Everywhere. When you go to the beach, you’re not swimming in ocean water, your swimming in ocean water plus the sperm and eggs of millions of sea animals. Many species, jellies included, are broadcast spawners. With few exceptions, they don’t have mating behavior or sexual intercourse. Instead, they dribble eggs and sperm out of their mouthes over the course of days or weeks. Some species will brood their eggs and young, but many don’t go to such efforts. So next time you’re swimming, just think of all the future jellies-to-be you’re traveling past. It beautiful  :’-)