University of Tasmania, Australia

Ecosystem processes in freshwater systems. The movement of carbon (energy) and nutrients in shallow lakes, streams and rivers have been central themes of our research since 1999. From this we have developed mechanistic models and complementary empirical research to demonstrate how these processes link with the conservation biology of aquatic plants and animals, and to support decision making in water and land-use management. This research has then fed into national and international collaborations on the impacts of climate change and the challenges for conservation planning in freshwater systems.

Carbon and nutrients in small headwater streams. Long-term (>7 years) research in the Southern Forests of Tasmania has developed hypotheses about the impacts of clearfell-burn-and-sow silviculture on in-stream processes from space-for-time surveys. These hypotheses are now being tested in a suite of long-term sites using Before-After-Control-Impact designs combined with novel, complementary studies of nutrient spiralling and the potential changes in the sources of Dissolved Organic Carbon – which is often the biggest pool of carbon in fresh waters.

Food webs in shallow lakes and regulated rivers. Using mechanistic models and long-term empirical data in shallow lakes, we have shown how water level manipulations can have contrasting impacts on internal loading of nutrients and the light climate of shallow lakes. This alters the food web with cascading impacts on endemic Tasmanian native fish. Most recently we have extended this research approach to contrast the food webs of regulated and unregulated eastern Tasmanian rivers in which we used stable isotope analyses to establish the central role of aquatic vascular plants as a food source despite their near-invisibility in these systems. Dead terrestrial plant material is by far the dominant potential food source in these systems, and we have been part of an international collaboration that has established the increasing importance of invertebrates in processing this material as one moves away from the equator. The impacts of climate change on this important process is now the focus of this group of collaborators.

Barmuta, L.A., Linke, S., and Turak, E. (2011) Bridging the gap between 'planning' and 'doing' for biodiversity conservation in freshwaters. Freshwater Biology 56(1), 180-195.

Boyero, L., Pearson, R.G., Dudgeon, D., Ferreira, V., Graça, M.A.S., Gessner, M.O., Boulton, A.J., Chauvet, E., Yule, C.M., Albariño, R.J., Ramírez, A., Helson, J.E., Callisto, M., Arunachalam, M., Chará, J., Figueroa, R., Mathooko, J.M., Gonçalves Jr, J.F., Moretti, M.S., Chará-Serna, A.M., Davies, J.N., Encalada, A., Lamothe, S., Buria, L.M., Castela, J., Cornejo, A., Li, A.O.Y., M'Erimba, C., Villanueva, V.D., del Carmen Zúñiga, M., Swan, C.M., and Barmuta, L.A. (In press) Global patterns of stream detritivore distribution: Implications for biodiversity loss in changing climates. Global Ecology and Biogeography.

Boyero, L., Pearson, R.G., Gessner, M.O., Barmuta, L.A., Ferreira, V., Graça, M.A.S., Dudgeon, D., Boulton, A.J., Callisto, M., Chauvet, E., Helson, J.E., Bruder, A., Albariño, R.J., Yule, C.M., Arunachalam, M., Davies, J.N., Figueroa, R., Flecker, A.S., Ramírez, A., Death, R.G., Iwata, T., Mathooko, J.M., Mathuriau, C., Gonçalves, J.F., Moretti, M.S., Jinggut, T., Lamothe, S., M’Erimba, C., Ratnarajah, L., Schindler, M.H., Castela, J., Buria, L.M., Cornejo, A., Villanueva, V.D., and West, D.C. (2011) A global experiment suggests climate warming will not accelerate litter decomposition in streams but might reduce carbon sequestration. Ecology Letters 14, 289-294.

Clapcott, J.E., and Barmuta, L.A. (2010) Forest clearance increases metabolism and organic matter processes in small headwater streams. Journal of the North American Benthological Society 29(2), 546-561.

Clapcott, J.E., and Barmuta, L.A. (2010) Metabolic patch dynamics in small headwater streams: Exploring spatial and temporal variability in benthic processes. Freshwater Biology 55(4), 806-824.

Hardie, S.A., White, R.W.G., and Barmuta, L.A. (2008) Reproductive biology of the threatened golden galaxias Galaxias auratus Johnston and the influence of lake hydrology (Journal of Fish Biology (2007) 71, (1820-1840)). Journal of Fish Biology 72(3), 785-786.

Watson, A., and Barmuta, L.A. (2010) Litter retention in Tasmanian headwater streams after clear-fell logging. Hydrobiologia 637, 197-206.

Watson, A., and Barmuta, L.A. (2011) Feeding-preference trials confirm unexpected stable isotope analysis results: Freshwater macroinvertebrates do consume macrophytes. Marine and Freshwater Research 62(10), 1248-1257.

Members (External)

Associate Professor Leon A. Barmuta, Freshwater Ecology Group, School of Zoology, Leon.Barmuta@utas.edu.au

Adjunct Professor Peter E. Davies, Freshwater Systems & School of Zoology., P.E.Davies@utas.edu.au

Dr Regina Magierowski,  Regina.Magierowski@utas.edu.au