Biologists have confirmed that a smallmouth bass which displayed a large tumor when caught on the Susquehanna river last year did, in fact, have cancer, raising serious questions about the health of the Pennsylvania waterway.
The fish was taken late last year from the middle of the river near Duncannon in Dauphin County, according to U.S. News and World Report. While biologists have previously observed sores and lesions on fish caught from the Susquehanna, the bass represents the first confirmed case of malignant cancer in the region.
According to John Arway, executive director of the Pennsylvania Fish & Boat Commission, finding a cancerous lesion on a fish is extremely unusual and rare, though there may be an explanation for the recent discovery.
"These cancers can be initiated by contaminants," he noted.
— Philly Mag (@phillymag) May 5, 2015
Scientists have observed increased mortality rates among fish in the river since 2005, according to NPR, and have documented other changes in some species. Intersex fish, male but carrying eggs, have been discovered previously in the Susquehanna. The effects noticed in the fish populations have raised concern among officials, pointing to broader problems of pollution in the Susquehanna river.
"The weight-of-evidence continues to build a case that we need to take some action on behalf of the fish," Arway noted.
— The Morning Call (@mcall) May 5, 2015
Sources of contamination are varied, likely including runoff from fertilizer as well as unused pharmaceuticals, and their effects are increasingly apparent in local fish populations, leading the Fish & Boat Commission to request that the Susquehanna be placed on a list of impaired waterways. Such a move would be the first step toward developing a plan to restore the river, yet the state is waiting for the results of a study currently underway.
Although the Susquehanna is hardly the only river exhibiting the effects of contamination, as the Inquisitr has previously reported, Arway hopes it will qualify for the Pennsylvania Department of Environmental Protection's 2016 list of impaired rivers, set to be released in September.
Catch-and-release regulations are already in place for the area of the Susquehanna where the fish was caught, and officials from the Pennsylvania Department of Health assert that there is little evidence that cancers in fish can prove harmful to humans. Still, they caution that anglers should avoid eating any fish caught in the Susquehanna that show visible signs of disease, such as lesions or tumors.
[Image: John Arway/Pennsylvania Fish & Boat Commission via NPR]