Central America Hit By Mass Die-Off of Sea Turtles Scientists aren't sure what's going on By Evann Gastaldo, Newser Staff Posted Nov 11, 2013 7:03 AM CST 10 comments Comments A turtle makes its way toward the ocean in La Libertad, El Salvador, Saturday, Sept. 18, 2010. (AP Photo/Edgar Romero) (Newser) – Between late September and mid-October, 114 sea turtles washed up dead on El Salvador's beaches. All across Central America, the same thing is happening: In Guatemala, 115 have died this year; in Costa Rica, 280; late last year, 200 died in Panama. In Nicaragua, in addition to the turtle deaths, some turtles are also arriving on shore weeks late to lay their eggs. And a particularly ominous detail: Dogs that ate some of the dead turtles died almost immediately. Scientists aren't sure what's going on, AFP reports, but they're alarmed—especially considering some of the dead turtles are endangered species. One possibility: A red tide (which occurs when a large amount of algae turns the sea water red) has resulted in a neurotoxin called saxitoxin, produced by algae, that's killing the turtles. Saxitoxin killed about 500 sea turtles in El Salvador in 2006, and 100 more four years later, but red tides happen almost every year and have never had such a dire effect as what's going on this year. Other possibilities involve human activities. "Some say it could be due to climate change, sea currents, or the techniques used by fishermen," says one biologist. Yet another problem: Fertility is down 40% for sea turtles in Honduras, and the turtles already have reproduction issues, with just one out of 1,000 hatched babies ever returning to lay eggs on shore.