Use of the Coefficient of Community Loss (I) to Assess Cultural Stresses on Monongahela River Tributary Fish Communities

Abstract

We utilized a single metric, the coefficient of community loss (I) to assess the health of fish communities inhabiting 27 low-order Monongahela River tributaries in Pennsylvania. All streams were sampled during summers of 2003 and 2004 utilizing two-pass back-pack electrofishing from the mouth extending 200 m upstream. Environmental stressors observed in and on-stream were habitat alteration and non-point source discharges due to urbanization and agriculture along with point-source discharges of raw and treated sewage, net alkaline mine drainage, and acid mine drainage (AMD). Species richness and I-metric scores in streams impacted by major AMD andlor untreated sewage were 0 and a, respectively. While those exhibiting minimal cultural stress had species richness totals and I-metric scores of 24 and 0.24, respectively. Values of I were negatively correlated with index of biotic integrity scores (-0.95 I), suggesting that I could provide a rapid comprehensive assessment of the relative health of fish communities within a major watershed.

Stream Fish Community Responses to a Gradient of Specific Conductance

“…We calculated the I-metric score (Argent and Kimmel 2006) to evaluate the fish community in one metric along the gradient of conductivity. Streams with I-values of ≥0.8 are (Courtemanch and Davies 1987).…”

Stable Isotope Analysis Reveals Anthropogenic Effects on Fish Assemblages in a Temperate Reservoir

“…Developed to assess relative taxa loss due to anthropogenic effects in macroinvertebrates (Courtemanch and Davies, ), the coefficient of community loss ( I ) has been closely correlated with index of biotic integrity scores in stream fish communities (Argent and Kimmel, ). Courtemanch and Davies () determined that I scores of >0.8 indicated stressed systems, whereas scores of <0.8 were indicative of relatively pristine or enriched conditions.…”