Apr 10, 2017

The effects of drought and fire in the extirpation of an abundant semi-aquatic turtle from a lacustrine environment in the southwestern USA

by
Jeffrey Edward Lovich, Mari Quillman, Brian Zitt, Adam Schroeder, David Earl Green, Charles Yackulic, Paul Gibbons, Eric Goode
,
Knowledge & Management of Aquatic Ecosystems
  • Documents a significant mortality event affecting a southwestern pond turtle ( Actinemys pallida ) population living in a lake in southern California, USA
  • States that the area around the lake was impacted by a large wildland fire in 2013 which occurred during a protracted drought
  • Collected data in 2014 on water quality, demographic structure, and short-term survivorship of the population as the mortality event was still unfolding
  • Finds that water quality was poor with low levels of dissolved oxygen and high salinity of 45.90 ppt
  • Finds that many turtles were severely emaciated and coated with a pale mineralized layer on their shells and skin
  • Finds that the estimated survival rate was low for a projected 90% decline in 134 days and a high probability of extirpation within a year
  • Finds the lake was dry in September 2015 with no evidence of live turtles
  • Concludes that although this semi-aquatic species has the ability to aestivate (spend a hot or dry period in a prolonged state of torpor or dormancy) in upland habitats during periods of low water or move to other nearby water bodies, it is unlikely that they are able to do so because of their extreme poor condition and the severity of the drought conditions throughout the area