WDFW showcases work at AFS & TWS joint conference
For the first time in organization history, the American Fisheries Society (est. 1870) and The Wildlife Society (est. 1937) will be hosting their first ever joint conference. The event, taking place in Reno, NV, is expected to be one of the largest gatherings of fish and wildlife professionals ever, making it the perfect place for Washington Department of Fish & Wildlife (WDFW) staff to share some of the new science and cutting-edge approaches to management that they have been working on at home.
The American Fisheries Society is one of the world’s oldest and largest organizations dedicated to strengthening the fisheries profession, advancing fisheries science and conserving fisheries resources. The Wildlife Society is an international non-profit involved with wildlife stewardship through science and education. Both missions are something that resonate with WDFW’s mission and we are especially proud to be a sponsor at the conference.
WDFW staff will be giving multiple presentations on a wide variety of topics, ranging from shell disease to fish passage at intertidal obstructions.
Some of these presentations provide the opportunity to highlight some of the more recent work that our amazing biologists and scientists have done.
Shell disease in Washington’s Northwestern Pond Turtle
The Northwestern Pond Turtle is an endemic west coast species that’s population has been on the decline since the 1980s. By 1990, the western pond turtle population in Washington had decline to an estimated 150 animals remaining in the wild near the Columbia River Gorge. Thanks to recovery efforts, there is an approximate 800 turtles in Washington.
However, one of the biggest threats to Washington’s Northwestern Pond Turtles is an unknown shell disease pathogen, Emydomyces testavorans, which is closely related to the pathogen that causes ophidiomycosis (snake fungal disease). Due to the many unknowns about this disease, WDFW scientists developed a method for disease assessment based on computed tomography (CT) scans. The technique allows for them to quantify both the severity and extent of the disease in individual turtles. Through repeated CT scans over several years, they were able to identify the usefulness of the tool to monitor disease progression and identifying treatment success.
To read more on this topic: https://afs.confex.com/afs/2019/meetingapp.cgi/Paper/38130 or visit: https://wdfw.wa.gov/species-habitats/species/actinemys-marmorata
Applying an Aerial Mark-Recapture Distance Sampling Approach to Estimate White-Tailed Deer Density in Northeast Washington State
While eastern Washington may seem full of white-tailed deer, they are actually quite difficult to monitor using conventional ground-based methods due to terrain, vegetarian and road access issues. Due to these issues, WDFW decided it was time to develop a more robust survey technique that would be able to provide defensible, baseline population data for management decisions.
WDFW decided to test the utility of an aerial-based mark-recapture distance sampling (MRDS) approach that pairs distance sampling with a double-observer (front and rear observers on one side) sampling technique to account for any difficulties n detection on the survey line. Early results show promise in MRDS surveys as an efficient and effective method for estimating density of deer in areas with rough terrain.
Learn more about MRDS: https://afs.confex.com/afs/2019/meetingapp.cgi/Paper/38030
Assessing the Performance of Washington State Hatchery Chinook Salmon with Coded-Wire Tag Data
Chinook salmon (also known as king salmon) are the largest species of the Pacific salmon family. They are native to the North Pacific Ocean and the river systems of western North America. As species decline worsens, biologists have started to seek new ways to gather salmon data. Each year, millions of Coded Wire Tagged (CWT) salmon are released from hatcheries operated by WDFW.
These tagged salmon provide a useful tool for managing fisheries and gauging the performance of hatcheries based off of smolt to adult survival, where fisheries benefits are achieved, stray rates from the hatcheries and more. WDFW analyzed four key production regions in Washington (Puget Sound, Coast, Lower Columbia River and Interior Columbia) with unique results.
To see the results of this study and learn more: https://afs.confex.com/afs/2019/meetingapp.cgi/Paper/39349