NOAA 2001-R307
Contact: Pat Viets


The annual summertime infestation of sea nettles, a type of stinging jellyfish, is in full force in the Chesapeake Bay, but boaters and swimmers now have a chance to avoid them, thanks to scientists at the Commerce Department's National Oceanic and Atmospheric Administration.

A team of scientists, led by Christopher Brown of NOAA's National
Environmental Satellite, Data, and Information Service
, has developed a method to map the locations where sea nettles are likely to be found. The method uses a computer model and sea-surface temperature data from NOAA's satellites to identify areas of moderate salinity and warm water. Because the sea nettles prefer these conditions, the scientists can predict where they are likely to occur.

"Sea nettle stings can ruin your day at the bay," Brown said. "While we can't eliminate the jellyfish, we can lessen the incidence of stings by letting swimmers and boaters know where they are likely to be, thereby avoiding or maintaining caution while in those areas."

The habitat model for sea nettles was constructed using historical data of sea nettle abundance and coincident temperature, salinity, and water depth in the Chesapeake. When used in conjunction with estimates of sea-surface temperature, salinity, and water depth, the habitat model identifies locations where the current conditions are favorable to sea nettles and indicates their likely distribution.

The salinity fields are derived from a numerical circulation model being run by Tom Gross and Zhen Li of NOAA's National Ocean Service.

The sea nettle mapping project is a collaboration among scientists from the University of Maryland Center for Environmental Science, the Virginia Institute of Marine Science at the College of William and Mary, and NOAA's National Ocean Service and NESDIS.

"We're delighted to provide scientific information that may ultimately help coastal visitors have a safer and more enjoyable beach experience," said Margaret Davidson, acting assistant administrator for NOAA's National Ocean Service.

NESDIS operates the nation's environmental satellites, which are used for weather forecasting, climate monitoring, and other environmental applications such as fire detection, ozone monitoring, and sea surface temperature measurements. NESDIS processes and distributes the millions of bits of data and images these satellites produce daily, and conducts research on the use of satellite data for monitoring the environment.

NESDIS also operates three data centers, which house global data bases in climatology, oceanography, solid earth geophysics, marine geology and geophysics, solar-terrestrial physics, and paleoclimatology.

For a recent map of sea nettle distribution in the Chesapeake Bay, and for more information please visit: