Fragments of rubber balloons, plastic bags and fishing line can cause fatal blockages and injuries in sea turtles, seabirds and marine mammals, according to a new analysis.By Teresa TomassoniIngesting just six pieces of rubber—each smaller than a pea—can all but seal a seabird’s fate, leaving it with a 90 percent chance of death. A 300-pound adult green sea turtle has about a 50 percent chance of survival after swallowing two golf balls’ worth of plastic bags and food wrappers. Gulping down less than a soccer ball’s volume of fishing line or nets is enough to kill nearly all sea lions, seals, dolphins and porpoises.