Sea nettle forecast map provided by NOAA Chesapeake Bay Office.
According to NOAA, the jellyfish often encountered in the Chesapeake Bay in the summer is the sea nettle Chrysaora quinquecirrha. The species is white and occurs most abundantly in the tributaries of the middle Bay, where salinities range from 10 to 20 parts per thousand (ppt). In the southern Bay, it often has red/maroon markings on the long central tentacles and on the swimming bell. C. quinquecirrha occurs from Cape Cod south along the U.S. East Coast, Caribbean, and Gulf of Mexico; it abounds in the Chesapeake Bay in numbers unequaled elsewhere.