For my project this summer, I am working with the fisheries division with the goal of monitoring populations and productivity of the many fish species found in streams throughout Great Smoky Mountains. Within the park there are almost 70 species of fish! This immense biodiversity also comes with the responsibility of making sure these species remain in the area for ecological health and for the enjoyment of park visitors!
Our primary sampling procedure consists of the 3-pass depletion methodology, wherein a 100m segment of stream is closed off with block nets both at the upstream boundary and downstream boundary. These nets ensure that a closed population is present during sampling. Once appropriate stream measurements are taken, the fun begins! with a team usually consisting of 6 people, we proceed up the stream with 2 backpack electrofishing units, typically delivering 650 volts to stun unsuspecting fish. Once fish are stunned, 2 people manning nets scoop them up, and drop them into buckets. Once the pass is finished, all captured fish are anesthetized with clove oil, measured for length and weight, and transferred to a holding cage until the next 2 passes are done. Then simply rinse and repeat 2 more times!
Once the sampling is finished, all fish are then redistributed throughout the sample area to forget about their “shocking” experience.