Gunbower Forest is an icon site and as such a watering strategy with multiple biodiversity benefits is implemented. However, along with these benefits there is also the detrimental impact that delivery of flows into Gunbower Forest also benefits the recruitment of carp. Apart from competing with native fish for resources, carp are also having impacts on the floodplain, especially in regard to native wetland vegetation. A Gunbower Forest carp movement study was undertaken to determine pathways of carp movement within the forest and for entry/exit locations between the forest and the river.
Forty carp were acoustically tagged in September 2016. Carp responded immediately to water inundation on the floodplain with some carp moving over large areas of the floodplain, whilst others showed limited floodplain movement. At least six entry/exit locations from the forest into the Murray River have been identified during the study. Several large river movement patterns were also observed, greater than 100 kilometres downstream and upstream. These fish moved away from a known carp breeding area during the spawning period, and returned after floodplain recession. Around a quarter of the tagged fish showed site fidelity, returning to their tagging location soon after the flood receded.