What's killing the Susquehanna and Juniata rivers' prized smallmouth bass?
A vexing decline in smallmouths has hurt the Susquehanna's famed fishing reputation.
For several years, anglers and guides have been pleading
for action on the mysterious die-offs, poor survival and
cigarette-burn-like lesions on juvenile bass in the summer.
In
addition to the disconcerting fish kills as far up the Susquehanna as
Tunkhannock on the North Branch, young of the year classes of
smallmouths have been below normal for six of the last eight years.
Now, a $378,000, three-year study is being launched to try to find answers.
The
Pennsylvania Fish and Boat Commission last week authorized up to
$200,000 in money and personnel for the study. The agency also took the
step of banning fishing tournaments in which bass are not released on
the main stem, North Branch and West Branch of the Susquehanna.
The multi-agency approach for the study also will include the
state Department of Environmental Protection, U.S. Geological Survey,
and likely the U.S. Fish and Wildlife Service as well as the
Susquehanna River Basin Commission.
"What they're trying to get
a handle on is is there a water-quality issue here that we can document
and then fix," says Bob Bachman, a PFBC commissioner from Denver.
"We're
very concerned about what's going on, too, and we're trying to diagnose
what's going on so we can look for causes and sources," adds John
Arway, the PFBC's director of environmental services, who will head the
study.
"We're serious about trying to diagnose it, and with any scientific program you have to take it one step at a time."
A key part of the study will be to put water-quality monitors
on the edges and shallows of the two rivers, where bass are hatched and
spend their early stages.
The DEP monitors water quality monthly
in the middle of the rivers, but it's the protected shallows where
juvenile bass go — and have been found dead in the summers of 2005 and
2007.
"We haven't monitored those edge areas because we've never had problems in them before," says Arway.
Those
riverbank monitors will extend as far down the Susquehanna as southern
Lancaster County where Pequea Creek enters the river.
Conditions
on those edges will be compared to similar fish habitat in the
Allegheny and Delaware rivers where no smallmouth fish kills have been
reported.
In addition to those monitors, there will be 31 sites
on the main stem of the Susquehanna, its two branches and the Juniata
where the amount and kinds of nutrients will be measured.
The biggest source of nutrients is agriculture, although urban runoff and lawn fertilizers also play a role.
Nutrients
could be causing the algae blooms found in the river, which eat up
oxygen so crucial to fish in times of low flow and high water
temperatures, says Arway.
On top of the network of water-quality
monitors being deployed, posters and information on the study will be
drawn up "to get anglers to watch the river and give us a better idea
where small fish are dying," according to Arway.
The study will
look for a broad range of possible pollution sources, from
pharmaceuticals to industrial to agricultural pollutants.
The sediment in shallow areas that harbor young bass will be analyzed for environmental contaminants.
"We're not ruling anything out right now," Arway emphasizes.
But
an underlying theory at this point, he says, is that the fish are being
stressed by low flows, high water temperatures and low dissolved
oxygen. Those conditions may be depressing the fish's immune system,
allowing bacteria to take hold.
"It's like a recipe for
disaster," says Arway, noting that bacteria is in the river all the
time, but does not affect healthy fish.
Famed Susquehanna river
guide and fly fisher Bob Clouser of Middletown has been especially
vocal in urging the state to test for contaminants that, he believes,
are responsible for sending the river's famous bronzeback fishing into
a tailspin.
"I think one of our biggest contributors is agriculture," says Clouser, who calls the new study "a step in the right direction."
"It's probably a number of things, but I still blame agriculture for the biggest mess."
He
thinks it no coincidence that the fish kills are occurring when farmers
are spreading fertilizer on bare fields and runoff is high. He says
officials in Virginia, where there have been repeated vexing smallmouth
kills on parts of the Shenandoah River, are taking a hard look at the
makeup of poultry manure.
Clouser stopped taking clients on the Susquehanna four years ago.
"Conditions on the lower Susquehanna don't even warrant a good-fun outing anymore," he says.
Bachman
says of the upcoming study on the Susquehanna and Juniata, "We know
it's a very complex issue. There's possibly things out there that we're
not sampling.
"It's definitely not easy, but I tell you what, if you don't look, you're not going to find it."
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