CSIRO Publishing blank image blank image blank image blank imageBooksblank image blank image blank image blank imageJournalsblank image blank image blank image blank imageAbout Usblank image blank image blank image blank imageShopping Cartblank image blank image blank image You are here: Journals > Marine and Freshwater Research   
Marine and Freshwater Research
Journal Banner
  Advances in the aquatic sciences
blank image Search
blank image blank image
blank image
  Advanced Search

Journal Home
About the Journal
Editorial Structure
Online Early
Current Issue
Just Accepted
All Issues
Special Issues
Research Fronts
Virtual Issues
Sample Issue
For Authors
General Information
Submit Article
Author Instructions
Open Access
For Referees
General Information
Review an Article
Referee Guidelines
For Subscribers
Subscription Prices
Customer Service
Print Publication Dates
Library Recommendation

blue arrow e-Alerts
blank image
Subscribe to our Email Alert or RSS feeds for the latest journal papers.

red arrow Connect with us
blank image
facebook twitter logo LinkedIn


Article << Previous     |     Next >>   Contents Vol 59(2)

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

Thomas S. Rayner A C D, Bradley J. Pusey B, Richard G. Pearson A

A School of Marine and Tropical Biology, James Cook University, Townsville, Queensland 4811, Australia.
B Australian Rivers Institute, Griffith University, Brisbane, Queensland 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
 Full Text
 PDF (455 KB)
 Export Citation


Strong relationships between seasonal flooding, instream habitat structure and fish assemblages have been well documented in large tropical rivers (e.g. the flood pulse concept). However, the mechanics of these relationships are likely to differ substantially in smaller coastal rivers, such as those in Costa Rica, south-east Brazil and Australia’s Wet Tropics. These systems typically feature steep upland streams with short, deeply incised lowland channels and poorly connected floodplains. This hypothesis was investigated by documenting spatial and temporal variation in fish-habitat relationships in the Mulgrave River, north-east Queensland. Sampling was conducted at four lowland sites under a range of flow conditions, from dry-season baseflows to a one-in-ten-year flood. Longitudinal environmental gradients and fine-scale habitat patches were important in regulating fish assemblage structure during the dry season. However, high wet-season flows, constrained by the deep channel, acted as disturbances rather than gentle flood-pulses. In particular, the mobilisation of bed sediments led to scouring of aquatic vegetation and a dramatic reduction in habitat heterogeneity. Seasonal movements of fish led to significant changes in assemblage structure – from a community dominated by Neosilurus ater, Hypseleotris compressa, Awaous acritosus and Redigobius bikolanus during the dry season, to one dominated by Nematalosa erebi, Ambassis agrammus and Glossamia aprion during the wet season. Based on these observations, together with information from the literature, a conceptual model of fish-habitat dynamics is presented that is better suited to small tropical rivers than those developed in larger systems with expansive floodplains.

Legal & Privacy | Contact Us | Help


© CSIRO 1996-2016