African Journal of
Environmental Science and Technology

  • Abbreviation: Afr. J. Environ. Sci. Technol.
  • Language: English
  • ISSN: 1996-0786
  • DOI: 10.5897/AJEST
  • Start Year: 2007
  • Published Articles: 1055

Article in Press

Establishing criteria to select reference sites for ecological and water quality assessment in Ethiopian highland streams

Aschalew Lakewa and Otto Moog

  •  Received: 31 December 2015
  •  Accepted: 31 August 2016
The concept of a reference condition is increasingly used to describe benchmarks against which current condition is compared. This study defines criteria that represent reference sites for assessing highland streams in four major river basins of Ethiopia. Twenty a priori criteria were chosen as representative for Ethiopian highlands and they reflect some aspects of naturalness and address wide range of human disturbances. The most relevant criteria were those related to point and diffuse source of pollution, land use change, riparian vegetation, and river morphology. Of 104 study sites 22 were selected as reference based on established criteria and benthic macro-invertebrate (BMI) were used for validation. BMI showed a clear stress gradient between a priori reference and impaired sites, although small overlap was observed with few impaired sites. Moreover, biotic score (ETHbios) established for Ethiopian highland streams revealed that 95% of a priori reference sites were within the range of ‘high’ ecological status. Reference criteria proposed in this study can be considered as valuable tool to implement biomonitoring program in Ethiopian highland freshwater ecosystems where true pristine areas are nonexistent as a result of different human activities and urbanization. Key words: Reference sites, biomonitoring, highland streams, a priori criteria