“Getting too close to and spending too much time along the shoreline means burning my eyes and lungs, and per my local physician, perhaps untold lasting damage,” wrote Surfer correspondent Owen James Burke reporting from the Lesser Antilles, back in May.  And what was Burke referring to? Ancient Napalm deposits in Asia? Monsanto pesticide runoff in Maui? Nope, he was reporting on the growing issue of sargassum onshore buildup at his homebreak. Sargassum is a free-floating brown macroalgae that drifts on ocean currents in vast rafts, sometimes the size of football fields. The seaweed itself is native to the Atlantic and has always existed in the Sargasso Sea, and in the open ocean is a genuinely valuable habitat, providing nursery grounds for mahi mahi, sea turtles, and dozens of other species.…