A hawksbill's narrow beak reaches into reef crevices that broader-headed turtles cannot work. What it extracts is largely sponge tissue, threaded with silica spicules and loaded with defensive compounds. Caribbean diet studies have found sponges dominating stomach contents, with a handful of species accounting for most of the intake.
The consequence carries up the food chain. Compounds from sponges and other prey can accumulate in hawksbill tissue, and eating hawksbill meat has caused outbreaks of poisoning, a syndrome recorded across the Indo-Pacific and known as chelonitoxism. Cooking does not remove it.
The more famous pressure on the species was not food but shell. Overlapping scutes of hawksbill carapace were worked into combs, boxes and inlay for centuries, and the trade continued at scale into the twentieth century. Commercial harvest is now banned under CITES, though illegal trade persists.