Josh T Ackerman
Biography
Dr. Ackerman is a Principal Investigator with USGS and an Associate in the Department of Wildlife, Fish, and Conservation Biology at the University of California-Davis. His research expertise is in wildlife ecology and ecotoxicology, and his research program focuses on bird ecology, wetland management and restoration, contaminant bioaccumulation in fish and wildlife, and effects of contaminants on animal health and populations.
Education
- Ph.D. 2002, Ecology, University of California-Davis
- B.S. 1997 (Magna Cum Laude), Wildlife, Fish, and Conservation Biology, University of California-Davis
Professional Experience
- Research Wildlife Biologist, U.S. Geological Survey, Western Ecological Research Center, Dixon Field Station, California (2006-present)
- Wildlife Biologist, U.S. Geological Survey, Western Ecological Research Center, San Francisco Bay Estuary Field Station, Vallejo, California (2004-2006)
- Post-doctoral Researcher, John Muir Institute of the Environment, University of California-Davis (2003-2004)
- Post-doctoral Researcher, Dept. of Wildlife, Fish, and Conservation Biology, University of California-Davis (2002-2003)
- Teaching Assistant, Ecology and Management of Waterfowl and Game Birds (Spring 2002) and Field Methods in Wildlife, Fish, and Conservation Biology (Summer 2001), Dept. of Wildlife, Fish, and Conservation Biology, University of California-Davis
- Waterfowl Researcher (1999-2000), Crew Leader (Spring 1998, 1999, 2000), and Technician (Spring 1997), California Waterfowl Association, Sacramento, California
- Doctoral Research, Dept. of Wildlife, Fish, and Conservation Biology, University of California-Davis (1997-2002)
- Biological Technician (Summer 1995) and Biological Aid (Summer 1994), U.S. Forest Service, Tahoe National Forest, Nevada City, California
Selected Publications
2020 Ackerman, JT, MP Herzog, DC Evers, DA Cristol, KP Kenow, GH Heinz, RA Lavoie, RL Brasso, ML Mallory, JF Provencher, BM Braune, A Matz, JA Schmutz, CA Eagles-Smith, LJ Savoy, MW Meyer, and CA Hartman. Synthesis of maternal transfer of mercury in birds: implications for altered toxicity risk. Environmental Science and Technology 54:2878-2891.
2016 Ackerman, JT, CA Eagles-Smith, MP Herzog, CA Hartman, SH Peterson, DC Evers, AK Jackson, JE Elliott, SS Vander Pol, and CE Bryan. Avian mercury exposure and toxicological risk across western North America: a synthesis. Science of the Total Environment 568:749-769.
2014 Ackerman, JT, MP Herzog, GS Yarris, ML Casazza, E Burns, and JM Eadie. Chapter 5: Waterfowl ecology and management in Suisun Marsh: Ecological History and Possible Futures. University of California Press: Berkeley, California.
Science and Products
Wetland Management Technique Designed to Reduce Mercury in Water and Fish Tested During a Short-Term Field Study
Results from a 3-year study indicate there was support for the use of open- and deep-water treatment pools at the downstream end of seasonal wetlands to reduce methylmercury concentrations in water exported from the wetlands, but the treatment had no measurable effect on wetland fish. Questions remain about the long-term potential for mercury removal using this wetland management strategy...
Science to Help Understand Exposure and Toxicological Effects of Environmental Mercury to Representative Birds
Exposure and toxicity of environmental mercury to birds can be enhanced or lessened due to the available sources and forms of mercury and other species dependent factors such as life stage, migratory patterns, foraging and nesting behaviors, transfer of mercury from mothers to eggs, and sex. For example, mercury exposure can lead to sublethal toxicological effects that can influence parental...
Ecologically-Driven Exposure Pathways Science Team
The Ecologically-Driven Exposure pathways team identifies internal and external pathways and processes that can alter exposure and toxicity of contaminants and pathogens to wildlife the environment. That information is used to distinguish actual health risks to fish and wildlife. If actual risks are identified this project will inform how to economically and effectively minimize risk...
Suisun Marsh Waterfowl and Wildlife Studies
Suisun Marsh provides critical habitat for wintering and breeding waterbirds in California. USGS WERC collaborates with the California Department of Water Resources to examine trends in bird declines and to assess the habitat factors driving long-term survival of waterfowl, rails, and other birds in this important area.
Scientists Identify Processes that Affect Fish Mercury Concentrations in Estuarine Wetlands
In a study designed to help resource managers when considering mercury exposure risk, scientists determined that sulfur cycling—a process closely related to mercury methylation rates—and ecological conditions that influence exposure are important factors affecting fish mercury concentrations in estuarine wetlands.
New Method Can Measure Naturally Occurring Element Exposure in Hummingbirds Without Harm
Seventeen naturally occurring trace elements, including those associated with adverse health impacts when birds are exposed to toxic levels (iron, lead, mercury, selenium, zinc, cadmium, and arsenic) were measured in small birds without harm. The nonlethal method was developed for hummingbirds, with Anna's hummingbirds (Calypte anna) as a test species and can be more broadly applied...
Waterbird Breeding Ecology and Management
The San Francisco Bay is designated as a site of hemispheric importance to shorebirds and annually supports over one million waterbirds. Within the USGS WERC waterbird breeding ecology program, Dr. Josh Ackerman and partners are studying habitat selection, movements, and factors influencing waterbird nest success and chick growth and survival.
Mercury Bioaccumulation in Wetlands
Wetlands provide numerous ecosystem services, but also can be sources of methylmercury production and export. Click the next tab to learn how WERC's Dr. Josh Ackerman is evaluating the ecological factors that drive contaminant bioaccumulation in wetland-dependent fish and wildlife.
Breeding and Wintering Ecology of Waterfowl
Western U.S. wetlands provide critical habitat for wintering and breeding waterfowl in California. WERC's Dr. Josh Ackerman is working toward collecting data to understand factors influencing duck nest success, to improve and restore breeding habitat for resident duck populations in California, and understand composition of predator communities. To learn more about how USGS WERC is...
Contaminants in Waterbirds and Effects on Avian Reproduction
California’s Central Valley and San Francisco Bay Estuary have a long history of mercury contamination from past mercury mining and gold extraction. Waterbirds are particularly susceptible to mercury because of their use of wetland habitats where methylmercury (the most toxic and biologically available form) is produced and relatively low methylmercury exposure can reduce reproductive success...
Efficacy of Eggshell Analyses as a Nonlethal Method to Estimate Mercury Exposure in Bird Embryos
U.S. Geological Survey (USGS) scientists evaluated a nonlethal method to estimate mercury in the embryos of 23 bird species using mercury content in eggshells. This method was effective for a wide range of ages and species.
Dixon Field Station
WERC scientists at the Dixon Field Station conduct studies from the San Francisco Bay-Delta in California to the Great Basin spanning California and Nevada.
Re-establishing Waterbird Breeding Colonies in San Francisco Bay
This U.S. Geological Survey (USGS), Western Ecological Research Center (WERC) story map details how partners are using science and management to maintain and establish new bird nesting colonies in support of the South Bay Salt Pond Restoration Project. Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government.
Fluctuating Asymmetry in Waterbirds in Relation to Mercury Exposure
The dataset includes the bird species, sex, mercury concentration in breast feathers and whole blood, and the composite measure of fluctuating asymmetry. Statistical models were developed for each species to analyze the relationship between mercury exposure in either breast feathers or whole blood and the composite measure of fluctuating asymmetry, while accounting for the sex of each bird....
USGS Wildlife and Sport Fish Risk Estimator Tool
The "USGS Wildlife and Sport Fish Risk Estimator Tool Final (.xlsx)" tool is available for download via https://pubs.er.usgs.gov/publication/ofr20151106. To learn more about this project, visit Monitoring Mercury'...
Migration stopover ecology of Cinnamon Teal in western North America
Identifying migration routes and fall stopover sites of Cinnamon Teal (Spatula cyanoptera septentrionalium) can provide a spatial guide to management and conservation efforts, and address vulnerabilities in wetland networks that support migratory waterbirds. Using high spatiotemporal resolution GPS-GSM transmitters, we analyzed 61 fall...
Mackell, Desmond Alexander; Casazza, Michael L.; Overton, Cory T.; Donnelly, J. Patrick; Olson, David; McDuie, Fiona; Ackerman, Joshua T.; Eadie, John M. Wetland availability and salinity concentrations for breeding waterfowl in Suisun Marsh, California
Availability of wetlands with low salinities during the breeding season can influence waterfowl reproductive success and population recruitment. Salinities as low as 2 ppt (3.6 mScm–1) can impair duckling growth and influence behavior, with mortality occurring above 9 ppt (14.8 mScm–1). We used satellite imagery to quantify the amount of available...
Schacter, Carley Rose; Peterson, Sarah H.; Herzog, Mark P.; Hartman, C. Alex; Casazza, Michael L.; Ackerman, Joshua T. Breeding waterbird populations have declined in south San Francisco Bay: An assessment over two decades
In south San Francisco Bay, former salt ponds now managed as wildlife habitat support large populations of breeding waterbirds. In 2006, the South Bay Salt Pond Restoration Project began the process of converting 50% to 90% of these managed pond habitats into tidal marsh. We compared American Avocet (Recurvirostra americana) and Black-necked Stilt...
Hartman, C. Alex; Ackerman, Joshua T.; Schacter, Carley Rose; Herzog, Mark P.; Tarjan, Max; Wang, Yiwei; Strong, Cheryl; Tertes, Rachel; Warnock, Nils Informing wetland management with waterfowl movement and sanctuary use responses to human-induced disturbance
Long-term environmental management to prevent waterfowl population declines is informed by ecology, movement behavior and habitat use patterns. Extrinsic factors, such as human-induced disturbance, can cause behavioral changes which may influence movement and resource needs, driving variation that affects management efficacy. To better...
McDuie, Fiona; Lorenz, Austen; Klinger, Robert C.; Overton, Cory T.; Feldheim, Cliff L.; Ackerman, Joshua T.; Casazza, Michael L. Nocturnal incubation recess and flushing behavior by duck hens
Incubating birds must balance the needs of their developing embryos with their own physiological needs, and many birds accomplish this by taking periodic breaks from incubation. Mallard (Anas platyrhynchos) and gadwall (Mareca strepera) hens typically take incubation recesses in the early morning and late afternoon, but recesses can also take...
Croston, Rebecca; Peterson, Sarah H.; Hartman, C. Alex; Herzog, Mark P.; Feldheim, Cliff L.; Casazza, Michael L.; Ackerman, Joshua T. Demethylation of methylmercury in bird, fish, and earthworm
Toxicity of methylmercury (MeHg) to wildlife and humans results from its binding to cysteine residues of proteins, forming MeHg-cysteinate (MeHgCys) complexes that hinder biological functions. MeHgCys complexes can be detoxified in vivo, yet how this occurs is unknown. We report that MeHgCys complexes are transformed into selenocysteinate (Hg(Sec)...
Manceau, Alain; Bourdineaud, Jean-Paul; Oliveira, Ricardo B.; Sarrazin, Sandra LF; Krabbenhoft, David P.; Eagles-Smith, Collin; Ackerman, Joshua T.; Stewart, Robin; Ward-Deitrich, Christian; del Castillo Busto, M Estela; Goenaga-Infante, Heidi; Wack, Aude; Retegan, Marius; Detlefs, Blanka; Glatzel, Pieter; Bustamante, Paco; Nagy, Kathryn L.; Poulin, Brett Foraging in marine habitats increases mercury concentrations in a generalist seabird
Methylmercury concentrations vary widely across geographic space and among habitat types, with marine and aquatic-feeding organisms typically exhibiting higher mercury concentrations than terrestrial-feeding organisms. However, there are few model organisms to directly compare mercury concentrations as a result of foraging in marine,...
Clatterbuck, Corey A.; Lewison, Rebecca L.; Orben, Rachael A; Ackerman, Joshua T.; Torres, Leigh G; Suryan, Robert M.; Warzybok, Peter; Jahncke, Jaime; Shaffer, Scott A. Isotope fractionation from In Vivo methylmercury detoxification in waterbirds
The robust application of stable mercury (Hg) isotopes for mercury source apportionment and risk assessment necessitates the understanding of mass-dependent fractionation (MDF) due to internal transformations within organisms. Here, we used high energy-resolution XANES spectroscopy and isotope ratios of total mercury (δ202THg) and methylmercury (...
Poulin, Brett; Janssen, Sarah Elizabeth; Rosera, Tylor; Krabbenhoft, David P.; Eagles-Smith, Collin; Ackerman, Joshua T.; Stewart, Robin; Kim, Eunhee; Baumann, Zofia; Kim, Jeong-Hoon; Manceau, Alain Interrupted incubation: How dabbling ducks respond when flushed from the nest
Nesting birds must provide a thermal environment sufficient for egg development while also meeting self‐maintenance needs. Many birds, particularly those with uniparental incubation, achieve this balance through periodic incubation recesses, during which foraging and other self‐maintenance activities can occur. However, incubating birds may...
Croston, Rebecca; Hartman, C. Alex; Herzog, Mark P.; Peterson, Sarah H.; Kohl, Jeffrey; Overton, Cory T.; Feldheim, Cliff L.; Casazza, Michael L.; Ackerman, Joshua T. Waterfowl use of wetland habitats informs wetland restoration designs for multi‐species benefits
Extensive global estuarine wetland losses have prompted intensive focus on restoration of these habitats. In California, substantial tracts of freshwater, brackish and tidal wetlands have been lost. Given the anthropogenic footprint of development and urbanization in this region, wetland restoration must rely on conversion of existing habitat...
Casazza, Michael L.; McDuie, Fiona; Jones, Scott; Lorenz, Austen; Overton, Cory T.; Yee, Julie L.; Feldheim, Cliff L.; Ackerman, Joshua T.; Thorne, Karen M. Mercury exposure in mammalian mesopredators inhabiting a brackish marsh
Bioaccumulation of environmental contaminants in mammalian predators can serve as an indicator of ecosystem health. We examined mercury concentrations of raccoons (Procyon lotor; n = 37 individuals) and striped skunks (Mephitis mephitis; n = 87 individuals) in Suisun Marsh, California, a large brackish marsh that is characterized by...
Peterson, Sarah H.; Ackerman, Joshua T.; Hartman, C. Alex; Casazza, Michael L.; Feldheim, Cliff L.; Herzog, Mark P. Ecological insights from three decades of animal movement tracking across a changing Arctic
The Arctic is entering a new ecological state, with alarming consequences for humanity. Animal-borne sensors offer a window into these changes. Although substantial animal tracking data from the Arctic and subarctic exist, most are difficult to discover and access. Here, we present the new Arctic Animal Movement Archive (AAMA), a growing...
Davidson, Sarah C; Bohrer, Gil; Gurarie, Eliezer; LaPoint, Scott; Mahoney, Peter J; Boelman, Natalie; Eitel, Jan UH; Prugh, Laura R.; Vierling, Lee A.; Jennewein, Jyoti; Grier, Emma; Couriot, Ophélie; Kelly, Allicia P; Meddens, Arjan JH; Oliver, Ruth Y; Kays, Roland; Wikelski, Martin; Aarvak, Tomas; Ackerman, Joshua T.; Almeida e Silva, Mónica; Alves, José A.; Bayne, Erin; Bedrosian, Bryan; Belant, Jerrold L.; Berdahl, Andrew M; Berlin, Alicia; Berteaux, Dominique; Bêty, Joël; Boiko, Dmitrij; Booms, Travis L.; Borg, Bridget L; Boutin, Stan; Boyd, W Sean; Brides, Kane; Brown, Stephen C.; Bulyuk, Victor N.; Burnham, Kurt K; Cabot, David; Casazza, Michael L.; Christie, Katherine S.; Craig, Erica H.; Davis, Shanti E.; Davison, Tracy; Demma, Dominic; DeSorbo, Christopher R.; Dixon, Andrew E.; Domenech, Robert; Eichhorn, Götz; Elliott, Kyle; Evenson, Joseph R.; Exo, Klaus-Michael; Ferguson, Steven; Fiedler, Wolfgang; Fisk, Aaron T.; Fort, J.; Franke, Alastair; Fuller, Mark R.; Garthe, Stefan; Gauthier, Gilles; Gilchrist, Grant; Glazov, Petr; Gray, Carrie E.; Grémillet, David; Griffin, Larry; Hallworth, Mike; Harrison, Autumn-Lynn; Hennin, Holly; Hipfner, J Mark; Hodson, James; Johnson, James A.; Joly, Kyle; Jones, Kimberly; Katzner, Todd E.; Kidd, Jeff W; Knight, Elly; Kochert, Michael N.; Kölzsch, Andrea; Kruckenberg, Helmut; Lagassé, Benjamin J; Lai, Sandra; Lamarre, Jean-François; Lanctot, Richard B.; Larter, Nicholas C; Latham, A David; Latty, Christopher J.; Lawler, James P.; Léandri-Breton, Don-Jean; Lee, Hansoo; Lewis, Stephen B.; Love, Oliver P.; Madsen, Jesper; Maftei, Mark; Mallory, Mark L.; Mangipane, Buck; Markovets, Mikhail Y.; Marra, Peter P.; McGuire, Rebecca L; McIntyre, Carol; McKinnon, Emily A; Miller, Tricia A.; Moonen, Sander; Mu, Tong; Müskens, Gerhard JDM; Ng, Janet; Nicholson, Kerry L; Jostein Øien, Ingar; Overton, Cory T.; Owen, Patricia A; Patterson, Allison G. L.; Petersen, Aevar; Pokrovsky, Ivan; Powell, Luke L.; Prieto, Rui; Quillfeldt, Petra; Rausch, Jennie; Russell, Kelsey; Saalfeld, Sarah T.; Schekkerman, Hans; Schmutz, Joel A.; Schwemmer, Philipp; Seip, Dale R.; Shreading, Adam; Silva, Mónica A.; Smith, Brian W.; Smith, Fletcher; Smith, Jeff P.; Snell, Katherine RS; Sokolov, Aleksandr; Sokolov, Vasiliy; Solovyeva, Diana V; Sorum, Mathew S; Tertitski, Grigori; Therrien, J F; Thorup, Kasper; Tibbitts, Lee; Tulp, Ingrid; Uher-Koch, Brian D.; van Bemmelen, Rob SA; Van Wilgenburg, Steve; Von Duyke, Andrew L.; Watson, Jesse; Watts, Bryan D; Williams, Judy A; Wilson, Matthew; Wright, Jay; Yates, Michael A; Yurkowski, David; Žydelis, Ramūnas; Hebblewhite, Mark
Establishing Forster's Tern Nesting Colonies
Scientists from the USGS Western Ecological Research Center (WERC) are conducting a "social attraction" study for seabirds in the Don Edwards San Francisco Bay National Wildlife Refuge. Historically, this region offered wetland habitats to local wildlife. With the introduction of industrial salt ponds and human development, however, much of this habitat was lost. Now,
Research Spotlight: High Salinity and Limited Wetlands Reduce Duckling Habitat for Waterfowl
A new publication by USGS scientists examines wetland availability and salinity in Suisun Marsh, with particular focus on the implications for young ducklings with low salinity tolerance. The results indicated that a majority of wetland area in Suisun Marsh has salinity concentrations high enough to have detrimental effects on duckling growth and survival.
Research Spotlight: New Study Explores Nocturnal Nest Breaks and Predation Events for Dabbling Ducks
A new study by USGS scientists, in collaboration with the California Department of Water Resources and California Department of Fish and Wildlife, examined whether female ducks (hens) in Suisun Marsh, California leave their nest at night voluntarily or in response to a predator. They find that most nest breaks at night are initiated by the hen, but a quarter of nest departures are the result...
Isotope Fractionation from In Vivo Methylmercury Detoxification in Waterbirds
Animals that are higher on the trophic chain, such as waterbirds that primarily rely on fish, are at risk for ingesting methylmercury in their diet, which is then stored in their tissues and cycles through their organs.
Research Spotlight: Precise Eggshell Thickness Measurements To Inform Bird Ecology And Mercury Monitoring
In a study published in the journal Ecology and Evolution, USGS biologists provide precise eggshell thickness measurements for 12 species of birds that breed in the San Francisco Bay Estuary.
Research Spotlight: Wetland Habitats and Aquatic Prey May Drive High Hair Mercury Concentrations in Suisun Marsh Raccoons
A new study by scientists from USGS in collaboration with the California Department of Water Resources has found that mercury concentrations detected in hair of raccoons living in Suisun Marsh, California are some of the highest levels observed in raccoons and for wild mammals overall.
Research Spotlight: Mercury Exposure in Wild Songbirds Associated with Disrupted Parental Care at the Nest
In a study published in the journal Environmental Science and Technology, U.S. Geological Survey biologists report that methylmercury concentrations in wild tree swallows (Tachycineta bicolor) in the California Central Valley are associated with disruption of parental care.
Research Spotlight: Ducklings Leave Nests in Early Morning, Suggesting Predator Avoidance
In a study published in the journal Ecology and Evolution, U.S. Geological Survey (USGS) biologists put small cameras next to duck nests to determine what time of day wild ducklings began hatching, when the hen and ducklings departed the nest, and if any predators came to the nest when ducklings were present.
Research Spotlight: New Guidelines and Tool for Assessing Mercury Contamination Using Bird Feathers
In a study published in the journal Environmental Toxicology and Chemistry, U.S. Geological Survey (USGS) biologists provide a detailed approach and guidelines for using bird feathers in mercury monitoring programs. From these results, USGS biologists were able to create a tool to help guide the appropriate experimental design, processing and mercury determination for feather mercury studies...
USGS Scientists Find Success in New "Real Estate" for Waterbirds
There’s hot new real estate for wildlife in south San Francisco Bay, and a report from USGS biologists shows that the waterbirds are flocking in.
Reducing Mercury Loads in The Cosumnes River
The Cosumnes River watershed has seasonal, non-point source hotspots for total mercury and methylmercury production, which discharge to the Sacramento-San Joaquin River Delta in north-central California. To reduce mercury loads to the Delta, researchers created open-water deep cells at the downstream end of wetlands.
Mercury Found in Birds Across Western North America
A recent landscape-scale study has documented mercury in birds throughout western North America, identifying hotspots and large-scale ecological attributes that influence mercury exposure and accumulation in birds.