Tributary Benthic Invertebrates, Oil Sands Region

Tributary Biomonitoring (Lower Athabasca River)

Benthic macroinvertebrates, comprising insects, crusteaceans, molluscs and worms, represent a group of organisms used widely in environmental monitoring programs as early warning indicators to assess the effects of change in water quality or physical habitat conditions on aquatic ecosystem health.

In addition to collecting benthic invertebrate samples, supporting water chemistry samples were taken on the same date.

The species richness of invertebrates recorded in tributary streams of Lower Athabasca River sites was reflective of the complex and diverse habitats found in that area. Diversity at these sites was as expected for northern tributary streams. Benthic assemblages in LAR tributaries generally exhibited good ecological condition with high abundance of intolerant mayfly, Plecoptera and caddisfly (EPT) taxa among the sites. Benthic communities were similar between reference sites that were located outside of the oil sands region compared to those within the natural deposit. In contrast, benthic assemblages in areas with an increased industrial footprint were divergent from reference sites. Observations at these sites displayed a lower proportion of sensitive EPT taxa, which may be indicative of mild environmental stress. However, further investigation is required to determine whether there is a causal relationship between exposure to environmental stressors and altered assemblage composition. Definitive conclusions regarding natural variations and impacts of development require additional analysis and the integration of the resultant macroinvertebrate data with additional environmental information to determine drivers of ecological change.

Biomonitoring Water Quality

Verified and validated water quality data from fall of 2011 through to the fall of 2013 collected to support Invertebrate and Ecosystem Health studies. Data was collected at twenty-one sites on the mainstem of the Athabasca River, sixty sites on its major tributaries and twenty-nine sites in the expanded geographic area, including deltaic wetlands and several streams.

The data include measures of nutrients, metals (dissolved and total), polycyclic aromatic hydrocarbons and major ions. Along with other environmental measures, the data are used to determine factors affecting the status and trends in the benthic invertebrate community composition and contribute to assessment of the health of the aquatic ecosystem.



Date modified: