Thousand-foot-long ships chug through the Panama Canal’s waters each day, over the submerged stumps of a forgotten forest and by the banks of a new one, its canopies full of screeching parrots and howler monkeys. Some 14,000 ships pass through its locks every year, their decks stacked high with 6 percent of the world’s commercial goods, crisscrossing the paths of tugboats on the voyage between…