Ambient water quality monitoring of the Quinsam River, British Columbia, began in 1986, a year prior to the activation of an upstream coal mine. The intent of monitoring was to evaluate potential water quality effects from mining and other activities in the basin. In 2001, biological assessment also commenced at this monitoring station in accordance with the Canadian Aquatic Biomonitoring Network (CABIN) protocols. Results of the 2001 assessment of the benthic community indicated significant impairment. Subsequent sampling from 2003 to 2006 investigated the longitudinal, temporal and within-site spatial variation of the benthic community along the river.

Since 2001, trends in the benthic communities and water quality along the river show a clear improvement. Several factors may have influenced the initially poor conditions assessed at the site. These include multiple land-uses such as forestry, mining, a fish hatchery, and recreation. The presence of an usually high number of salmon carcasses in 2000 may have caused unusually elevated nutrient levels, and extreme hydrologic events in 2000 and 2001 may have caused habitat changes due to bank instability. It was recommended to continue to monitor this Quinsam River location along with sites above and below the hatchery, to ensure the observed improvement is maintained and to identify any future disturbances.