Quantitative relationships between benthic diatom assemblages and water chemistry in Macquarie Island lakes and their potential for reconstructing past environmental changes

• Published in: Antarctic Science
• Main Authors: Saunders, KM, Hodgson, DA, McMinn, A
• Format: Article in Journal/Newspaper
• Language: English
• Published: Cambridge Univ Press 2009
• Subjects: Biological Sciences; Ecology; Marine and Estuarine Ecology (incl. Marine Ichthyology); Island Lakes; Antarc*; Antarctic Science; Macquarie Island
• Online Access: http://journals.cambridge.org; https://doi.org/10.1017/S0954102008001442; http://ecite.utas.edu.au/62720

This study is the first published survey of diatom-environment relationships on sub-AntarcticMacquarie Island. Fifty-eight sites in 50 coastal and inland lakes were sampled for benthic diatoms andwater chemistry. 208 diatom species from 34 genera were identified. Multivariate analyses indicated thatthe lakes were distributed along nutrient and conductivity gradients. Conductivity, pH, phosphate (SRP),silicate and temperature all explained independent portions of the variance in the diatom data. Transferfunctions provide a quantitative basis for palaeolimnological studies of past climate change and humanimpacts, and can be used to establish baseline conditions for assessing the impacts of recent climatechange and the introduction of non-native plants and animals. Statistically robust diatom transferfunctions for conductivity, phosphate and silicate were developed, while pH and temperature transferfunctions performed less well. The lower predictive abilities of the pH and temperature transferfunctions probably reflect the broad pH tolerance range of diatoms on Macquarie Island and unevendistribution of lakes along the temperature gradient. This study contributes to understanding thecurrent ecological distribution of Macquarie Island diatoms and provides transfer functions thatwill be applied in studies of diatoms in lake sediment cores to quantitatively reconstruct pastenvironmental changes.