Alter water flow rates

Overall effectiveness category Awaiting assessment
Number of studies: 1
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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.}

Study locations

Key messages

One study evaluated the effects of altering water flow rates on reptile populations. This study was in Australia.

COMMUNITY RESPONSE (0 STUDIES)

POPULATION RESPONSE (1 STUDY)

Abundance (1 study): One before-and-after study in Australia found that releasing a large flow of water into a wetland system had mixed effects on relative abundance of eastern long-necked turtles and the number of turtles caught.
Condition (1 study): One before-and-after study in Australia found that after releasing a large flow of water into a wetland system, body condition of eastern long-necked turtles improved.

BEHAVIOUR (0 STUDIES)

About key messages

Key messages provide a descriptive index to studies we have found that test this intervention.

Studies are not directly comparable or of equal value. When making decisions based on this evidence, you should consider factors such as study size, study design, reported metrics and relevance of the study to your situation, rather than simply counting the number of studies that support a particular interpretation.

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
Referenced paper
Howard K., Beesley L., Ward K. & Stokeld D. (2017) Preliminary evidence suggests freshwater turtles respond positively to an environmental water delivery during drought. Australian Journal of Zoology, 64.

Please cite as:

Sainsbury K.A., Morgan W.H., Watson M., Rotem G., Bouskila A., Smith R.K. & Sutherland W.J. (2021) Reptile Conservation: Global Evidence for the Effects of Interventions for reptiles. Conservation Evidence Series Synopsis. University of Cambridge, Cambridge, UK.

Where has this evidence come from?

List of journals searched by synopsis

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This Action forms part of the Action Synopsis:

Reptile Conservation

Related Actions

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Maintain dams or water impoundments Action Link	Awaiting assessment	1	Synopsis Link
Alter water flow rates Action Link	Awaiting assessment	1	Synopsis Link
Modify dams or water impoundments to enable wildlife movements Action Link	Awaiting assessment	1	Synopsis Link