Maritime Antarctic freshwater lakes and their catchments are inherently simple systems in an environment which is characterized by strong seasonality. Such lakes offer excellent opportunities to study the interaction of water chemistry and plant communities. The response of diatom species to environmental gradients was assessed by constructing a diatom and water chemistry dataset from 59 lakes at two locations (Livingston Island, South Shetland Islands and Signy Island, South Orkney Islands). Results indicate that diatom species abundance is predominately related to nutrient and salinity gradients. The dataset will be used to create transfer functions which can be applied to sediment core diatom assemblages to reconstruct historical patterns of lake chemistry.