This volume is derived from a symposium on High Latitude Limnology held during the 23rd Congress of the Societas Internationalis Limnologiae in Hamilton, New Zealand. The symposium stemmed from our belief that an exchange of views between limnologists working in the north and south polar zones would be timely and productive. Over the last decade there has been a major increase in the limnological research effort in Antarctica with the expansion of science programmes there by many nations from both the northern and southern hemispheres. Freshwater research has also continued to develop in the Arctic, stimulated by the need for basic information to assess environmental impacts of the oil industry, mining, urbanisation and other human activities. By bringing together aquatic investigators from both poles we hope to draw attention to the distinctive features that high latitude systems hold in common, and to the marked contrasts between and within each zone. The dominant impression from the assemblage of papers presented here is one of great limnological diversity. The studies include clear, turbid and brown water rivers in the sub Arctic (LaPerriere, Van Nieuwenhuyse & Anderson); chlorophyte dominated streams in the maritime Antarctic (Hawes); streams on the antarctic continent lined with thick cyanobacterial mats (Howard-Williams & Vincent); meromictic waters in the Arctic (Ouellet, Dickman, Bisson & Page) and Antarctic (e. g.