Diatom data from north Baffin Island

Surface sediments from 20 lakes and ponds in Sirmilik National Park were collected using a gravity corer or an Ekman dredge. Water samples were taken for detailed chemical analysis of nutrient status and major ions. Diatom assemblages were also analyzed from short sediment cores (<50 cm) collected from two lakes. The lakes were chosen to span the major physiographic sectors of the park. Modern diatom assemblages differed significantly between the two sectors of SNP, indicating strong relationships between species composition and water chemistry. Fossil diatom assemblages also differed considerably between the two lakes. Coupled with the modern diatom data, the study showed that diatom assemblages began to change around 1900 AD at both lake sites, but the sites differed in their responses as a function of lake morphology and pre-existing limnological conditions.