Blooms, or proliferations, of jellyfish can show a substantial, visible impact on coastal populations -- clogged nets for fishermen, stinging waters for tourists, even choked cooling intake pipes for power plants -- and recent media reports have created a perception that the world's oceans are experiencing trending increases in jellyfish. Now, a new multinational collaborative study suggests these trends may be overstated, finding that there is no robust evidence for a global increase in jellyfish over the past two centuries....