Isotopic and modelling studies of food web structure in wet and dry conditions, Yanga wetlands NSW, Australia

Simple item page
dc.contributor.authorMazumder, Den_AU
dc.contributor.authorJohansen, MPen_AU
dc.contributor.authorSaintilan, Nen_AU
dc.contributor.authorIles, Jen_AU
dc.contributor.authorKnowles, Len_AU
dc.contributor.authorKobayashi, Yen_AU
dc.contributor.authorWen, Len_AU
dc.date.accessioned2010-09-21T03:27:51Zen_AU
dc.date.available2010-09-21T03:27:51Zen_AU
dc.date.issued2010-05-11en_AU
dc.date.statistics2010-05-11en_AU
dc.description.abstractFloodplain wetlands provide habitat for a diverse range of aquatic biota, as well as performing other important ecosystem functions such as transformation of nutrients, providing breeding and nursery grounds for numerous species. Overall productivity and biodiversity of floodplain wetlands are closely linked with water availability, and in particular to the reliable reoccurrence of water inflows. Alteration of wetland inflow and outflow regimes can greatly impact the functioning of food-webs through biodiversity loss, diversion of energy flow and ecosystem functionality. In the present study stable isotope ratios (δ13C and δ15N) of primary producers, sediment organic matter (SOM) and a variety of invertebrate and fish species are used to gain better understanding of the food-web relations at various waterholes in wetter and drier conditions in Yanga National Park, in the lower Murrumbidgee floodplain. Mass-balance mixing models were used to examine relative food source contributions to consumer diet. We also employed probabilistic simulation software to better understand trends of trophic positions, diet shifts and varying contributions from sources to consumers in waterholes of the Yanga wetlands. We compared δ13C and δ15N data from wetter (greater surface water area and depth) conditions in February, with data from the drier (smaller surface water area an depth) conditions in August. The data indicated contraction in the trophic position of Hypseleotris spp. (carp guudgeon) in August consistent with shrinking waterholes where species were forced into competing for overlapping, and a more limited variety, of food sources. In particular the endemic Hypseleotris spp. appears to be forced into greater competition with the exotic C. carpio (carp). Data also indicated that energy source of consumer species varied with changing water levels among all waterholes. The drier (August) δ13C values for fish and insects were typically shifted ~1-3‰ lower than the corresponding wetter (February) values. These shifts appear to correspond to depletion in the δ13C algal values, and appear to indicate a greater proportional contribution of δ13C from algae to the δ13C in consumers. This study provides δ13C and δ15N values for endemic and exotic aquatic species in Australian semi-arid wetlands. It provides modelling results indicating shifts in energy source and trophic position relative to water fluctuations and indicates increased competition among similar species that may adversely impact endemic species populations.en_AU
dc.description.sponsorshipNSW Department of Environment, Climate Change and Water; CSIRO Water for a Healthy Country Flagshipen_AU
dc.identifier.citationMazumder, D., Johansen, M., Saintilan, N., Iles, J. Knowles, L., Kobayashi, Y., & Wen, L. (2010). Isotopic and modelling studies of food web structure in wet and dry conditions, Yanga wetlands NSW, Australia. Paper presented to the Ecosystem Response Modelling in the Murray-Darling Basin: Better Use of Environmental Water, 11th - 12th May 2010. Sydney Olympic Park, Australia: Waterview Conference Centre, (pp. 25).en_AU
dc.identifier.conferenceenddate12 May 2010en_AU
dc.identifier.conferencenameEcosystem Response Modelling in the Murray-Darling Basin: Better Use of Environmental Wateren_AU
dc.identifier.conferenceplaceSydney Olympic Park, Australiaen_AU
dc.identifier.conferencestartdate11 May 2010en_AU
dc.identifier.govdoc2701en_AU
dc.identifier.pagination25en_AU
dc.identifier.urihttp://apo.ansto.gov.au/dspace/handle/10238/2541en_AU
dc.language.isoenen_AU
dc.publisherCSIROen_AU
dc.subjectAustraliaen_AU
dc.subjectWetlandsen_AU
dc.subjectFooden_AU
dc.subjectSpecies diversityen_AU
dc.subjectEcosystemsen_AU
dc.subjectSimulationen_AU
dc.titleIsotopic and modelling studies of food web structure in wet and dry conditions, Yanga wetlands NSW, Australiaen_AU
dc.typeConference Presentationen_AU
Files
Original bundle
Now showing 1 - 1 of 1
Thumbnail Image
Name:
ermMurraydarling.pdf
Size:
918.19 KB
Format:
Adobe Portable Document Format
Description:
Download
License bundle
Now showing 1 - 1 of 1
Thumbnail Image
Name:
license.txt
Size:
1.71 KB
Format:
Item-specific license agreed upon to submission
Description:
Download
Collections
Conference Publications