Smallmouth bass

Healthy smallmouth bass netted before release back into the Susquehanna by two anglers north of Harrisburg.

Smallmouth bass again are disappearing from the Susquehanna River.

Only a couple of years ago, anglers, guides, state fisheries officials and anyone else who had fretted for more than a decade over the mysterious collapse of the lower and middle Susquehanna River’s prized smallmouth bass were letting out a sigh of relief.

Good classes of young smallmouths again were being recorded, and a moratorium on keeping bass allowed large numbers of bass to reach trophy size, keeping anglers’ fishing poles bent.

Also, scientists were seeing fewer fish with gaudy open sores and abnormal intersex fish. And it was discovered to everyone’s surprise that a virus normally found in largemouth bass was killing many of the fish, but the smallmouths in the Susquehanna seemed to be building an immunity to the killer.

There were still concerns about flooding from climate change affecting successful spawning. And warnings that pharmaceutical chemicals from sewage plants and pesticides and herbicides washing off farm fields were stressing and sexually altering fish.

But it seemed the corner had been turned.

No longer.

A major problem

Local anglers and guides traveled to West Virginia in August for a Mid-Atlantic Smallmouth Bass Health Assessment meeting and told the assembled fisheries managers from Pennsylvania, Maryland, Virginia and West Virginia that bass again were getting scarce.

One of those sounding the alarm at the meeting was David Neuman, of York County, a bass guide for Koinonia Guide Service who fishes a large section of the river 200 days a year.

“We have a major problem on the river, that is correct,” Neuman said in an interview. “It’s absolutely in decline.”

Neuman estimates that the section from Wrightsville to York Haven has seen a 70% decline in bass in the last two years. From York Haven upriver to Sunbury, he pegs the decline at between 30% and 50%.

The paucity of bass in the last two years has prompted Neuman and other river guides to rely more on trips to catch flathead catfish to satisfy customers. “We’re back to being a fishery where you better know how to fish if you want to catch fish,” he says.

Jim Martin, a bass angler from East Hempfield Township, wasn’t at the West Virginia gathering, but he, too, has noticed the smallmouth disappearing act. In 16 hours of wade-fishing from late July until recently in the Wrightsville area, he recorded not a single hit in prime areas he honed in over 20 years of fishing. In a kayak trip with a friend, the pair fished above Harrisburg’s City Island for four hours with a scant two fish, one with a sore on its side.

“I thought, ‘I can’t be the lone ranger out there.’ ” he says. “I’m just not coming across the fish.”

Says Neuman, “There’s a whole pile of guys who didn’t want to talk about it, but after this summer they realized they couldn’t keep quiet anymore.”

But why?

The Pennsylvania Fish and Boat Commission is acknowledging the new spike downward for smallmouths and is trying to figure out why.

“We just completed our survey (of adults) over the last three weeks. Abundance is down,” says Geoff Smith, the agency’s Susquehanna River biologist.

Each fall, the agency uses mild electroshocking to survey the number of adult smallmouths from 1 year old and older, typically 8 to 21 inches long. The surveys are done at the same spots on sections of the river from Sunbury to the Holtwood Dam in Lancaster County.

For those looking for some good news in all of this, Smith said spring surveys in the same areas showed the highest catch of fingerling bass since 2005. That indicates very good spawning success.

While maintaining “there’s still quite a few fish out there,” Smith readily acknowledges a declining number of adults is worrisome and that fish managers are scratching their heads over what is happening.

“Anglers had great spring fishing. During the summer we started hearing there are no fish around,” he says.

“If the abundance is down (in adults), we’re in a different set of scenarios now. Ten years ago, we weren’t getting new fish. Recruitment is not our problem anymore.”

What is?

He wonders if high flows at the end of the spawning period in the spring could have stressed fish. Sudden drops in temperatures can cause a thermal shock, resulting in a fish kill. Or high water can stress adult female bass that don’t eat much while guarding nests. Cloudy water hinders their ability to forage for food.

Smith does not think the largemouth bass virus is the culprit because that usually takes hold in higher water temperatures that just weren’t there this year. Also, masses of sick fish were not observed in surveys.

Could voracious invasive flathead catfish be gobbling up smallies? It’s a possibility, but it’s unknown. Research has just been approved for a Fish and Boat Commission survey to study just what flatheads are eating in the Susquehanna and how much.

Is it the water?

Vicki Blazer, the main federal researcher of the causes of declines in smallmouth bass in various rivers in the Mid-Atlantic, thinks it’s about what’s in the water — namely chemicals that don’t get taken out at sewage treatment plants and that run off farm fields.

“Largemouth bass virus is not the smoking gun,” says Blazer, research field biologist with the U.S. Geological Survey. “Same with bacterial pathogens. To me that says there are a lot of things that the fish are being exposed to and they might get sick from it if they are immune suppressed.

“We want a smoking gun so we can say we want to do something about it or not do something about it and move on. We need to move past that and take a bigger look at what is going on in the environment.”

The fact is, not enough observations have been done to determine which chemicals are weakening and altering bass and at what concentrations, she says. “The only way we’re going to get some true answers to some of these things is long-term monitoring.”

Guide Neuman also is convinced that what we are putting into the water is taking our bass.

“It’s a chemical problem,” he says. “We have bass with compromised immune systems. There is a solution. We’re going to have to change the way we do business as far as farming practices and all the plastics floating down the river.

“We have to educate the public. Nobody is going to fix these problems unless you put people in power that want clean water.”

Ad Crable is an LNP outdoors writer. Email him at acrable@lnpnews.com.