The Chesapeake Bay Foundation Thursday issued a special report on smallmouth bass fish kills in the lower Susquehanna River and the Chesapeake Bay watershed concluding, “Although the mystery of what is causing smallmouth bass deaths and illnesses is not yet fully solved, scientists know enough to guide policy makers to move ahead with these basic steps.”
Those steps include listing the lower Susquehanna River as an impaired waterway and continuing to implement the Chesapeake Bay nutrient pollution reduction strategy.
The Chesapeake Bay Foundation compiled the report by interviewing five leading smallmouth bass experts and examining peer-reviewed journal articles, as well as reports from federal and state agencies.
“Many factors appear to be affecting the health of the smallmouth bass in the Lower Susquehanna. Of those currently being studied, pollution levels are one we can control,” said Harry Campbell, CBF’s Pennsylvania Executive Director. “Pennsylvania has made notable progress in the last 25 years, but in order to reduce stress on the smallmouth bass and other aquatic species, we must continue to reduce the amount of pollution getting into the river, and that requires everyone work together.”
“Everyone who values healthy fish and the clean water they need to thrive should be concerned,” said CBF President Will Baker. “The Susquehanna needs our help. CBF is encouraged by the Commonwealth’s recent actions to ramp up research. But as our report indicates we must continue to implement pollution reduction plans and to commit the necessary resources to clean water programs while studying this complex issue.”
In March, The Department of Environmental Protection released a work plan outlining intensive efforts to continue studying and sampling dozens of locations in the Susquehanna River basin throughout 2013 in hopes of identifying the cause of the smallmouth bass fish kills.
On May 8, the Chesapeake Bay Foundation will hold a Susquehanna River Forum in Harrisburg discussing the smallmouth bass issue.
Here are some excerpts from the new CBF report--
Over the last decade, one of the most prized freshwater sport-fish species—smallmouth bass—has suffered fish kills and perplexing illnesses in several Bay tributaries. These tributary rivers include the South Branch of the Potomac River in West Virginia, the Shenandoah and Cowpasture Rivers in Virginia, the Monocacy River in Maryland, and the Susquehanna River in Pennsylvania.
Problems with the fish have included lesions, blotchy skin, wart-like growths, excessive mucus covering their bodies, lethargic behavior, and abnormal sexual develop- ment in which males grow eggs in their testes.
In the Susquehanna River, smallmouth bass populations have plummeted, with catch rates of adults falling 80 percent between 2001 and 2005 in some areas. According to the Pennsylvania Fish and Boat Commission, the population has not recovered.
In 2012, this dramatic decline prompted the state agency to impose emergency regulations that prohibit fishing for the species in much of the river from May 1 to June 15. This ban in the
Susquehanna River—the largest source of fresh water to the Chesapeake Bay—will continue in 2013.
Smallmouth bass do not tolerate pollution well. Thus, they are an indicator of water quality. While the specific causes of the deaths and illnesses among smallmouth bass remain unclear, leading fisheries biologists studying the problem believe that a “perfect storm” of contributing factors has overwhelmed a sensitive species.
In fact, some suggest that smallmouth bass may be like a “canary in the coal mine,” indicating possible future health problems with other species of fish. High levels of nitrogen and phosphorus pollution, rising water temperatures, and chemical contaminants may have combined to weaken the immune systems of smallmouth bass and make them more susceptible to naturally occurring bacteria, viruses, and parasites.
Some conclusions include:
-- Fishing for the species is responsible for $630 million annually in sales in Pennsylvania, Maryland, Virginia, and West Virginia, the four Bay states where fish kills and diseases have occurred. Sales of boats, fishing rods, and more contribute to that figure. Additionally, smallmouth bass are responsible for $193 million annually in salaries and wages for about 5,700 people employed in fishing-related jobs and $41 million in state and local tax revenues.
-- Phosphorus and nitrogen pollution levels are high in many of the river segments where fish have died or become sick. In the Susquehanna River and tributaries, average phosphorus pollution levels in 12 of 24 sites monitored by the U.S. Geological Survey between 2007 and 2011 were among the worst in the Chesapeake Bay watershed. And 11 of these 24 sites had total nitrogen pollution levels that were among the worst in the region. (“Worst” is defined as ranking in the top third for levels of these pollutants among 65 sites studied in the Bay watershed). Some monitoring sites along the Monocacy River and the Potomac River and its tributaries also registered high levels of these pollutants.
-- Scientists believe that nitrogen and phosphorus pollution may be contributing to fish deaths and diseases in two ways. The first is by spurring the growth of parasites (myxozoans and trematoads) and their hosts (worms and snails). The second is by feeding algal blooms that raise pH levels and lower oxygen concentrations, stressing young smallmouth bass.
Dr. Vicki Blazer, Research Fisheries Biologist with the U.S. Geological Survey, and colleagues recently identified a type of parasite (Myxobolus inornatus) in juvenile smallmouth bass that have been dying in the Susquehanna River. This parasite is similar to one that causes a deadly disease in trout. The parasite’s possible host (a bottom-dwelling worm) may be encouraged by nitrogen and phosphorus pollution.
While more study into the causes of the fish kills and illnesses is required, one fact is clear. To restore populations of smallmouth bass, as well as the health of the Chesapeake Bay and its rivers and streams, we must reduce nitrogen and phosphorus pollution. Of the myriad of contributing factors, this is one factor that people can easily control. And addressing the problem will help sustain the economic benefits of smallmouth bass.
Cutting back nitrogen and phosphorus pollution will help reduce stress on smallmouth bass and other fish. Reducing pollution will also further efforts the Bay states—New York, Pennsylvania, Maryland, Delaware, Virginia, and West Virginia—and the District of Columbia are making to meet mandatory limits on pollution entering the Chesapeake Bay.
In 2010, EPA established science-based limits for nitrogen, phosphorus, and sediment pollution and allocated reduction targets to each state. The states then developed and now are beginning to put into effect plans that should restore clean water sufficiently to remove the Bay from the notorious Clean Water Act ‘dirty waters’ list (of section 303[d] of the act). The plans must be in place by 2025. Together the limits and the states’ plans are the Clean Water Blueprint for the Chesapeake and its rivers and streams.
The Bay states are making good progress already. But the story of the smallmouth bass reminds us that the job is far from done. The good news is that as we accelerate implementation of the Blueprint, we can expect healthier fishing and swimming, the creation of thousands of jobs,18 and a proud legacy of restoration for our children and grandchildren. Truly, we find ourselves at the moment in time for the Bay.
The report recommends--
--State and local governments should continue the nitrogen and phosphorus pollution reductions required by the Chesapeake Clean Water Blueprint. This means encouraging runoff-control projects and improved fertilizer management on farms; upgrading wastewater treatment plants; rebuilding crumbling urban sewage infrastructure; and reducing urban and suburban stormwater runoff. These actions will restore water quality in rivers and streams and, ultimately, the Chesapeake Bay. Cutting pollutants will help fish health by reducing algal blooms, parasites, and bacterial growth, as well as high pH levels and low-oxygen conditions.
-- Pennsylvania should list the Lower Susquehanna River as impaired under the federal Clean Water Act. This will prioritize federal resources to spur greater cross-agency collaborative scientific research to identify the sources and causes of the problems plaguing the smallmouth bass, and create a detailed plan to resolve these problems. In March 2013, the Pennsylvania Department of Environmental Protection announced intensified efforts to expand the study of pollutants in the Susquehanna River basin, and this is a good first step.
-- In Virginia, the Commonwealth should ensure that water quality standards for freshwater rivers and streams (such as the Cowpasture and Shenandoah Rivers) are as protective of recreational uses and fish populations as they are in tidal bodies of water. Evaluation of these standards should take place during the review process that Virginia conducts every three years.
-- All of the Chesapeake Bay states should invest more to help farmers fence cattle out of streams. This will reduce the amount of animal waste containing hormones in waterways that could be disrupting fish endocrine and immune systems.
-- Local, state, and federal governments and private citizens should prioritize planting and preserving trees and shrubs along streams. These vegetated buffers help filter nitrogen and phosphorus runoff, as well as absorb and degrade herbicides like Atrazine and lawn chemicals.
-- Multi-jurisdictional, cross-agency, and academic researchers should continue investigations into endocrine-disrupting chemicals and their potential impact on fish health.
Although the mystery of what is causing smallmouth bass deaths and illnesses is not yet fully solved, scientists know enough to guide policy makers to move ahead with these basic steps. There is no need to wait. The Chesapeake Clean Water Blueprint is a science- based plan to reduce pollution and improve water quality that requires all parties—from suburban governments to businesses and farmers—to do their fair shares.
With this cooperative effort, the region is making progress toward cleaner waterways. We owe it to ourselves and our children to finish the job and restore the health of our fish, streams, rivers, and the Chesapeake Bay.
A copy of the full report is available online.
