NOAA and partners have rolled out Chesapeake Bay tools that forecast Vibrio risk for oyster growers and the public, including a model that predicts Vibrio parahaemolyticus concentrations up to 48 hours ahead.
A separate public tool estimates Vibrio vulnificus levels from six previous days through the next day using temperature, salinity and two decades of state sampling and DNA testing.
The push comes as infections rise: Maryland reported 260 vibrio cases in 2025, up from 100 in 2018, while Virginia reported 151, up from 86; the two states logged more than 400 cases combined last year.
Scientists tie the increase largely to warming and nutrient-rich waters. Chesapeake Bay water temperatures have risen 1.8 degrees over 30 years, extending the bacteria's season beyond its traditional May-to-October window.
V. vulnificus remains uncommon but dangerous: the CDC sees 150 to 200 U.S. cases a year, about one in five fatal, and Maryland and Virginia reported four deaths from it in 2025.