Why Is a Huge Seaweed Blob Headed for Florida?

You’ve likely been hearing it in the media for weeks now: A giant mass of seaweed, some 5,000 miles wide, is headed for Florida, where it will engulf beaches with tons of icky and decaying seaweed, emitting a noxious gas all the while.
Inevitably, stories about this massive swath of seaweed tend to call it a blob, stirring up images of some 1950s B-movie monster coming to absorb the Sunshine State, beaches, tourists, retirees and all. In reality, the so-called blob, while big, is well-known to scientists and has been carefully studied for more than a decade. And it won’t just affect Florida. Here’s what we know about it.