Long Term Trout Monitoring
Long-term Monitoring of Wild Trout Populations in North Carolina
Currently, the North Carolina Wildlife Resources Commission (NCWRC) manages wild, self-sustaining trout populations in approximately 1,000 miles of streams via its Public Mountain Trout Waters program. Brook trout Salvelinus fontinalis, rainbow trout Oncorhynchus mykiss, and brown trout Salmo trutta populations comprise these fisheries. In addition to the ecological importance of these resources, North Carolina’s trout streams are popular destinations for anglers and contribute substantially to local economies.
From 1989 to 1996, the NCWRC conducted extended monitoring on several wild trout populations. This effort marked NCWRC’s first attempt to capture multiple years of data from individual trout streams. These data provided insight into annual variation and temporal trends of trout populations. However, long-term monitoring has not continued on these or other trout resources, and these data represent the bulk of information known about wild trout population dynamics in waters managed by the NCWRC.
In an effort to complement the information previously collected by NCWRC, staff recently established long-term monitoring sites on six trout streams in western NC. The streams selected for monitoring are dispersed geographically across the mountain region. All are located on protected lands, to increase the understanding of natural processes and diminish the threat of impacts from man-made disturbances. In northwest NC, the two streams selected were Garden Creek in Wilkes County, and Boone Fork in Watauga County.
Survey site on Boone Fork, Watauga County
Fish surveys on these six streams first occurred in 2012, and will continue annually for the next four years. All streams will then be put on a sampling rotation, ensuring each is surveyed every few years in the future. On each stream, two 200-m sampling sites were marked and trout were collected from each site using backpack electrofishing gear. All captured trout were weighed and length measured, and non-trout species were identified and counted. All fish were returned to the stream following the survey. Estimates of trout density, biomass, and condition will be calculated each year from the data collected, and compared over time. This information will provide insight into natural fluctuations of wild trout populations, as well as a better understanding of the impacts of natural events such as floods and droughts.
Brown trout and brook trout captured from Boone Fork, Watauga County
In addition to monitoring trout, NCWRC staff are installing long-term water quality monitoring devices into each stream, which will collect temperature, pH, conductivity, dissolved oxygen, and discharge levels throughout the year. Having frequent water quality data will further help understand the impact of climatic events on our trout populations, including potential impacts from global climate change.
Due to the frequency that these streams will be surveyed, coupled with the intensive nature of the work, NCWRC staff are more than happy to have volunteer help from anyone interested in assisting. For anyone that enjoys time spent on a trout stream, these outings can be a lot of fun and very rewarding. Feel free to email or give me a call if you are interested in learning more about the long-term trout monitoring project, and/or assisting with these and other surveys.
Thanks and best of luck fishing,
District 7 Fisheries Biologist I
NC Wildlife Resources Commission
AFS Certified Fisheries Professional
Fleetwood, NC 28626