Diversity and distribution of benthic invertebrates in lakes and ponds of Nunavut, Arctic, Canada

Benthic macroinvertebrates were collected from lakes and ponds near Iqaluit and Rankin Inlet, Nunavut, Canada, via D-net (500 mum mesh) transect sampling. Multivariate statistical analyses suggest that macroinvertebrate communities are influenced by lake characteristics that are related to landscape position and adjacent landscape influence, such as concentrations of total phosphorus, major ions (sodium, calcium), silica, and dissolved inorganic carbon, in addition to dissolved oxygen and water depth. This thesis also examined the spatial pattern of larval and subfossil chironomid assemblages in ponds located near Iqaluit and Rankin Inlet, via transect sampling of sediment cores. It was determined that remains of larvae are sparse compared to head capsules, and therefore characterization of lakes based on chironomid communities would be more accurate using subfossil assemblages. Results also suggest that paleolimnological reconstructions in these systems reflect conditions adjacent to the coring location, as opposed to representing the whole lake basin.