June 16 , 2006 Fish kill investigation continues for the Lower Potomac River

A fish kill was investigated by Maryland Department of the Environment (MDE), Virginia Department of Environmental Quality (VA DEQ) and Maryland Department of Natural Resources (MD DNR) on June 5th involving at least 8000 fish of 11 species, mostly white perch and croaker, on the lower reach of the tidal Potomac River, southwest of St. Clements Island (St. Mary's County). Fish were estimated as days old with only a few freshly dead fish present. The fish were washed up on shore near Nomini Bay, VA up to Colonial Beach, VA. The investigations suggested multiple potential causes that could have worked individually but likely combined their effects over this region of the river to produce the event. Multiple effects being investigated included 1) weather events, 2) toxic algae Karlodinium veneficum effects and 3) incidental death of fish in a pound net unable to seek refuge from a seiche-induced influx of oxygen depleted (anoxic) bottom water. There is no evidence at this time to suggest that a sewage spill of 17 million gallons from Blue Plains Wastewater Treatment Plant, Washington, DC, on May 19th is linked with the events.

Data continues to be summarized to assess whether or not weather events allowing hypoxic and anoxic (low oxygen and no oxygen) deep river waters to move onshore and trap fish within water of stressful quality leading to a kill. Such an event is known as a seiche. Wind data for the days suggests a change in direction and magnitude that could promote a seiche.

Water samples were collected by VADEQ, MDE and Morgan State University Estuarine Research Center during the investigations. The potentially toxic dinoflagellate algae Karlodinium veneficum was found in bloom conditions in the area on May 19 th and again in during the June 5 th fish kill investigations. Samples from both dates were tested by the laboratory of Dr. Allen Place at the University if Maryland Biotechnology Institute Center of Marine Biotechnology and determined to be positively toxic for karlotoxins. Karlotoxins affect fish at their gills. The toxin impact on gill tissue reduces the ability of fish to obtain oxygen and they suffocate. Karlodinium has confirmed links with fish kills in the Chesapeake Bay and other regions of the world.

The Virginia Health Department received a report from a fisherman who admitted dumping a net full of dead fish in the area of the kill from his pound net. However, because of the size range and diversity of fish in relation to the net mesh, this factor alone did not account for all the fish observed in the kill investigation. Additional data sets are becoming available to further evaluate the water quality conditions of the region surrounding the time of the kill. Updates will be provided as new data are evaluated.

The Chesapeake Bay Safety and Environmental Hotline is a toll-free phone number for Maryland citizens to call to report a problem on the tidal portions of Maryland's portion of the Chesapeake Bay as well as the Coastal Bays. One phone call will now direct citizens to the appropriate agency to make a report 24 hours a day, 7 days a week.

Effective immediately, 1-877-224-7229 will allow citizens to report any of the following:

• Boating accident or reckless activity
• Fish kill or algal bloom
• Floating debris that poses a hazard to navigation
• Illegal fishing activity
• Public sewer leak or overflow
• Oil or hazardous material spill
• Critical area or wetlands violation
• Suspicious or unusual activity

 Maryland Department of Natural Resources will continue to actively monitor and report on the condition of the river. Citizens are advised to take common precautions around bloom waters to reduce the possible risk of illness or discomfort related to blue-green algal blooms:

• The public should not swim in areas where a blue-green algae bloom is evident.



• Do not drink water from any area with the appearance of a blue-green algae bloom.



• If contact is made with problem water, simply wash off with fresh water.
  In some cases, skin irritations may occur after prolonged contact. If irritations persist, see a physician or local health care provider.



• Keep pets and livestock away from bloom areas.
  Blue-green algal blooms may contain toxins that could be harmful or fatal to pets and livestock.



• Do not eat viscera (internal organs) of fish caught in bluegreen bloom waters.



• Inhalation exposure to blue-green algal bloom waters may result in irritation of the eyes, ears, nose and throat with extended recreational activity on such waterways.

Please note that illness associated with harmful algal blooms is now a reportable illness so physicians should be reporting these to local health departments. The MD DNR in coordination and cooperation with DHMH and MDE will continue to monitor all blue-green algal blooms throughout the state. For up to date information on all of Maryland's harmful algal blooms and water quality, please visit Eyes on the Bay