Testing/evaluating the use of fish habitat availability for monitoring the anthropogenic impact on dry season flows in the Katherine River, tropical Australia. — ASN Events
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  3. Testing/evaluating the use of fish habitat availability for monitoring the anthropogenic impact on dry season flows in the Katherine River, tropical Australia.

Testing/evaluating the use of fish habitat availability for monitoring the anthropogenic impact on dry season flows in the Katherine River, tropical Australia. (#215)

Jayne Brim-Box 1 , Simon Townsend 2 , Alison King 3 , Mark Kennard 4
  1. Aquatic Health Unit, Department of Land Resource Management, Alice Springs, NT, Australia
  2. Aquatic Health Unit, Department of Land Resource Management, Darwin, NT, Australia
  3. Research Institute for the Environment and Livelihoods, Charles Darwin University, Darwin, NT, Australia
  4. Australian Rivers Institute, Griffith University, Nathan, Queensland, Australia

We developed Habitat Suitability Curves (HSC) for 26 fish species that occur in the Katherine River in the top end of the Northern Territory.  These models, based on depth and velocity, were then used to investigate relationships between optimal habitat availability and dry-season environmental flows.   As expected, the HSC performed best with species that showed strong fidelity to particular depths and velocities (e.g., species found in shallow, swift habitats).  For a sub-set of species we used a two-dimensional depth averaged finite element hydrodynamics model, developed for a 9-km reach of the Katherine River, to examine changes in optimal habitat availability over 16 modeled discharge scenarios.   Not surprisingly, the total optimal habitat available varied greatly between species and discharge scenarios.  We then tested the relationship between habitat availability and species abundance for an eight-year period to gain insight into the strength of habitat availability as a driver of end-of-dry season species abundance.  Implications for monitoring the anthropogenic impact on dry-season flows are discussed. 

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