2023 Early Hearing Detection & Intervention Conference
March 5-7, 2023 • Cincinnati, OH
5/20/2019 | 10:15 AM - 10:30 AM | QUANTIFYING THE EFFECTS OF ALTERED HYDROLOGY AND FOOD-WEB STRUCTURE ON ECOSYSTEM CARRYING CAPACITY IN A FLOODPLAIN RIVER | 250 DE
QUANTIFYING THE EFFECTS OF ALTERED HYDROLOGY AND FOOD-WEB STRUCTURE ON ECOSYSTEM CARRYING CAPACITY IN A FLOODPLAIN RIVER
There is widespread evidence for a reduction in biomass of tertiary consumers such as large predatory fish in lowland rivers. These declines are caused by a myriad of factors such as overfishing, habitat loss, fragmentation, declining water quality and lost spawning cues. Recently research has also emphasized the role of altered food-webs and changes in energy production as factors that may limit the current carrying capacity of higher consumers in these systems. Here we present a novel ecosystem approach to quantifying the effects of altered hydrology and altered food-web structure on the carrying capacity of large-bodied native fish in the Murray River, southeastern Australia. We combine estimates of current and historical primary production with current and historic food-webs to estimate energy available to support native fish species such as Murray cod and golden perch. Our results suggest that river regulation and food-web changes have reduced energy fluxes to these native tertiary consumers by roughly 70% relative to historic levels, due to reduced production and the presence of trophic dead ends (notably carp). Both limitations will need to be addressed contemporaneously if carrying capacity of native fish is to be restored.
- Fish
- Floodplain
- Hydrology
Presentation:
This presentation has not yet been uploaded.
Handouts:
Handout is not Available
Transcripts:
CART transcripts are NOT YET available, but will be posted shortly after the conference
Presenters/Authors
Nick Bond
(), La Trobe University, n.bond@latrobe.edu.au;
ASHA DISCLOSURE:
Financial -
Nonfinancial -
Jian Yen
(), University of Melbourne, j.yen@unimelb.edu.au;
ASHA DISCLOSURE:
Financial -
Nonfinancial -
James Thomson
(), Monash University, Melbourne, Victoria, Australia, jim.thomson@delwp.vic.gov.au;
ASHA DISCLOSURE:
Financial -
Nonfinancial -
Keller Kopf
(), Charles Sturt University, rkopf@csu.edu.au;
ASHA DISCLOSURE:
Financial -
Nonfinancial -
Daryl Nielsen
(), CSIRO, Daryl.Nielsen@csiro.au;
ASHA DISCLOSURE:
Financial -
Nonfinancial -
Nicole McCasker
(), Charles Sturt University, nmccasker@csu.edu.au;
ASHA DISCLOSURE:
Financial -
Nonfinancial -
Paul Humphries
(), Charles Sturt University, PHumphries@csu.edu.au;
ASHA DISCLOSURE:
Financial -
Nonfinancial -
John Morrongiello
(), University of Melbourne, john.morrongiello@unimelb.edu.au;
ASHA DISCLOSURE:
Financial -
Nonfinancial -
David Crook
(), La Trobe University, David.Crook@latrobe.edu.au;
ASHA DISCLOSURE:
Financial -
Nonfinancial -
Paul Reich
(), DELWP, p.reich@delwp.vic.gov.au;
ASHA DISCLOSURE:
Financial -
Nonfinancial -
Mark Kennard
(), Australian Rivers Institute, Griffith University, m.kennard@griffith.edu.au;
ASHA DISCLOSURE:
Financial -
Nonfinancial -
Gavin Butler
(), NSW Dept of Primary Industries, gavin.butler@dpi.nsw.gov.au;
ASHA DISCLOSURE:
Financial -
Nonfinancial -