Images

This is a diagram of a cross section of a dam. This diagram is to show where gas bubble trauma could occur.

To understand gas bubble trauma, imagine scuba divers surfacing too quickly. As pressure decreases, dissolved gases in their blood can form bubbles, causing joint pain, paralysis, and even death—a condition commonly known as “the bends.” Fish can experience something similar. 

Since the early 1990s, WFRC has supported state and federal agencies by providing regular assessments of gas bubble trauma in salmon. But salmon aren’t the only fish affected. In 2020, scientists at the Cook lab began monitoring GBT in resident species like sculpin, northern pikeminnow, and three-spined stickleback.

This is fieldwork from a Chinook salmon egg survival pilot study in the Sacramento River. Egg boxes were placed in the river at different locations to collect data on egg-to-fry survival. Some examples of data collected include water velocity and river flow, gravel temperature, scour and deposition, and sediment type.

This is a photo from our scientists working with the Yakama Nation to remove smallmouth bass and other invasive salmon-eating predators. The work involves taking fin clips, scales, diet samples, and tagging and releasing larger fish. This fieldwork will continue through late May 2025. The crew shown in the photos are Ben, Becky, Jeff, and Chloe. 

California Department of Fish & Wildlife boat on Shasta Reservoir partnering with USGS Western Fisheries Research Center to conduct telemetry studies.

Mitchell Morse and Caitlin Stockwell drove down to Redding, CA to wrap up the Shasta Reservoir fish telemetry project. They worked with California Department of Fish and Wildlife partners to remove 16 submersible acoustic telemetry receivers within the reservoir, and 5 receivers installed on Shasta Dam.

A photo of the McCloud arm looking upstream from one of the telemetry deployment sites.

This is Shasta Dam in California. Mitchell Morse and Caitlin Stockwell drove down to Redding, CA to wrap up the Shasta Reservoir fish telemetry project. They worked with California Department of Fish and Wildlife partners to remove 16 submersible acoustic telemetry receivers within the reservoir, and 5 receivers installed on Shasta Dam.

View of Owyhee Reservoir in Oregon.  Water samples collected from this reservoir are used to validate satellite remote sensing of water quality. 

Northwestern pond turtles are sexually dimorphic (females and males look different). One way to tell female and male turtles apart is that they often have different color patterns on their face and throats. Females have a more speckled throat, while males throats tend to be more solidly white/yellow.

These turtles are considered juveniles until they reach about 5 inches long. In this part of their range turtles remain juveniles and usually do not begin to reproduce until they are over ten years old.  

Photo taken at Lookout Point Reservoir, Oregon. 

This is a juvenile turtle. When they aren't in scared or in danger, northwestern turtles are very curious and will look towards movements and unusual sounds to figure out what is going on. They have excellent vision and hearing.  

Photo taken at Hills Creek Reservoir, Oregon. 

We glue transmitters onto their upper shells (called their carapace) using non-permanent epoxy. We will track these turtles until the transmitter battery dies (about 2 years) and soon after that the epoxy degrades, and the transmitter will fall off the turtle without harming the turtle or it's shell. 

Turtle found in the spring coming out of brumation. It is still covered in mud from being buried in the ground all winter.  They can brumate up to several months! 

Photo taken at Lookout Point Reservoir, Oregon. 

Northwestern pond turtles often return to the same area each winter for brumation. We tracked this turtle overwintering in almost the exact same area in the winters of 2023 and 2024. It's brumation location was only 11m apart between the two years.  

Photo taken at Fall Creek Reservoir, Oregon. 

Ramona Rapp is preparing the surgery station where adult Lost River suckers are surgically implanted with acoustic telemetry transmitters. This study is being conducted to understand seasonal survival and habitat use of Lost River suckers in Upper Klamath Lake.

This turtle crossed a road leaving the reservoir and will cross it again to return to the reservoir. Road crossings present high risk to turtles and are a large source of mortality.  

Photo taken at Lookout Point Reservoir, Oregon

Sarah Flores collecting snails from the marshes of Upper Klamath Lake. At the Western Fisheries Research Center, scientists are conducting research on parasites in Upper Klamath Lake, Klamath Falls, OR.

Sarah Flores presenting her lab's work at the 2025 International Symposium on Fish Parasites in Mérida Yucatán, Mexico. Sarah Flores works with the Western Fisheries Research Center in Seattle, WA to help suckers in the Upper Klamath Lake in Klamath Falls, OR.

This is a photo of fish pathogenic cercariae collected from intermediate snail hosts. The Western Fisheries Research Center (WFRC) is working to determine the extent of the effects of these parasitic organisms on suckers in Klamath Falls, OR. Top: Diplostomum gavium; Bottom: Bolbophorus sp.