Craig A Stricker, PhD
Craig Stricker is an ecologist at the Fort Collins Science Center that specializes in the application of chemical and isotopic tracers for addressing societally relevant questions related to ecosystem ecology. His research interests are focused on biogeochemistry, food webs, and animal resource allocation and movement.
Geology, Geophysics, and Geochemistry Stable Isotope Laboratory (GSIL)
Geology, Geophysics, and Geochemistry Stable Isotope Laboratory (GSIL)
The GSIL is a state-of-the-art facility located on the Denver Federal Center that specializes in the measurement of light stable isotope — Hydrogen (H), Carbon (C), Nitrogen (N), Oxygen (O), and Sulfur (S) — compositions and other chemical and biomarker analytes in matrices relevant to the Earth sciences.
Research Highlights
Research Highlights
- Continental-scale nutrient and contaminant delivery by Pacific salmon
- Diet and macronutrient assimilation in an Arctic predator
- Animal tracing with sulfur isotopes
- Effects of protein overconsumption limit dietary adaptation in an apex predator
- Carbon chemistry of peatlands in the southeastern USA
- Design, development, and implementation of IsoBank
- Diet energy density associated with survival, habitat, and population dynamics
As an ecologist at the Fort Collins Science Center, Craig Stricker’s research program focuses on an improved understanding of the roles of hydrology, biogeochemistry, and food web interactions on ecosystem structure and function with the goal of assisting land managers. His expertise in chemical and isotopic tracers offers novel insights in ecosystem ecology and has benefitted multidisciplinary collaborations across a variety of state, federal, and academic institutions. Tracer-based approaches to studying wildlife and ecosystems is a capability unique to Stricker’s research and the Fort Collins Science Center with examples ranging from wildlife nutrition, trophic dynamics, impacts of invasive species, animal movements and phenology, biogeochemistry, and environmental stressors such as fire and drought. The spatial domain of his work ranges from discrete habitats, regional assessments, to continental and oceanic basins, with studies from the sub-tropics to the high Arctic. Results of these projects inform on species life history and fitness to ecosystem health and function, but also offer frameworks for monitoring programs, model development, restoration, and risk assessment.
Professional Experience
2009 - Present, Research Biologist, US Geological Survey, Fort Collins Science Center
2005 - 2008, Research Biologist, US Geological Survey, Geologic Division - Crustal, Geology, and Geochemistry
2002 - 2004, Mendenhall Postdoctoral Fellow, US Geological Survey, Geologic Division - Crustal, Geology, and Geochemistry
Education and Certifications
PhD in Limnology, Michigan State University, 2003
MS in Aquatic Ecology, Central Michigan University, 1997
BS in Biology, Central Michigan University, 1994
Science and Products
Filter Total Items: 22
No Result Found
Filter Total Items: 86
Mercury cycling in agricultural and managed wetlands, Yolo Bypass, California: Spatial and seasonal variations in water quality Mercury cycling in agricultural and managed wetlands, Yolo Bypass, California: Spatial and seasonal variations in water quality
The seasonal and spatial variability of water quality, including mercury species, was evaluated in agricultural and managed, non-agricultural wetlands in the Yolo Bypass Wildlife Area, an area managed for multiple beneficial uses including bird habitat and rice farming. The study was conducted during an 11-month period (June 2007 to April 2008) that included a summer growing season and...
Authors
Charles Alpers, Jacob Fleck, Mark Marvin-DiPasquale, Craig Stricker, Mark Stephenson, Howard Taylor
Mercury cycling in agricultural and managed wetlands: a synthesis of methylmercury production, hydrologic export, and bioaccumulation from an integrated field study Mercury cycling in agricultural and managed wetlands: a synthesis of methylmercury production, hydrologic export, and bioaccumulation from an integrated field study
With seasonal wetting and drying, and high biological productivity, agricultural wetlands (rice paddies) may enhance the conversion of inorganic mercury (Hg(II)) to methylmercury (MeHg), the more toxic, organic form that biomagnifies through food webs. Yet, the net balance of MeHg sources and sinks in seasonal wetland environments is poorly understood because it requires an annual...
Authors
Lisamarie Windham-Myers, Jacob A. Fleck, Joshua T. Ackerman, Mark Marvin-DiPasquale, Craig Stricker, Wesley Heim, Philip Bachand, Collin Eagles-Smith, Gary Gill, Mark Stephenson, Charles Alpers
Hydrogeochemistry of prairie pothole region wetlands: Role of long-term critical zone processes Hydrogeochemistry of prairie pothole region wetlands: Role of long-term critical zone processes
This study addresses the geologic and hydrogeochemical processes operating at a range of scales within the prairie pothole region (PPR). The PPR is a 750,000 km2portion of north central North America that hosts millions of small wetlands known to be critical habitat for waterfowl and other wildlife. At a local scale, we characterized the geochemical evolution of the 92-ha Cottonwood Lake...
Authors
Martin Goldhaber, Christopher T. Mills, Jean Morrison, Craig Stricker, David Mushet, James LaBaugh
Holocene dynamics of the Florida Everglades with respect to climate, dustfall, and tropical storms Holocene dynamics of the Florida Everglades with respect to climate, dustfall, and tropical storms
Aeolian dust is rarely considered an important source for nutrients in large peatlands, which generally develop in moist regions far from the major centers of dust production. As a result, past studies assumed that the Everglades provides a classic example of an originally oligotrophic, P-limited wetland that was subsequently degraded by anthropogenic activities. However, a multiproxy...
Authors
Paul H. Glaser, Barbara C. S. Hansen, Joseph J. Donovan, Thomas Givnish, Craig Stricker, John Volin
Mercury in gray wolves (Canis lupus) in Alaska: Increased exposure through consumption of marine prey Mercury in gray wolves (Canis lupus) in Alaska: Increased exposure through consumption of marine prey
Mercury (Hg) bioaccumulates in the tissues of organismsand biomagnifies within food-webs. Graywolves (Canis lupus) in Alaska primarily acquire Hg through diet; therefore, comparing the extent of Hg exposure inwolves, in conjunction with stable isotopes, from interior and coastal regions of Alaska offers important insight into their feeding ecology. Liver, kidney, and skeletal muscle...
Authors
Ashley McGrew, Lora Ballweber, Sara Moses, Craig Stricker, Kimberlee Beckmen, Mo Salman, Todd O’Hara
Seasonal persistence of marine-derived nutrients in south-central Alaskan salmon streams Seasonal persistence of marine-derived nutrients in south-central Alaskan salmon streams
Spawning salmon deliver annual pulses of marine-derived nutrients (MDN) to riverine ecosystems around the Pacific Rim, leading to increased growth and condition in aquatic and riparian biota. The influence of pulsed resources may last for extended periods of time when recipient food webs have effective storage mechanisms, yet few studies have tracked the seasonal persistence of MDN. With...
Authors
Daniel Rinella, Mark Wipfi, Coowe Walker, Craig Stricker, Ron Heintz
Retrospective analysis of bottlenose dolphin foraging: a legacy of anthropogenic ecosystem disturbance Retrospective analysis of bottlenose dolphin foraging: a legacy of anthropogenic ecosystem disturbance
We used stable isotope analysis to investigate the foraging ecology of coastal bottlenose dolphins (Tursiops truncatus) in relation to a series of anthropogenic disturbances. We first demonstrated that stable isotopes are a faithful indicator of habitat use by comparing muscle isotope values to behavioral foraging data from the same individuals. δ13C values increased, while δ34S and δ15N...
Authors
Sam Rossman, Nélio B. Barros, Peggy H. Ostrom, Craig Stricker, Aleta Hohn, Hasand Gandhi, Randall Wells
Mercury cycling in agricultural and managed wetlands of California: experimental evidence of vegetation-driven changes in sediment biogeochemistry and methylmercury production Mercury cycling in agricultural and managed wetlands of California: experimental evidence of vegetation-driven changes in sediment biogeochemistry and methylmercury production
The role of live vegetation in sediment methylmercury (MeHg) production and associated biogeochemistry was examined in three types of agricultural wetlands (domesticated or white rice, wild rice, and fallow fields) and adjacent managed natural wetlands (cattail- and bulrush or tule-dominated) in the Yolo Bypass region of California's Central Valley, USA. During the active growing season...
Authors
Lisamarie Windham-Myers, Mark Marvin-DiPasquale, Craig Stricker, Jennifer Agee, Le Kieu, Evangelos Kakouros
Mercury cycling in agricultural and managed wetlands of California: seasonal influences of vegetation on mercury methylation, storage, and transport Mercury cycling in agricultural and managed wetlands of California: seasonal influences of vegetation on mercury methylation, storage, and transport
Plants are a dominant biologic and physical component of many wetland capable of influencing the internal pools and fluxes of methylmercury (MeHg). To investigate their role with respect to the latter, we examined the changing seasonal roles of vegetation biomass and Hg, C and N composition from May 2007-February 2008 in 3 types of agricultural wetlands (domesticated or white rice, wild...
Authors
Lisamarie Windham-Myers, Mark Marvin-DiPasquale, Evangelos Kakouros, Jennifer Agee, Le Kieu, Craig Stricker, Jacob A. Fleck, Joshua T. Ackerman
Variation in hair δ13C and δ15N values in long-tailed macaques (Macaca fascicularis) from Singapore Variation in hair δ13C and δ15N values in long-tailed macaques (Macaca fascicularis) from Singapore
Much of the primatology literature on stable isotope ratios of carbon (δ13C) and nitrogen (δ15N) has focused on African and New World species, with comparatively little research published on Asian primates. Here we present hair δ13C and δ15N isotope values for a sample of 33 long-tailed macaques from Singapore. We evaluate the suggestion by a previous researcher that forest degradation...
Authors
Michael Schillaci, J. Margaret Castellini, Craig Stricker, Lisa Jones-Engel, Benjamin P.Y.-H. Lee
The early bird gets the shrimp: Confronting assumptions of isotopic equilibrium and homogeneity in a wild bird population The early bird gets the shrimp: Confronting assumptions of isotopic equilibrium and homogeneity in a wild bird population
1. Because stable isotope distributions in organic material vary systematically across energy gradients that exist in ecosystems, community and population structures, and in individual physiological systems, isotope values in animal tissues have helped address a broad range of questions in animal ecology. It follows that every tissue sample provides an isotopic profile that can be used...
Authors
Michael Wunder, Joseph Jehl, Craig Stricker
Carbon and sediment accumulation in the Everglades (USA) during the past 4000 years: rates, drivers, and sources of error Carbon and sediment accumulation in the Everglades (USA) during the past 4000 years: rates, drivers, and sources of error
Tropical and sub-tropical wetlands are considered to be globally important sources for greenhouse gases but their capacity to store carbon is presumably limited by warm soil temperatures and high rates of decomposition. Unfortunately, these assumptions can be difficult to test across long timescales because the chronology, cumulative mass, and completeness of a sedimentary profile are...
Authors
Paul H. Glaser, John Volin, Thomas Givnish, Barbara C. S. Hansen, Craig Stricker
Non-USGS Publications**
Uzarski, D., Burton, T. & Stricker, C. Hydrobiologia (2001) 455: 137. doi:10.1023/A:1011929719866
Burton, T.M., Uzarski, D.G., Gathman, J.P. et al. Wetlands (1999) 19: 869. doi:10.1007/BF03161789
**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.
Science and Products
Filter Total Items: 22
No Result Found
Filter Total Items: 86
Mercury cycling in agricultural and managed wetlands, Yolo Bypass, California: Spatial and seasonal variations in water quality Mercury cycling in agricultural and managed wetlands, Yolo Bypass, California: Spatial and seasonal variations in water quality
The seasonal and spatial variability of water quality, including mercury species, was evaluated in agricultural and managed, non-agricultural wetlands in the Yolo Bypass Wildlife Area, an area managed for multiple beneficial uses including bird habitat and rice farming. The study was conducted during an 11-month period (June 2007 to April 2008) that included a summer growing season and...
Authors
Charles Alpers, Jacob Fleck, Mark Marvin-DiPasquale, Craig Stricker, Mark Stephenson, Howard Taylor
Mercury cycling in agricultural and managed wetlands: a synthesis of methylmercury production, hydrologic export, and bioaccumulation from an integrated field study Mercury cycling in agricultural and managed wetlands: a synthesis of methylmercury production, hydrologic export, and bioaccumulation from an integrated field study
With seasonal wetting and drying, and high biological productivity, agricultural wetlands (rice paddies) may enhance the conversion of inorganic mercury (Hg(II)) to methylmercury (MeHg), the more toxic, organic form that biomagnifies through food webs. Yet, the net balance of MeHg sources and sinks in seasonal wetland environments is poorly understood because it requires an annual...
Authors
Lisamarie Windham-Myers, Jacob A. Fleck, Joshua T. Ackerman, Mark Marvin-DiPasquale, Craig Stricker, Wesley Heim, Philip Bachand, Collin Eagles-Smith, Gary Gill, Mark Stephenson, Charles Alpers
Hydrogeochemistry of prairie pothole region wetlands: Role of long-term critical zone processes Hydrogeochemistry of prairie pothole region wetlands: Role of long-term critical zone processes
This study addresses the geologic and hydrogeochemical processes operating at a range of scales within the prairie pothole region (PPR). The PPR is a 750,000 km2portion of north central North America that hosts millions of small wetlands known to be critical habitat for waterfowl and other wildlife. At a local scale, we characterized the geochemical evolution of the 92-ha Cottonwood Lake...
Authors
Martin Goldhaber, Christopher T. Mills, Jean Morrison, Craig Stricker, David Mushet, James LaBaugh
Holocene dynamics of the Florida Everglades with respect to climate, dustfall, and tropical storms Holocene dynamics of the Florida Everglades with respect to climate, dustfall, and tropical storms
Aeolian dust is rarely considered an important source for nutrients in large peatlands, which generally develop in moist regions far from the major centers of dust production. As a result, past studies assumed that the Everglades provides a classic example of an originally oligotrophic, P-limited wetland that was subsequently degraded by anthropogenic activities. However, a multiproxy...
Authors
Paul H. Glaser, Barbara C. S. Hansen, Joseph J. Donovan, Thomas Givnish, Craig Stricker, John Volin
Mercury in gray wolves (Canis lupus) in Alaska: Increased exposure through consumption of marine prey Mercury in gray wolves (Canis lupus) in Alaska: Increased exposure through consumption of marine prey
Mercury (Hg) bioaccumulates in the tissues of organismsand biomagnifies within food-webs. Graywolves (Canis lupus) in Alaska primarily acquire Hg through diet; therefore, comparing the extent of Hg exposure inwolves, in conjunction with stable isotopes, from interior and coastal regions of Alaska offers important insight into their feeding ecology. Liver, kidney, and skeletal muscle...
Authors
Ashley McGrew, Lora Ballweber, Sara Moses, Craig Stricker, Kimberlee Beckmen, Mo Salman, Todd O’Hara
Seasonal persistence of marine-derived nutrients in south-central Alaskan salmon streams Seasonal persistence of marine-derived nutrients in south-central Alaskan salmon streams
Spawning salmon deliver annual pulses of marine-derived nutrients (MDN) to riverine ecosystems around the Pacific Rim, leading to increased growth and condition in aquatic and riparian biota. The influence of pulsed resources may last for extended periods of time when recipient food webs have effective storage mechanisms, yet few studies have tracked the seasonal persistence of MDN. With...
Authors
Daniel Rinella, Mark Wipfi, Coowe Walker, Craig Stricker, Ron Heintz
Retrospective analysis of bottlenose dolphin foraging: a legacy of anthropogenic ecosystem disturbance Retrospective analysis of bottlenose dolphin foraging: a legacy of anthropogenic ecosystem disturbance
We used stable isotope analysis to investigate the foraging ecology of coastal bottlenose dolphins (Tursiops truncatus) in relation to a series of anthropogenic disturbances. We first demonstrated that stable isotopes are a faithful indicator of habitat use by comparing muscle isotope values to behavioral foraging data from the same individuals. δ13C values increased, while δ34S and δ15N...
Authors
Sam Rossman, Nélio B. Barros, Peggy H. Ostrom, Craig Stricker, Aleta Hohn, Hasand Gandhi, Randall Wells
Mercury cycling in agricultural and managed wetlands of California: experimental evidence of vegetation-driven changes in sediment biogeochemistry and methylmercury production Mercury cycling in agricultural and managed wetlands of California: experimental evidence of vegetation-driven changes in sediment biogeochemistry and methylmercury production
The role of live vegetation in sediment methylmercury (MeHg) production and associated biogeochemistry was examined in three types of agricultural wetlands (domesticated or white rice, wild rice, and fallow fields) and adjacent managed natural wetlands (cattail- and bulrush or tule-dominated) in the Yolo Bypass region of California's Central Valley, USA. During the active growing season...
Authors
Lisamarie Windham-Myers, Mark Marvin-DiPasquale, Craig Stricker, Jennifer Agee, Le Kieu, Evangelos Kakouros
Mercury cycling in agricultural and managed wetlands of California: seasonal influences of vegetation on mercury methylation, storage, and transport Mercury cycling in agricultural and managed wetlands of California: seasonal influences of vegetation on mercury methylation, storage, and transport
Plants are a dominant biologic and physical component of many wetland capable of influencing the internal pools and fluxes of methylmercury (MeHg). To investigate their role with respect to the latter, we examined the changing seasonal roles of vegetation biomass and Hg, C and N composition from May 2007-February 2008 in 3 types of agricultural wetlands (domesticated or white rice, wild...
Authors
Lisamarie Windham-Myers, Mark Marvin-DiPasquale, Evangelos Kakouros, Jennifer Agee, Le Kieu, Craig Stricker, Jacob A. Fleck, Joshua T. Ackerman
Variation in hair δ13C and δ15N values in long-tailed macaques (Macaca fascicularis) from Singapore Variation in hair δ13C and δ15N values in long-tailed macaques (Macaca fascicularis) from Singapore
Much of the primatology literature on stable isotope ratios of carbon (δ13C) and nitrogen (δ15N) has focused on African and New World species, with comparatively little research published on Asian primates. Here we present hair δ13C and δ15N isotope values for a sample of 33 long-tailed macaques from Singapore. We evaluate the suggestion by a previous researcher that forest degradation...
Authors
Michael Schillaci, J. Margaret Castellini, Craig Stricker, Lisa Jones-Engel, Benjamin P.Y.-H. Lee
The early bird gets the shrimp: Confronting assumptions of isotopic equilibrium and homogeneity in a wild bird population The early bird gets the shrimp: Confronting assumptions of isotopic equilibrium and homogeneity in a wild bird population
1. Because stable isotope distributions in organic material vary systematically across energy gradients that exist in ecosystems, community and population structures, and in individual physiological systems, isotope values in animal tissues have helped address a broad range of questions in animal ecology. It follows that every tissue sample provides an isotopic profile that can be used...
Authors
Michael Wunder, Joseph Jehl, Craig Stricker
Carbon and sediment accumulation in the Everglades (USA) during the past 4000 years: rates, drivers, and sources of error Carbon and sediment accumulation in the Everglades (USA) during the past 4000 years: rates, drivers, and sources of error
Tropical and sub-tropical wetlands are considered to be globally important sources for greenhouse gases but their capacity to store carbon is presumably limited by warm soil temperatures and high rates of decomposition. Unfortunately, these assumptions can be difficult to test across long timescales because the chronology, cumulative mass, and completeness of a sedimentary profile are...
Authors
Paul H. Glaser, John Volin, Thomas Givnish, Barbara C. S. Hansen, Craig Stricker
Non-USGS Publications**
Uzarski, D., Burton, T. & Stricker, C. Hydrobiologia (2001) 455: 137. doi:10.1023/A:1011929719866
Burton, T.M., Uzarski, D.G., Gathman, J.P. et al. Wetlands (1999) 19: 869. doi:10.1007/BF03161789
**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.