June 24 , 2004
Blue-green algae (Cyanobacteria) blooms continue on the Bush River; Seneca Creek (Baltimore Co.) new bloom location.

Maryland Department of Natural Resources sampled water from the middle to upper Bush River (Harford Co.) between June 14-16 during routine water quality monitoring and continued tracking of existing cyanobacterial (blue-green algal) bloom conditions. Bloom conditions remain widespread but intensity declined from concentrations detected between June 1 and 9 at Flying Point State Park and Otter Point State Park (see HAB News from June 11, 2004: "Blue-green algal blooms expanding in Chesapeake Bay tributaries since June 1."). The greatest concentrations of cyanobacteria were detected in samples taken between Flying Point State Park and the mouth of Lauderick Creek at the station XJG4451 (east of Fairview Point) and the long term monitoring station WT 1.1 east of Gum Point (Figure 1). Four samples were sent to Wright State University laboratory for toxin testing, results are pending completion of the tests.

Maryland Department of the Environment investigated a Seneca Creek bloom site on June 17 in response to a citizen water quality complaint. The investigation indicated Seneca Creek was simultaneously experiencing a filamentous algal bloom and a cyanobacterial bloom (see HAB News from June 24, 2004: "Nuisance filamentous macroalgae expands in Baltimore County to include Seneca Creek."). Microcystis cell concentrations were estimated at 304,628 cells per milliliter. This is the first algal bloom report of the year for the Seneca River system and further expands the waterways where cyanobacterial blooms have been identified in 2004 (Figure 2).

During summer 2003, the Bush, Potomac and Sassafras Rivers were three of several river systems where widespread blue-green algal blooms were found. Inadvertent swimmers reported skin rashes, itching eyes, stomach aches and fever, and the hepatotoxin (i.e., liver toxin) microcystin was detected in association with summer cyanophyte (blue-green) blooms (see HAB News from October 30, 2003: "Microcystin toxins found across Maryland's Chesapeake Bay in summer 2003."). Not all blooms of blue-green algae produce toxins. Samples in 2004 from the Bush River, Potomac River and Frog Mortar Creek have been sent to Wright State University to test for microcystin toxin content. Results are pending.

Pockets of blue-green algal blooms may be encountered during boating and other recreational activities. People should take common precautions to reduce the 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