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Pesticides in the Prairie Pothole Region Completed

By Fort Collins Science Center August 16, 2016

Wetlands of the northern Great Plains are crucial feeding grounds for migrating birds and waterfowl embedded in an agricultural landscape. Land use and hydrology can affect adult aquatic insects – crucial prey for critically declining populations of insectivorous birds. Current studies focus on effects of current-use pesticides on adult aquatic insects to inform decision making about contaminants of emerging environmental concern.

Scientists work on insect traps in the Prairie Pothole region of North Dakota.
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Scientists work on insect traps in the Prairie Pothole region of North Dakota. This work was done in the wetlands in Southeast/Central ND - Stutsman and Kidder counties, ND in grassland and on farms. Rachel Harrington, USGS Public domain

Wetlands of the northern Great Plains are crucial feeding grounds for migrating birds and waterfowl embedded in an agricultural landscape. Land use and hydrology can affect adult aquatic insects – crucial prey for critically declining populations of insectivorous birds. Current studies focus on effects of current-use pesticides on adult aquatic insects to inform decision making about contaminants of emerging environmental concern.

Below are publications associated with this project.

A modeling approach to compare ΣPCB concentrations between congener-specific analyses

Changes in analytical methods over time pose problems for assessing long-term trends in environmental contamination by polychlorinated biphenyls (PCBs). Congener-specific analyses vary widely in the number and identity of the 209 distinct PCB chemical configurations (congeners) that are quantified, leading to inconsistencies among summed PCB concentrations (ΣPCB) reported by different studies. Her
Authors
Polly P. Gibson, Marc A. Mills, Johanna M. Kraus, David M. Walters
By
Ecosystems Mission Area, Contaminant Biology, Environmental Health Program, Fort Collins Science Center

Aquatic pollution increases use of terrestrial prey subsidies by stream fish

Stream food webs are connected with their riparian zones through cross-ecosystem movements of energy and nutrients. The use and impact of terrestrial subsidies on aquatic consumers is determined in part by in situ biomass of aquatic prey. Thus, stressors such as aquatic pollutants that greatly reduce aquatic secondary production could increase the need for and reliance of stream consumers on terr
Authors
Johanna M. Kraus, Justin F. Pomeranz, Andrew S. Todd, David M. Walters, Travis S. Schmidt, Richard B. Wanty
By
Ecosystems Mission Area, Contaminant Biology, Environmental Health Program, Fort Collins Science Center, Geology, Geophysics, and Geochemistry Science Center

Metamorphosis alters contaminants and chemical tracers in insects: implications for food webs

Insects are integral to most freshwater and terrestrial food webs, but due to their accumulation of environmental pollutants they are also contaminant vectors that threaten reproduction, development, and survival of consumers. Metamorphosis from larvae to adult can cause large chemical changes in insects, altering contaminant concentrations and fractionation of chemical tracers used to establish c
Authors
Johanna M. Kraus, David M. Walters, Jeff S. Wesner, Craig A. Stricker, Travis S. Schmidt, Robert E. Zuellig
By
Ecosystems Mission Area, Contaminant Biology, Environmental Health Program, Colorado Water Science Center, Fort Collins Science Center

Metamorphosis enhances the effects of metal exposure on the mayfly, Centroptilum triangulifer

The response of larval aquatic insects to stressors such as metals is used to assess the ecological condition of streams worldwide. However, nearly all larval insects metamorphose from aquatic larvae to winged adults, and recent surveys indicate that adults may be a more sensitive indicator of stream metal toxicity than larvae. One hypothesis to explain this pattern is that insects exposed to elev
Authors
Jeff S. Wesner, Johanna M. Kraus, Travis S. Schmidt, David M. Walters, William H. Clements
By
Ecosystems Mission Area, Contaminant Biology, Environmental Health Program, Colorado Water Science Center, Fort Collins Science Center

Emergence flux declines disproportionately to larval density along a stream metals gradient

Effects of contaminants on adult aquatic insect emergence are less well understood than effects on insect larvae. We compared responses of larval density and adult emergence along a metal contamination gradient. Nonlinear threshold responses were generally observed for larvae and emergers. Larval densities decreased significantly at low metal concentrations but precipitously at concentrations of m
Authors
Travis S. Schmidt, Johanna M. Kraus, David M. Walters, Richard B. Wanty
By
Water Resources Mission Area, Colorado Water Science Center, Geology, Geophysics, and Geochemistry Science Center

Transfer of trace metals from streams to terrestrial food webs by emerging aquatic insects in mineralized alpine ecosystems

No abstract available.
Authors
Johanna M. Kraus, R. B. Wanty, Travis S. Schmidt, David M. Walters, Craig A. Stricker

Variation in active and passive resource inputs to experimental pools: mechanisms and possible consequences for food webs

1. Cross-ecosystem movements of resources, including detritus, nutrients and living prey, can strongly influence food web dynamics in recipient habitats. Variation in resource inputs is thought to be driven by factors external to the recipient habitat (e.g. donor habitat productivity and boundary conditions). However, inputs of or by ‘active’ living resources may be strongly influenced by recipien
Authors
Johanna M. Kraus, Leanna T. Pletcher, James R. Vonesh

Diet shift of lentic dragonfly larvae in response to reduced terrestrial prey subsidies

Inputs of terrestrial plant detritus and nutrients play an important role in aquatic food webs, but the importance of terrestrial prey inputs in determining aquatic predator distribution and abundance has been appreciated only recently. I examined the numerical, biomass, and diet responses of a common predator, dragonfly larvae, to experimental reduction of terrestrial arthropod input into ponds.
Authors
Johanna M. Kraus