Sick fish

Pinkish skin lesions are visible on a pair of dead, young smallmouth bass taken from the Susquehanna River .

Is the Susquehanna River “sick” or not?

Federal regulators say a diagnosis may be ready by this summer.

With a collapse of the river’s prized smallmouth bass fishery, the Pennsylvania Fish and Boat Commission, anglers and environmental groups have unsuccessfully pleaded for state regulators to declare the river impaired, from Sunbury to the Holtwood Dam. A portion of the Juniata River also would  be included.

One top emerging theory is that phosphorous nutrients from farm runoff is stressing the bass, killing them, causing lesions and male fish with eggs.

An impaired determination would force the state to find the causes and take steps to fix them. Such a classification could have widespread consequences, potentially affecting farmers, sewage plants and industries.

It probably would not affect recreational uses on the river, since the Fish and Boat Commission already has banned all taking of smallmouth bass from the lower Susquehanna.

But last year, the state Department of Environmental Protection ruled that there was inadequate data to determine if the river is indeed impaired.

Instead, the agency promised to step up water-quality monitoring and investigate root causes of the river’s decline.

Last week, the federal Environmental Protection Agency, in its every-two-year review of Pennsylvania’s water-quality plans, said it agreed that there is still a lack of data to declare the Susquehanna sick or not.

But that determination may be soon at hand, EPA said.

“EPA understands and shares the concerns of the public related to the Susquehanna River smallmouth bass health,” EPA said in its review.

“Based on the forthcoming Susquehanna River monitoring and assessment results and the CADDIS report, EPA expects there will be sufficient data for DEP to make assessment determinations for the mainstem Susquehanna River for the 2016 (water quality plan).”

CADDIS refers to DEP’s assembling a panel of experts charged with examining the results of recent water tests and making a determination if the river is impaired.

EPA said  a final report detailing the results is expected by this summer. However, in a press release, DEP said it “would continue and expand its intense studies of the river and tributaries through 2015.

The panel includes members of the Fish and Boat Commission, Susquehanna River Basin Commission. U.S. Geological Survey, U.S. Fish and Wildlife Service, EPA and the Susquehanna River Heartland Coalition for Environmental Studies.

Possible sources of the smallmouth decline have included farm runoff of nutrients, low dissolved oxygen, high acidity, increased algae that robs the water of oxygen needed by young fish and contaminants in the water including pesticides, pharmaceuticals, PCBs, personal-care products and compounds found in flame retardants.

Fish and Boat Commission chief John Arway has been vocal in his criticism of the state for not declaring the Susquehanna a “sick river” and getting on with fixing the problem.

In a letter to EPA in July, Arway  urged federal regulators to take steps to improve the river’s condition “before it becomes too late to repair the damage.”

Specifically, he asked federal regulators to increase oversight of pollutants from agriculture.

“Further investigation into the agricultural contribution will be challenging but one that is much needed and long overdue,” he said.

He said dissolved phosphorous is “plaguing the water quality of the river and Chesapeake Bay.” He said dissolved phosphorus is “fueling algal blooms...creating the primary stressor that cause young bass immune systems to be stressed, the fish to become weakened, then become infected with bacteria and die.”