Freshwater diatoms on sub-Antarctic Macquarie Island: an ecological survey of 14 lakes

A survey of the diatom (Bacillariophyceae) populations in 14 lakes and ponds on sub-Antarctic Macquarie Island identified 102 species from 34 genera, including species considered endemic to the sub-Antarctic region. Multivariate analysis of the diatom communities divided the lakes into two broad groups; oligotrophic plateau lakes dominated by species including Bmchysira exilis, Fragilaria capucina var. gracilis, Psammothidium abundans, Ps. confosum and Ps. confusum var. atomoides, and lowland peat-based lakes dominated by species including Fragilaria pulchella, Planothidium lanceolatum and Pl. quadripunctatum. Factors relating to lake elevation rather than water pH or conductivity appeared to have most influence on the lake diatom communities.