The jellyfish Pelagia noctiluca is becoming more abundant in the Atlantic Ocean and the Mediterranean Sea. A 50-year study published in the journal Biology Letters has revealed that warmer winters and over-fishing, which result in fewer jellyfish predators, may be the driving factors behind the jellyfish population boom.
"We have shown that they can reproduce rapidly if the conditions are right, and can reach large densities throughout the whole year, particularly if winters are warm," said María Luz Fernández de Puelles, a co-author of the study, and a researcher at the IEO's Balearic Oceanography Centre.
The study also revealed that warm winters influence the currents into the Meidterranean Sea, and possibly contribute to jellyfish blooms in the waters along the coast of Spain.
The effects of jellyfish blooms is significant. They impact fisheries, fish farming, and tourism. Jellyfish inflict toxic stings on anyone or any animal they encounter. They stings can kill small fish and cause much pain to larger animals, including humans. Jellyfish are predatory invertebrates. The feed primarily on fish larvae. When present in large numbers, jellyfish severely alter the marine food webs they encounter.
Licandro, P. (2010-10-23) A blooming jellyfish in the northeast Atlantic and Mediterranean. Biology Letters, 2(3), 1-691. DOI: 10.1098/rsbl.2010.0150
Photo © Hans Hillewaert / Centro Oceanografico de Baleares. The jellyfish Pelagia noctiluca.
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