Brown Algae Plague infects Va. Rivers
Pastor Dale Morgan
Aug 13, 5:20 PM EDT
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Brown Algae Plague infects Va. Rivers*
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NORFOLK, Va. (AP) -- A burst of brown algae bloomed over portions of the
Elizabeth and Lafayette rivers in the Hampton Roads region - a so-called
"mahogany tide" that can have lethal consequences for fish and shellfish.
Algal blooms have become common in the Chesapeake Bay watershed, the
result of excessive nutrient pollution - mostly nitrogen and phosphorus
- from too much fertilizer, vehicle exhaust, stormwater runoff and
development activity.
All major tributaries of the bay in Virginia have had blooms of various
algae species this summer, Christy Everett, Hampton Roads regional
director of the Chesapeake Bay Foundation, said Monday.
Everett spotted the brown algal bloom last Wednesday, near Old Dominion
University in Norfolk. On Thursday, during a flight over the region, she
saw the bloom had spread to the Western Branch of the Elizabeth River,
in Portsmouth and Chesapeake, and up into the Lafayette River in Norfolk.
ODU scientists examined samples and confirmed that a brown-colored
species of algae had bloomed locally.
Such blooms usually last several days, Everett said. Chesapeake Bay
Foundation scientists plan to fly over various Virginia rivers this
Thursday to monitor the condition of the mahogany tide and check for
other algal blooms, she said.
The algae soak up oxygen from waterways, and that can suffocate fish,
crabs, oysters and clams. Nutrient enrichment also clouds the water,
making it difficult for sunlight to reach the bottom so vital underwater
grasses can grow and shelter bay creatures.
"They're completely preventable," Everett said of the blooms. "When we
reduce the nutrients, there won't be these algal blooms."
Virginia lawmakers this year approved spending $250 million to upgrade
sewage treatment plants, including several in Hampton Roads, to curb
nutrients.
Algal blooms typically occur in summer and early fall because hot
temperatures hasten plant growth. The dense patches of plant life, grow
and move with the currents.
The mahogany tide in Hampton Roads is not believed to be toxic, though
experts cautioned against swimming in waters with blooms.
"Common sense should tell anyone to avoid them," said Harold Marshall,
an aquatic plants expert and professor emeritus at Old Dominion University.
Marshall said the species in question has increased in Virginia over the
past decade.
He traced the beginning of this trend to 1992, when a massive mahogany
tide swept from the Rappahannock River south to lower James River, out
into the Atlantic Ocean and down to the North Carolina coast.
That event "seeded" local waters with the species so that, almost every
summer, it multiplies when conditions are right, he said.
The blooms dissipate with a strong tidal exchange or wash into the open
bay, he said.
The Chesapeake Bay Foundation has started a "Bad Water Hotline," (866)
666-9260, for residents to report algae blooms and fish kills.
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On the Net:
Chesapeake Bay Foundation: http://www.cbf.org