Fish Health

The objective of this research is to assess the sensitivity of female and male LMB reproductive capabilities at the time of year when they are physiologically preparing for spawning season (also known as gonad recrudescence).

The WFRC has partnered separately with both the Skagit River System Tribal Cooperative and the Nisqually Tribe to research the use of otoliths (calcium carbonate deposits beneath the brain used in hearing and balance that grow in proportion to the overall growth of the fish) as a tool in examination of Puget Sound Fall Chinook salmon life history.

The potential for invasive species introductions in Arctic and Subarctic ecosystems is growing as climate change manifests and human activity increases in high latitudes.

This study is designed to be a high-throughput alternative to traditional methods of using whole fish assays to screen compounds for toxicity. This approach involves an initial pre-screening of a chemical databank to select molecules possessing characteristics identified as predictive criteria for potential toxicity to the fathead minnow, followed by cytotoxicity screening of selected compounds...

Fish are an important component of marine ecosystems, but relatively little is known of their health, in part because sick and dying fish are difficult to detect.

Increases in summer stream temperature may exceed the thermal tolerances of aquatic biota that are adapted to colder environments. Information on thermal patterns can aid in the conservation of cold-water aquatic organisms such as Pacific salmon and help identify important habitat for restoration.

Differentiating diploids from triploids at the earliest life stage possible allows for a more efficient use of resources including production time and rearing space. Thus, a reliable flow cytometric (FCM) method has been developed to discriminate triploids from diploids at the larval stage. In order to help simplify the process of differentiating triploids from diploids, we propose a simple...

Rivermouth ecosystems, or freshwater estuaries, are the focus of human and wildlife interactions with the Great Lakes. They are highly valued as the region’s urban, industrial, shipping and recreational centers; and home to recreational harbors, wildlife viewing and production, beaches and urban riverfronts. Rivermouths are also both the mixing zones where nutrients from upstream watersheds are...

Invasive fishes are of considerable concern to aquatic resource managers. For example, the common carp (Cyprinus carpio), originally brought over from Eurasia sometime in the 1800s are now ubiquitous in U.S. waters. Although they have been around for over 100 years and have become part of U.S. culture, they are still highly detrimental to aquatic ecosystems and a method to eradicate and control of...

Introduced rainbow trout and brown trout are considered a threat to the endangered humpback chub in the Colorado River in Grand Canyon. These introduced species eat native fish, but impacts are difficult to assess because predation vulnerability depends on the physical conditions under which predation takes place. We studied how predation vulnerability of juvenile humpback chub changes in response...

It's hard to imagine a better job than doing fieldwork with the USGS Coastal Ecology crew as they work to keep tabs on the Gulf sturgeon population.

Freshwater mussels are considered the most imperiled group of animals in the United States. These animals provide valuable ecological services by filtering water, sequestering nutrients, and providing forage for migratory birds, small mammals, and turtles. They also have a unique and complex life cycle that makes them especially vulnerable to human disturbances. It includes a parasitic larval...