How Far the Light Reaches: A Life in Ten Sea Creatures

by Sabrina Imbler

Entire ecosystems depend on these deaths, creatures whose lives revolve around chance windfalls of blubber, gut, and bone. Whale falls linger for decades, feeding scavengers in roughly three stages. The first invites mobile scavengers seeking flesh: sleeper sharks and bludgeon-headed rattails, hagfish and isopods. They swim from afar and congregate to strip the carcass to the bone, with sleeper sharks ripping off soft tissue in chunks and hagfish rasping at the flesh. These scavengers work fast, devouring the equivalent of a small person each day, but still it can take two years to strip all the flesh. The second stage attracts fewer species of scavengers but far greater numbers of them. Invertebrates reign here, with worms that resemble shag carpets and tiny crustaceans called comma shrimp feeding on the rich organic material left inside the bones and scattered in the surrounding sediment. The third stage of whale fall, called the sulfophilic stage, happens when the carcass is reduced to a skeleton. The creatures that arrive have specifically evolved to feast on the lipids locked inside the skeleton. Dense, glowing meadows of bacteria descend on the skeleton and feed on the fats and oils inside the bones. Feasting like this produces hydrogen sulfide, which sustains chemosynthetic clams and gutless, mouthless bone-eating worms. The worms root themselves in bones like blossoms and feast on the lipids.