Thursday, June 09, 2011

"Changing Jellyfish Season Could Alter Chesapeake Bay Food Chain"

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By Alyson Kenward

First came hundreds of reports of jellyfish washing ashore in central Florida over the Memorial Day weekend. Since then, people have been spotting blooms of the gelatinous drifters off the coasts Connecticut, Virginia, and South Carolina, all earlier in the summer than expected.

The early appearance of jellyfish along the East Coast is more than just a nuisance for beachgoers. According to scientists, it’s a sign that coastal waters are warmer than usual for time of year, and recent studies suggest the early jellyfish blooms could upset the marine ecosystem in coastal areas, like Maryland's Chesapeake Bay.

“The key thing with jellies is that they do everything so much faster than everything else, they grow and reproduce and are voracious predators, that other animals like fish can’t keep up,” says ecologist Rob Condon from the Dauphin Island Sea Lab in Alabama.

For several years, Condon and colleagues from the Sea Lab and the Virginia Institute of Marine Science (VIMS) have been studying jellyfish that live in the York River, a southern tributary of Chesapeake Bay. They’ve discovered that rapidly-growing blooms of jellyfish are feeding on some of the most nutritious parts of the food web, including small crustaceans, and are converting them into products that sustain bacteria that leave little valuable energy supplies for fish and other sea life.

Condon says the jellyfish are making a similar source of energy-rich material that bacteria feast upon, but that strips the nutritional value out of the river’s food web.

“Ultimately, there is less food for the fish, because the jellyfish are eating it all,” he says. And because not too many animals (including us humans) eat jellyfish, it doesn't seem as though the food energy going into the jellies is moving up the food chain. This week, Condon and his colleagues published a study in the Proceedings of the National Academy of Sciences, detailing how jellyfish blooms reduce diversity in the marine food chain....

According to Condon, if these warm waters continue to arrive in the earlier and earlier in the springtime, the effects could be felt throughout Chesapeake Bay. "Jellyfish are an important indicator of the health of a marine ecosystem," he says. "If the jellyfish blooms come earlier, there will be big consequences for fish production in the Bay."

I think we are going to have to learn to like eating jellyfish. I think it can be done.

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