Urban Development — Impacts on the Urban Water Cycle and Nutrient Export
PIs: C. Welty, AJ Miller, M. McGuire, J. Smith, E. Bou-Zeid, S. Kaushal, P. Groffman, A. Gold, M. Grove, E. Irwin, C. Towe, A. Klaiber, E. Doheny
Sponsor: National Science Foundation, Water Sustainability and Climate Program
The goal of this project is to evaluate the interactions between urban development patterns and the hydrologic cycle and its associated nutrient cycles, within the context of regional and local climate variability. Our specific objective is to create a modeling system capable of simulating the feedback relationships that control urban water sustainability. We are addressing the following research questions: (1) How do human locational choices, water-based ecosystem services, and regulatory policies affect the supply of land and pattern of development over time? (2) How do the changing composition and variability of urbanizing surfaces affect local and regional climate? (3) How do patterns of development (including the engineered water system) and climate variability affect fluxes, flow paths and storage of water and nitrogen in urban areas? Core elements include spatial modeling of urban development patterns and individual land use and location processes at parcel and neighborhood scales and for different policy scenarios; three-dimensional modeling of coupled surface water-groundwater and land surface-atmospheric systems at multiple scales (including consideration of the engineered water system), where development patterns are incorporated as input; and field work and modeling aimed at quantifying flow paths and fluxes of water and nitrogen in this system. We are using the Baltimore Ecosystem Study LTER (http://beslter.org), as a platform for place-based research to carry out the work.
Integrating Climate Change into the Restoration of the Chesapeake Bay and Watershed
PI (UMBC): Claire Welty; PI (U MD): M. Palmer; co-PIs: S. Filoso (CBL), L. Harris (CBL), C. Swan (UMBC), M. Williams (CBL)
The Chesapeake Bay and its tributaries have been ecologically impaired from stressors including intensive agriculture and urban development. These land uses are associated with increased impervious substrate that increases the magnitude of stormflow and associated nutrient and sediment fluxes, resulting in erosion and reduced biogeochemical efficiency and aquatic biodiversity. Best management practices are being used to mitigate the deleterious effects of development, yet how climate and land use changes will interact with these factors is unclear. To better understand the impact of these anticipated changes, our interdisciplinary approach combines (1) development of a conceptual model of factors responsible for restoration and recovery of streams and freshwater wetlands in the Chesapeake Bay watershed, (2) empirical research directed at filling important gaps in our understanding of these factors related to stream and freshwater wetland restoration effectiveness and biodiversity, (3) integration of empirical experimental data derived from these projects with anticipated climate and land use changes to determine how these factors will affect streams, rivers and freshwater wetlands and their restoration effectiveness, (4) development of coupled groundwater/surface water mathematical models of flow and nitrogen transport to enable integration of spatial and temporal climate and land use changes anticipated within the Chesapeake Bay watershed, and (5) the advancement of a spatio-temporal data warehousing system that will enable data storage, retrieval, and mining of empirical and model data generated by this project.
Green Infrastructure for Urban Landscapes (MD)
PI: Stuart Schwartz
Sponsor: National Fish and Wildlife Foundation, Chesapeake Bay Innovative Nutrient and Sediment Reduction Program
The goal of this project is to assemble a showcase portfolio of green infrastructure projects that advance applications of pervious concrete and subsoiling in urban landscapes. The project will target key institutional obstacles to adopting these technologies, including specifications, training, performance monitoring, and long-term maintenance. The project includes sites in Baltimore’s Inner Harbor and Charles, Montgomery, and Anne Arundel Counties.
Restoring Hydrologic Function in the Urban Landscape
PI: Stuart Schwartz
Sponsor: National Fish and Wildlife Foundation, Chesapeake Bay Innovative Nutrient and Sediment Reduction Program
This project will advance the use of subsoiling, soil amendment practices, and pervious concrete to reduce urban runoff and restore infiltration in highly disturbed soils. The project will demonstrate design and implementation, perform consistent monitoring, and conduct targeted outreach, education, and technology transfer to regulatory, management, and practitioner communities throughout the Bay watershed. Implementation locations include: Montgomery, Queen Anne, Baltimore, and Caroline Counties., MD, & DC; Education, Outreach and Technology Transfer: PA, VA, MD, & DC
CDI-Type II: GLOBE: Evolving New Global Workflows for Land Change Science
PI: Erle Ellis; co-PIs: T. Oates, W. Lutters, T. Finin, P. Rheingans
This project will accelerate the emergence of new global workflows in land change science through GLOBE: an online collaboration environment combining quantitative real-time global relevance assessment, geovisualization, social-computational structures and machine learning algorithms. This will be accomplished in collaboration with international Land Change Science (LCS) institutions and experts, enabling researchers and institutions to rapidly share, compare, and synthesize local and regional studies by combining these with global datasets for human and environmental variables using a combination of machine learning, advanced visualization, semantic analysis and social networking. The project has four core objectives that will be achieved through the integrated activities: (1) creation of an online collaboration environment leveraging real-time global relevance analysis, geovisualization and social-computational knowledge generation towards the generation and sharing of new global workflows for land change science; (2) understanding how to build effective social media tools organized around structured and informal scientific workflows; (3) development of evaluation methods and metrics and use them to demonstrate the utility of workflow-based social media tools in the context of scientists testing LCS hypotheses; and (4) leveraging GLOBE to characterize and optimize global knowledge generation in LCS.
ABI Development: Ecosynth: An Advanced Open-Source 3D Toolkit for Forest Ecology
PI: Erle Ellis; co-PI: T. Olano
This project will develop Ecosynth, an open-source 3D toolkit for scanning woodland ecosystems based on recent innovations in computer-vision technologies coupled with an online community system for browsing, sharing, visualizing, tagging and analyzing 3D scans of terrestrial ecosystems. This project aims to transform the practice of field ecology in woodlands by enabling the routine and frequent acquisition, use, and sharing of 3D scanning data by both ecologists and citizen scientists. Ecosynth 3D scanning technology applies Structure from Motion algorithms to images acquired in the field using ordinary consumer-grade digital cameras, including camera-equipped cell phones, deployed in computer-optimized patterns on the ground or from the air by hobbyist remote controlled aircraft. The Ecosynth toolkit developed by this project will be offered as an open-source development resource on the community website (http://ecotope.org/projects/ecosynth/)
Collaborative Research: The role of network topology and environmental filtering in shaping the ecology of spatially structured communities
PI: Christopher Swan; co-PI: Matthew Baker
Why are species found in certain combinations and not others? Why are some species not found in habitats that seem suitable for their needs? A fundamental goal of ecology is to understand the processes that drive patterns in species occurrence. An organism’s “local” environment can exert influence on where it occurs, e.g., climate, competition for resources, and disturbance. However, “regional” factors – such as the ability of organisms to colonize available habitat – are also important. This project addresses two fundamental questions: 1) What is the relative importance of local versus regional factors in controlling species composition? 2) How does that relative importance shift with elements of landscapes, and the ability of organisms to move across those landscapes? The project will address these two questions using communities of aquatic invertebrates in river networks. The project takes advantage of stream restoration activity, which almost always includes large-scale habitat modification. Three types of approaches will be employed to address the research questions: surveys of restoration sites, experimental manipulations of local factors – specifically stream-bottom habitat features – in river systems, and experiments using artificial streams to control for both local and regional processes.
CNH: Urban Disamenities and Pests: Coupled Dynamics of Urban Mosquito Ecology and Human Systems Across Socioeconomically Diverse Communities
PI: Shannon LaDeau (Cary Institute of Ecosystem Studies); Co-PIs: Paul Leisnham, Dawn Biehler (UMBC), Sacoby Wilson, Rebecca Jordan.
This project will test whether urban social and economic decay and urban infestations of mosquitoes feedback upon one another and, if so, how to break this vicious cycle. Research in Baltimore, Maryland, will examine whether features of urban decay such as population decline, abandoned lots, and unmanaged refuse promote mosquito production and whether this in turn discourages care for and use of the outdoor environment by residents and exacerbates urban decay. Comprehensive sampling in three focal neighborhoods will quantify the association between the abundances of mosquitoes and the physical and socio-economic status of neighborhoods, and how mosquito exposure influences resident support for and participation in outdoor activities and urban revitalization. Experiments will identify activities that best support and motivate resident-led strategies to control mosquitoes.
Combining bioavailability assays with modeling to predict PCBs in fish after remediation
PI: Upal Ghosh
Sponsor: National Institute of Environmental Health Sciences
Ecological and human health impacts of bioaccumulative contaminants like PCBs are primarily manifested through accumulation of the toxic compounds in higher trophic level organisms like fish that are consumed by humans and top predators in the ecosystem. However, changes in fish are slow to manifest as a consequence of a remedial action and often one has to wait for several years to see such change. To make timely assessments of remediation progress, one alternative is to perform appropriate measurements that indicate changes in key pathways of exposure to fish. Although some advances have been made recently to assess porewater concentrations using passive sampling techniques which respond more rapidly to in-situ remedies, relationship of such measures to accumulation is fish has not been demonstrated. Also, there is a major gap in the development and utilization of fate and biouptake models that can use passive sampling measurements and quantitatively link those measurements to uptake pathways and predict eventual changes in fish concentrations. This project will refine sampling methods to assess PCB uptake pathways and work with practitioners to incorporate such measures into PCB fate and biouptake models to assess changes in fish concentration over time, and validate the approach through controlled laboratory exposure studies and measurements in the field.
Pervious Concrete: Technology Demonstration and Information Needs
PI: S. Schwartz
Sponsor: Chesapeake Bay Trust
Among low impact development hydrology practices, pervious concrete and other pervious paving systems offer great promise for on-site, infiltration-based storm water management in urban and suburban development. Despite this potential and a substantial body of proven experience with the material, pervious concrete is not widely used in the state of Maryland or the Chesapeake Bay watershed. To overcome the barriers to successful specification, design, and regulatory approval of pervious concrete as a valuable element in integrated site design, the goals of this project are to develop (1) a well-instrumented pervious concrete demonstration site with long-term monitoring for performance evaluation and (2) educational and outreach workshops to deliver design, specification, installation and permitting information to regulators, practitioners, and community stakeholders. The project integrates field demonstrations and education and outreach workshops with rigorous site monitoring to address the need for consistent knowledge and information that currently limits the effective use of this material as an integral component of sustainable site design in the state of Maryland and the Chesapeake Bay watershed.
Baseflow Signatures of Sustainable Water Resources
PI: S. Schwartz
Sponsor: Harry R. Hughes Center for Agroecology
The goal of this project is to link regional low flow characteristics to spatial patterns and trends in land transformation, and to establish benchmark sustainability measures for managing the growing competition for Maryland�s limited water resources among demands from agriculture, forest, and development.
Integrating Real-Time Chemical Sensors into Understanding of Groundwater Contributions to Surface Water in a Model Urban Observatory
PIs: C. Welty, S. Kaushal, P. Groffman, L. Band, A. J. Miller, M. McGuire, R. Maxwell, K. Belt, J. Duncan
Sponsor: National Science Foundation
The purpose of this project is to build onto previous efforts to quantify the significance of groundwater in the urban water cycle. We will deploy nitrate analyzers and electrical conductivity sensors in Baltimore watersheds and conduct mathematical modeling to address the following questions: (1) How can sources, timing and fluxes of solutes from groundwater to surface water vary as a function land use (ultraurban, suburban, exurban, forest) and stream position (headwater vs downstream)? (2) How can transport time scales and subsurface flowpaths vary with flow regime (base flow vs storms) and antecedent conditions? (3) How can information from high frequency sensor deployment across a range of hydrologic conditions be used to �fill in the gaps� from our current weekly long-term monitoring to explain interannual changes in residence times and flushing of solutes? (4) How well can a physically-based watershed flow and transport model represent solute transport behavior across a range of time scales?
Microbial Nitrogen Sequestration in Detrital-Based Streams of the Chesapeake Bay Watershed Under Stress from Road-Salt Runoff
PI: C. Swan
Sponsor: Maryland Water Resources Research Institute
This project is a multi-factorial study to elucidate how ecological interactions (i.e., organic matter-microbial-invertebrate) react to a gradient of salt stress currently imposed on freshwater ecosystems in the region, and how this changes the capacity for the stream community to remove nitrogen from streams. Road-salt runoff has been recently identified as a stressor to freshwater streams. Given the negative effect of salt stress on carbon mineralization that has been documented for microbial communities in freshwater streams, road salt is expected to alter rates of nitrogen sequestration. As a result, road salt runoff might alter the natural ability of headwater streams to ameliorate excess nutrient delivery to larger, downstream water bodies (e.g., the Chesapeake Bay). This effect is being evaluated in this study.
CNH: Collaborative Research: Dynamic Coupling of the Water Cycle with Patterns of Urban Growth
PI: C. Welty; Co-PIs: AJ Miller, B. Hanlon, M. McGuire; J. Smith (Princeton U) R. Maxwell (Colorado School of Mines); C. Jantz, S. Drzyzga (Shippensburg U); E. Doheny (USGS)
The objective of this work is to link an urban growth model with a fully-coupled, physically-based three-dimensional hydrologic model to evaluate the effects of growth on water availability and limits to water supply using the Baltimore metropolitan region as a case study. Combining a physically-based regional hydrologic model with urban growth modeling allows an assessment of the coupled feedbacks between growth projections (and the socio-economic variables that affect growth) and surface and subsurface water resources. Changes in stream base flow and groundwater availability may in turn influence regulatory decisions on development permits in exurban areas. The project represents a collaboration among social scientists and physical scientists having expertise in urban systems. PARFLOW is being used as the coupled watershed model for this project at the scales of Dead Run, the Gwynns Falls, and the Gunpowder Patapsco.
Integrative Education, Research, and Training (IGERT) Program “Water in the Urban Environment”
PI: C. Welty; Co-PIs: Andrew Miller, Brian Reed, Virginia McConnell, Peter Groffman; 20 senior investigators
Urban development changes the ways that water moves through the landscape, altering the water cycle and increasing flood hazards, channel degradation, and water-quality impairment. These problems have led to successive generations of regulatory policy and engineering measures designed to mitigate negative impacts, with varying degrees of success. The effects on human health and social welfare are complex, and designing effective long-term solutions requires integrated ecological, economic and engineering approaches, as well as innovations in policy-making.
The UMBC IGERT program centers on three interwoven themes: (1) urban hydrology and contaminant transport; (2) urban biogeochemical cycles, aquatic ecosystems, and human health; and (3) urban water policy, management, and institutions. New integrative curricula have been developed in Water in the Urban Environment, Research Methods for the Urban Environment, Modeling and Spatial Statistics for the Urban Environment, which together with required seminar courses bring together students from nine Ph.D. degree programs to gain an appreciation of the varied disciplinary viewpoints, terminology, and data sets required to address urban environmental problems. All IGERT Fellows do internships in state or federal agencies and research laboratories, nongovernmental organizations, industry or consulting, or teaching, to expand their academic and career path horizons. Up to 20 PhD students are to be supported by the program.
Science-Based Negotiation of Multiobjective Resources Disputes
PI: AJ Miller; co-PIs: M Rivera, Daniel Sheer
An academic-industry partnership has been formed to create an upper-level undergraduate course, Computer Aided Negotiation of Water Resources Disputes, in which students tackle a real-world, interdisciplinary problem in the form of an interstate water supply dispute. Students integrate science, technology, public policy, and law to create mutually beneficial solutions to resource disputes. Each student plays the role of a lawyer, biologist, geologist or engineer employed by one of the water supply stakeholders. The stakeholder groups use (1) web-based, pedagogically-sound instructional tools, (2) a multi-disciplinary panel of working professionals, and (3) a computer model that utilizes linear programming algorithms to derive optimal solutions in accordance with priorities determined jointly by the stakeholders. The computer-aided negotiation process, which has been applied successfully to water resources disputes over the past two decades, is being used to develop and seek consensus on a set of operating rules for the system. Students learn to utilize scientific knowledge and technological tools, function effectively on interdisciplinary teams, and successfully negotiate with disparate interests. Moreover, students learn the background information required to participate in resource negotiations using research-supported pedagogy.
Pilot-Scale Research of Novel Amendment Delivery for In-situ Sediment Remediation
PI: U. Ghosh; CA Menzie (Exponent)
Sponsor: National Institute of Environmental Health Sciences (NIH)
Human health risks associated with the presence of chemicals in sediments arise from either direct contact with the sediments or by eating fish and shellfish that have accumulated chemicals from the sediments. Emerging laboratory-scale research has shown that contaminant transport pathways and bioavailability can be interrupted by modifying and enhancing the binding and contaminant assimilation capacity of natural sediments. This is achieved by adding sorbent amendments such as activated carbon for binding persistent organic pollutants and natural minerals such as apatite, zeolites, or bauxite for the binding of toxic metals in sediments. Critical barriers in the adoption of this in-situ remediation approach are the availability of efficient delivery methods for amendments to impacted sediments and understanding of physical and biological processes in field sites that control technology effectiveness. The main aim of this research project is to develop the in-situ remediation technology through a pilot-scale investigation aimed at addressing the critical barriers in the advancement of the technology.
Development and Application of Tools to Measure PCB Microbial Dechlorination and Flux into Water During In-situ Treatment of Sediments
PIs: J. Baker, K. Sowers, U. Ghosh
Sponsor: Strategic Environmental Research and Developmental Program (DOD)
This research is quantifying the two most important long-term loss processes of PCBs in sediments: 1) microbial degradation and 2) diffusive and resuspension-related losses to the water column. These main PCB loss mechanisms from sediments depend upon the ease with which PCBs can partition between solid and porewater phases and may be impacted by in-situ remediation. Recent laboratory tests demonstrated that amendment of sediment with activated carbon results in large reductions in the bioaccumulation of PCBs by clams, worms, and amphipods. Two important questions that are being addressed in this research are (1) how is natural PCB microbial dechlorination activity in sediment affected by the addition of activated carbon and (2) how is PCB mobility altered by the addition of activated carbon?
Determination of Sediment Polycyclic Aromatic Hydrocarbon (PAH) Bioavailability using Supercritical Fluid Extraction (SFE) and Ultra-Trace Porewater (UTP) Analysis
PIs: D. Nakles, A. Hawkins, S. Hawthorne, T. S. Bridges, U. Ghosh
Sponsor: Environmental Security Technology Certification Program (DOD)
This demonstration/validation project is designed to build upon the data developed to date demonstrating how site-specific estimates of PAH bioavailability in freshwater sediments can be used to predict toxicity to benthic freshwater species. The goal of the project is to extend the application of supercritical fluid extraction SFE and UTP estimates of PAH bioavailability to marine/estuarine sediments and species. Specifically, the project objectives are to (1) use SFE and UTP analyses to predict the bioavailability of PAHs in marine/estuarine sediments collected from two Navy facilities, (2) show the relationship between predictions of PAH bioavailability and the actual measured toxicity to a marine/estuarine macro invertebrate species and (3) demonstrate the application and develop technical guidance on the use of SFE and UTP as site-specific measurements of PAH bioavailability for assessing risk.