Smallmouth bass with cancerous tumors and lesions may indicate significant water quality problems.
Smallmouth bass are worth hundreds of millions of sport fishing dollars to the Chesapeake Bay fishery.
But in recent years more frequent catches of smallies exhibiting physical abnormalities have Pennsylvania Fish and Boat Commission officials and anglers concerned.
Last November a Susquehanna River angler caught a smallmouth bass with a strange growth. Two independent laboratories, the U.S. Fish and Wildlife Service and the Aquatic Animal Health Laboratory at Michigan State University, confirmed that the growth on the fish's lower lip was a cancerous tumor.
While this particular fish was the first Pennsylvania smallmouth to be confirmed as diseased with cancer, the number of fish being caught with various other defects has risen in the last decade or so.
The Chesapeake Bay Foundation released a report indicating that fish in the watershed, and the lower Susquehanna River in particular, are being adversely affected by pollution, parasites, and disease. The report also refers to a separate study from the Pennsylvania Fish and Boat Commission that indicates an 80 percent decline from 2001 to 2005 in the smallmouth catch rate.
While the cancerous bass in question is the only fish identified as having a tumorous growth thus far, the Fish and Boat commission has observed high rates of other lesions and infections on young bass during spring and summer fish surveys.
Perhaps even more shocking than the presence of cancerous tumors is the discovery of numbers of young male smallmouth with eggs in their reproductive systems, indicating gender mutation. This unsettling development is being blamed on the presence of endocrine disruptors in the water.
The Chesapeake Bay Foundation has asked the EPA to designate a large stretch of the Susquehanna as officially "impaired" under the federal Clean Water Act. An impaired status could result in stronger policies and legislation regulating nitrogen and phosphorous pollution levels. The Pennsylvania Department of Environmental Protection is, however, objecting to the foundation's request.
DEP spokesman Kevin Sunday indicated that, "We don't make impairment designations based on the health of a species of fish. We make them based on water quality."
William Baker, CBF president countered Sunday's approach, saying that the foundation's report "must not be ignored," and that smallmouth bass serve as a "canary in the coal mine" by revealing larger, more significant problems.
Fish and Boat Commission Executive Director John Arway further emphasized the seriousness of the situation:
If we do not act to address the water quality issues in the Susquehanna River, Pennsylvania risks losing what is left of what was once considered a world-class smallmouth bass fishery.
While there is no evidence of a clear risk to humans from the diseased and malformed fish, the Pennsylvania Department of Health is advising anglers to avoid consuming diseased fish.
"We've found black spots on adult fish, exotic viruses, parasites and invasive species...some of which we've never seen in our waters before," concludes Arway. "We can't wait to research when our final bass dies."