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Cancerous fish found in Pennsylvania river

A smallmouth bass with a cancerous tumor was caught on a Pennsylvania river. John Arway

For the first time ever, Pennsylvania officials have confirmed that a fish caught in Susquehanna River had cancer.

The smallmouth bass, with a huge growth on its mouth, was caught last year by an angler. Two independent laboratories have confirmed a "malignant, or cancerous, tumor" on the bass, the Pennsylvania Fish and Boat Commission said in a statement.

While only one fish, PFBC Executive Director John Arway said it provides additional evidence that the health of the fish community residing in the river is being compromised.

"As we continue to study the river, we find young-of-year and now adult bass with sores, lesions and more recently a cancerous tumor, all of which continue to negatively impact population levels and recreational fishing," he said. "The weight-of-evidence continues to build a case that we need to take some action on behalf of the fish."

Although the cancer had never before been seen in adults, the state acknowledged "biologists continue to find sores and lesions on young-of-year bass during late spring and early summer surveys at alarming rates."

It also follows reports last year of intersex fish turning up on Pennsylvania rivers.

The state was quick to say there was no threat to humans.

"There is no evidence that carcinomas in fish present any health hazard to humans," Karen Murphy, acting Secretary of the Pennsylvania Department of Health, said. "However, people should avoid consuming fish that have visible signs of sores and lesions."

The state has not said what might have caused the cancer. But finding the sick fish is likely to add momentum to efforts by the PFBC and others to add the river to the state's bi-annual list of impaired waterways. So far, the state's Department of Environmental Protection has refused to add it to the list.

"The impairment designation is critical because it starts a timeline for developing a restoration plan," Arway said. "We've known the river has been sick since 2005, when we first started seeing lesions on the smallmouth. Now we have more evidence to further the case for impairment."

A growing list of rivers across the United States are under threat due to the drought in the West and pollution, including the illegal pumping of coal ash into a North Carolina river.