‘I couldn’t breathe’: the sinister spread of France’s killer seaweed

After a series of deaths on the beaches of Brittany, one bereaved family set out to prove the foul-smelling bloom was to blameWhen her phone rang at around 5pm on 8 September 2016, Rosy Auffray was still at work. It was one of her daughters, distressed, calling to tell her that their father, Jean-René, had not come back from his daily run. Only the family dog had returned, alone and exhausted. Rosy rushed back home.When she arrived, Rosy noticed that the dog was behaving bizarrely: she refused to walk, then collapsed under a bush. Her fur stank of rotten eggs, of overflowing sewers. Rosy knew where that smell came from: the mudflats roughly three miles from the family home in Brittany, where seaweed had been accumulating and putrefying. The soggy, decomposing seaweed stretched for miles along the shore, sometimes as much as five feet thick, killing other plants and suffocating fish and small birds.