A characterization of benthic invertebrate communities in Northwestern Ontario Streams

This research paper was completed and submitted at Nipissing University, and is made freely accessible through the University of Toronto’s TSpace repositoryBenthic invertebrates have a variety of tolerance levels to environmental stresses. Some groups are very sensitive to the stress produced by pollution or habitat modification, whereas others are more tolerant of these stresses. As such, benthic invertebrate community (BIC) composition is commonly used as an indicator of ecosystem health. One of the largest undeveloped mineral reserves in northwestern Ontario is in the region commonly known as the Ring of Fire. This region of Ontario is remote, with few year-round residents. There is a general lack of available information to characterize the aquatic ecosystem in streams and rivers of this region. As a result, the composition of benthic invertebrate communities and their relationship with physical and chemical habitat variables is not well known. Additional research is required to address some of these deficiencies in order to help deal with the gaps in knowledge and to establish a baseline prior to potential development. This study utilized biological, physical and chemical data collected in 2011 and 2014, along a proposed transportation corridor into the Ring of Fire. The overall objective of this research was to identify environmental features that are correlated with BIC metrics used for the assessment of aquatic ecosystem health. This research 1) identified environmental features that most influence BIC structure in the study area streams of northern Ontario, 2) investigated spatial differences in these environmental features within the study area, 3) evaluated if the construction of winter roads, specifically the placement of corduroy crossings influence BIC structure, and 4) examined potential effects of degraded water quality in relation to BIC structure. The analysis investigated associations between the benthic invertebrate communities and environmental features that could be extrapolated in order to help understand conditions in other regional streams not sampled. These data were collected in support of an Environmental Assessment (EA) for Canadian mining company Noront Resources Ltd. The EA included aquatic assessments of stream crossings along a proposed transportation corridor from existing infrastructure to the project site. The individual taxa count data and a suite of BIC metrics were used in statistical analyses that included redundancy analysis (RDA), multivariate analysis of variance (MANOVA) and partitioning of variance to evaluate the influence of environmental features at the sample stations and reveal spatial patterns of BIC structure within the study area. Results of the above analysis revealed turbidity, average water depth and dominant substrate type most influenced the BIC structure. No spatial effect was evident for these main variables, suggesting location does not significantly influence the BIC structure within the study area. Comparisons among and between replicate sample stations positioned upstream, at the corduroy crossing structure and downstream of the structure did not show corduroy bridges within the study area significantly influenced the BIC structure. The water quality parameters were compared to the Provincial objectives to identify potentially degraded water quality. The total aluminum and iron concentrations exceeded the objectives at several stations which were compared to the remaining stations with concentrations below the objectives, as well as other subsets of the laboratory data. These concentrations did not show a significant effect influencing the BIC structure; however, a biological effect was observed at two stations where a gastropod taxon appeared to show a tolerance to these metals. This research contributes to a better understanding of northern Ontario ecological systems to support future assessments of change and the potential effects of development