A new study by researchers at the Virginia Institute of Marine Science (VIMS) shows that jellyfish are more than a nuisance to bathers and boaters, drastically altering marine food webs by shunting food energy from fish toward bacteria.
An apparent increase in the size and frequency of jellyfish blooms in coastal and estuarine waters around the world during the last few decades means that jellies' impact on marine food webs is likely to increase into the future.
The results of the study, led by recent VIMS Ph.D. graduate Rob Condonnow a faculty member at the Dauphin Island Sea Lab (DISL) in Alabamaappear in the latest issue of the Proceedings of the National Academy of Sciences. His co-authors are VIMS professors Deborah Steinberg and Deborah Bronk, Paul del Giorgio of the Universit du Qubec Montral, Thierry Bouvier of Universit Montpellier in France, Monty Graham of DISL, and Hugh Ducklow of the Marine Biological Laboratory in Woods Hole, Massachusetts.
Condon conducted his field studies by sampling jellyfish blooms in the York River, a tributary of lower Chesapeake Bay. The team's experimental work took place in laboratories at VIMS, and in Canada and France. The researchers tracked the flow of food energy in the lab by measuring the amount of carbon taken up and released by jellyfish and bacteria within closed containers during "incubation" experiments of varying length. Carbon is the "currency" of energy exchange in living systems.
"Jellyfish are voracious predators," says Condon. "They impact food webs by capturing plankton that would otherwise be eaten by fish and converting that food energy into gelatinous biomass. This restricts the transfer of energy up the food chain, because jellyfish are not readily consumed by other predators."
Jellyfish and Marine Bacteria
Jellyfish also shunt food energy away from fish and shellfish that humans like to eat through their affects on the bacterial com
|Contact: David Malmquist|
Virginia Institute of Marine Science