Spatio-temporal dynamics of fish feeding in the lower Mulgrave River, north-eastern Queensland: the influence of seasonal flooding, instream productivity and invertebrate abundance
Thomas S. Rayner A C D , Bradley J. Pusey B and Richard G. Pearson AA School of Marine and Tropical Biology, James Cook University, Townsville, Qld 4811, Australia.
B Australian Rivers Institute, Griffith University, Brisbane, Qld 4111, Australia.
C Present address: School of Biological, Earth and Environmental Sciences, University of New South Wales, Sydney, NSW 2052, Australia.
D Corresponding author. Email: thomas.rayner@unsw.edu.au
Marine and Freshwater Research 60(2) 97-111 https://doi.org/10.1071/MF08055
Submitted: 27 February 2008 Accepted: 3 September 2008 Published: 20 February 2009
Abstract
Wet-season flooding causes dietary shifts in tropical freshwater fish by regulating instream productivity, habitat structure and food availability. These dynamics have been comprehensively documented worldwide, but data are limited for Australia’s Wet Tropics rivers. The aim of the present study was to extend our earlier fish–habitat model for these systems by examining the role of trophic dynamics in determining fish assemblage composition. Chlorophyll a and phaeophytin concentrations, benthic and littoral invertebrates and fish were collected at four sites in the lower Mulgrave River under a range of flow conditions. Wet-season flooding caused significant reductions in instream productivity, whereas habitat disturbance reduced densities and abundances of littoral and benthic invertebrates. However, volumetric gut contents of 1360 fish, from 36 species, revealed seasonal shifts in guild membership by only two species, with fish moving between sites to target their preferred prey items – largely irrespective of differences in habitat structure. As a result, the food consumed by the fish community present at each site closely reflected the seasonal availability of food resources. The present paper questions whether fish community composition in small tropical rivers can be accurately predicted from habitat surrogates alone and encourages consideration of constraints imposed by the trophic dynamics and reproductive ecology of fish.
Additional keywords: Australia, Chordata, diet, flow, food webs, guild, niche, Pisces, tropical, vertebrates.
Acknowledgements
This project was funded by grants from the Cooperative Research Centre for Tropical Rainforest Ecology and Management and James Cook University (JCU). Fish were collected under Queensland Department of Primary Industries – Fisheries permit PRM03040F and JCU Animal Care and Ethics permit A818_03. Mike Steele (JCU), Lee Belbin (Blatant Fabrications) and Mark Kennard (Griffith University) assisted with statistical analyses. In-kind support was provided by Queensland Department of Primary Industries – Fisheries. Field assistance was provided by Colton Perna, Zoë Baker, Paul Thuesen, Paul Godfrey, Amanda Soymonoff, Mo Healy, Anne Gulliard, Megan Barnes, Cameron Crothers-Stomp, Andrew Kaus, Andrew Jones, Rusty Ligon and Michael Pusey. Access to private land and other assistance in the field was provided by the Rossi, Thomasen and Moller families. Two anonymous reviewers provided comments on the manuscript.
Angermeier, P. L. (1982). Resource seasonality and fish diets in an Illinois stream. Environmental Biology of Fishes 7, 251–264.
| Crossref | GoogleScholarGoogle Scholar |
Arthington, A. H. , Balcombe, S. R. , Wilson, G. A. , Thoms, M. , and Marshall, J. (2005). Spatial and temporal variation in fish-assemblage structure in isolated waterholes during the 2001 dry season of an arid-zoe floodplain river, Cooper Creek, Australia. Marine and Freshwater Research 56, 25–35.
| Crossref | GoogleScholarGoogle Scholar |
Clarke, K. R. , and Green, R. H. (1988). Statistical design and analysis for a ‘biological effects’ study. Marine Ecology Progress Series 46, 213–226.
| Crossref | GoogleScholarGoogle Scholar |
Hart, D. D. , and Finelli, C. M. (1999). Physical-biological coupling in streams: the pervasive effects of flow on benthic organisms. Annual Review of Ecology and Systematics 30, 363–395.
| Crossref | GoogleScholarGoogle Scholar |
Little, A. S. , Tonn, W. M. , Tallman, R. F. , and Reist, J. D. (1998). Seasonal variation in diet and trophic relationships within the fish communities of the lower Slave River, Northwest Territories, Canada. Environmental Biology of Fishes 53, 429–445.
| Crossref | GoogleScholarGoogle Scholar |
Piet, G. J. , and Guruge, W. A. H. P. (1997). Diel variation in feeding and vertical distribution of ten co-occurring fish species: consequences for resource partitioning. Environmental Biology of Fishes 50, 293–307.
| Crossref | GoogleScholarGoogle Scholar |
Rabeni, C. I. , and Minshall, G. M. (1977). Factors affecting microdistribution of stream benthic insects. Oikos 29, 33–43.
| Crossref | GoogleScholarGoogle Scholar |
Rayner, T. S. , Pusey, B. J. , and Pearson, R. G. (2008). Seasonal flooding, instream habitat structure and fish assemblages in the Mulgrave River, north-east Queensland: towards a new conceptual framework for understanding fish-habitat dynamics in small tropical rivers. Marine and Freshwater Research 59, 97–116.
| Crossref | GoogleScholarGoogle Scholar |
Russell, D. J. , Ryan, T. J. , McDougall, A. J. , Kistle, S. E. , and Aland, G. (2003). Species diversity and spatial variation in fish assemblage structure of streams in connected tropical catchments in northern Australia with reference to the occurrence of translocated and exotic species. Marine and Freshwater Research 54, 813–824.
| Crossref | GoogleScholarGoogle Scholar |
Thorp, J. H. , and Delong, M. D. (1994). The riverine productivity model: an heuristic view of carbon sources and organic processing in large river ecosystems. Oikos 70, 305–308.
| Crossref | GoogleScholarGoogle Scholar |
Webster, I. T. , Rea, N. , Padovan, A. V. , Dostine, P. , Townsend, S. A. , and Cook, S. (2005). An analysis of primary production in the Daly River, a relatively unimpacted tropical river in northern Australia. Marine and Freshwater Research 56, 303–316.
| Crossref | GoogleScholarGoogle Scholar | CAS |
Werner, E. E. , and Gilliam, J. F. (1984). The ontogenetic niche and species interactions in size-structured populations. Annual Review of Ecology and Systematics 15, 393–425.
| Crossref | GoogleScholarGoogle Scholar |
Xie, S. , Cui, Y. , Zhang, T. , and Li, Z. (2000). Seasonal patterns in feeding ecology of three small fishes in the Biandantang Lake, China. Journal of Fish Biology 57, 867–880.
| Crossref | GoogleScholarGoogle Scholar |
Zaret, T. M. , and Rand, A. S. (1971). Competition in tropical stream fishes: support for the competitive exclusion principle. Ecology 52, 336–342.
| Crossref | GoogleScholarGoogle Scholar |