Judith Drexler is a Research Hydrologist/Wetland Ecologist at the California Water Science Center. She specializes in ecosystem ecology with a special emphasis on the interactions among biogeochemical, ecological, and hydrologic processes in wetland and aquatic ecosystems.
RESEARCH
My research is focused on biological carbon sequestration and the impact of disturbance including climate change and sea-level rise, invasive species, land use change, and hydrologic alteration on ecosystem sustainability. Throughout my career, I have chosen to conduct much of this research in a wide variety of terrestrial and coastal wetlands and aquatic systems. In recent years, I have been studying how to regain critical ecosystem services, such as carbon storage and habitat for threatened and endangered species, through restoration. As part of my research, I use marsh sustainability modeling to better understand the vulnerability of wetlands to drowning under future sea-level rise scenarios. My current work on the island of Moloka‘i, Hawai‘i has allowed me to combine my interests in Western science and indigenous knowledge to evaluate potential options for restoring coastal wetlands and their critical linkages to adjacent ecosystems.
Professional Experience
I began my career at the U.S. Environmental Protection Agency in the Drinking Water Branch. As a postdoc, I worked at the USDA Forest Service in Honolulu, Hawai‘i studying groundwater-surface water interactions in coastal wetland complexes in Micronesia. I have been at the USGS California Water Science Center since 2000.
Education and Certifications
Ph.D., Natural Resources, Cornell University
M.A., Geography, University of Colorado, Boulder
B.A., Environmental Science, University of California, Berkeley
Science and Products
Ecology and ecosystem impacts of submerged and floating aquatic vegetation in the Sacramento-San Joaquin Delta
An assessment of future tidal marsh resilience in the San Francisco Estuary through modeling and quantifiable metrics of sustainability
A summary of water-quality and salt marsh monitoring, Humboldt Bay, California
Can coastal habitats rise to the challenge? Resilience of estuarine habitats, carbon accumulation, and economic value to sea-level rise in a Puget Sound estuary
Carbon flux, storage, and wildlife co-benefits in a restoring estuary
Influence of invasive submerged aquatic vegetation (E. densa) on currents and sediment transport in a freshwater tidal system
We present a field study combining measurements of vegetation density, vegetative drag, and reduction of suspended-sediment concentration (SSC) within patches of the invasive submerged aquatic plant Egeria densa. Our study was motivated by concern that sediment trapping by E. densa, which has proliferated in the Sacramento–San Joaquin Delta, is impacting marsh accretion and reducing turbidity. In
On the human appropriation of wetland primary production
Carbon storage and sediment trapping by Egeria densa Planch., a globally invasive, freshwater macrophyte
Influenza A viruses remain infectious for more than seven months in northern wetlands of North America
Trapping of suspended sediment by submerged aquatic vegetation in a tidal freshwater region: Field observations and long-term trends
Carbon sources in the sediments of a restoring vs. historically unaltered salt marsh
Carbon stock losses and recovery observed for a mangrove ecosystem following a major hurricane in Southwest Florida
Delta Wetlands and Resilience: Blue Carbon and Marsh Accretion
A Prioritization Plan for Coastal Wetland Restoration on Moloka‘i
A Prioritization Plan for Coastal Wetland Restoration on Moloka‘i
Ecosystem Engineering Impacts of Water Primrose in the Sacramento-San Joaquin Delta
Science to Inform the Management of Mangrove Ecosystems Undergoing Sea Level Rise at Ding Darling National Wildlife Refuge, Sanibel Island, Florida
NASA-USGS National Blue Carbon Monitoring System
Assessing the Benefits and Vulnerability of Current and Future Potential Ecosystem Services of the Nisqually River Delta and other Puget Sound Estuaries
Ecosystem Engineers: Impacts of Invasive Aquatic Vegetation on the Delta’s Critical Ecosystems
Fate of Endangered Species in San Francisco Bay Tidal Marshes with Sea-Level Rise
Salt marsh monitoring during water years 2013 to 2019, Humboldt Bay, CA – water levels, surface deposition, elevation change, and carbon storage
Projected future habitat, elevation change, and carbon accumulation of coastal wetlands in the Nisqually River Delta, Washington
Radioisotopes, percent organic carbon, percent inorganic sediment, and bulk density for peat and sediment cores collected in the Sacramento-San Joaquin Delta, California
Sediment transport and aquatic vegetation data from three locations in the Sacramento-San Joaquin Delta, California, 2017 to 2018
Temporal Viral Viability Data from Avian Influenza A Viruses Maintained in North American Wetlands Under Experimental and Environmental Conditions
Science and Products
- Publications
Filter Total Items: 49
Ecology and ecosystem impacts of submerged and floating aquatic vegetation in the Sacramento-San Joaquin Delta
Substantial increases in non-native aquatic vegetation have occurred in the upper San Francisco Estuary over the last 2 decades, largely from the explosive growth of a few submerged and floating aquatic plant species. Some of these species act as ecosystem engineers by creating conditions that favor their further growth and expansion as well as by modifying habitat for other organisms. Over the laAuthorsMairgareth A. Christman, Shruti Khanna, Judith Z. Drexler, Matthew YoungAn assessment of future tidal marsh resilience in the San Francisco Estuary through modeling and quantifiable metrics of sustainability
Quantitative, broadly applicable metrics of resilience are needed to effectively manage tidal marshes into the future. Here we quantified three metrics of temporal marsh resilience: time to marsh drowning, time to marsh tipping point, and the probability of a regime shift, defined as the conditional probability of a transition to an alternative super-optimal, suboptimal, or drowned state. We usedAuthorsJames Morris, Judith Z. Drexler, Lydia Smith Vaughn, April RobinsonA summary of water-quality and salt marsh monitoring, Humboldt Bay, California
This report summarizes data-collection activities associated with the U.S. Geological Survey Humboldt Bay Water-Quality and Salt Marsh Monitoring Project. This work was undertaken to gain a comprehensive understanding of water-quality conditions, salt marsh accretion processes, marsh-edge erosion, and soil-carbon storage in Humboldt Bay, California. Multiparameter sondes recorded water temperatureAuthorsJennifer A. Curtis, Karen M. Thorne, Chase M. Freeman, Kevin J. Buffington, Judith Z. DrexlerCan coastal habitats rise to the challenge? Resilience of estuarine habitats, carbon accumulation, and economic value to sea-level rise in a Puget Sound estuary
Sea-level rise (SLR) and obstructions to sediment delivery pose challenges to the persistence of estuarine habitats and the ecosystem services they provide. Restoration actions and sediment management strategies may help mitigate such challenges by encouraging the vertical accretion of sediment in and horizontal migration of tidal forests and marshes. We used a process-based soil accretion model (AuthorsMonica Mei Jeen Moritsch, Kristin B. Byrd, Melanie J. Davis, Anthony J. Good, Judith Z. Drexler, James T. Morris, Isa Woo, Lisamarie Windham-Myers, Eric E. Grossman, Glynnis Nakai, Katrina L. Poppe, John M. RybczykCarbon flux, storage, and wildlife co-benefits in a restoring estuary
Tidal marsh restorations may result in transitional mudflat habitats depending on hydrological and geomorphological conditions. Compared to tidal marsh, mudflats are thought to have limited value for carbon sequestration, carbon storage, and foraging benefits for salmon. We evaluated greenhouse gas exchange, sediment carbon storage, and invertebrate production at restoration and reference tidal maAuthorsIsa Woo, Melanie J. Davis, Susan E. W. De La Cruz, Lisamarie Windham-Myers, Judith Z. Drexler, Kristin B. Byrd, Ellen Stuart-Haëntjens, Frank E Anderson, Brian A. Bergamaschi, Glynnis Nakai, Christopher S. Ellings, Sayre HodgsonInfluence of invasive submerged aquatic vegetation (E. densa) on currents and sediment transport in a freshwater tidal system
We present a field study combining measurements of vegetation density, vegetative drag, and reduction of suspended-sediment concentration (SSC) within patches of the invasive submerged aquatic plant Egeria densa. Our study was motivated by concern that sediment trapping by E. densa, which has proliferated in the Sacramento–San Joaquin Delta, is impacting marsh accretion and reducing turbidity. In
AuthorsJessica R. Lacy, Madeline R. Foster-Martinez, Rachel M. Allen, Judith Z. DrexlerOn the human appropriation of wetland primary production
Humans are changing the Earth's surface at an accelerating pace, with significant consequences for ecosystems and their biodiversity. Landscape transformation has far-reaching implications including reduced net primary production (NPP) available to support ecosystems, reduced energy supplies to consumers, and disruption of ecosystem services such as carbon storage. Anthropogenic activities have reAuthorsJames E. Cloern, Samuel M. Safran, Lydia Smith Vaughn, April Robinson, Alison Whipple, Katharyn E. Boyer, Judith Z. Drexler, Robert J. Naiman, James L. Pinckney, Emily R. Howe, Elizabeth A. Canuel, J. Letitia GrenierCarbon storage and sediment trapping by Egeria densa Planch., a globally invasive, freshwater macrophyte
Invasive plants have long been recognized for altering ecosystem properties, but their long-term impacts on ecosystem processes remain largely unknown. In this study, we determined the impact of Egeria densa Planch, a globally invasive freshwater macrophyte, on sedimentation processes in a large tidal freshwater region. We measured carbon accumulation (CARs) and inorganic sedimentation rates in suAuthorsJudith Z. Drexler, Shruti Khanna, Jessica R. LacyInfluenza A viruses remain infectious for more than seven months in northern wetlands of North America
In this investigation, we used a combination of field- and laboratory-based approaches to assess if influenza A viruses (IAVs) shed by ducks could remain viable for extended periods in surface water within three wetland complexes of North America. In a field experiment, replicate filtered surface water samples inoculated with duck swabs were tested for IAVs upon collection and again after an overwAuthorsAndrew M. Ramey, Andrew B. Reeves, Judith Z. Drexler, Josh T. Ackerman, Susan E. W. De La Cruz, Andrew S. Lang, Christina Leyson, Paul T. Link, Diann Prosser, Gregory J. Robertson, Jordan Wight, Sungsu Youk, Erica Spackman, Mary Pantin-Jackwood, Rebecca L. Poulson, David E. StallknechtTrapping of suspended sediment by submerged aquatic vegetation in a tidal freshwater region: Field observations and long-term trends
Widespread invasion by non-native, submerged aquatic vegetation (SAV) may modify the sediment budget of an estuary, reducing the availability of inorganic sediment required by marshes to maintain their position in the tidal frame. The instantaneous trapping rate of suspended sediment in SAV patches in an estuary has not previously been quantified via field observations. In this study, flows of watAuthorsPaul A. Work, Maureen A. Downing-Kunz, Judith Z. DrexlerCarbon sources in the sediments of a restoring vs. historically unaltered salt marsh
Salt marshes provide the important ecosystem service of carbon storage in their sediments; however, little is known about the sources of such carbon and whether they differ between historically unaltered and restoring systems. In this study, stable isotope analysis was used to quantify carbon sources in a restoring, sparsely vegetated marsh (Restoring) and an adjacent, historically unaltered marshAuthorsJudith Z. Drexler, Melanie J. Davis, Isa Woo, Susan E.W. De La CruzCarbon stock losses and recovery observed for a mangrove ecosystem following a major hurricane in Southwest Florida
Studies integrating mangrove in-situ observations and remote sensing analysis for specific sites often lack precise estimates of carbon stocks over time frames that include disturbance events. This study quantifies change in mangrove area from 1985 to 2018 with Landsat time series analysis, estimates above and belowground stored carbon using field data, and evaluates aboveground carbon stock changAuthorsElitsa I. Peneva-Reed, Ken Krauss, Eric L. Bullock, Zhiliang Zhu, Victoria Woltz, Judith Z. Drexler, Jeremy R. Conrad, Stephen V Stehman - Science
Delta Wetlands and Resilience: Blue Carbon and Marsh Accretion
Blue carbon ecosystems (BCEs) are coastal ecosystems, such as tidal marshes, mangroves, and seagrasses, with manageable and atmospherically significant carbon stocks and fluxes. The tidal marshes and scrub-shrub wetlands in the Sacramento-San Joaquin Delta (Delta) of California are examples of BCEs. The Delta is a 2,400 square kilometer tidal freshwater region located at the landward end of the...A Prioritization Plan for Coastal Wetland Restoration on Moloka‘i
Wetland restoration on Moloka'i is needed to expand habitat for endangered species, improve ecosystem services, increase access to cultural resources including sedges for weaving, and increase opportunities for growing taro. The goal of this project is to assess the current status of wetlands on the island of Moloka‘i, evaluate potential impacts of projected sea level rise on these habitats, and...A Prioritization Plan for Coastal Wetland Restoration on Moloka‘i
Moloka‘i has great wetland restoration potential in Hawaiʻi, but most remaining sites are highly degraded. The future of several endangered waterbirds and insects relies on restoring coastal wetland habitat that is resilient under sea-level rise and coastal flooding. Currently, managers lack background data on Molokaʻi to prioritize sites for restoration. In this project, Researchers will developEcosystem Engineering Impacts of Water Primrose in the Sacramento-San Joaquin Delta
Many non-native fish, invertebrates, and plants have colonized the Sacramento-San Joaquin Delta (Delta) of California, the landward most region of the San Francisco Estuary. Included among these invasive species is the water primrose (Ludwigia spp.), an aggressive floating aquatic plant that is native to South and Central America and parts of the US, but invasive in California. Water primrose is...Science to Inform the Management of Mangrove Ecosystems Undergoing Sea Level Rise at Ding Darling National Wildlife Refuge, Sanibel Island, Florida
Mangroves are forested tidal wetlands that occur in tropical, sub-tropical, and warm temperate coastal regions around the world. Mangroves occupy a significant area of coastlines globally and provide important ecosystem services to humans and wildlife. These services include aesthetic value, storm protection, food provisioning, recreation, critical wildlife habitat, and biological carbon sequestraNASA-USGS National Blue Carbon Monitoring System
The NASA-USGS National Blue Carbon Monitoring System project will evaluate the relative uncertainty of iterative modeling approaches to estimate coastal wetland (marsh and mangrove) C stocks and fluxes based on changes in wetland distributions, using nationally available datasets (Landsat) and as well as finer scale satellite and field derived data in six sentinel sites.Assessing the Benefits and Vulnerability of Current and Future Potential Ecosystem Services of the Nisqually River Delta and other Puget Sound Estuaries
The Nisqually River Delta represents the largest wetland restoration in the Pacific Northwest. The restoration resulted in a 50% increase in potential salt marsh habitat. The Delta supports threatened salmon fisheries, large populations of migratory birds, and provides unique opportunities for recreation. The Delta also provides multiple ecosystem services, which are the benefits that wildlife orEcosystem Engineers: Impacts of Invasive Aquatic Vegetation on the Delta’s Critical Ecosystems
The Sacramento-San Joaquin Delta (Delta) is home to a diverse community of plants and animals and is the hub of California’s freshwater delivery system. The Delta supplies water for over 25 million Californians and supports millions of acres of farming, commercial and sport fishing, shipping and ports, and recreational boating.Fate of Endangered Species in San Francisco Bay Tidal Marshes with Sea-Level Rise
The San Francisco Bay estuary contains the largest remaining expanse of tidal salt marshes in the western U.S. These marshes are home to a variety of federal and state protected species, such as the California clapper rail, California black rail, and the salt marsh harvest mouse. The estuary is also located on the Pacific Flyway, and is an important site for migrating and wintering birds. As clima - Data
Salt marsh monitoring during water years 2013 to 2019, Humboldt Bay, CA – water levels, surface deposition, elevation change, and carbon storage
This data release includes montorting data collected by the U.S. Geological Survey (USGS) Humboldt Bay Water Quality and Salt Marsh Monitoring Project. The datasets include continuous water levels collected at a 6-minute timestep collected in two study marshes (Mad River and Hookton). Surface deposition, elevation changes and carbon storage (in marsh edge environments) measured in five USGS studyProjected future habitat, elevation change, and carbon accumulation of coastal wetlands in the Nisqually River Delta, Washington
This dataset consists of raster geotiff outputs from modeling habitat change, marsh vertical accretion, and carbon accumulation in the Nisqually River Delta, Washington, USA. These rasters represent projections of future habitat type, change in surface elevation above Mean Sea Level, and total sediment carbon accumulation since 2011 in coastal wetland habitats. Projections were generated in 20-yeaRadioisotopes, percent organic carbon, percent inorganic sediment, and bulk density for peat and sediment cores collected in the Sacramento-San Joaquin Delta, California
This data release contains data from cores collected in marshes and in sediments under invasive Brazilian waterweed (Egeria densa Planchon) in the Sacramento-San Joaquin Delta of California during the spring of 2018. Data are provided in two text files in comma separated columns. The first Core_Sites_Details.txt contains core site location, collection dates, and naming information. The second fileSediment transport and aquatic vegetation data from three locations in the Sacramento-San Joaquin Delta, California, 2017 to 2018
We measured currents, suspended-sediment concentration (SSC), bed sediment characteristics, and vegetation biomass density in the Sacramento-San Joaquin Delta in 2017-2018, as part of a project investigating the influence of invasive aquatic vegetation (IAV) on flow and sediment flux. This data release includes data from three sites: Lindsey Slough (April 2017), Middle River (March 2018) and the lTemporal Viral Viability Data from Avian Influenza A Viruses Maintained in North American Wetlands Under Experimental and Environmental Conditions
Data sets containing: (1) sample collection and influenza A virus (IAV) screening information for wild ducks, (2) water temperature data for six North American wetlands, (3) water quality measurement from those wetlands, (4) laboratory-based study of viral viability using Minnesota wetland water, (5) naive mallards challenged experimentally with IAVs identified from the field experiment, and (6) g - Multimedia
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