History of fish kills in the Shenandoah River watershed, 2004 - 2007

2004 - 2005

A fish kill resulting in the loss of an estimated 80 percent of the adult smallmouth bass and redbreast sunfish occurred in more 100 miles of the South Fork Shenandoah River in Virginia between April and July 2005. Nearly identical fish kills were observed in the South Branch Potomac in 2002 and North Fork Shenandoah River in 2004. Biologists with the Virginia Department of Environmental Quality and the Virginia Department of Game and Inland Fisheries have been investigating the cause of the fish kills in the Shenandoah River system.

Several unusual patterns have been found in these fish kills:

The majority of fish lost were adult smallmouth bass and redbreast sunfish. Juvenile bass and sunfish did not seem to be affected, and other species were only lightly affected.
The fish deaths were preceded by the formation of bacterial skin lesions, which progressed to the point that the fish finally died.
The kills began in early spring and continued for two to three months. At any point in time, only low numbers of fish were dying, but the cumulative effect was very severe, killing approximately 80 percent of the adult smallmouth bass and redbreast sunfish.
The sequence of the fish kills suggests a geographic movement, with the first kill in West Virginia's South Branch Potomac in 2002, the second in Virginia's North Fork Shenandoah in 2004, and the latest in the South Fork Shenandoah River in 2005.
The kill area occurred throughout the entire length of the respective rivers, with no clear upstream or downstream boundaries.

Fish pathologists at Virginia Tech and the U.S. Fish & Wildlife Service examined specimens and determined that these fish were being stressed by undetermined factors and the bacterial lesions were only a secondary effect. Review of water quality data by DEQ did not indicated the presence of any chemicals at toxic levels, although routine samples are collected only once per month. Much of the concern from citizen callers has focused on possible impacts from agricultural, construction and urban runoff.

There has been a high level of interest in these fish kills from the news media, citizens, river guides, environmental groups, and local, state and federal agencies. DEQ and DGIF have maintained close contact with this diverse group of individuals and organizations, both during and after the fish kills. To ensure a collaborative investigative and communication process, DEQ and DGIF formed the Shenandoah River Fish Kill Task Force in July 2005. The task force includes representatives of state and federal agencies, agriculture, industry, riparian landowners, anglers, academia, and citizen environmental groups from the Shenandoah watershed. The group’s mission is to evaluate the potential factors resulting in fish lesions and deaths with the goal of determining a cause and communicate findings to those who can promote or implement corrective actions.

2006

The Shenandoah River Fish Kill Task Force investigated reports of fish deaths and fish with lesions in the Shenandoah watershed during spring 2006 and again in December.

Spring 2006 efforts

In the North Fork Shenandoah, numerous smallmouth bass and sunfish with lesions were found and a significant number died. The cause was unknown. These problems began in March and continued through May in the lower North Fork, generally downstream of the Woodstock area. There was also a brief fish kill involving smallmouth bass and sunfish in the lower South River near Grottoes in April.
The task force received no reports of fish deaths in the South Fork Shenandoah in spring 2006. During fish collections in late May, however, about 20 percent of smallmouth bass and sunfish on the South Fork were found with lesions. DGIF and the DEQ continued to monitor these species.
Also in late May, a large number of northern hogsuckers died in the mainstem Shenandoah between the Route 7 and Route 50 bridges in Clarke County. The task force investigated the cause of this fish kill and collected dead and live fish for examination. Though there were no lesions on the dead hogsuckers, the task force found lesions on redhorse suckers, some smallmouth bass and some sunfish.
The U.S. Geological Survey studied these fish at its laboratory in Leetown, W.Va., and conducted fish health studies on samples collected earlier from the Shenandoah fish kills.
The task force also worked with fishery and environmental agencies in West Virginia and Maryland, where fish kills involving suckers were reported this spring on the South Branch of the Potomac and the mainstem Potomac. Most of the dead fish were redhorse suckers, though some northern hogsuckers also died. These kills were similar in timing and types of fish to the one on the Shenandoah River in May.
The task force, led by DEQ and DGIF, pursued a number of investigations into water quality and fish health in 2006. Preliminary results from these studies did not identify a specific cause of the fish kills, but they suggest that several stress factors affecting fish may be involved. The task force developed a plan and budget request to continue this work through 2007.

2006 monitoring plan

The task force resumed collecting fish and water samples in March 2006 in the Shenandoah River, the North and South Forks of the Shenandoah, and a reference stream, the Cowpasture River.

2006 work focused on:

• Scattered reports of dead fish and fish with lesions during spring 2006.

• The discovery of fish with male and female characteristics.

The task force evaluated a recent study that found individual fish with characteristics of both sexes, usually identified through microscopic examination of fish tissue. Fish with these characteristics are known as “intersex” fish.
The affected fish were smallmouth bass analyzed by the USGS in 2005 in connection with Virginia’s investigation of the fish deaths. Fish from the North and South Forks, the Shenandoah and the Cowpasture had occurrences of intersex. The Cowpasture River was included in the study to help determine background information on fish health.
The USGS conducted a similar study in the South Branch Potomac River in West Virginia in 2004 and found the same condition in smallmouth bass. Virginia and West Virginia worked in cooperation with the USGS Leetown Science Center in West Virginia, which has national experience in fish health studies.
Microscopic analysis of the testes of some male smallmouth bass revealed the presence of immature eggs. Despite the fish kills and the intersex condition, DGIF fisheries biologists saw good reproduction of smallmouth bass in these waters.
Similar fish have been found in other parts of the country, mainly among largemouth bass. (The fish question and answer web page contains additional information about fish with this condition.)
There currently is no known correlation between this condition and the fish kills Virginia has experienced. The focus of the task force will continue to be the cause of the fish deaths.

• Daily water quality testing in the North and South Forks.

Among the key investigations in spring 2006 was a comprehensive DEQ water quality study in which daily samples were collected at nine sites on the North and South Forks of the Shenandoah River. (Normally, samples were collected about once a month.) This expanded effort evaluated short-term changes in water quality to identify stressors that are missed during routine sampling. This study intensified during periods of heavy storm water runoff with the collection of samples several times a day at each site.

• “Real-time” monitoring of water quality.

The USGS conducted “real-time” monitoring to measure factors such as ammonia, pH, temperature and dissolved oxygen in the North and South Forks every hour around the clock.

• An extensive fish health study of the Shenandoah, North and South Forks, and Cowpasture to seek signs of chronic stress and immune system effects.

DGIF and the USGS, along with the U.S. Fish and Wildlife Service’s Fish Disease Laboratory, conducted an extensive fish health study on the Shenandoah, the North and South Forks, and the Cowpasture. Fish were evaluated for indications of stress in their organs, and their blood was analyzed.

The Shenandoah River Fish Kill Task Force also supported additional research as part of its investigation. In summer 2006, researchers from Virginia universities began investigating aquatic insects in the Shenandoah and testing for disease-causing microorganisms using DNA technology. The USGS also began an evaluation of algae in the North Fork and how algae may affect water quality.

Governor Kaine announces funds to support investigation, October 2006

Governor Timothy M. Kaine announced on October 17 that up to $150,000 is available to support a scientific investigation into the cause of the Shenandoah River fish kills.

The Governor authorized the use of the Virginia Environmental Emergency Response Fund as the source of the additional money, which will help continue research on the fish kills through early 2007. The task force currently is funded through a $200,000 direct appropriation.

December 2006

The task force, with the assistance of river enthusiasts from throughout the watershed, investigated reports of fish kills on the North and South Fork Shenandoah, as well as a fish kill on the mainstem Shenandoah in early December 2006.

On December 11, dead sunfish were found on the North Fork near Passage Creek, and dead sunfish and a smallmouth bass were found on the South Fork in Front Royal.

During the week of December 3, anglers fishing the Shenandoah River between Route 50 and the Lockes Landing access in Clarke County reported seeing numerous dead fish on the bottom of the river. Biologists with DGIF identified the fish as northern hogsuckers and indicated that some of the fish had been dead for several days.

Also that week, the Shenandoah Riverkeeper, members of the Potomac Smallmouth Club, local fishing guides, DGIF and DEQ personnel, riparian landowners, and members of the Shenandoah River Fish Kill Task Force canvassed the South Fork, North Fork and mainstem Shenandoah River to determine the extent of the fish kill. Though observers did find one dead northern hogsucker at one location on the North Fork Shenandoah, the kill appeared to be centered on the mainstem Shenandoah downstream of Morgan’s Ford.

The task force contacted West Virginia authorities, who have received no reports of dead fish in the West Virginia portion of the Shenandoah River. At the time, no dead fish were observed on the South Fork Shenandoah.

Biologists will not be able to fully assess the impact to the sucker population until sampling the river in spring 2007. This is the same area of the river where a similar fish kill involving northern hogsuckers occurred in late May 2006. Investigators were not able to determine the cause of that kill.

The task force did not know whether the December 2006 fish kills were related to fish kills that have occurred throughout the Shenandoah watershed in the past three years. Information collected from these incidents will be included in the Shenandoah watershed fish kill investigation.

Fish kills that have affected the Shenandoah, James, Cowpasture and Maury rivers this spring apparently are abating, investigators announced today. This matches the pattern seen in similar fish kills on the North and South Forks of the Shenandoah that began in 2004.

Fish collections this week from the affected rivers have shown fewer problems than those taken earlier in the season, and reports from citizens have been declining. Though scientists have not confirmed any causes of the fish kills, the investigation is making progress and is now concentrating on several key areas.

The Department of Environmental Quality and the Department of Game and Inland Fisheries are coordinating the fish kill investigation. Numerous studies are under way to narrow the focus of possible causes of the fish illnesses and deaths. The current investigation includes:

• An expanded advisory group of scientists to include areas such as fisheries, fish diseases, microbiology, chemistry and agriculture to provide additional expertise for the investigation. DEQ and DGIF expect the panel to be in place in July.

• Analysis of the chemical makeup of agricultural waste streams in the river watersheds. Many of the water quality tests so far have been evaluations of river water and have focused specifically on nutrients and ammonia, which are normally associated with agricultural waste. A plan is under development for expanded, comprehensive testing of waste streams and sources connected with agricultural land uses, with assistance from the Department of Conservation and Recreation. That information will be compared with chemicals found in fish tissue, sediments and water in the fish kill areas.

• Continued evaluation of viruses, bacteria and parasites. This is being coordinated with work by the U.S. Geological Survey, the U.S. Fish and Wildlife Service disease laboratory, and Cornell University. Also, numerous fish collected this spring are being saved for further analysis, after additional chemical information comes in from water quality and agricultural samples.

The task force encourages the public to report any information on the location, number and type of fish found dead or sick in the Shenandoah, Cowpasture and James river systems.

2007

Virginia focuses fish kill investigation efforts, March 2007

DEQ and the Department of Game and Inland Fisheries, along with their partners on the Shenandoah River Fish Kill Task Force, have focused their research and monitoring efforts to address the most likely causes of the fish kills that have occurred in the Shenandoah River watershed each spring since 2004.

Dr. Greg Garman of the Virginia Commonwealth University Center for Environmental Studies and Dr. Donald Orth of Virginia Tech have offered recommendations on which efforts to continue after analyzing past studies. Based on these suggestions, DEQ and DGIF will pursue a research and monitoring plan that includes three key areas:

Continue and expand ongoing fish studies to address possible diseases caused by bacteria, viruses, fungi and chemicals.
Evaluate characteristics of chemical compounds or biological agents that would have effects on the biological community that are consistent with those observed during the Shenandoah fish kills. An outgrowth of this evaluation would focus on chemicals used in Shenandoah Valley agricultural and industrial practices.
Continue and expand ongoing water quality studies, including an investigation on the interaction between ground water and surface waters, river sampling during storms, continuous pH monitoring, and weekly river basin sampling.

The task force, led by DEQ and DGIF, has conducted a number of investigations into water quality and fish health since 2004. Preliminary results from these studies suggest that multiple stress factors affecting fish may be involved. The latest efforts build upon this work.

Money to conduct the additional research and monitoring is available from the Virginia Environmental Emergency Response Fund. In October 2006, Governor Timothy M. Kaine authorized the use of up to $150,000 from the fund to support scientific investigations of the Shenandoah River fish kills.

Scientists collect fish for fish kill investigation, March 2007

DEQ, DGIF and the U.S. Geological Survey met at Strasburg Park on March 27 to collect fish for the Shenandoah River fish kill investigation.

DGIF and DEQ collected fish from the North Fork of the river through electroshocking or temporarily stunning them. Biologists then selected smallmouth bass and redbreast sunfish for testing.

USGS biologists measured and weighed the fish, checked the health of the gills and scales, and collected blood and tissue samples and bacteria cultures. The USGS will test the samples for viruses, bacteria, intersex conditions and other factors in the overall health of the fish.

Task force investigates new fish deaths in Shenandoah watershed, April 25, 2007

DEQ has received reports this week of dead fish on the North and South Forks of the Shenandoah River. Dead and dying smallmouth bass and redbreast sunfish were found in at least three areas: a section of the North Fork several miles downstream of Woodstock, from the South Fork between Bentonville and Front Royal, and about six miles upstream of Elkton on the South Fork.

Sampling in these areas by DEQ, DGIF and others on April 24, 2007, confirmed that problems are occurring. Though only a few dead fish were found, a number of live fish with skin lesions or abnormal behavior were observed. Live specimens were collected and immediately delivered to the Virginia Tech Veterinary School pathology lab and the U.S. Geological Survey fish health lab in Leetown, W.Va. These fish will be thoroughly examined, with evaluations for diseases, viruses, parasites and organ-by-organ anomalies.

DEQ and DGIF have been monitoring the river almost daily during the spring of 2007. Except for two small, isolated, short-term incidents, no notable fish kills have been found this spring until now.

The partners of the Shenandoah River Fish Kill Task Force will continue to monitor the river closely for water quality and fish issues. Crews are canvassing the North and South Forks and the mainstem Shenandoah at multiple points this week.

Virginia seeks public's help in fish kill investigation, April 26, 2007

Reports of dead and dying fish throughout the Shenandoah River watershed this week have prompted Virginia officials to seek the public’s assistance in determining the extent of the problem.

The Shenandoah River Fish Kill Task Force encourages the public to provide any information on the location, number and type of fish found dead or sick in the mainstem Shenandoah, the North and South Forks, South River, Middle River or North River. Distressed fish are found mainly in eddies, shallow areas and slow-moving waters away from the main current.

DEQ began receiving reports on Monday of dead and dying fish on the North and South Forks of the Shenandoah River. Since then, DEQ, DGIF, and other members of the task force have been canvassing the river system to determine the condition of fish, primarily smallmouth bass and redbreast sunfish.

About two dozen dead fish were found Monday on the North Fork several miles downstream of Woodstock, on the South Fork between Bentonville and Front Royal, and about six miles upstream of Elkton on the South Fork. A number of live fish with skin lesions or abnormal behavior also were observed. Along the South Fork on Tuesday, an undetermined number of dead and dying fish were found between Bentonville and Karo, and about a dozen fish were found between Island Ford and Elkton.

Fish kill reports on upper James, lower Cowpasture rivers, May 17, 2007

Virginia officials again are seeking the public’s assistance in determining the extent of fish kills as reports of dead and dying fish are investigated on the upper James River and the lower Cowpasture River.

The public is encouraged to provide any information on the location, number and type of fish found dead or sick in the Shenandoah, Cowpasture and James river systems. Distressed fish are found mainly in eddies, shallow areas and slow-moving waters away from the main current.

Anyone with information is asked to call the DEQ regional office in Harrisonburg at (540) 574-7800, or toll-free in Virginia at 1-800-592-5482. Information also can be emailed to fishreports@deq.virginia.gov.

In the past two weeks, DEQ and DGIF received scattered reports of dead fish in the lower Cowpasture. This week, reports surfaced of affected fish in the upper James. DEQ and DGIF investigated these reports more thoroughly on May 16 and found affected fish on the Cowpasture, mainly downstream of Route 39; on the James near Buchanan in Botetourt County; and on the James at Horseshoe Bend, also known as Narrow Passage, upstream of Buchanan.

On the Cowpasture, rock bass, smallmouth bass and redbreast sunfish had lesions. The number of fish with lesions near Buchanan was small, but scientists believe the situation requires further investigation. Smallmouth bass, rock bass and redbreast sunfish are the main species affected. At Horseshoe Bend, numerous fish with larger lesions were found. Northern hogsucker, smallmouth bass, rock bass, largemouth bass and redbreast sunfish are mainly affected, and numerous dead fish also were observed. The observations on the James River are similar to fish kills in the Shenandoah River watershed in the past three years.

The internal organs of these fish have been preserved for analysis. In addition, DEQ and DGIF plan a combined effort the week of May 21 to collect fish on the James, Cowpasture and Shenandoah rivers. The fish will be sent to several laboratories, microscopically examined, and tested for bacteria and viruses. Scientists have found no indication of human health concerns with the water or fish.

The Shenandoah River Fish Kill Task Force is coordinating this latest investigation with additional biologists from DEQ and DGIF, as well as with angler groups and university scientists. The task force continues to receive reports of fish kills on the North and South Forks of the Shenandoah.

Fish kills continue; task force expands investigation, June 11, 2007

The Virginia fish kill task force has expanded its work to include the Cowpasture, Maury and upper James rivers. Fish that have either died or are ill have been observed in these rivers for the past several weeks.

The fish species mainly affected continue to be smallmouth bass and redbreast sunfish, though other types of fish have been found with sores. The task force, headed by DEQ and DGIF, is coordinating efforts with anglers, conservation organizations and university scientists to identify the location and extent of the fish kills.

In the past three weeks, the number of reports of distressed fish has continued to increase. On the James, the fish have been found as far downstream as Lynchburg. DEQ and DGIF biologists also are investigating new reports from Buena Vista on the Maury River and the mainstem Shenandoah River.

The U.S. Environmental Protection Agency collected sediment samples in late May to test for toxicity and estrogen-related chemicals in some of the rivers. Water samples have been collected from the affected rivers to be tested for known fish viruses. Weekly and continuous water quality monitoring is still under way, and the task force remains in contact with counterparts in West Virginia as they investigate similar fish kills in the Potomac River system.

Fish kills diminish; Investigation narrows focus, June 15, 2007

• An expanded advisory group of scientists to include areas such as fisheries, fish diseases, microbiology, chemistry and agriculture to provide additional expertise for the investigation. DEQ and DGIF expect the panel to be in place in July.

• Analysis of the chemical makeup of agricultural waste streams in the river watersheds. Many of the water quality tests so far have been evaluations of river water and have focused specifically on nutrients and ammonia, which are normally associated with agricultural waste. A plan is under development for expanded, comprehensive testing of waste streams and sources connected with agricultural land uses, with assistance from the Department of Conservation and Recreation. That information will be compared with chemicals found in fish tissue, sediments and water in the fish kill areas.

• Continued evaluation of viruses, bacteria and parasites. This is being coordinated with work by the U.S. Geological Survey, the U.S. Fish and Wildlife Service disease laboratory, and Cornell University. Also, numerous fish collected this spring are being saved for further analysis, after additional chemical information comes in from water quality and agricultural samples.