Vicki S. Blazer, PhD (Former Employee)

Striped bass ( Morone saxatilis) displaying ulcerative skin lesions and chronic wasting, both typical clinical signs of mycobacteriosis, a bacterial disease that is problematic among many types of fishes around the world.

Whirling disease, caused by the myxosporean parasite Myxobolus cerebralis was identified as an emerging pathogen of trout in the intermountain west region of the U.S. in the early 1990’s. Investigators here worked collaboratively with others to further our understanding of this disease and its impacts on trout and other salmonid fishes.

This rainbow trout is displaying clinical signs of enteric redmouth disease caused by a systemic bacterial infection.

The incidence of particular skin and liver tumors on white suckers collected from some Wisconsin rivers corresponded to the degree of urban development within the watershed. Further research is needed to understand the relationship between exposure to urban-sourced contaminants and the initiation, promotion, and potential for population-level effects of these tumors.

Research by the USGS identified a fish pathogen similar to one previously found in the United States only in Pacific salmonids -- salmon and trout species -- in the eastern United States and in a non-salmon species.

USGS fish biologist describes what the Chesapeake Bay means to her.

Testing of U.S. streams has detected glucocorticoid and androgen biological activity. In a collaborative study between the National Cancer Institute (NCI), Laboratory of Receptor Biology and Gene Expression, the U.S. Geological Survey (USGS), and others, scientists studied the potential for the biological activity in streams of glucocorticoids and androgens hormones—both potential endocrine...

The USGS works with U.S. Fish & Wildlife Service and Maryland Department of Natural Resources to summarize the effects of suburban lands and contaminants on the health of yellow perch in the Chesapeake Bay.

As the largest and most productive estuary in North America, Chesapeake Bay is a vital ecological and economic resource. The bay and its watershed have been degraded, however, by poor water quality, loss of habitat, and overharvesting. The Chesapeake Bay Program, a cooperative program among several Federal and State agencies, is working to restore fish and wildlife in the bay watershed and the...

As the largest and most productive estuary in North America, Chesapeake Bay is a vital ecological and economic resource. The bay and its tributaries have been degraded in recent decades, however, as a result of excessive inputs of nutrients and sediment and by the impacts of toxic contaminants on the health of fish and wildlife. Although a Total Maximum Daily Load (TMDL) has been established to...