23 Aug Fishing for Fishies: continuing Basinwide Habitat Surveys
The Basinwide Systematic Surveys are still underway! If you haven’t read my last blog post detailing the first step of our current survey process, I recommend it for an in-depth explanation! For those who haven’t, our basinwide systematic survey process begins with habitat typing, which involves moving through the creek and dividing it into small sections, or ‘units’, and taking measurements such as depth and width of these sections. After they are classified, these units are selected at random intervals to be subjected to the second part of this process, snorkeling!
Snorkeling takes place to identify and count the species present in the unit of interest. While we focus on salmonids, this includes anything from sculpin, a freshwater fish in this region, to crayfish! The process involves one or two snorkelers swimming (and more often army crawling) through the unit with a flashlight and tallying any species they see. This tends to be the most accurate way to count the fish, as they are not too disturbed by the snorkeler passing through the creek. Once this process is complete, units are randomly chosen for the last step in this process, electrofishing.
Electrofishing, or e-fishing, involves using an electrofisher to stun the fish in the creek and remove them to get a more concrete count of what occupies the unit. It may sound a little scary, but I promise it isn’t as bad as it may sound! This process can be shown in the picture below- the person operating the e-fisher stands in the middle and uses a wand that emits a low voltage of electricity that attracts and temporarily stuns fish. The fish recover within seconds, so the two netters on either side have to be alert enough to catch any fish that come near the wand. Once the fish are netted, length and weight measurements are taken, after which they are returned to the creek.