Date of Graduation
Master of Science in Environmental Management (MSEM)
College of Arts and Sciences
Dr. Deneb Karentz
This project provides insight into western pond turtle (Actinemys marmorata) population health at sites in three states on the western part of the United States. Washington, Oregon and California have identified the western pond turtle as endangered, a critical and a species of special concern in that respective order. Washington has implemented a recovery plan for western pond turtles and Oregon has established best management practices for the conservation of native turtles. California has yet to establish any guidelines for the conservation of western pond turtles. This species is endemic to the western United States and has been suffering from declining populations since the late 1800s. The factors that have contributed to the decline in western pond turtle numbers include: historical commercial food use, habitat destruction and fragmentation by water diversions, urbanization and agriculture, non-native species interactions, fire, drought, and flood which are increased by climate change due to anthropogenic activity. Reptiles in general do not do well with high disturbance rates in their environment, due to their slow movements. Western pond turtles have also been afflicted by different diseases, such as a respiratory illness that decimated one-third of the population in Washington and shell disease that has been affecting populations in Washington, Oregon and California. Exposure to diseases is proliferated by contact with released pet turtles, as captive turtles contain different bacteria. The western pond turtle sites analyzed are in the Columbia Gorge and South Puget Sound in Washington, Willamette Drainage in Oregon and sites in Lake County, San Diego County and Yolo County in California. These sites were analyzed through a combination of data from peer-reviewed, unpublished literature and government agency reports. The purpose of this research is to determine the effectiveness of management plans and strategies used for the recovery and conservation of western pond turtle populations, with an emphasis on head-starting programs, non-native species removal, habitat restoration and enhancement. The results will be analyzed by looking at historical data and more recent results in relatively the same area to determine if the western pond turtle populations have increased or decreased at those sites, in order to best allocate resources and prepare management plans for the conservation of western pond turtle populations in California. The recommendations being propose are surveying and monitoring, collaboration, habitat restoration/enhancement, non-native species removal, head-start programs and land acquisition. The analysis between sites in Washington, Oregon and California showed some progress but requires further research.
Yarnal, Cristina, "Best Management Practices for the Conservation of Western Pond Turtle Populations in California" (2019). Master's Projects and Capstones. 976.