Associate Professor Skye Wassens & Nick Whiterod. (Aquasave)
This contingency monitoring project is monitoring the current population of juvenile golden perch in the Yanga National Park floodplain (Tala and Yanga Lakes) to establish spawning times of the cohort and relate to prevailing flow conditions.
It will integrate findings with data from previous surveys done in 2018 for the Native and invasive fish dispersal, spawning and trophic dynamics during a managed river-floodplain connection project which coincided with a watering action in 2018 timed to coincide with the golden perch's key breeding time, based on the model of how golden perch respond in rivers.
From those surveys the researchers found that resident adults from the floodplain responded to the inundation by moving short distances up the floodplain creeks, spawning and recruiting all within the floodplain.
While it was very dry the following year (2019) with limited environmental water available, the research team, while doing routine sampling of Tala Creek and even though the creek which was completed disconnected from the river throughout the year, discovered golden perch with total lengths consistent with those of young-of-year fish - an indication that the fish may have spawned under low flow conditions or during late summer to early autumn.
With a release of Commonwealth environmental water into the system in October 2020, the team returned to the area to collect and age golden perch in the system before watering commenced.
In February/March 2021 (Stage 2) the researchers will return to the area to assess again what impact the watering action has had on the fish.
From this work the researchers expect to:
This work will inform management strategies for the floodplain Golden Perch population and contribute to broader knowledge of Golden Perch spawning and recruitment. It is also expected to lead to a much better understanding of the dynamics between native fish and the floodplains in general and could lead to the long-term goal of introducing 'lost' species such as Murray hardyheads and Olive perchlets to a few high priority locations once the hydrological regime and ecological function of those locations has been restored.
Skye Wassens email