A 20-year-old man fishes local waters every day for his meals and scoffs at the idea he might ingest too much mercury. “I ain’t dead yet,” said Justin Baird, who stopped at a Sebastian Inlet tackle shop one gusty afternoon after making his day’s catch. “I’ve been eating fish since I was a little kid.” His haul included mackerel, sheepshead, red drum and speckled trout. Baird, who is jobless, figured he would gobble it up in two days. Chances are, all the fish contained some mercury.