Lesions on smallmouth bass. Photo by C. Yamashita/Pennsylvania Fish and Boat Commission
The Link Between Smallmouth Bass Mortality and Disease and the Need to Reduce Water Pollution in Chesapeake Bay Tributaries
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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. 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.
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.
The Chesapeake Bay Foundation (CBF) compiled this report by interviewing five leading smallmouth bass experts and examining peer-reviewed journal articles, as well as reports from federal and state agencies. Some conclusions include: