Fish, flows, isotopes and food webs: the importance of connectivity in northern Australian rivers

Bradley J. Pusey (Centre of Excellence in Natural Resource Management, The University of Western Australia, Australia.)

Proceedings of Annual International Conference Syiah Kuala University - Life Sciences & Engineering Chapter
Vol 3, No 1 (2013): Life Sciences

Northern Australia contains a rich freshwater biodiversity due largely to low levels of human impact. Most rivers remain unimpacted and free-flowing. The latter characteristic is important as it ensures that natural levels of connectivity throughout the riverine landscape exist and organisms and, importantly,carbon and nutrients, can be shifted between ecosystems and different parts of the landscape. This high degree of connectivity differs between rivers according to their flow regime however; most rivers of northern Australia are highly seasonal and flow intermittently. The present paper details the importance ofmaintaining connectivity within the river and between the river and its floodplain for the maintenance of species diversity and the structure of aquatic food webs. It draws upon large datasets concerning fish biodiversity and several foodweb studies using stable isotopes assembled or conducted with the TropicalRivers and Coastal Knowledge program to illustrate the importance of connectivity