Mark-Recapture Estimation of Razor-backed Musk Turtle Abundance in Louisiana Active
USGS scientists are working to determine the baseline population numbers of the Razor-backed Musk Turtle.
The Science Issue and Relevance: The Razor-backed Musk Turtle (Sternotherus carinatus) is a Tier 3, Species of Greatest Conservation Need (SGCN) in Louisiana. From 2009 through 2016, there was a commercial rush on Razor-backed Musk Turtles in Louisiana, with total exports increasing from 9,000 in 2009 to an average of 100,000 turtles per year from 2014 to 2017. Due to the potential impact of limitless harvest, a moratorium was placed on wild harvest of Razor-backed Musk Turtles in October 2016. To justify or suspend the moratorium, baseline population data are necessary for evaluation by biologists from Louisiana Department of Wildlife and Fisheries (LDWF) biologists. USGS scientists are working to determine the baseline population numbers through mark and recapture of the Razor-backed Musk Turtle in order to provide LDWF with information necessary to ensure persistence of the species.
Methodology for Addressing the Issue: Razor-backed Musk Turtles will be trapped at 16 sites with 8 in southwestern Louisiana and 8 sites in southeastern Louisiana. Each site will be trapped for three consecutive nights using up to 20 baited turtle traps based on modified crab traps. Captured turtles will be measured, sexed, and marked by filing notches on the carapace before being released at their point of capture. Recapture data collected over the three consecutive trap nights will be used in closed population capture-mark-recapture models to obtain estimates of population abundance at each site.
Future Steps: We plan to continue trapping and working on modeling that will allow us to estimate the abundance and site occupancy rate of this species in southern Louisiana.
USGS scientists are working to determine the baseline population numbers of the Razor-backed Musk Turtle.
The Science Issue and Relevance: The Razor-backed Musk Turtle (Sternotherus carinatus) is a Tier 3, Species of Greatest Conservation Need (SGCN) in Louisiana. From 2009 through 2016, there was a commercial rush on Razor-backed Musk Turtles in Louisiana, with total exports increasing from 9,000 in 2009 to an average of 100,000 turtles per year from 2014 to 2017. Due to the potential impact of limitless harvest, a moratorium was placed on wild harvest of Razor-backed Musk Turtles in October 2016. To justify or suspend the moratorium, baseline population data are necessary for evaluation by biologists from Louisiana Department of Wildlife and Fisheries (LDWF) biologists. USGS scientists are working to determine the baseline population numbers through mark and recapture of the Razor-backed Musk Turtle in order to provide LDWF with information necessary to ensure persistence of the species.
Methodology for Addressing the Issue: Razor-backed Musk Turtles will be trapped at 16 sites with 8 in southwestern Louisiana and 8 sites in southeastern Louisiana. Each site will be trapped for three consecutive nights using up to 20 baited turtle traps based on modified crab traps. Captured turtles will be measured, sexed, and marked by filing notches on the carapace before being released at their point of capture. Recapture data collected over the three consecutive trap nights will be used in closed population capture-mark-recapture models to obtain estimates of population abundance at each site.
Future Steps: We plan to continue trapping and working on modeling that will allow us to estimate the abundance and site occupancy rate of this species in southern Louisiana.