Kelleway, Jeff

Mazumder, Debashish

Wilson, Geoffrey

Saintilan, Neil

Knowles, Lisa

Iles, Jordan

Kobayashi, Tsuyoshi

2010

Riverine food webs are often laterally disconnected (i.e. between watercourses) in regulated floodplain wetlands for prolonged periods. We compared the trophic structure of benthic resources and consumers (crustaceans and fish) of the three watercourses in a regulated floodplain wetland (the Gwydir Wetlands, Australia) that shared the same source water but were laterally disconnected. The crustaceans 'Cherax destructor' (yabby), 'Macrobrachium australiense' (freshwater prawn), the exotic fish 'Cyprinus carpio' (European carp) and 'Carassius auratus' (goldfish) showed significantly different δ¹³C values among the watercourses, suggesting spatial differences in primary carbon sources. Trophic positions were estimated by using δ¹⁵N values of benthic organic matter as the base of the food web in each watercourse. The estimated trophic positions and gut contents showed differences in trophic positions and feeding behaviours of consumers between watercourses, in particular for 'Melanotaenia fluviatilis' (Murray–Darling rainbowfish) and 'M. australiense'. Our findings suggest that the observed spatial variation in trophic structure appears to be largely related to the spatial differences in the extent and type of riparian vegetation (i.e. allochthonous carbon source) across the floodplain that most likely constituted part of the benthic resources.

Marine and Freshwater Research, 61(4), p. 430-440

1448-6059

1323-1650

https://hdl.handle.net/1959.11/6011

CSIRO Publishing

Trophic structure of benthic resources and consumers varies across a regulated floodplain wetland

Journal Article

Publication