A smallmouth bass pulled from the Susquehanna River in Pennsylvania has been discovered to have a malignant cancerous tumor, reports the Pennsylvania Fish and Boat Commission.

While there is no research to show that cancerous fish pose a harm to humans, “people should avoid consuming fish that have visible signs of sores and lesions,” advises Dr. Karen Murphy, Secretary of the Pennsylvania Department of Health. 

Laboratory tests conducted by the PFBC confirmed that growths found on the fish were cancerous. The case is the first of its kind in Pennsylvania, but frequent reports of sores and lesions on smallmouth in the Susquehanna has raised concerns about the condition of the river’s ecosystem. 

“The weight of evidence continues to build a case that we need to take action on behalf of the fish,” reported PFBC Executive Director John Arway to the local CBS news in Harrisburg

More than 10 years of study have yielded several instances of fish dying as a result of disease. The PFBC has so far been unsuccessful in its attempts to add the Susquehanna River to the list of impaired waterways, but it is still resilient and hopeful, as doing so would allow a timeline for a successful restoration of the river.

Photo credit: Smallmouth bass with confirmed malignant tumor. Caught by angler in Susquehanna River near Duncannon, Dauphin County, on Nov. 3, 2014. Photo by John Arway