Jellyfish Sting?
Sea Nettle The sea nettle {em}Chrysaora quinquecirrha{/em} is the iconic jellfyfish of Chesapeake Bay in summer. It occurs from Cape Cod south along the U.S. East Coast into the Caribbean and Gulf of Mexico, but is most abundant in Chesapeake Bay, particularly in middle-Bay tributaries, where it is white. In the southern Bay, it often has red markings on the tentacles and swimming bell. Its sting is annoying, but not dangerous to swimmers. Rob Condon
Sea Nettle A sea nettle ({em}Chrysaora quinquecirrha{/em}) pulses through the York River. Note the white color and absence of red markings typical of sea nettles from lower Chesapeake Bay. David Malmquist.
Comb Jelly These barrel-shaped jellyfish ({em}Mnemiopsis leidyi{/em}) have a transparent body with four rows of ciliated “combs” that emit an iridescent glow when disturbed. Unlike other jellies, comb jellies don't sting. They are 3-5 inches long and about an inch in diameter. {em}Mnemiopsis {/em} eats zooplankton (including copepods), other comb jellies, and the eggs and larvae of fish. It thus plays an important role in the Chesapeake Bay food web.
Lion's Mane Jellyfish The Lion's Mane jellyfish ({em}Cyanea capillata{/em}) is most common in Chesapeake Bay during the winter. It has long tentacles and a potent sting. While it is not dangerous to swimmers, it is very unpleasant to encounter. Rob Condon.
Sea Nettle Sting VIMS graduate student Jessie Campbell shows the typical sting marks left by the tentacles of the sea nettle {em}Chrysaora quinquecirrha{/em}. Rob Condon.
I want to avoid jellyfish while swimming in Chesapeake Bay. What steps can I take?
Several different species of jellyfish inhabit Chesapeake Bay and nearby coastal waters. The most common jellyfish in the summertime Bay, and the one most responsible for stinging swimmers, is the sea nettle Chrysaora chesapeakei. Because these organisms occur within a narrow range of temperature (78 to 86°F) and salinity (brackish waters of 10 to 16 parts per thousand), VIMS scientists have been able to develop an experimental real-time computer model that predicts the likelihood that sea nettles might be found in an area based on the appearance of water masses that meet these criteria. The model uses no field data concerning sea nettle abundance or distribution, it simply shows where the water is of the appropriate temperature and salinity to support sea-nettle blooms.
Because jellyfish are planktonic animals that tend to move with tides and currents, another way to minimize the likelihood of encountering sea nettles and other jellyfish is to avoid swimming or boating along windward shorelines or where a flood tide encounters an obstacle.
Covering exposed areas may also help prevent stings. Beached jellyfish and dislodged stinging cells can continue to sting, so avoid touching any jelly-like masses you might encounter on the beach.