Assessing temporal changes in macroinvertebrate community structure in a remote wetland through DNA metabarcoding

Wright, Michael TG
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University of Guelph

This thesis investigates the use of DNA metabarcoding as a tool for assessing biodiversity patterns in freshwater macroinvertebrate communities within the Peace-Athabasca Delta. Macroinvertebrate samples were collected in June and August of 2012 and 2013 from both the Peace and Athabasca River deltas in northern Alberta. Following the morphological identification of a subset of individuals within the samples, macroinvertebrates were homogenized, bulk DNA was extracted, and two fragments of the mitochondrial Cytochrome c oxidase I (COI) gene were sequenced and compared against two reference libraries obtained 18 months apart. When comparing taxa identified via DNA metabarcoding to those identified through morphology, 73% of the total occurrences were the same. This number increased to 84% through passive additions to online genomic repositories over the course of this study, emphasizing the importance of reference library coverage in metabarcoding analysis. Despite some taxa known to be present in the samples by morphological identification not being identified by DNA metabarcoding, general diversity patterns were consistent between the two methods of identification. The river delta of origin was the primary factor separating macroinvertebrate communities, followed by season of sampling.

DNA metabarcoding, wetland, macroinvertebrate