‘Cod Squad’ turns sky-high snaps into new snag maps

15 February, 2012

Researchers from the Department of Sustainability and Environment’s (DSE) Arthur Rylah Institute (ARI) are using high definition aerial photography as part of a project assessing instream habitat such as snags across Victorian rivers and streams.

ARI fish ecologist Jarod Lyon said: “The information will help river managers to address the loss of snags and other habitat in our waterways which has become a big problem for native fish species including the threatened Murray Cod (Maccullochella peelii peelii) and Trout Cod (Maccullochella macquariensis).”

“We need a detailed picture of how much instream woody habitat is available for these native fish so we can provide guidance to river managers on maintaining and reinstating snags,” Mr Lyon said.

“The research includes ‘correcting’ the instream habitat maps derived from the aerial photographs by sending teams out to selected sites to check the accuracy of the images using high resolution GPS and sonar.”

“The result will be a map of all our rivers and streams that will show the current condition of instream habitat, information which is vital for future protection and restoration actions.”

“We are also assessing the health of the native fish population at the sites we are visiting to add to our knowledge about the role played by snags in maintaining or enhancing fish numbers, particularly for large bodied fish like the Murray Cod and Trout Cod.”

“We know these big native fish species often hide, feed and breed around submerged logs, and the loss of this habitat has contributed to them becoming threatened right across their range.”

“However, details such as how much wood is required, what types of streams and which fish communities still require further investigation.”

The Victorian Government has provided funding for this research.

The Victorian Government has a responsibility under the Wildlife Act 1975 and the Flora and Fauna Guarantee Act 1988 to protect threatened species. These animals and plants contribute significantly to the biodiversity of their ecosystems. The knowledge we acquire about these species helps us to then take the on-ground steps needed to ensure their survival.

For more information about native fish and instream habitat go to:

http://www.dse.vic.gov.au/arthur-rylah-institute/research-themes/riverine-ecology