Using baited remote underwater videos to survey freshwater turtles

Freshwater turtles play an important role in aquatic ecosystems. They are long-lived and charismatic animals that contribute to improved water quality and nutrient cycling by scavenging for food. Turtles require river flows to support their movement, feeding and reproductive cycles.

The Department's Surface Water Science team is using new and innovative survey techniques with underwater cameras to track changes in turtle populations. Baited Remote Underwater Videos (or BRUVs) are underwater video cameras attached to a frame that can be lowered into the river. Bait can be attached to the frame to attract freshwater turtles and other wildlife, which are then recorded by the video camera when they approach the BRUV to feed. This survey method is more cost-effective and less invasive than traditional trapping surveys, which can cause some stress to captured wildlife.

We have published a study that tested the use of Baited Remote Underwater Videos to survey freshwater turtle populations in NSW, Australia. BRUVs produced similar catch per unit effort results to cathedral traps, making them a useful, time-effective, non-invasive technique for relative abundance and species richness estimates for freshwater turtles.

We are now using BRUVs as a tool to monitor turtle populations in NSW, such as the endangered Manning River turtle. Our first survey was undertaken in February 2023, with 39 eastern long-neck turtles, 8 Macquarie River turtles and 19 endangered Manning River turtles documented across 12 sites. This work will help us to ensure that adequate flows are provided to protect freshwater turtles, and to evaluate the effectiveness of water sharing rules that aim to protect flows for the environment.