Live Oral Presentation in person as part of National Virtual Conference AFSS Conference 2020

Effects of climate and landscape change on endemic freshwater macrocrustacean persistence in south-western Australia. (#26)

Holly E. Emery-Butcher 1 2 , Stephen J. Beatty 1 2 , Belinda J. Robson 1
  1. Environmental and Conservation Science, Murdoch University, Murdoch, WA, Australia
  2. Harry Butler Institute, Murdoch University, Perth, WA, Australia

Climate change is warming the Earth, but in southwestern Australia the climate is also drying, changing the duration and extent of suitable habitat for aquatic fauna including freshwater crustaceans. Despite the important roles that macrocrustaceans play in freshwater ecosystems, how climatic drying is impacting them has not been well documented. In the southwestern Australian biodiversity hotspot, little is known of the life history characteristics of many endemic fauna. Therefore, this project seeks to characterise the life histories of some endemic crustaceans and determine their potential responses to drying and prolonged dry periods. A combination of laboratory habitat drying experiments and a field survey were used to examine these responses in two model species; the amphipod Austrochiltonia subtenuis, and the isopod Paramphisopus palustris. Results suggest P. palustris is capable of aestivation for short periods and specific strategies to survive drying differ between populations (e.g. digging into sediment, use of vegetation etc.). However, survival was generally lower in the dry experimental group when compared with the moist (water level with substrate surface) or control (fully inundated) microcosms. Therefore, extended dry periods may exceed their capacity to survive and affect population survival differently. Field surveys suggest that the distribution and abundance of P. palustris and A. subtenuis across Swan Coastal Plain wetlands appears to have decreased in comparison to historical data, creating concern about their long-term persistence as the climate continues to dry and warm. A. subtenuis is seemingly associated with the emergent macrophyte Baumea articulata which could act as a drying and/or predation refuge. However, the range of B. articulata may have contracted, further limiting A. subtenuis persistence. Examining the biology of these species allows a greater understanding of the potential impacts of climate change on these endemic macrocrustaceans and the ecosystem services they provide.