Pest report: Bugs down, jellyfish up
News Source: Asbury Park Press
July 31, 2011
By KIRK MOORE, STAFF WRITER
Slowly making their way across the mouth of Kettle Creek, a trio of scientists looked at an array of jellyfish sliding past their boat — ghostly white bells trailing stinging tentacles, spaced four to five feet apart, as far as the eye could see.
“Look at the density of this. It’s like a horror movie,” said Jack Gaynor, a professor of biology at Montclair State University who is studying the genetics of Barnegat Bay’s sea nettle infestation.
“Boy, we’ve seen it like this before, but never at this density,” said his colleague Paul Bologna, the Montclair State professor leading the research effort to learn more about population, and how much of the bay’s tiny animals called zooplankton are being gobbled up by the nettles.
Bologna has worked on the bay for years, so when jellyfish numbers impress him, you know it’s a problem. The annual eruption of sea nettles seems to get worse every year, and the 2011 outbreak started chasing people out of the water around Father’s Day.
It’s making for a miserable summer in the northern bay, along with washups of rotting algae, twin signals of the bay’s deteriorating ecosystem, scientists say. Along much of the bayfront and residental lagoons, above-ground swimming pools have appeared alongside the docks.
“To get away from the greenhead flies, you’d jump into the lagoon. Now, the jellyfish will get you,” said Linda Chris, a longtime resident of Shorewood Harbor in Brick.
As far as greenheads and mosquitoes go, what looked like a challenging year early on has turned into just an average season, said Richard Candeletti, superintendent of the Ocean County Mosquito Extermination Commission.
“The mosquitoes did have a peak a few weeks ago. We had very high tides,” and those floated mosquito larvae and eggs out of potholes and across the salt marsh grasses, Candelitti said. That makes it much harder to eradicate the larvae by spraying.
“The tides would not go away. But now they’ve declined, and we’re back to normal,” he said.
But the freshwater Asian tiger mosquito is expanding its range through Monmouth and Ocean counties. “They’re on the spread,” Candelitti said. “We’re urging people to clean up their yards.
The Asian imports have established themselves on the northern Monmouth Bayshore and are showing up in Howell, Jackson, Lakewood and Toms River.
They are especially annoying as aggressive day biters, and able to breed in tiny puddles of water on plastic tarps and idle flowerpots. Mosquito control workers say they find them breeding in bottle caps.
A century ago, New Jersey led the nation in mosquito control, to protect public health and help economic development of Shore resorts.
But sea nettles may be an even more implacable foe. Thriving in Barnegat Bay’s nutrient pollution, they appear to be here to stay for the forseeable future, Bologna glumly predicts.
Overloading the bay with nitrogen-based nutrients flowing in from storm water may have set the stage for jellyfish dominance, by feeding algae blooms that shade and crowd out underwater eelgrass and widgeon grass, scientists say.
Those grasses are important habitat for small fish, and reducing the bay’s finfish population means there are fewer to eat jellyfish in their early life stages, Bologna suggests.
Fish may have kept the sea nettles in check, but now the tables are turned. Bologna examined a bit of food in a sea nettle’s transparent stomach, before packing the animal in ethanol and a plastic bag for laboratory testing.
“It could be a copepod, or a larval crab,” he said. “I won’t know until I get it under the microscope.”
Another big factor in spreading sea nettles is the use of vinyl plastic in docks. In their anchored polyp life stage, sea nettles settle on the shaded underside of floating docks, and pump out baby jellyfish when spring arrives.
“Mosquitoes you can get away from, you can spray, you can put on repellent. With these things, you can’t go into the water,” Bologna said. “If you look at the potential tourism impact of not being able to use the northern third of the bay, it’s really substantial.
There is one bright spot in the pest picture. For the second year in a row, a wet spring helped generate a big hatch of dragonflies, among the few predators that eat greenhead horseflies.
Swarms of seaside dragonlets — the only dragonfly species that breeds in the salt marsh — are again starting to provide air cover for humans, just as they did this time last year.