Wildlife nutrition is an essential element of fitness, and contextualizing resource use within the broader framework of local and regional food webs is paramount to species health, function, and management.
An understanding of a species' life history and habitat requirements is incomplete without insight into nutrition. Traditional diet studies have relied on observations, stomach lavage, and scat analysis, all of which impart bias due to logistics, temporal scales, and differential digestion.
In contrast, intrinsic tracers such as biomarkers and naturally occurring isotopes provide a powerful alternative that integrate broader timescales, target resources assimilated and related routing or allocation, and offer non-invasive sampling schemes. Moreover, these techniques also provide opportunities for expanding inference by assessing resource use within a food web context, assessing the role of habitat change, trophic dynamics, and ecosystem stressors.
In collaboration with other USGS scientists, Federal and State agencies, and university researchers, examples from this project include new insights into wildlife nutrition and food web interactions of logistically challenging to study species (for example, polar bears, Stellar sea lions, seabirds), non-native species introductions (for example, reptiles), and economically important fisheries (for example, Pacific salmon).
Geology, Geophysics, and Geochemistry Stable Isotope Laboratory (GSIL)
Ecosystem Biogeochemistry
Wildlife Biogeography
Environmental Stressors
Water chemistry, stable isotopes, and trace metals in sediment, water and biota in Torch Lake and Gratiot Lake, Keweenaw Peninsula, Michigan, USA, July and October 2021
Laboratory analyses for fish tissue from Lake Koocanusa and Kootenai River Basin, Montana, 2022
Modeled Pacific salmon escapement biomass and nutrient and contaminant concentrations across western North America, 1976-2015 (version 2.0, October 2024)
Total mercury, methylmercury, and isotopic composition in various life stages of boreal chorus frogs (Pseudacris maculata) at two subalpine ponds in the Rocky Mountains, CO, USA, 2015
Mercury concentrations, isotopic composition, biomass, and taxonomy of stream and riparian organisms in the vicinity of Yellow Pine, Idaho, 2015-2016.
Dataset for temporal influences on selenium partitioning, trophic transfer, and exposure in a major U.S. river
Stable carbon and nitrogen isotope data for: 'Ecotoxicoparasitology of the gastrointestinal tracts of pinnipeds: effect of parasites on bioavailability of total mercury (THg)'
Zinc concentrations and isotopic signatures of an aquatic insect (mayfly, Baetis tricaudatus)
Metal-rich lacustrine sediments from legacy mining perpetuate copper exposure to aquatic-riparian food webs
Continental-scale nutrient and contaminant delivery by Pacific salmon
Complex life histories alter patterns of mercury exposure and accumulation in a pond-breeding amphibian
Diet energy density estimated from isotopes in predator hair associated with survival, habitat, and population dynamics
Summer/fall diet and macronutrient assimilation in an Arctic predator
Increased mercury and reduced insect diversity in linked stream-riparian food webs downstream of a historical mercury mine
Energetic and health effects of protein overconsumption constrain dietary adaptation in an apex predator
Temporal influences on selenium partitioning, trophic transfer, and exposure in a major U.S. river
Juvenile Coho and Chinook salmon growth, size, and condition linked to watershed-scale salmon spawner abundance
Benthic algal (Periphyton) growth rates in response to nitrogen and phosphorus: Parameter estimation for water quality models
Bridging the gap between salmon spawner abundance and marine nutrient assimilation by juvenile salmon: Seasonal cycles and landscape effects at the watershed scale
Temporal records of diet diversity dynamics in individual adult female Steller sea lion (Eumetopias jubatus) vibrissae
Wildlife nutrition is an essential element of fitness, and contextualizing resource use within the broader framework of local and regional food webs is paramount to species health, function, and management.
An understanding of a species' life history and habitat requirements is incomplete without insight into nutrition. Traditional diet studies have relied on observations, stomach lavage, and scat analysis, all of which impart bias due to logistics, temporal scales, and differential digestion.
In contrast, intrinsic tracers such as biomarkers and naturally occurring isotopes provide a powerful alternative that integrate broader timescales, target resources assimilated and related routing or allocation, and offer non-invasive sampling schemes. Moreover, these techniques also provide opportunities for expanding inference by assessing resource use within a food web context, assessing the role of habitat change, trophic dynamics, and ecosystem stressors.
In collaboration with other USGS scientists, Federal and State agencies, and university researchers, examples from this project include new insights into wildlife nutrition and food web interactions of logistically challenging to study species (for example, polar bears, Stellar sea lions, seabirds), non-native species introductions (for example, reptiles), and economically important fisheries (for example, Pacific salmon).