We spent a day assisting USGS with their efforts out on Clear Lake in California. For several years they have trapped and PIT tagged adult suckers in the lake. The lake is a natural freshwater lake, but was dammed at its outlet in 1914 to increase its capacity. Around the lake cattle graze and it was a historical site used by the native tribes of the area. USGS puts out trammel nets, which are long nets that layout and act similar to mist nets, that are used to trap birds. When a fish swims into the net it creates a pocket and gets trapped. We placed seven nets and set them for 2 hours. For the day our boat caught over 70 fish, another boat caught over 100. Most fish caught were adult Shortnose suckers, we only caught about 4 Lost River. Each fish was measured, scanned for a previous tag, and if one was not found, was then PIT tagged. It was my first time handling adult suckers, work all summer has only dealt with juveniles.

Measuring fish out on Clear Lake

Lost River Sucker

Threemile creek is about an hour north of Klamath Falls and a few years ago Bull trout was found in the stream. Bull trout are a listed threatened species and are a char in the Salmonidae family. Since its discovery in the stream, efforts to remove Brown trout, an introduced species from Europe, started. Brown trout compete with the threatened Bull trout for resources. They were manually removed from the stream at first. Then electroshocking was used, and finally a chemical treatment to ensure no fish remained. We assisted with one last effort of electroshocking before the placement of large woody debris. These downed tress would be helicoptered in to create fish habitat, such as pools, and eventually level out the stream. Barriers were placed downstream to prevent brown trout from traveling back upstream. Once the woody debris is placed the hope is bull trout will then recolonize from upstream.

Electrofishing Threemile Creek

We spent a few days in the Gerber reservoir area searching pools for juvenile suckers. We used electroshocking to catch the fish and collect genetic samples. A small clip of a pectoral fin was enough to test for DNA.

My internship is wrapping up shortly with only a little over a week left. But there’s plenty more fieldwork planned before I leave.