Angling for Healthier RiversThe Link Between Smallmouth Bass Mortality and Disease

and the Need to Reduce Water Pollution in Chesapeake Bay Tributaries

Summary May 2013

Angling for Healthier RiversThe Link Between Smallmouth Bass Mortality and Disease and the Need to Reduce Water Pollution in Chesapeake Bay TributariesThis is a summary of CBF’s April 2013 report, Angling for Healthier Rivers. The full report can be found online at cbf.org/smallmouthbass.

“perfect storm” of pollution, parasites,warming water temperatures, and

endocrine-disrupting chemicals is threateningone of the Chesapeake Bay region’s most pop-ular sport fish, smallmouth bass.

CBF’s recent report, Angling for HealthierRivers, details how smallmouth bass havesuffered disease, die-offs, and sexual abnor-malities over the last decade in five Bay tributaries: the Susquehanna River inPennsylvania; the Monocacy River inMaryland; the South Branch of the PotomacRiver in West Virginia; and the Shenandoahand Cowpasture Rivers in Virginia.

Smallmouth bass are beloved by freshwateranglers because they are spectacular fighters.They are beautiful fish, often with a shim-mering bronze or golden color, red eyes, ver-tical stripes, and sunburst patterns on theside of their heads.

“Smallmouth bass is one of the great sportfisheries,” said CBF President Will Baker.“But in the Susquehanna and other rivers inthe region, smallmouth bass are in serioustrouble. The good news is that implement-ing the Chesapeake Clean Water Blueprintcan make a difference.”

Although the problems afflicting small-mouth bass are complex and still only par-tially understood, one factor is clear and canbe controlled. Reducing phosphorus andnitrogen pollution to meet the Clean WaterBlueprint will help reduce stress on small-mouth bass and other fish, even as itimproves water quality for everyone whoenjoys the Bay’s rivers and streams.

Fishing for smallmouth bass is important forthe region’s economy, responsible for about

5,700 jobs and $630 million annually insales of boats, fishing gear, and other goodsin Pennsylvania, Maryland, Virginia, andWest Virginia, according to the report.

The report explains that smallmouth bass areintolerant of pollution, and as such are oftenlikened to a “canary in a coal mine” by pro-viding scientists with a reliable gauge ofwater quality.

John Arway, Executive Director of thePennsylvania Fish and Boat Commission,said that other freshwater fish might also besuffering die-offs like the smallmouth bass.But fisheries managers wouldn’t necessarily

know about the problems in these otherspecies, because they are not as popularamong anglers and therefore as closely mon-itored as smallmouth bass.

“I am truly concerned that I’ll be Directorwhen the last bass is caught out of the(Susquehanna) River,” said Arway, in theCBF report.

Catch rates of smallmouth bass in the mid-dle Susquehanna River fell by 80 percentbetween 2001 and 2005, and have notrecovered since. This is largely becausesmallmouth less than a year old are dying athigh rates, according to the report.

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Angling for Healthier RiversThe Link Between Smallmouth Bass Mortality and Disease

and the Need to Reduce Water Pollution in Chesapeake Bay Tributaries

April 2013

Nitrogen and phosphorus pollution contribute to a “perfect storm” of problems that are killing small-mouth bass. This smallmouth bass, caught in Pennsylvania, suffered from gill erosion.

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CBF joined with thePennsylvania Fish andBoat Commission andother allies in calling onthe Pennsylvania Dep-artment of EnvironmentalProtection and U.S.Environmental ProtectionAgency to designate theSusquehanna River as“impaired” with pollutionunder the federal CleanWater Act. This designa-tion would prioritize fed-eral and state resourceson creating a plan to cleanup the river and save the bass.

Research Fisheries Bio-logist, Dr. Vicki Blazer,who helped with thereport, concluded thatphosphorus and nitrogenpollution, rising watertemperatures, and a vari-ety of endocrine (hor-mone)-disrupting chemi-cals appear to be playingroles in weakening theimmune systems of thefish, making them morevulnerable to naturallyoccurring bacteria, viruses,and parasites.

“It’s almost like you reachthe perfect storm situa-tion,” said Dr. Blazer in the CBF report. “Therehave been stressors andsmallmouth bass havebeen able to overcomethem or deal with them.But eventually, they get to apoint where they cannotdeal with them anymore.”

Some of the worst prob-lems with the fish havebeen in the Susquehanna River. Twelve of24 monitoring stations along the river andits tributaries had average levels of phosphorus pollution between 2007 and 2011 that were among the worst in the Chesapeake Bay watershed. Elevenof the sites had nitrogen pollution levels that were also high, according to theCBF report.

Scientists believe that phosphorus and nitrogen pollution may be contributing to fish deaths and diseases in two ways. The first is by spurring the growth of para-sites (myxozoans and trematodes) and theirhosts (worms and snails). The second is byfeeding algal blooms that raise pH levels andlower oxygen concentrations, stressingsmallmouth bass.

Fortunately, state and local governments canreduce these pollutants by investing instormwater-control projects, upgrades towastewater treatment plants, and programsto fence cattle out of streams. Cleaner riverswill give these valuable sportfish a sportingchance to live.

uTo read the report, visit cbf.org/smallmouthbass.

Smallmouth bass live in many rivers and streams. Above in red are waterways in the Chesapeake Bay region where thefish have suffered fish kills, disease, and sexual abnormalities over the last decade.

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South BranchShenandoah River

Potomac River

Monocacy River

Susquehanna River

South Branch of Potomac River

Cowpasture River

North Branch Shenandoah River

Shenandoah River

Chesapeake Bay Watershed

Chesapeake Bay

Tributaries where smallmouth bass have suffered

The Chesapeake Bay’s 64,000-square-milewatershed covers parts of six states and ishome to more than 17 million people.

April 2013

MarylandPhilip Merrill Environmental Center6 Herndon AvenueAnnapolis, MD 21403410/268-8816

Eastern Shore Office102 East DoverEaston, MD 21601410/543-1999

PennsylvaniaThe Old Water Works Building614 North Front Street, Suite GHarrisburg, PA 17101717/234-5550

VirginiaCapitol Place1108 East Main Street, Suite 1600Richmond, VA 23219804/780-1392

Hampton Roads142 West York Street, Suite 618Norfolk, VA 23510757/622-1964

Washington, D.C.1615 M Street NWWashington, DC 20036202/544-2232

Website: cbf.orgE-mail: chesapeake@cbf.orgInformation: 888/SAVEBAY (888/728-3229)

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HOW THE REPORT WAS COMPILED:

Chesapeake Bay Foundation Senior Writer and Investiga-tive Reporter Tom Pelton wrote the report after interviewing smallmouth bass biologists and anglers, reading scientific journal articles, and reviewing reports and data from federal and state agencies. The report was then reviewed by Dr. Vicki Blazer, Research Fisheries Biologist with the U.S. Geological Survey; John Mullican, Western Region, District II Manager, Inland Fisheries Division of the Maryland Department of Natural Resources; and Geoff Smith, Susquehanna River Biologist with the Pennsylvania Fish and Boat Commission. Thanks also to Michael Langland and Scott Phillips of the U.S. Geological Survey for water pollution data and to Dr. Douglas Lipton, Program Leader of Sea Grant Programs at the University of Maryland College of Agriculture and Natural Resources, for guidance on economic impact figures. (Designed by Chelsea Hachey.)

The development and distribution of this report has been made possible by the generous support of The Seraph Foundation.