James J Willacker, Jr.
I am an Ecologist specializing in aquatic and trophic ecology at the USGS Forest and Rangeland Ecosystem Science Center in Corvallis, OR
I am broadly interested in aquatic ecology and in particular the application of trophic ecology to questions of ecotoxicology, evolution, physiology, and conservation biology. My current research focuses on understanding the interplay among ecological, biogeochemical, and physiological processes that govern contaminant accumulation in biota, particularly fishes and other aquatic taxa. My work is also aimed at quantifying ecological risk and toxicological impacts associated with contaminants, particularly mercury.
Professional Experience
2013 - Present: Ecologist, USGS Forest and Rangeland Ecosystem Science Center, Corvallis, OR
2009 - 2013: Doctoral Researcher, University of Alaska Fairbanks, Fairbanks, AK
2009 - 2012: Instructor, Alaska Community Action on Toxics, Anchorage, AK
2007 - 2009: Aquatic Ecologist, Environmental and Natural Resource Institute, Anchorage, AK
Education and Certifications
Ph.D., Biological Sciences, University of Alaska, Fairbanks, AK (2013)
M.S., Biological Sciences, University of Alaska, Anchorage, AK (2009)
B.S., Environmental and Forest Biology- Summa cum laude, State University of New York College of Environmental Science and Forestry (2006)
Honors and Awards
Outstanding Graduate Researcher Award, Environment and Natural Resources Institute, University of Alaska, Anchorage, AK. (2011)
Valedictorian, SUNY ESF (2007)
University Scholar, SUNY (2007)
Faculty Honors, Department of Environmental and Forest Biology, SUNY ESF (2007)
Robin Hood Oak Award, SUNY ESF (2006)
Science and Products
If you are unable to access or download a product, email fresc_outreach@usgs.gov a request, including the full citation, or call (541) 750-1030.
Filter Total Items: 31
In-reservoir physical processes modulate aqueous and biological methylmercury export from a seasonally anoxic reservoir In-reservoir physical processes modulate aqueous and biological methylmercury export from a seasonally anoxic reservoir
Anoxic conditions within reservoirs related to thermal stratification and oxygen depletion lead to methylmercury (MeHg) production, a key process governing the uptake of mercury in aquatic food webs. Once formed within a reservoir, the timing and magnitude of the biological uptake of MeHg and the relative importance of MeHg export in water versus biological compartments remain poorly...
Authors
Austin Baldwin, Collin A. Eagles-Smith, James Willacker, Brett Poulin, David Krabbenhoft, Jesse Naymik, Michael T. Tate, Dain Bates, Nick Gastelecutto, Charles Hoovestol, Christopher Larsen, Alysa Yoder, James Chandler, Ralph Myers
Small mammal shooting as a conduit for lead exposure in avian scavengers Small mammal shooting as a conduit for lead exposure in avian scavengers
Lead (Pb) exposure is a widespread wildlife conservation threat. Although commonly associated with Pb-based ammunition from big-game hunting, small mammals (e.g., ground squirrels) shot for recreational or pest-management purposes represent a potentially important Pb vector in agricultural regions. We measured the responses of avian scavengers to pest-shooting events and examined their...
Authors
Garth Herring, Collin A. Eagles-Smith, John Goodell, Jeremy Buck, James Willacker
Fish habitat use and food web structure following pond and plug restoration of a Montane Meadow in the Sierra Nevada, California Fish habitat use and food web structure following pond and plug restoration of a Montane Meadow in the Sierra Nevada, California
Montane meadows are areas of high biodiversity and provide many important ecosystem services; however, degradation of 40–60% of these habitats in the Sierra Nevada region of California has left many of these areas impaired. The “pond-and-plug” meadow-restoration technique is 1 type of treatment implemented to restore montane meadows. The objectives of this technique are to re-water the...
Authors
Lora Tennant, Collin A. Eagles-Smith, James Willacker, Matthew Johnson
A national-scale assessment of mercury bioaccumulation in United States National Parks using dragonfly larvae as biosentinels through a citizen-science framework A national-scale assessment of mercury bioaccumulation in United States National Parks using dragonfly larvae as biosentinels through a citizen-science framework
We conducted a national-scale assessment of mercury (Hg) bioaccumulation in aquatic ecosystems using dragonfly larvae as biosentinels, by developing a citizen science network to facilitate biological sampling. Implementing a carefully designed sampling methodology for citizen scientists, we developed an effective framework for landscape-level inquiry that might otherwise be resource...
Authors
Collin A. Eagles-Smith, James Willacker, Sarah Nelson, Collen Flanagan Pritz, David Krabbenhoft, Celia Chen, Joshua T. Ackerman, Evan Campbell Grant, David Pilliod
Mercury bioaccumulation in freshwater fishes of the Chesapeake Bay watershed Mercury bioaccumulation in freshwater fishes of the Chesapeake Bay watershed
Chemical contaminants are a threat to the Chesapeake Bay watershed, with mercury (Hg) among the most prevalent causes of impairment. Despite this, large-scale patterns of Hg concentrations, and the potential risks to fish, wildlife, and humans across the watershed, are poorly understood. We compiled fish Hg data from state monitoring programs and recent research efforts to address this...
Authors
James Willacker, Collin A. Eagles-Smith, Vicki S. Blazer
Mercury and selenium concentrations in fishes of the Upper Colorado River Basin, southwestern United States: A retrospective assessment Mercury and selenium concentrations in fishes of the Upper Colorado River Basin, southwestern United States: A retrospective assessment
Mercury (Hg) and selenium (Se) are contaminants of concern for fish in the Upper Colorado River Basin (UCRB). We explored Hg and Se in fish tissues (2,324 individuals) collected over 50 years (1962–2011) from the UCRB. Samples include native and non-native fish collected from lotic waterbodies spanning 7 major tributaries to the Colorado River. There was little variation of total mercury...
Authors
Natalie Day, Travis Schmidt, James Roberts, Barbara C. Osmundson, James Willacker, Collin A. Eagles-Smith
Timber harvest alters mercury bioaccumulation and food web structure in headwater streams Timber harvest alters mercury bioaccumulation and food web structure in headwater streams
Timber harvest has many effects on aquatic ecosystems, including changes in hydrological, biogeochemical, and ecological processes that can influence mercury (Hg) cycling. Although timber harvest’s influence on aqueous Hg transformation and transport are well studied, the effects on Hg bioaccumulation are not. We evaluated Hg bioaccumulation, biomagnification, and food web structure in...
Authors
James Willacker, Collin Eagles-Smith, Brandon M Kowalski, Robert Danehy, Allyson K. Jackson, Evan Adams, David Evers, Chris Eckley, Michael T. Tate, David Krabbenhoft
Mercury bioaccumulation in estuarine fishes: Novel insights from sulfur stable isotopes Mercury bioaccumulation in estuarine fishes: Novel insights from sulfur stable isotopes
Estuaries are transitional habitats characterized by complex biogeochemical and ecological gradients that result in substantial variation in fish total mercury concentrations (THg). We leveraged these gradients and used carbon (δ13C), nitrogen (δ15N), and sulfur (δ34S) stable isotopes to examine the ecological and biogeochemical processes underlying THg bioaccumulation in fishes from the...
Authors
James Willacker, Collin Eagles-Smith, Joshua T. Ackerman
Reservoirs and water management influence fish mercury concentrations in the western United States and Canada Reservoirs and water management influence fish mercury concentrations in the western United States and Canada
Anthropogenic manipulation of aquatic habitats can profoundly alter mercury (Hg) cycling and bioaccumulation. The impoundment of fluvial systems is among the most common habitat manipulations and is known to increase fish Hg concentrations immediately following impoundment. However, it is not well understood how Hg concentrations differ between reservoirs and lakes at large spatial and...
Authors
James Willacker, Collin Eagles-Smith, Michelle Lutz, Michael T. Tate, Jesse Lepak, Joshua T. Ackerman
Assessing potential health risks to fish and humans using mercury concentrations in inland fish from across western Canada and the United States Assessing potential health risks to fish and humans using mercury concentrations in inland fish from across western Canada and the United States
Fish represent high quality protein and nutrient sources, but Hg contamination is ubiquitous in aquatic ecosystems and can pose health risks to fish and their consumers. Potential health risks posed to fish and humans by Hg contamination in fish were assessed in western Canada and the United States. A large compilation of inland fish Hg concentrations was evaluated in terms of potential...
Authors
Jesse Lepak, Mevin Hooten, Collin Eagles-Smith, Michael T. Tate, Michelle A. Lutz, Joshua T. Ackerman, James Willacker, Allyson Jackson, David Evers, James Wiener, Colleen Pritz, Jay Davis
Mercury risk to avian piscivores across western United States and Canada Mercury risk to avian piscivores across western United States and Canada
The widespread distribution of mercury (Hg) threatens wildlife health, particularly piscivorous birds. Western North America is a diverse region that provides critical habitat to many piscivorous bird species, and also has a well-documented history of mercury contamination from legacy mining and atmospheric deposition. The diversity of landscapes in the west limits the distribution of...
Authors
Allyson K. Jackson, David Evers, Collin Eagles-Smith, Joshua T. Ackerman, James Willacker, John E. Elliott, Jesse Lepak, Stacy Vander Pol, Colleen Bryan
Mercury in western North America: A synthesis of environmental contamination, fluxes, bioaccumulation, and risk to fish and wildlife Mercury in western North America: A synthesis of environmental contamination, fluxes, bioaccumulation, and risk to fish and wildlife
Western North America is a region defined by extreme gradients in geomorphology and climate, which support a diverse array of ecological communities and natural resources. The region also has extreme gradients in mercury (Hg) contamination due to a broad distribution of inorganic Hg sources. These diverse Hg sources and a varied landscape create a unique and complex mosaic of ecological...
Authors
Collin Eagles-Smith, James Wiener, Chris Eckley, James Willacker, David Evers, Mark Marvin-DiPasquale, Daniel Obrist, Jacob Fleck, George Aiken, Jesse Lepak, Allyson K. Jackson, Jackson Webster, A. Stewart, Jay Davis, Charles Alpers, Joshua T. Ackerman
Non-USGS Publications**
Willacker Jr., J.J., Sobczak, W.V., Colburn, E.A., 2009, Stream macroinvertebrate communities in paired hemlock and deciduous watersheds: Northeastern Naturalist, v. 16, no. 1, p. 101-112, https://doi.org/10.1656/045.016.0108.
Willacker Jr., J.J., von Hippel, F.A., Wilton, P.R., Walton, K.M., 2010, Classification of threespine stickleback along the benthic–limnetic axis: Biological Journal of the Linnean Society, v. 101, p. 595-608, https://doi.org/10.1111/j.1095-8312.2010.01531.x.
Kenney, L.A., von Hippel, F.A., Willacker Jr., J.J., O'Hara, T.M., 2012, Mercury concentrations of a resident freshwater forage fish at Adak Island, Aleutian Archipelago, Alaska: Environmental Toxicology and Chemistry, v. 31, no. 11, p. 2647-2652, https://doi.org/10.1002/etc.1990.
Walton, K.M., Spalinger, D.E., Harris, N.R., Collins, W.B., Willacker Jr., J.J., 2013, High spatial resolution vegetation mapping for assessment of wildlife habitat: Wildlife Society Bulletin, v. 37, no. 4, p. 906-915, https://doi.org/10.1002/wsb.344.
Willacker Jr., J.J., von Hippel, F.A., Ackerly, K.L., O'Hara, T.M., 2013, Habitat-specific foraging and sex determine mercury concentrations in sympatric benthic and limnetic ecotypes of threespine stickleback: Environmental Toxicology and Chemistry, v. 32, no. 7, p. 1623-1630, https://doi.org/10.1002/etc.2213.
Shedd, K.R., F.A. von Hippel, J.J. Willacker, T.R. Hamon, O.L. Schlei, J.K. Wenburg, J.L. Miller, and S.A. Pavey. 2015. Ecological release leads to novel ontogenetic diet shift in kokanee (Oncorhynchus nerka). Canadian Journal of Fisheries and Aquatic Sciences 72: 1718-1730.
Willacker, J.J. 2013. Ecological drivers of mercury accumulation in Threespine Stickleback fish. Doctor of Philosophy, University of Alaska Fairbanks, Fairbanks, AK, USA.
Willacker, J.J. 2009. Geometric morphometrics of Threespine Stickleback in the Cook Inlet Basin, Alaska. Master of Science, University of Alaska Anchorage, Anchorage, AK, USA.
Willacker, J.J., D. Rinella, and D. Bogan. 2008. Aquatic macroinvertebrate and diatom surveys in Tetlin National Wildlife Refuge, AK. Environmental and Natural Resources Institute Annual Progress Report to the U.S. Fish and Wildlife Service.
Willacker, J.J., D. Rinella, and D. Bogan. 2007. Macroinvertebrate abundance in the Eklutna River, AK: an estimate of food supply for rearing salmonids. Environmental and Natural Resources Institute Final Report to the Eklutna River Restoration Project, U.S. Army Corps of Engineers.
**Disclaimer: The views expressed in Non-USGS publications are those of the author and do not represent the views of the USGS, Department of the Interior, or the U.S. Government.
If you are unable to access or download a product, email fresc_outreach@usgs.gov a request, including the full citation, or call (541) 750-1030.
Filter Total Items: 15
Total Mercury Concentrations in Smallmouth Bass from Chesapeake Bay Tributaries, USA Dataset, 2013-2017 Total Mercury Concentrations in Smallmouth Bass from Chesapeake Bay Tributaries, USA Dataset, 2013-2017
This dataset includes fish scientific name, fish common name, site identification codes, latitude, longitude, site name, sample identification codes, collection date, tissue type, percent moisture content in fish samples, and wet and dry total mercury concentrations in fish tissues.
Fish tissue mercury and selenium concentrations in Upper Colorado River Basin: 1962-2011 Fish tissue mercury and selenium concentrations in Upper Colorado River Basin: 1962-2011
These data were compiled to study mercury and selenium concentrations in fish species and assemblages in lotic waterbodies across the Upper Colorado River Basin. Data were compiled from State and Federal agencies. This data table contains raw concentration data, as well as standardized concentrations corrected for differences based on sample type (i.e., tissue type), species-specific
Trask River Watershed Study Area Forestry Bioaccumulation Dataset, 2011-2015 Trask River Watershed Study Area Forestry Bioaccumulation Dataset, 2011-2015
This dataset includes timber harvest treatments; mercury concentrations in aquatic macroinvertebrates, salamanders, and riparian songbirds; carbon and nitrogen stable isotopes in aquatic macroinvertebrates and salamanders; and Bayesian estimates of food web length, basal resource diversity, and isotopic niche size for individual feeding guilds.
Science and Products
If you are unable to access or download a product, email fresc_outreach@usgs.gov a request, including the full citation, or call (541) 750-1030.
Filter Total Items: 31
In-reservoir physical processes modulate aqueous and biological methylmercury export from a seasonally anoxic reservoir In-reservoir physical processes modulate aqueous and biological methylmercury export from a seasonally anoxic reservoir
Anoxic conditions within reservoirs related to thermal stratification and oxygen depletion lead to methylmercury (MeHg) production, a key process governing the uptake of mercury in aquatic food webs. Once formed within a reservoir, the timing and magnitude of the biological uptake of MeHg and the relative importance of MeHg export in water versus biological compartments remain poorly...
Authors
Austin Baldwin, Collin A. Eagles-Smith, James Willacker, Brett Poulin, David Krabbenhoft, Jesse Naymik, Michael T. Tate, Dain Bates, Nick Gastelecutto, Charles Hoovestol, Christopher Larsen, Alysa Yoder, James Chandler, Ralph Myers
Small mammal shooting as a conduit for lead exposure in avian scavengers Small mammal shooting as a conduit for lead exposure in avian scavengers
Lead (Pb) exposure is a widespread wildlife conservation threat. Although commonly associated with Pb-based ammunition from big-game hunting, small mammals (e.g., ground squirrels) shot for recreational or pest-management purposes represent a potentially important Pb vector in agricultural regions. We measured the responses of avian scavengers to pest-shooting events and examined their...
Authors
Garth Herring, Collin A. Eagles-Smith, John Goodell, Jeremy Buck, James Willacker
Fish habitat use and food web structure following pond and plug restoration of a Montane Meadow in the Sierra Nevada, California Fish habitat use and food web structure following pond and plug restoration of a Montane Meadow in the Sierra Nevada, California
Montane meadows are areas of high biodiversity and provide many important ecosystem services; however, degradation of 40–60% of these habitats in the Sierra Nevada region of California has left many of these areas impaired. The “pond-and-plug” meadow-restoration technique is 1 type of treatment implemented to restore montane meadows. The objectives of this technique are to re-water the...
Authors
Lora Tennant, Collin A. Eagles-Smith, James Willacker, Matthew Johnson
A national-scale assessment of mercury bioaccumulation in United States National Parks using dragonfly larvae as biosentinels through a citizen-science framework A national-scale assessment of mercury bioaccumulation in United States National Parks using dragonfly larvae as biosentinels through a citizen-science framework
We conducted a national-scale assessment of mercury (Hg) bioaccumulation in aquatic ecosystems using dragonfly larvae as biosentinels, by developing a citizen science network to facilitate biological sampling. Implementing a carefully designed sampling methodology for citizen scientists, we developed an effective framework for landscape-level inquiry that might otherwise be resource...
Authors
Collin A. Eagles-Smith, James Willacker, Sarah Nelson, Collen Flanagan Pritz, David Krabbenhoft, Celia Chen, Joshua T. Ackerman, Evan Campbell Grant, David Pilliod
Mercury bioaccumulation in freshwater fishes of the Chesapeake Bay watershed Mercury bioaccumulation in freshwater fishes of the Chesapeake Bay watershed
Chemical contaminants are a threat to the Chesapeake Bay watershed, with mercury (Hg) among the most prevalent causes of impairment. Despite this, large-scale patterns of Hg concentrations, and the potential risks to fish, wildlife, and humans across the watershed, are poorly understood. We compiled fish Hg data from state monitoring programs and recent research efforts to address this...
Authors
James Willacker, Collin A. Eagles-Smith, Vicki S. Blazer
Mercury and selenium concentrations in fishes of the Upper Colorado River Basin, southwestern United States: A retrospective assessment Mercury and selenium concentrations in fishes of the Upper Colorado River Basin, southwestern United States: A retrospective assessment
Mercury (Hg) and selenium (Se) are contaminants of concern for fish in the Upper Colorado River Basin (UCRB). We explored Hg and Se in fish tissues (2,324 individuals) collected over 50 years (1962–2011) from the UCRB. Samples include native and non-native fish collected from lotic waterbodies spanning 7 major tributaries to the Colorado River. There was little variation of total mercury...
Authors
Natalie Day, Travis Schmidt, James Roberts, Barbara C. Osmundson, James Willacker, Collin A. Eagles-Smith
Timber harvest alters mercury bioaccumulation and food web structure in headwater streams Timber harvest alters mercury bioaccumulation and food web structure in headwater streams
Timber harvest has many effects on aquatic ecosystems, including changes in hydrological, biogeochemical, and ecological processes that can influence mercury (Hg) cycling. Although timber harvest’s influence on aqueous Hg transformation and transport are well studied, the effects on Hg bioaccumulation are not. We evaluated Hg bioaccumulation, biomagnification, and food web structure in...
Authors
James Willacker, Collin Eagles-Smith, Brandon M Kowalski, Robert Danehy, Allyson K. Jackson, Evan Adams, David Evers, Chris Eckley, Michael T. Tate, David Krabbenhoft
Mercury bioaccumulation in estuarine fishes: Novel insights from sulfur stable isotopes Mercury bioaccumulation in estuarine fishes: Novel insights from sulfur stable isotopes
Estuaries are transitional habitats characterized by complex biogeochemical and ecological gradients that result in substantial variation in fish total mercury concentrations (THg). We leveraged these gradients and used carbon (δ13C), nitrogen (δ15N), and sulfur (δ34S) stable isotopes to examine the ecological and biogeochemical processes underlying THg bioaccumulation in fishes from the...
Authors
James Willacker, Collin Eagles-Smith, Joshua T. Ackerman
Reservoirs and water management influence fish mercury concentrations in the western United States and Canada Reservoirs and water management influence fish mercury concentrations in the western United States and Canada
Anthropogenic manipulation of aquatic habitats can profoundly alter mercury (Hg) cycling and bioaccumulation. The impoundment of fluvial systems is among the most common habitat manipulations and is known to increase fish Hg concentrations immediately following impoundment. However, it is not well understood how Hg concentrations differ between reservoirs and lakes at large spatial and...
Authors
James Willacker, Collin Eagles-Smith, Michelle Lutz, Michael T. Tate, Jesse Lepak, Joshua T. Ackerman
Assessing potential health risks to fish and humans using mercury concentrations in inland fish from across western Canada and the United States Assessing potential health risks to fish and humans using mercury concentrations in inland fish from across western Canada and the United States
Fish represent high quality protein and nutrient sources, but Hg contamination is ubiquitous in aquatic ecosystems and can pose health risks to fish and their consumers. Potential health risks posed to fish and humans by Hg contamination in fish were assessed in western Canada and the United States. A large compilation of inland fish Hg concentrations was evaluated in terms of potential...
Authors
Jesse Lepak, Mevin Hooten, Collin Eagles-Smith, Michael T. Tate, Michelle A. Lutz, Joshua T. Ackerman, James Willacker, Allyson Jackson, David Evers, James Wiener, Colleen Pritz, Jay Davis
Mercury risk to avian piscivores across western United States and Canada Mercury risk to avian piscivores across western United States and Canada
The widespread distribution of mercury (Hg) threatens wildlife health, particularly piscivorous birds. Western North America is a diverse region that provides critical habitat to many piscivorous bird species, and also has a well-documented history of mercury contamination from legacy mining and atmospheric deposition. The diversity of landscapes in the west limits the distribution of...
Authors
Allyson K. Jackson, David Evers, Collin Eagles-Smith, Joshua T. Ackerman, James Willacker, John E. Elliott, Jesse Lepak, Stacy Vander Pol, Colleen Bryan
Mercury in western North America: A synthesis of environmental contamination, fluxes, bioaccumulation, and risk to fish and wildlife Mercury in western North America: A synthesis of environmental contamination, fluxes, bioaccumulation, and risk to fish and wildlife
Western North America is a region defined by extreme gradients in geomorphology and climate, which support a diverse array of ecological communities and natural resources. The region also has extreme gradients in mercury (Hg) contamination due to a broad distribution of inorganic Hg sources. These diverse Hg sources and a varied landscape create a unique and complex mosaic of ecological...
Authors
Collin Eagles-Smith, James Wiener, Chris Eckley, James Willacker, David Evers, Mark Marvin-DiPasquale, Daniel Obrist, Jacob Fleck, George Aiken, Jesse Lepak, Allyson K. Jackson, Jackson Webster, A. Stewart, Jay Davis, Charles Alpers, Joshua T. Ackerman
Non-USGS Publications**
Willacker Jr., J.J., Sobczak, W.V., Colburn, E.A., 2009, Stream macroinvertebrate communities in paired hemlock and deciduous watersheds: Northeastern Naturalist, v. 16, no. 1, p. 101-112, https://doi.org/10.1656/045.016.0108.
Willacker Jr., J.J., von Hippel, F.A., Wilton, P.R., Walton, K.M., 2010, Classification of threespine stickleback along the benthic–limnetic axis: Biological Journal of the Linnean Society, v. 101, p. 595-608, https://doi.org/10.1111/j.1095-8312.2010.01531.x.
Kenney, L.A., von Hippel, F.A., Willacker Jr., J.J., O'Hara, T.M., 2012, Mercury concentrations of a resident freshwater forage fish at Adak Island, Aleutian Archipelago, Alaska: Environmental Toxicology and Chemistry, v. 31, no. 11, p. 2647-2652, https://doi.org/10.1002/etc.1990.
Walton, K.M., Spalinger, D.E., Harris, N.R., Collins, W.B., Willacker Jr., J.J., 2013, High spatial resolution vegetation mapping for assessment of wildlife habitat: Wildlife Society Bulletin, v. 37, no. 4, p. 906-915, https://doi.org/10.1002/wsb.344.
Willacker Jr., J.J., von Hippel, F.A., Ackerly, K.L., O'Hara, T.M., 2013, Habitat-specific foraging and sex determine mercury concentrations in sympatric benthic and limnetic ecotypes of threespine stickleback: Environmental Toxicology and Chemistry, v. 32, no. 7, p. 1623-1630, https://doi.org/10.1002/etc.2213.
Shedd, K.R., F.A. von Hippel, J.J. Willacker, T.R. Hamon, O.L. Schlei, J.K. Wenburg, J.L. Miller, and S.A. Pavey. 2015. Ecological release leads to novel ontogenetic diet shift in kokanee (Oncorhynchus nerka). Canadian Journal of Fisheries and Aquatic Sciences 72: 1718-1730.
Willacker, J.J. 2013. Ecological drivers of mercury accumulation in Threespine Stickleback fish. Doctor of Philosophy, University of Alaska Fairbanks, Fairbanks, AK, USA.
Willacker, J.J. 2009. Geometric morphometrics of Threespine Stickleback in the Cook Inlet Basin, Alaska. Master of Science, University of Alaska Anchorage, Anchorage, AK, USA.
Willacker, J.J., D. Rinella, and D. Bogan. 2008. Aquatic macroinvertebrate and diatom surveys in Tetlin National Wildlife Refuge, AK. Environmental and Natural Resources Institute Annual Progress Report to the U.S. Fish and Wildlife Service.
Willacker, J.J., D. Rinella, and D. Bogan. 2007. Macroinvertebrate abundance in the Eklutna River, AK: an estimate of food supply for rearing salmonids. Environmental and Natural Resources Institute Final Report to the Eklutna River Restoration Project, U.S. Army Corps of Engineers.
**Disclaimer: The views expressed in Non-USGS publications are those of the author and do not represent the views of the USGS, Department of the Interior, or the U.S. Government.
If you are unable to access or download a product, email fresc_outreach@usgs.gov a request, including the full citation, or call (541) 750-1030.
Filter Total Items: 15
Total Mercury Concentrations in Smallmouth Bass from Chesapeake Bay Tributaries, USA Dataset, 2013-2017 Total Mercury Concentrations in Smallmouth Bass from Chesapeake Bay Tributaries, USA Dataset, 2013-2017
This dataset includes fish scientific name, fish common name, site identification codes, latitude, longitude, site name, sample identification codes, collection date, tissue type, percent moisture content in fish samples, and wet and dry total mercury concentrations in fish tissues.
Fish tissue mercury and selenium concentrations in Upper Colorado River Basin: 1962-2011 Fish tissue mercury and selenium concentrations in Upper Colorado River Basin: 1962-2011
These data were compiled to study mercury and selenium concentrations in fish species and assemblages in lotic waterbodies across the Upper Colorado River Basin. Data were compiled from State and Federal agencies. This data table contains raw concentration data, as well as standardized concentrations corrected for differences based on sample type (i.e., tissue type), species-specific
Trask River Watershed Study Area Forestry Bioaccumulation Dataset, 2011-2015 Trask River Watershed Study Area Forestry Bioaccumulation Dataset, 2011-2015
This dataset includes timber harvest treatments; mercury concentrations in aquatic macroinvertebrates, salamanders, and riparian songbirds; carbon and nitrogen stable isotopes in aquatic macroinvertebrates and salamanders; and Bayesian estimates of food web length, basal resource diversity, and isotopic niche size for individual feeding guilds.