LA Times has a nice 5 parter - worth reading.  There's serious untightness going on.  Read it.

http://www.latimes.com/news/local/oceans/la-oceans-series,0,7842752.special

The fireweed began each spring as tufts of hairy growth and spread across the seafloor fast enough to cover a football field in an hour.

When fishermen touched it, their skin broke out in searing welts. Their lips blistered and peeled. Their eyes burned and swelled shut. Water that splashed from their nets spread the inflammation to their legs and torsos.

"It comes up like little boils," said Randolph Van Dyk, a fisherman whose powerful legs are pocked with scars. "At nighttime, you can feel them burning. I tried everything to get rid of them. Nothing worked."

As the weed blanketed miles of the bay over the last decade, it stained fishing nets a dark purple and left them coated with a powdery residue. When fishermen tried to shake it off the webbing, their throats constricted and they gasped for air.

After one man bit a fishing line in two, his mouth and tongue swelled so badly that he couldn't eat solid food for a week. Others made an even more painful mistake, neglecting to wash the residue from their hands before relieving themselves over the sides of their boats.

For a time, embarrassment kept them from talking publicly about their condition. When they finally did speak up, authorities dismissed their complaints — until a bucket of the hairy weed made it to the University of Queensland's marine botany lab.

Samples placed in a drying oven gave off fumes so strong that professors and students ran out of the building and into the street, choking and coughing.