Phytoplankton and zooplankton samples collected from Quesnel Lake between Aug. 8 and 13, 2014 are consistent with plankton samples in other similar large, deep lakes indicating the overall concentrations found are typical of large lakes with low levels of nutrients.

Results for phytoplankton show green algae are the dominant plankton species for most of the sampling sites. The Quesnel Lake near Hazeltine Creek deep station site had lower concentrations of phytoplankton overall. However, the Quesnel Lake Green Buoy deep station has the highest concentrations of phytoplankton and the most diversity.

Zooplankton results show higher concentrations of copepods and rotifers, an important food source for larval, juvenile and adult fish. These types of zooplankton were found in most of the sampling sites.

Without pre-event plankton samples for comparison, ministry staff are unable to determine if any impacts to plankton are linked to the Mount Polley tailings storage facility breach. Sampling over time will determine potential impacts on aquatic life and plankton species. At this time, the sampling results are expected for a lake of this type, size and depth.

Both phytoplankton and zooplankton are the basic food sources for aquatic species. Phytoplankton, plant-based organisms, survives off nutrients from the water and through photosynthesis. Zooplankton, animal-based organisms, feed on other plankton species including phytoplankton and zooplankton. Both are indicators of water quality as plankton populations are continuously changing with weather, water temperature, and nutrients.

Plankton samples were sent to a taxonomist for species identification and count. Phytoplankton samples were collected at surface in a one litre grab samples, whereas zooplankton samples were collected using a plankton net.

Additional zooplankton samples were collected by UNBC research staff in late September following the Department of Fisheries and Oceans (DFO) zooplankton collection methods for historical comparison. These samples are also being analysed for metal concentrations and results will be reported as information becomes available.

All results and explanations are publically available on the Ministry of Environment’s dedicated Mount Polley site: www.env.gov.bc.ca/eemp/incidents/2014/mount-polley.htm

Media Contacts:

Media Relations
Ministry of Environment
250 953-3834