Evaluating water quality and biotic indices in the Lower Little Bow River, Alberta

• Author / Creator

  Scott, Janet L

• Environmental indices are useful tools for distilling significant messages out of complex monitoring datasets. A case study of Agriculture and Agri-Food Canada’s Watershed Evaluation of Beneficial Management Practices (WEBs) micro-watershed on the lower Little Bow River, Alberta, was used to address two topics: modifications of the Canadian Water Quality Index (CWQI) to provide ecologically relevant monitoring information at the micro-watershed scale, and inclusion of fish species and habitat assessments to support WEBS’ broader evaluation of aquatic ecosystem health.
  Water quality data collected between 2004-2007 from five study reaches on 5.5 km of the lower Little Bow River were used to calculate CWQI scores under two scenarios: seasonal vs. annual index calculation; and total vs. sub-index (i.e., biological, chemical, and physical) divisions of parameters. Fish diversity and habitat information was collected in a single season in 2009.
  Overall, water quality ranged from good to poor. Summer criteria exceedances in fecal coliform, Escherichia coli, dissolved oxygen, and total suspended solids produced marginal scores for summer and annual periods, and poor scores for physical and biological sub-indexes. Fish collection found largely generalist warmwater fish species, including minnows, suckers, and northern pike, so index criteria suited to these species were employed. Habitat permanence relied upon maintenance of minimum instream flows, bank stability, and access to overwintering habitats.
  Both seasonal and sub-index methods are recommended for use in micro-watershed monitoring as they produced wider score ranges than the standard CWQI and can inform reservoir management of stream flows when related to local fish requisites.

• Subjects / Keywords

  • Environmental index
  • IBI
  • Fish community assessment
  • Little Bow River
  • Fish index of biotic integrity
  • Water quality index
  • CWQI

• Graduation date

  Fall 2012

• Type of Item

  Thesis

• Degree

  Master of Science

• DOI

  https://doi.org/10.7939/R3GM72

• License

  This thesis is made available by the University of Alberta Libraries with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.