The smelly, gigantic blobs of brown seaweed that drift across the Atlantic Ocean every summer may not seem like a major threat at first glance. Sargassum is a genus of brown seaweed (and therefore an algae) abundantly found across many of the planet’s oceans. Researchers became particularly interested in the seaweed after the first appearance of the Great Atlantic Sargassum Belt in 2011. From there, it likely enters the open ocean through the Loop Current and Gulf Stream, where it eventually feeds into Sargasso seaweed. Credit: Joe Raedle / Getty ImagesBut what’s causing the Great Atlantic Sargassum Belt’s exponential growth in recent years?