Image from www.destinationriverland.org.au
By Michael Hammer & Scotte Wedderburn
Recently we lost one of the greats of Australian limnology, with the unexpected passing of Keith Walker. Keith was a prominent pioneer of river ecology in Australia with a keen focus on the River Murray and the Murray–Darling Basin. Indeed he was often referred to as ‘Mr Murray’. He made a huge contribution to the field directly with his research and through his teaching and mentoring – he inspired many people. We strongly believe that Keith’s contribution to river ecology will continue to benefit the management of the River Murray for decades or even centuries to come.
Keith began his academic career in Melbourne, completing honours with Bill Williams on the ecology of the humble freshwater crab Amarinus (Halicarinus) lacustris.Here, his flair for both the fine scale, bottom-up detail (how a species interacts with its local environment) and top-down understanding (biogeography and landscape dynamics) was first on display (Walker 1969). He continued this superbly throughout his career examining ecosystem processes, especially the influence of river regulation (seminal papers including: Walker 1985; Walker & Thoms 1993; Walker et al. 1995; Walker 2006), while perusing species-level ecological and taxonomic interests, with a view to conservation, especially on freshwater mussels (e.g. Walker et al. 2001; Walker et al. 2014). The title ‘Mussel Man’ is appropriate given this contribution, and was first coined to us during a field trip to the Riverland in South Australia, where the landholders fondly recalled their interactions with an energetic ecologist diving for mussels along the river banks at their property in the 1980s.
Keith was a prolific author who showed distinctive flair and a succinct writing style. He published over 100 journal papers, 37 book chapters and a range of scientific reports. His ResearchGate page is a great read and resource (records a whopping 5000+ citations!), and is now a legacy that will be maintained so that others can continue to access his substantial contribution. Publications were achieved with a wide collaborative network, and countless co-authors were touched with his gift for writing. As a supervisor he encouraged us to ‘think big’, develop lateral and cross-disciplinary approaches, and ‘give it a go’, and always provided meaningful contributions and fast turn-around on drafts of papers or theses. He was very fond of “The Elements of Style” by Strunk and White, which he often encouraged his students to read when developing their writing skills. His knowledge and application of statistics in ecology was also profound, having founded the popular undergraduate subject Research Methods in Ecology. Overall Keith’s positive demeanour, enthusiasm, and polite manner were outstanding personal features. At his funeral and in subsequent discussions with colleagues the resounding reflection is just of how nice a guy Keith was, and that memory of him alone is significant.
Research gate page:
Walker, K. (1969) The ecology and distribution of Halicarcinus lacustris (Brachyura: Hymenosomatidae) in Australian inland waters. Australian Journal of Marine and Freshwater Research, 20, 163-173.
Walker, K.F. (1985) A review of the ecological effects of river regulation in Australia. Hydrobiologia, 125, 111-129.
Walker, K.F. (2006) Serial weirs, cumulative effects: the Lower River Murray, Australia. In: Kingsford, R. (Ed.) The Ecology of Desert Rivers. Cambridge University Press, pp. 248-279.
Walker, K.F., Byrne, M., Hickey, C.W., & Roper, D.S. (2001) Freshwater mussels (Hyriidae) of Australasia. In: Ecology and Evolution of the Freshwater Mussels Unionoida. Springer Berlin Heidelberg.
Walker, K.F., Jones, H.A., & Klunzinger, M.W. (2014) Bivalves in a bottleneck: taxonomy, phylogeography and conservation of freshwater mussels (Bivalvia: Unionoida) in Australasia. Hydrobiologia, 735, 61-79.
Walker, K.F., Sheldon, F., & Puckridge, J.T. (1995) A perspective on dryland river ecosystems. Regulated Rivers: Research and Management, 11, 85-104.
Walker, K.F., & Thoms, M.C. (1993) Environmental effects of flow regulation on the River Murray, South Australia. Regulated Rivers: Research and Management, 8, 103-119.
Editor’s note: Keith’s time on this planet and his contributions to Australian river ecology were indeed one gigantic magic moment. What a top fella.