In Past the Shallows, the boys' father is an abalone fisherman off the southern Tasmanian coast. Abalone are gastropods—single-shelled molluscs—similar to snails, but with a more flattened shell. Other than their size and respiratory pores—large holes near the edge—their outer shell is often unremarkable. However, their inner iridescent appearance is prized by collectors and used for mother-of-pearl jewelry. Primarily, abalone are hunted and sold as a culinary delicacy. Although abalone farms also provide demanding consumers with these tasty molluscs, wild abalone are more highly valued. In Australia, the largest abalone producing country in the world, there are two types: blacklip and the more valuable greenlip. China is the largest importer of Australian abalone and an increase in demand has led to greater profits and therefore greater risks have been taken to procure them.

To look at an abalone, it is difficult to imagine any danger associated with ...