"Following Hurricane Floyd, record-breaking rains continued to soak the area, washing mountains of sediment and waste into the water system," said Gene Feldman, of NASA's Goddard Space Flight Center. "Now rivers and tributaries along the Atlantic are choked and major ecological changes are happening."

Scientists are studying Hurricane Floyd's effect on algae blooms and phytoplankton -- important links in the regional marine food chain. Their data also will help them understand how the hurricane's aftermath may affect the fragile environment in the coming months.

"Periodically, levels of dissolved oxygen in the water have dropped dramatically as organic matter decomposes, and aquatic life has been threatened in dozens of estuaries and peripheral habitats, commonly referred to as 'dead zones'," Feldman said. "The current changes in the area may have lasting repercussions for hundreds of thousands of people."

According to Pat Tester, a NOAA scientist at the Center for Coastal Fisheries and Habitat Research in Beaufort, N.C., fertilizer and other nutrients that flowed down the storm-flooded rivers in eastern North Carolina are feeding the algae and phytoplankton in the sounds.

The satellite image data will be combined with sea and air measurement techniques to get a better picture of the changes occurring in the region.

"One question is what happens to the aquatic activity in the sounds when this algae dies and begins to starve the waters of oxygen," Tester said. "The long-term observations provided by the NASA technology will help us monitor the phytoplankton in the water."