NASA funded researchers are using satellite imagery and water quality models to map the impact of a September algae bloom on oyster farms along Virginia’s Eastern Shore.
NASA funded researchers are helping Virginia officials assess damage to oyster farms after a harmful algae bloom affected parts of the Chesapeake Bay’s Eastern Shore in September 2026.
The Virginia Marine Resources Commission is using maps and scientific guidance from researchers to identify affected oyster-growing and restoration areas. The assessment builds on a NASA Earth Action Water Resources project designed to improve water quality forecasting through satellite observations and information from shellfish growers.
Researchers from William & Mary’s Virginia Institute of Marine Science and Batten School documented a nearly continuous algae bloom stretching about 15 miles along Virginia’s Eastern Shore, from Cape Charles to south of Nassawadox Creek. The bloom included Alexandrium monilatum a species known to harm aquatic life, and coincided with reports of fish deaths and oyster losses.
At the commission’s request, scientists analysed satellite images from the European Space Agency’s Copernicus Sentinel-2 mission to identify areas with elevated concentrations of microscopic algae. They also used the Chesapeake Bay Environmental Forecast System to reconstruct water temperatures, salinity and wind conditions before and during the bloom.
The analysis found that water temperatures during much of early September were higher than those recorded during the same period between 2018 and 2025. Temperatures were around 80 degrees Fahrenheit when the bloom began, potentially placing additional stress on oysters.
Researchers also found that calm winds may initially have allowed the algae to remain in the affected waters, while stronger winds later could have pushed the bloom towards the shoreline and into areas used for oyster farming.
The findings are expected to help officials and shellfish growers better understand the factors behind harmful algae blooms, assess their effects on aquaculture and improve preparations for similar events in the future.