WASHINGTON – Smallmouth bass that draw hundreds of millions of dollars to the Chesapeake Bay region for sport fishing are sick.
A report released Thursday by the Chesapeake Bay Foundation says the fish, particularly those in the lower Susquehanna River, have been struck by pollution, parasites, disease and endocrine disrupters that are changing the sex of males.
The catch rates of adult bass fell 80 percent between 2001 and 2005 in some areas of the Susquehanna River, the report said, citing a study by the Pennsylvania Fish and Boat Commission.
John Arway, the director of the commission, said Thursday that he caught and released 200 bass on a summer night before 2005 and now catches only three or four. Arway said that anglers who come up empty-handed are shying away from the smallmouth bass, valued at nearly $650 million in 2011, according to the American Sportfishing Association.
The foundation is calling on the Environmental Protection Agency (EPA) to designate a 157-km stretch of the river as “impaired” under the federal Clean Water Act, “and a decision is due any day,” said William Baker, the foundation’s president. If the EPA makes the designation, Pennsylvania could be forced to require farms and cities to limit nitrogen and phosphorous pollution that runs into the bay more aggressively than the current cleanup plan, which is set to run until 2025.
The Pennsylvania Department of Environmental Protection has said an impaired designation is premature. It said that baby smallmouth bass succumb to disease in some of Pennsylvania’s most pristine waters, a mystery that requires more study.
“We don’t make impairment designations based on the health of a species of fish. We make them based on water quality,” said Kevin Sunday, a department spokesman.
Baker called smallmouth bass a “canary in the coal mine” because the fish is sensitive to pollution, and what harms that fish could later affect others. “This report and its findings must not be ignored,” Baker said.
In a bit of good news from an unrelated study released this week, the U.S. Fish and Wildlife Service said bullhead catfish in the Anacostia River were found to have about half as many cancerous liver tumors and skin lesions than when a similar survey was completed in 2001. It attributes the decline to efforts to decrease pollution in the Anacostia.
Despite the improvement, bullheads from the Anacostia and several Potomac watershed locations still have liver tumor prevalence significantly higher than the baywide estimate for cancer, the study said.
Bullhead catfish are one of several species of catfish in the river that runs through the District of Columbia and Maryland suburbs. Cancer is so prevalent that local health departments strongly discourage eating catfish from the river.
The Maryland General Assembly recently passed a bill that requires farmers to report the exact amounts of insecticides used to treat their fields. Biologists fear that pesticides, mixed with hormones from human pharmaceuticals in urban wastewater that pours into rivers, are causing male bass to develop eggs in their testes, switching sex.