A large number of jellyfish have been reported in various locations, with some areas experiencing an invasion of the creatures. The jellyfish have been found in both freshwater and saltwater environments, including in europe and on beaches in australia, and have caused problems such as shutting down nuclear reactors and threatening fishermen. The influx of jellyfish has also led to an increase in stings in some areas, prompting concerns from researchers and efforts to curb the invasion.