The invention comes from the Korea Advanced Institute of Science and Technology. Engineer Hyeon Myeong and colleagues developed it to help clear fishing waters of jellyfish blooms. Jellyfish populations have exploded over the past 10 years as overfishing opened up new ecological spaces for jellies, Yale Environment 360 reported in 2011. Jellies are a part of many healthy ocean ecosystems, but if an area has too many of them, the blobby predators will further deplete fish populations by gobbling up fish eggs and plankton fish would otherwise eat. They're especially a problem in northern Asia. In Korea, they cost the fishing industry 300 billion won (about $280,000) a year, according to KAIST.