Alter water flow rates
Overall effectiveness category Awaiting assessment
Number of studies: 1
Background information and definitions
Changes to natural stream flows, for example channelization, may negatively impact reptiles due to faster moving water (Bodie 2001), and changes in summer flow rates may alter the time available for nesting, impact the timing of hatching and affect survival rates (Lenhart et al. 2013). Interventions aimed at recovering natural flows, for example by removing the structures causing channelization and increasing flow rates or providing areas that have varied flow rates may address this threat.
Bodie J.R. (2001) Stream and riparian management for freshwater turtles. Journal of Environmental Management, 62, 443–444.
Lenhart C.F., Naber J.R. & Nieber J.L. (2013) Impacts of hydrologic change on sandbar nesting availability for riverine turtles in Eastern Minnesota, USA. Water, 5, 1243–1261.
Supporting evidence from individual studies
A before-and-after study in 2008 in an area of wetland and creeks along a river in south-eastern Australia (Howard et al. 2017) found that after a large flow of water was released into the system the relative abundance of eastern long-necked turtles Chelodina longicollis remained similar, and turtle body condition improved. Following the provision of a large flow of water, a similar number of turtles were caught in a refuge pool (0.02 turtles/trap/hour) compared to before (0.15 turtles/trap/hour). However, authors reported that only six turtles were caught after the water flow, whereas 44 were caught before. Turtles in the refuge pool had higher body condition after the flow than before (reported as condition index). In 2008, water flow into Barmah National Park was increased by opening regulators along a river that feeds into the wetlands and creeks of the park. This released 300 ML of water into the system. One pool was surveyed for turtles in October 2008, just prior to the water release, and again in February 2009, three months after the water release. Turtles were trapped using six fyke nets (50 mm mesh) that were set in shallow water in the early evening and retrieved the following morning. Captured turtles were measured and released.Study and other actions tested