Josh T Ackerman
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.
Avian mercury exposure and toxicological risk across western North America: A synthesis
Avian mercury exposure and toxicological risk across western North America: A synthesis
Mercury contamination of birds is prevalent in many areas throughout western North America, and large-scale ecological attributes are important factors influencing bird mercury concentrations. This report synthesizes the available data on mercury contamination of birds in western North America.
Development of methylmercury toxicity reference values in birds
Development of methylmercury toxicity reference values in birds
Birds are used as bioindicators of environmental mercury contamination, and toxicity reference values are needed for injury assessments. We conducted a comprehensive review, summarized data from 168 studies, performed a series of meta-analyses, and developed new toxicity reference values for the effects of methylmercury on birds.
Josh's 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.
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
Education and Certifications
Ph.D. 2002, Ecology, University of California-Davis
B.S. 1997 (Magna Cum Laude), Wildlife, Fish, and Conservation Biology, University of California-Davis
Science and Products
Filter Total Items: 17
Filter Total Items: 40
No Result Found
Synthesis of maternal transfer of mercury in birds: Implications for altered toxicity risk
Maternal transfer is the predominant route of methylmercury (MeHg) exposure to offspring. We reviewed and synthesized published and unpublished data on maternal transfer of MeHg in birds. Using paired samples of females’ blood (n=564) and their eggs (n=1814) from 26 bird species in 6 taxonomic orders, we conducted a meta-analysis to evaluate whether maternal transfer of MeHg to eggs differed amo
Authors
Joshua T. Ackerman, Mark P. Herzog, David C. Evers, Daniel A. Cristol, Kevin P. Kenow, Gary Heinz, Raphael A Lavoie, Rebecka Brasso, Mark L. Mallory, Jennifer F Provencher, Birgit M Braune, Angela Matz, Joel A. Schmutz, Collin A. Eagles-Smith, Lucas J Savoy, Michael W. Meyer, C. Alex Hartman
Filter Total Items: 202
Spatial and temporal patterns of mercury concentrations in freshwater fish across the Western United States and Canada
Methylmercury contamination of fish is a global threat to environmental health. Mercury (Hg) monitoring programs are valuable for generating data that can be compiled for spatially broad syntheses to identify emergent ecosystem properties that influence fish Hg bioaccumulation. Fish total Hg (THg) concentrations were evaluated across the Western United States (US) and Canada, a region defined by e
Authors
Collin A. Eagles-Smith, Joshua T. Ackerman, James J. Willacker, Michael T. Tate, Michelle A. Lutz, Jacob Fleck, A. Robin Stewart, James G. Wiener, David C. Evers, Jesse M. Lepak, Jay A. Davis, Colleen Flanagan Pritz
Avian mercury exposure and toxicological risk across western North America: A synthesis
Methylmercury contamination of the environment is an important issue globally, and birds are useful bioindicators for mercury monitoring programs. The available data on mercury contamination of birds in western North America were synthesized. Original data from multiple databases were obtained and a literature review was conducted to obtain additional mercury concentrations. In total, 29219 origi
Authors
Joshua T. Ackerman, Collin A. Eagles-Smith, Mark P. Herzog, C. Alex Hartman, Sarah H. Peterson, David C. Evers, Allyson K. Jackson, John E. Elliott, Stacy S. Vander Pol, Colleen E. Bryan
Hg concentrations in fish from coastal waters of California and Western North America
The State of California conducted an extensive and systematic survey of mercury (Hg) in fish from the California coast in 2009 and 2010. The California survey sampled 3483 fish representing 46 species at 68 locations, and demonstrated that methylHg in fish presents a widespread exposure risk to fish consumers. Most of the locations sampled (37 of 68) had a species with an average concentration abo
Authors
Jay Davis, John Ross, Shira Bezalel, Lawrence Sim, Autumn Bonnema, Gary Ichikawa, Wes Heim, Kenneth C Schiff, Collin A. Eagles-Smith, Joshua T. Ackerman
Differentiating sex and species of Western Grebes (Aechmophorus occidentalis) and Clark's Grebes (Aechmophorus clarkii) and their eggs using external morphometrics and discriminant function analysis
In birds where males and females are similar in size and plumage, sex determination by alternative means is necessary. Discriminant function analysis based on external morphometrics was used to distinguish males from females in two closely related species: Western Grebe (Aechmophorus occidentalis) and Clark's Grebe (A. clarkii). Additionally, discriminant function analysis was used to evaluate mor
Authors
C. Alex Hartman, Joshua T. Ackerman, Collin A. Eagles-Smith, Mark P. Herzog
Evaluation of Caspian tern (Hydroprogne caspia) and snowy plover (Charadrius alexandrinus nivosus) nesting on modified islands at the Don Edwards San Francisco Bay National Wildlife Refuge, California—2015 Annual Report
Executive Summary
In order to address the 2008/10 NOAA Fisheries Biological Opinion for operation of the Federal Columbia River Power System, the U.S. Army Corps of Engineers (USACE) and the Bureau of Reclamation (Reclamation) have developed and begun implementation of Caspian tern (Hydroprogne caspia) management plans. This implementation includes relocating nesting Caspian terns out of the Colum
Authors
C. Alex Hartman, Joshua T. Ackerman, Mark P. Herzog, Cheryl Strong, David Trachtenbarg, Kimberley A. Sawyer, Crystal A. Shore
It’s what’s inside that counts: Egg contaminant concentrations are influenced by estimates of egg density, egg volume, and fresh egg mass
In egg contaminant studies, it is necessary to calculate egg contaminant concentrations on a fresh wet weight basis and this requires accurate estimates of egg density and egg volume. We show that the inclusion or exclusion of the eggshell can influence egg contaminant concentrations, and we provide estimates of egg density (both with and without the eggshell) and egg-shape coefficients (used to e
Authors
Mark P. Herzog, Joshua T. Ackerman, Collin A. Eagles-Smith, C. Alex Hartman
Maternal transfer of contaminants in birds: Mercury and selenium concentrations in parents and their eggs
We conducted a detailed assessment of the maternal transfer of mercury and selenium to eggs in three bird species (n = 107 parents and n = 339 eggs), and developed predictive equations linking contaminant concentrations in eggs to those in six tissues of the mother (blood, muscle, liver, kidney, breast feathers, and head feathers). Mercury concentrations in eggs were positively correlated with mer
Authors
Joshua T. Ackerman, Collin A. Eagles-Smith, Mark P. Herzog, C. Alex Hartman
Mercury correlations among blood, muscle, and hair of northern elephant seals during the breeding and molting fasts
Mercury (Hg) biomonitoring and toxicological risk assessments for marine mammals commonly sample different tissues, making comparisons to toxicity benchmarks and among species and regions difficult. Few studies have examined how life history events, such as fasting, influence the relationship between total Hg (THg) concentrations in different tissues. We evaluated the relationships between THg con
Authors
Sarah H. Peterson, Joshua T. Ackerman, Daniel P. Costa
Habitat edges have weak effects on duck nest survival at local spatial scales
Edge effects on nesting success have been documented in breeding birds in a variety of contexts, but there is still uncertainty in how edge type and spatial scale determine the magnitude and detectability of edge effects. Habitat edges are often viewed as predator corridors that surround or penetrate core habitat and increase the risk of predation for nearby nests. We studied the effects of three
Authors
Amelia J Raquel, Kevin M. Ringelman, Joshua T. Ackerman, John M. Eadie
Science foundation Chapter 5 Appendix 5.1: Case study dabbling ducks
Dabbling ducks are the most abundant group of waterfowl that overwinter in the shallow wetlands and ponds of San Francisco Bay (SFB). Species within this group are primarily omnivorous, feeding on both plant material and macroinvertebrate prey by “tipping” to access benthic foods in bottom sediments or by foraging in the water column. Although the majority of these ducks are migratory, smaller num
Authors
Gregory S. Yarris, Joshua T. Ackerman
Science foundation Chapter 5 Appendix 5.1: Case study diving ducks
Diving ducks are the most abundant group of waterfowl that overwinter in the open bays and ponds of San Francisco Bay (SFB). Species within this group are primarily benthivores that dive to obtain their macroinvertebrate prey in bottom sediments, although at times they may eat plant matter or forage in the water column. These migratory species include bay ducks (lesser scaup Aythya affinis, greate
Authors
John Y. Takekawa, Susan De La Cruz, Joshua T. Ackerman, Gregory S. Yarris
Science foundation Chapter 5 Appendix 5.1: Case study Forester's tern (Sterna forsteri) and California least tern (Sternula antillarum browni)
This case study considers two tern species that breed within the San Francisco Bay Estuary, Forster’s Terns (Sterna forsteri) and California Least Terns (Sternula antillarum browni). Forster’s Terns are medium-sized (140 g) terns that breed in coastal and interior marshes of North America. Forster’s Terns can exploit ephemeral habitats, and colony locations often move among years with change in ha
Authors
Joshua T. Ackerman, C. Alex Hartman, Cheryl Strong
Filter Total Items: 18
Science and Products
Filter Total Items: 17
Filter Total Items: 40
No Result Found
Synthesis of maternal transfer of mercury in birds: Implications for altered toxicity risk
Maternal transfer is the predominant route of methylmercury (MeHg) exposure to offspring. We reviewed and synthesized published and unpublished data on maternal transfer of MeHg in birds. Using paired samples of females’ blood (n=564) and their eggs (n=1814) from 26 bird species in 6 taxonomic orders, we conducted a meta-analysis to evaluate whether maternal transfer of MeHg to eggs differed amo
Authors
Joshua T. Ackerman, Mark P. Herzog, David C. Evers, Daniel A. Cristol, Kevin P. Kenow, Gary Heinz, Raphael A Lavoie, Rebecka Brasso, Mark L. Mallory, Jennifer F Provencher, Birgit M Braune, Angela Matz, Joel A. Schmutz, Collin A. Eagles-Smith, Lucas J Savoy, Michael W. Meyer, C. Alex Hartman
Filter Total Items: 202
Spatial and temporal patterns of mercury concentrations in freshwater fish across the Western United States and Canada
Methylmercury contamination of fish is a global threat to environmental health. Mercury (Hg) monitoring programs are valuable for generating data that can be compiled for spatially broad syntheses to identify emergent ecosystem properties that influence fish Hg bioaccumulation. Fish total Hg (THg) concentrations were evaluated across the Western United States (US) and Canada, a region defined by e
Authors
Collin A. Eagles-Smith, Joshua T. Ackerman, James J. Willacker, Michael T. Tate, Michelle A. Lutz, Jacob Fleck, A. Robin Stewart, James G. Wiener, David C. Evers, Jesse M. Lepak, Jay A. Davis, Colleen Flanagan Pritz
Avian mercury exposure and toxicological risk across western North America: A synthesis
Methylmercury contamination of the environment is an important issue globally, and birds are useful bioindicators for mercury monitoring programs. The available data on mercury contamination of birds in western North America were synthesized. Original data from multiple databases were obtained and a literature review was conducted to obtain additional mercury concentrations. In total, 29219 origi
Authors
Joshua T. Ackerman, Collin A. Eagles-Smith, Mark P. Herzog, C. Alex Hartman, Sarah H. Peterson, David C. Evers, Allyson K. Jackson, John E. Elliott, Stacy S. Vander Pol, Colleen E. Bryan
Hg concentrations in fish from coastal waters of California and Western North America
The State of California conducted an extensive and systematic survey of mercury (Hg) in fish from the California coast in 2009 and 2010. The California survey sampled 3483 fish representing 46 species at 68 locations, and demonstrated that methylHg in fish presents a widespread exposure risk to fish consumers. Most of the locations sampled (37 of 68) had a species with an average concentration abo
Authors
Jay Davis, John Ross, Shira Bezalel, Lawrence Sim, Autumn Bonnema, Gary Ichikawa, Wes Heim, Kenneth C Schiff, Collin A. Eagles-Smith, Joshua T. Ackerman
Differentiating sex and species of Western Grebes (Aechmophorus occidentalis) and Clark's Grebes (Aechmophorus clarkii) and their eggs using external morphometrics and discriminant function analysis
In birds where males and females are similar in size and plumage, sex determination by alternative means is necessary. Discriminant function analysis based on external morphometrics was used to distinguish males from females in two closely related species: Western Grebe (Aechmophorus occidentalis) and Clark's Grebe (A. clarkii). Additionally, discriminant function analysis was used to evaluate mor
Authors
C. Alex Hartman, Joshua T. Ackerman, Collin A. Eagles-Smith, Mark P. Herzog
Evaluation of Caspian tern (Hydroprogne caspia) and snowy plover (Charadrius alexandrinus nivosus) nesting on modified islands at the Don Edwards San Francisco Bay National Wildlife Refuge, California—2015 Annual Report
Executive Summary
In order to address the 2008/10 NOAA Fisheries Biological Opinion for operation of the Federal Columbia River Power System, the U.S. Army Corps of Engineers (USACE) and the Bureau of Reclamation (Reclamation) have developed and begun implementation of Caspian tern (Hydroprogne caspia) management plans. This implementation includes relocating nesting Caspian terns out of the Colum
Authors
C. Alex Hartman, Joshua T. Ackerman, Mark P. Herzog, Cheryl Strong, David Trachtenbarg, Kimberley A. Sawyer, Crystal A. Shore
It’s what’s inside that counts: Egg contaminant concentrations are influenced by estimates of egg density, egg volume, and fresh egg mass
In egg contaminant studies, it is necessary to calculate egg contaminant concentrations on a fresh wet weight basis and this requires accurate estimates of egg density and egg volume. We show that the inclusion or exclusion of the eggshell can influence egg contaminant concentrations, and we provide estimates of egg density (both with and without the eggshell) and egg-shape coefficients (used to e
Authors
Mark P. Herzog, Joshua T. Ackerman, Collin A. Eagles-Smith, C. Alex Hartman
Maternal transfer of contaminants in birds: Mercury and selenium concentrations in parents and their eggs
We conducted a detailed assessment of the maternal transfer of mercury and selenium to eggs in three bird species (n = 107 parents and n = 339 eggs), and developed predictive equations linking contaminant concentrations in eggs to those in six tissues of the mother (blood, muscle, liver, kidney, breast feathers, and head feathers). Mercury concentrations in eggs were positively correlated with mer
Authors
Joshua T. Ackerman, Collin A. Eagles-Smith, Mark P. Herzog, C. Alex Hartman
Mercury correlations among blood, muscle, and hair of northern elephant seals during the breeding and molting fasts
Mercury (Hg) biomonitoring and toxicological risk assessments for marine mammals commonly sample different tissues, making comparisons to toxicity benchmarks and among species and regions difficult. Few studies have examined how life history events, such as fasting, influence the relationship between total Hg (THg) concentrations in different tissues. We evaluated the relationships between THg con
Authors
Sarah H. Peterson, Joshua T. Ackerman, Daniel P. Costa
Habitat edges have weak effects on duck nest survival at local spatial scales
Edge effects on nesting success have been documented in breeding birds in a variety of contexts, but there is still uncertainty in how edge type and spatial scale determine the magnitude and detectability of edge effects. Habitat edges are often viewed as predator corridors that surround or penetrate core habitat and increase the risk of predation for nearby nests. We studied the effects of three
Authors
Amelia J Raquel, Kevin M. Ringelman, Joshua T. Ackerman, John M. Eadie
Science foundation Chapter 5 Appendix 5.1: Case study dabbling ducks
Dabbling ducks are the most abundant group of waterfowl that overwinter in the shallow wetlands and ponds of San Francisco Bay (SFB). Species within this group are primarily omnivorous, feeding on both plant material and macroinvertebrate prey by “tipping” to access benthic foods in bottom sediments or by foraging in the water column. Although the majority of these ducks are migratory, smaller num
Authors
Gregory S. Yarris, Joshua T. Ackerman
Science foundation Chapter 5 Appendix 5.1: Case study diving ducks
Diving ducks are the most abundant group of waterfowl that overwinter in the open bays and ponds of San Francisco Bay (SFB). Species within this group are primarily benthivores that dive to obtain their macroinvertebrate prey in bottom sediments, although at times they may eat plant matter or forage in the water column. These migratory species include bay ducks (lesser scaup Aythya affinis, greate
Authors
John Y. Takekawa, Susan De La Cruz, Joshua T. Ackerman, Gregory S. Yarris
Science foundation Chapter 5 Appendix 5.1: Case study Forester's tern (Sterna forsteri) and California least tern (Sternula antillarum browni)
This case study considers two tern species that breed within the San Francisco Bay Estuary, Forster’s Terns (Sterna forsteri) and California Least Terns (Sternula antillarum browni). Forster’s Terns are medium-sized (140 g) terns that breed in coastal and interior marshes of North America. Forster’s Terns can exploit ephemeral habitats, and colony locations often move among years with change in ha
Authors
Joshua T. Ackerman, C. Alex Hartman, Cheryl Strong
Filter Total Items: 18