Marine habitats around the world are undergoing changes caused by a variety of sources ranging from natural disasters to agricultural runoff. Marine creatures are being exposed to such changes in sea water as temperature, salinity, and nutrient load.
Jellies seem to be finding these changes beneficial. They are thriving. Jelly populations are exploding around the world, with swarms of the stinging creatures making headlines for shutting down nuclear power plants in Japan, Scotland, and Israel. Some individual jellies have grown to sizes that once were the domain of B list science fiction movies, shredding commercial fishing nets into which they blunder.
Researchers are now studying sea nettles off the New Jersey coast in hopes of understanding the driving factors behind these population explosions.