Shenandoah, Cowpasture, and James River Fish Kills

Shenandoah River Fish Kills - October 2009 Update

Beginning in 2004, widespread fish kills have occurred each spring in the Shenandoah River drainage. In 2004, the fish kills affected nearly the entire length of the North Fork of the Shenandoah River. In 2005, over 100 miles of the South Fork Shenandoah River were impacted. In 2006, the fish kills returned to the North Fork, a portion of the South River, and the mainstem Shenandoah River. In 2007 identical fish kills and events of fish morbidity occurred throughout the Cowpasture and upper James River. Light fish kills also occurred in the Shenandoah River system in Spring 2007. In 2008 light kills and episodes of fish stress were observed in the North and South Fork Shenandoah, Cowpasture, upper James and lower Jackson River downstream of Covington. In spring 2009 light fish kills and events of fish stress were observed in the same locations as 2008. However, reports of sick or dead fish by anglers or observations by biologists on the Cowpasture and upper James River were light in 2009.

To ensure a collaborative investigative and communication process, DEQ and DGIF formed the Shenandoah River Fish Kill Task Force in July, 2005. With the fish kills now encompassing both the Shenandoah and upper James River, the group is now referred to as the Fish Kill Task Force. Active Task Force participants include representatives from DEQ, DGIF, 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 & James 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.

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 reported low numbers of other fish species being affected. The impact on the fish population varies throughout the affected rivers. VDGIF fisheries staff has documented a small reduction in the numbers of older smallmouth bass in these rivers to the extent where anglers would expect to see reduced catch rates of these fish. However, in summer 2009 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 Fish Kill Task Force has been conducting a multitude of research and monitoring on the Shenandoah and upper James 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. An outline of up to date findings from research and monitoring efforts can be viewed at: www.deq.virginia.gov/info/srfishkill.html.

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 all the ongoing efforts, go to the following website:

Frequently Asked Questions

Where are these fish kills occurring?

The upper reaches of the North Fork Shenandoah and South Fork Shenandoah River; Main tributaries of the South Fork Shenandoah River (North River, Middle River, South River); Cowpasture River; Jackson River downstream of Covington; Upper James River downstream to Lynchburg.

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 has been the impact to the fish population?

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 five 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. However, in 2008 DGIF conducted an angler creel survey on the South Fork and Main stem Shenandoah River and angler catch rates of smallmouth bass were excellent. In 2009-2010 anglers should expect respectable catch rates of smallmouth in the 9-14 inch range, with respectable numbers of 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.

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 with anomalies. DGIF fisheries biologists attempted to chart the course of the fish kill from a perspective of time and distance.

Smallmouth bass catch rates (and overall health) at Griffith have improved since 2007. In the fall of 2007, only 30 smallmouths per hour were collected, but this improved to 58 in 2008 and 97 in 2009. Smallmouth bass observed by staff in 2009 were healthy. Rock bass seem to be susceptible to springtime bacterial infection in the Cowpasture River, and their rate of infection was high in 2008. However, citizen calls reporting sick fish dropped off considerably in spring of 2009, so it is hopeful that we have seen the worst of these infections in this watershed.

James River

Fish kills on the James River in 2007-2009 have primarily occurred upstream from Lynchburg. Many species have been observed with lesions, but the primary species that have died from these kills were smallmouth bass, rock bass, redbreast sunfish, catfish, and suckers. While alarming, these kills have not had major population-level impacts. We have estimated the total mortality rates to be no more than 10%/year from these kills. This should result in a slight decrease in angler success, but not something that will be immediately obvious. At their current level of intensity and distribution, continued spring fish kills may begin to have more noticeable affects on this fishery in another 2-5 years. It may take that long for the increase in mortality rates (although small) to begin noticeably affecting the total number of large smallmouth bass in the river.

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/James kills have learned. Much of the information that has been collected to date on these rivers 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 October 2009