Citation | Limnotek Research and Development. 2010. Cheakamus River benthic community monitoring for water license requirements: Cheakamus River Monitoring Program #7, Final Report. Prepared for BC Hydro. |
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Organization | BC Hydro |
URL | https://www.bchydro.com/content/dam/hydro/medialib/internet/documents/planning_regulatory/wup/lower_mainland/2012q3/cmsmon_7_Yr2_2010_12_31.pdf |
Abstract/Description or Keywords | Statistical modeling was used to examine the importance of flow and other habitat attributes on the abundance and composition of benthic communities in the Cheakamus River. The modeling was recognized by a Consultative Committee (CC) of the Cheakamus water use plan as a useful tool to support future decisions on water release from the Daisy Dam. The study answered two management questions raised by the CC: 1. What habitat attributes best determine the composition, abundance, and biomass of benthic invertebrates in the Cheakamus River? 2. Among all habitat attributes, what is the relative importance and magnitude of effect of flow in determining the composition, abundance, and biomass of benthic communities in the Cheakamus River? Benthic invertebrate and periphyton count and biomass data were collected from five stations downstream of the Daisy Dam along with measurements of up to 53 habitat variables. The sampling occurred during all seasons in 2009. The data were appended to similar measurements from 1996 and 1999. Multiple regression analysis was used to develop models that were used to identify and rank the most important attributes of habitat and food web interactions that determined each of six dependent variables. Those dependent variables, also known as endpoints, were as follows: 1. Benthic invertebrate biomass, 2. An index of benthic invertebrate abundance called the Cheakamus benthos index (CBI), 3. Benthic invertebrate diversity, 4. Periphyton biomass, 5. Periphyton diversity, 6. Biovolume of Didymosphenia geminata (Didymo), a stalked diatom that formed large mats in 2009 and could potentially affect water quality . Stomach contents of juvenile salmonids and resident rainbow trout were also examined to determine the extent of links between benthos produced in the Cheakamus River and food that is ingested by fishes. Best fit of the multiple regression models to the data occurred with one to eight predictor variables describing flow metrics, temperature, turbidity, elevation, presence of Didymo, riparian vegetation, food web interactions, and flow variance. All predictor variables were independent and the models were computationally stable. The selected predictors explained 54-68% of observed variance of the biological metrics among all years, seasons, and locations. |
Information Type | report |
Regional Watershed | Howe Sound & Sunshine Coast |
Sub-watershed if known | Cheakamus River |
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Project status | complete |
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