Hot, dry weather made the Chesapeake Bay saltier two summers… (Karl Merton Ferron )
Further news of note for beachgoers: This could be a bad year for stinging nettles in the Chesapeake Bay, a University of Maryland scientist says.
Maggie Sexton, with the UM Center for Environmental Science, has been checking for jellyfish daily in the Choptank River at the Horn Point Environmental Laboratory near Cambridge.
"The conditions are right to have a large population," she said. "We saw the first one two weeks ago, and now we're starting to see one every day," she said. "In couple of weeks to a month, we expect to see a lot more."
The unusually warm spring this year likely triggered the jellies' early arrival and set the stage for a large bloom, according to Sexton. Jellyfish larvae overwinter on the bottom of the bay in anemone-like polyps. Warming temperatures along with saltier water prompt the polyps to produce tiny sea nettles, which develop stinging tentacles as they grow.
Two years ago, dry, hot weather brought a bumper crop of jellies up the bay, even making a noticeable appearance in Baltimore's Inner Harbor. Last year, though, the bay was relatively jellyfish-free, as spring deluges made the water practically fresh.
"The salinity was so low that the polyps never really got going," Sexton said. "We saw a few, but not a lot of them," said Sexton. "This year I would guess that we will see more."
While sea nettles may make for wary Bay swimming, they do have an upside, the UM scientist said. The nettles eat comb jellies, which in turn eat fish and oyster larvae.
"If nettles can knock down the comb jelly population, they give a lot of fish a greater shot at survival," she said.
Sea nettle concentrations vary around the bay. To find out the likelihood of running into them at various locations, people can now go online and check to see how ripe water conditions are for jellyfish. The National Oceanic and Atmospheric Administration has outfitted its interpretive buoy system to include a "sea nettle probabiilty" reading, along with other measures of water quality. To check the buoys, go here.