Jellyfish invasion in southern U.S.

Lately, swimmers and hikers on southern U.S. beaches have noticed many shimmering, translucent globs -- an annoying dead jellyfish plague, caused by humans catching too many fish and shrinking the jellies' food supply, a recent study suggested.

Climate change and over-fishing are to blame for jellyfish blooms and die-offs, according to Roger Williams University marine biologist Sean Colin, who participated in an international research team that studied jellyfish strengths, and published the findings in the September 2011 issue of the journal Science. Since late summer, local and international media have reported about this unsightly, oozing scourge that has dismayed locals and tourists alike. Beachcombers have reacted to the larger-than usual numbers of beached, dead or dying jellyfish with disgust or fascination, and swimmers have dreaded bumping into the live blobs as they splash in the surf because jellyfish tentacles sting (and sometimes, because of the"yuck-factor"). Despite the advantages and success worldwide of the various classes of jellyfish, the marine animals remain vulnerable to water temperature changes and large-scale over-fishing, both of which affect the fish the jellies eat, as well as other fish predators competing for the same ocean food sources, according to Colins. According to the U.S. Department of Natural Resources, both nearly harmless and potentially harmful jellyfish species inhabit all U.S. coastal waters.