Minnows exposed to samples of red tide from waters in southeastern Virginia and the lower Chesapeake Bay died within hours, scientists report. The findings are the first indication the burgundy-hued algae blooms could cause serious aquatic harm.
NORFOLK, Va. (AP) -- Minnows exposed to samples of red tide from waters in southeastern Virginia and the lower Chesapeake Bay died within hours, scientists report.
The findings are the first indication the burgundy-hued algae blooms could cause serious aquatic harm.
Scientists stressed Thursday that the widespread algae blooms, which smell of rotten eggs, are not harmful to humans. Still, state health and environmental officials caution against swimming through the discolored waters.
At Old Dominion University, 12 sheepshead minnows were put into a lab tank filled with algae species thought to be responsible for the red tide. The algae came from the lower James River, at the mouth of the Nansemond River in Suffolk.
Within hours, the fish died - one after 37 minutes, said Margaret Mulholland, an ODU associate professor and expert in harmful algae blooms.
The algae species, called Cochlodinium polykrikoides, appeared to secrete a mucous that clogged fish gills and killed the 2-week-old juveniles.
Over the past 30 years, algae blooms have become common occurrences in the Chesapeake Bay, the result of summer heat, spring rains and excessive nutrient pollution. It is the bay's No. 1 pollutant.
Too much nitrogen and phosphorus are entering the bay from sewage plants, lawn fertilizers, and other sources in the bay's vast watershed.
Mulholland and a team of scientists and students on Thursday sampled more algae blooms in Hampton Roads. Chris Gobler, a scientist from the State University of New York at Stony Brook, joined the scientists to compare blooms here to those off Long Island.
A similar algae species has begun to crop up each summer for the past three or four years in coastal New York, he said. Lab tests involving the New York red tide also found that juvenile fish routinely died when exposed to dense concentrations of the algae.
Roger Everton, a water quality specialist with the Virginia Department of Environmental Quality, said new reports of blooms have begun to taper off the past week.
Information from: The Virginian-Pilot, http://www.pilotonline.com