The Effects of Common Carp on Nitrogen Dynamics and Mass Transport of Phosphorous and Sediment in a Eutrophic Stream

EPA Grant Number: FP916944
Title: The Effects of Common Carp on Nitrogen Dynamics and Mass Transport of Phosphorous and Sediment in a Eutrophic Stream
Investigators: Hochhalter, Samuel J
Institution: Utah State University
EPA Project Officer: Michaud, Jayne
Project Period: September 1, 2008 through August 31, 2010
RFA: STAR Graduate Fellowships (2008) RFA Text |  Recipients Lists
Research Category: Academic Fellowships


As a powerful invasive species and an ecosystem engineer, common carp proliferate and subsequently degrade many aquatic environments globally. Despite numerous studies on the impacts of common carp invasions on lake ecosystems, little is known of their effects on streams. The ecosystem altering aptitude of common carp has been shown to elicit considerable controls on ecosystem function and provides substantial evidence that carp may significantly influence nutrient retention within streams. As such, the presence of common carp is likely to confound management efforts aimed at maintaining and restoring water quality within streams. The objectives of this research are to determine the effects of common carp on the flow, availability and retention of nutrients within a eutrophic stream.


Research will occur in an agricultural stream in Northern Utah listed as impaired for elevated levels of ammonium and phosphorous. A four week, continuous injection of the stable isotope nitrogen 15 (15N) will occur in two stream reaches separated by a partial fish barrier. The downstream reach has a high biomass of carp and the upstream reach has a low biomass of carp. Five fish exclosures within each reach will help elucidate carp mediated effects. Assimilation, regeneration, and retention of 15N within all major benthic compartments will be measured inside and outside of exclosures. Weekly measures of stream discharge and water column phosphorous, nitrogen, and particulate concentrations will allow for calculation of mass transport.

Expected Results:

Results from this research will advance our understanding of the influence of a prevalent invasive species on water quality within fluvial environments. These data will serve to direct water quality managers and aquatic ecologists in restoration of freshwater ecosystems harboring common carp. Additionally, nutrient retention within streams is a fundamentally important ecosystem service. By contributing to our understanding of processes governing nutrient retention, the project will also contribute to societal benefits.

Supplemental Keywords:

Invasive species, water quality, carp, nutrients,

Progress and Final Reports:

  • 2009
  • Final