Shenandoah, Cowpasture, and James River Fish Kills

The Shenandoah River (North and South Forks) has been experiencing substantial fish kills since 2004. These kills have primarily occurred in the spring of the year and have mostly affected smallmouth bass and redbreast sunfish. Additional kills involving suckers have also been observed. Virginia Department of Game and Inland Fisheries (VDGIF) fisheries staff has been working closely with Virginia Department of Environmental Quality (DEQ) staff in the Valley Region Office since 2004 investigating the cause of these fish kills.

In July 2005 DEQ and VDGIF in the Shenandoah Valley Region formed the Shenandoah River Fish Kill Task Force. The Task Force is lead by DEQ and VDGIF and active participants include representatives from the Virginia Department of Conservation and Recreation (DCR), U.S. Geological Survey (USGS), Environmental Protection Agency (EPA), James Madison University, Virginia Tech University, Virginia Commonwealth University, Friends of the North Fork, Friends of the Shenandoah River, Shenandoah Riverkeeper, Anglers, Riparian Landowners, Potomac Conservancy, Chesapeake Bay Foundation, Shenandoah Pure Water Forum, etc. VDGIF and DEQ staff have also been coordinating research and monitoring efforts with the West Virginia Department of Environmental Protection and West Virginia Department of Natural Resources. Similar fish kills have also been occurring in the South Branch Potomac River in West Virginia since 2002. VDGIF fisheries staff has continuously networked with scientists outside of Virginia as part of this fish kill investigation.

In spring 2007 similar fish kills and fish showing signs of stress began to occur in the Cowpasture River and the upper James River. VDGIF staff has been working diligently assessing the spatial extent of the fish kills and stressed fish in the upper James River Watershed. To date this fish kill/stress event appears to be mostly occurring upstream of Lynchburg. However, staff will continue to determine the extent and severity of this fish health event.

View Large Map (PDF)

Species Affected

In both the Shenandoah and James River watersheds the primary fish species being affected are smallmouth bass, redbreast sunfish, and rock bass. Biologists and anglers have also documented fish of other species being affected. The impact on the fish population varies throughout the affected rivers. VDGIF fisheries staff has documented a reduction in the smallmouth bass and sunfish populations in certain sections of the Shenandoah River to the extent where anglers would expect to see reduced catch rates of fish. However, many anglers are reporting good catch rates in many areas of the Shenandoah River. In contrast, some anglers are reporting poor fishing success. Angler reports from the James River have been similar.

Research and Monitoring

The Shenandoah River Fish Kill Task Force has been conducting a multitude of research and monitoring on the Shenandoah and Cowpasture River since early 2006. These projects include: water quality monitoring, contaminants analysis, fish health analysis (pathology/bacteriology/virology), temperature modeling, aquatic insect evaluation, algae analysis etc. To date, investigators have not been able to determine the cause of these fish mortality or morbidity events. The Task Force has not been able to rule out either a biological agent or chemical contaminant at this point. All "theories" are still on the table. Work on determining the contaminant profile within the river ecosystem is something that the research team worked toward in 2007. In 2008 water quality, contaminant, blood chemistry, bacterial pathogen, and fish health data will be collected from the Shenandoah and upper James Rivers and will also be collected from several "reference" rivers in Virginia where fish kills have not been occurring. Information from the Rappahannock, New, and North Fork Holston Rivers will be compared with identical data obtained from the Shenandoah, Cowpasture and upper James River. More detailed research and monitoring findings and planned studies can be viewed at: 2007 Findings (PDF) and 2008 Plans.

Reporting Sick, Dying, or Dead Fish

Anglers have been a big help with these investigations; many anglers are reporting steady fishing on many sections on these rivers, but are also reporting incidences of fish with lesions, and a few dying or dead fish. VDGIF fisheries biologists encourage anglers to continue reporting what they are seeing when they get back from their fishing trips; there are a lot more anglers than biologists and angler reports are very important to help document the upstream and downstream extent and severity of the problem.

To report sick, dying, or dead fish in these rivers anglers can contact DEQ's Harrisonburg Office at (540) 574-7800 or (toll-free in Virginia) (800) 592-5482. Information can also be emailed to fishreports@deq.virginia.gov.

Report the location, number of fish, and type of fish.

Or, you can call VDGIF's offices at Forest (434) 525-7522 or Verona (540) 248-9360.

For more information about ongoing efforts, go to the following Web sites:

Frequently Asked Questions

Where are these fish kills occurring?

The entire North Fork Shenandoah, South Fork Shenandoah, and Main stem Shenandoah River. Main tributaries of the South Fork Shenandoah River (North River, Middle River, South River) 2004-2007; Cowpasture River and Upper James River from Lick Run downstream to Lynchburg (2007).

What time of year are these fish kills occurring?

Spring of the year March-June. There have been some kills involving suckers in November and December in the Main stem Shenandoah River.

What species of fish are being affected?

Primarily smallmouth bass, redbreast sunfish, and rock bass. Small numbers of white suckers, northern hogsuckers, largemouth bass, chubs, fallfish, and a few bullhead catfish have also been affected. Additional species have been reported by anglers.

What symptoms do these fish exhibit?

Some dead fish have no visual external problems. Dying or stressed fish sometimes are covered in a heavy layer of mucus, have "blotched" coloration, are extremely dark in color, have external patches of fungus or protozoans on them that appear to be fuzzy-like cotton, bloody spots under the scales, or open bloody lesions caused by bacteria. Some fish may be lethargic and found swimming near the surface, while others may be acting normally and are even caught by anglers.

What have been the impacts to fish populations?

Shenandoah River

Fish kills in the Shenandoah River system (North Fork, South Fork, and Main stem) have not been uniform in spatial extent (location) or severity from year to year. Mortality has been observed in mainly older smallmouth bass and redbreast sunfish. There has been some indication of stress in other fish species, but mortalities in other species have been light. The most noticeable impact to the fish population has been the loss of larger/older smallmouth bass and redbreast sunfish. Across the entire river, overall numbers of smallmouth bass and redbreast sunfish have not changed significantly since before the kills. This is primarily due to excellent spawning success of these two species over the past four years. Several continuous years of fish recruiting into the population has minimized the "observed" impacts to the smallmouth bass population. The annual mortality rate for smallmouth bass has increased by roughly 10-15% since the start of the fish kills. With this mild increase in mortality rate, the most noticeable change to anglers will be the reduction of larger/older smallmouth bass. The growth rate of juvenile smallmouth bass has also increased since the start of the kills. While biologists cannot fully explain this increase in growth, it probably has something to do with reduced predation and changes in inter-specific competition between young smallmouth bass. For whatever the reason, smallmouth bass are reaching 12 inches in about half the time as prior to the fish kills. In 2008, anglers should expect respectable catch rates of smallmouth in the 9-13 inch range, with a few larger bronzebacks being available. Continued monitoring of the fish population will be needed to determine the long-term effects of these fish kills on the Shenandoah River fishery. VDGIF has developed a more detailed Shenandoah River Fish Population Assessment report (PDF).

Cowpasture River

The Cowpasture River suffered its first expansive fish kills during spring and early summer 2007. Reports of sick or dying fish were documented from the Williamsville area to 60 miles downriver at its confluence with the Jackson River at Iron Gate. At a routine electrofishing sample on April 19, 2007 at the Walton Tract, adult smallmouth bass with lesions, fin rot, fungus, and discolored skin were collected. Some of the bass were dead and others were in a state of severe stress. Most of the smallmouth bass collected that day exhibited similar symptoms to those found in the Shenandoah River fish kills. Over the course of the survey year, black jumprocks, fallfish, bull chubs, rock bass, redbreast sunfish, and white suckers were all affected by anomalies. VDGIF fisheries biologists attempted to chart the course of the fish kill from a perspective of time and distance.

Twelve fish samples were spread from Fort Lewis to Iron Gate, from April through October. Diseased fish were found from April - July, with no signs of infection by October. An interesting observation was that rock bass were greatly affected by lesions, particularly around the mouth. These anomalies persisted through mid-summer with this popular species. It is difficult to assess whether the 2007 smallmouth bass spawn was successful, because catch rates were low in the fall. Because the Cowpasture River was selected as a reference stream by the Fish Kill Task Force, fish and water quality data has been taken over time. Passive sampling devices were deployed at the Walton Tract in 2007 to see if herbicides, hormones, pesticides, and other types of organic contaminants are present in the Cowpasture. Results are being analyzed by DEQ at this time.

James River

Fish kills on the James River in 2007 were concentrated from Bent Creek upstream to Iron Gate. Lesions were observed in all species examined, although most of the dead fish observed were smallmouth bass, sunfish, rock bass, channel catfish, and suckers. Overall mortality of fish in 2007 from this kill event was 10-15% or less. Results from sampling in the fall of 2007 indicated that population-level impacts from the 2007 fish kill were negligible for most species. There appears to have been a slight decline in larger (older) smallmouth bass densities in the upper James River (above Lynchburg). In general, last year's kill event did not have catastrophic impacts on the fish community. The impacts to most species were insignificant, but there may have been a slight reduction in the numbers of larger smallmouth bass. On the positive side, spawning success of smallmouth bass in 2007 was excellent, which may help alleviate some of the kill impacts.

At the time of this writing, there have been angler reports of dead smallmouth bass in the upper James River near Glasgow. It is not known at this time if these reports are unrelated to past kill events or if it's the beginning of another kill in 2008.

What are some of the top "theories" investigators believe is causing these fish deaths and stress?

While there is not yet enough supporting data/evidence to link these events to any one cause, researchers are focusing on two main areas.

  1. A biological agent like a virus, bacteria or other pathogen;
  2. Some type of contaminant.

This is an extremely complex situation as investigators working on the Shenandoah kills have learned. Much of the information that has been collected to date on the Shenandoah River suggests multiple stressors acting collectively. More data collection and analysis will need to be preformed before the cause(s) of this problem can be narrowed-down.

Do these fish kills pose any human health threats? Is it safe to wade, swim, canoe, or eat fish from these rivers?

Staff has been referring these questions by the public to the Virginia Department of Health, since it is that agency who would determine any human health warnings. Staff has been informing the public about any fish consumption advisories in place within these watersheds (that were there previously to these kill events) due to contaminants. Staff has also been telling the public to use common sense and practice good hygiene when recreating in these rivers (or any stream, reservoir, or river. To not eat any fish that is showing signs of stress; treat any cuts exposed to river water with antiseptics; wash hands with antibacterial soaps or antiseptics before consuming any food if handling fish or river water.

Updated May 2008.