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Andrew Todd

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This data release includes sampling location data; field-collected stream attribute data; laboratory-analyzed chemistry concentrations (total mercury, methyl mercury) and isotopic composition (total mercury, carbon, and nitrogen) for stream biota (seston, periphyton, benthic insects, emerging adult insects, riparian spiders, and fish); density, body length, and taxonomic information for benthic insects; and density, biomass, and taxonomic information for emerging adult aquatic insects for biota sampled from stream reaches up and downstream of an historical mercury mine site. Sampling took place during summer low-flow conditions in 2015 and 2016. Stream reaches were located on USFS land near the Cinnabar Mine Site...
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The Impacts of Drought on Fish and Wildlife in the Southwestern U.S.
Species that inhabit the arid Southwest are adapted to living in hot, dry environments. Yet the increasing frequency and severity of drought in the region may create conditions that even these hardy species can’t survive. This project examined the impacts of drought in the southwestern U.S. on four of the region’s iconic species: desert bighorn sheep, American pronghorn, scaled quail, and Rio Grande cutthroat trout. Grasping the impacts of drought on fish and wildlife is critical for management planning in the Southwest, as climate models project warmer, drier conditions for the region in the future. Species are known to respond to environmental changes such as drought in different ways. Often, before changes...
This dataset was collected to build on past and ongoing monitoring and research efforts within Colorado’s Rocky Mountain National Park (RMNP). Specifically, the data were collected to test the hypothesis that reductions in canopy cover due to natural disturbances (i.e. wildfire and beetle kill) result in increases in water temperature, or the longitudinal thermal gradient of a stream. Data values include stream temperature paired with light intensity data, and air temperature data to determine the influence of riparian canopy condition and longitudinal warming across a 1 km reach. Two control streams were selected: Ouzel Creek, which has virtually no riparian canopy due to a previous wildfire; and Hunters Creek,...
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This data set characterizes the thermal regime in a number of Colorado and New Mexico streams that contain populations of Rio Grande Cutthroat Trout (Oncorhynchus clarkii virginalis) or have been considered potential restoration areas for the fish. The majority of these streams had no previous record of continual temperature records. When compared to Colorado water temperature criteria (Cold Tier 1), a portion of these populations appeared to be at risk from elevated stream temperatures, as indicated by exceedance of both acute and chronic water quality metrics. Summer water temperature profiles recorded at sites within current Rio Grande Cutthroat Trout habitat indicated that although the majority of currently...
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