Deep beneath the ocean’s surface, this homebody holds tight to the rocky seafloor.

While most other sea cucumbers meander across the seafloor, the armored sea cucumber (Psolus squamatus) is a sedentary species. 

Their flat underside acts like a suction cup, gripping the bottom and rarely letting go. Psolus cannot outrun predators. Instead, tough, hardened scales cover their body, serving as protective armor. A low profile and muted color help too—with their tentacles tucked in, Psolus looks like a rock to a crab that walks past.

A hungry armored sea cucumber orders room service from the currents that sweep along the seafloor. Psolus unfurls long, finely branched tentacles up into the water column. Sticky mucus collects tiny plankton and bits of organic material. One by one, the sea cucumber sweeps those tentacles and food into their mouth.

Sometimes, we see white fields of armored sea cucumbers covering the rocky walls of Monterey Canyon and the slopes of neighboring seamounts, where strong currents provide a feast. In fact, up to 20 percent of all animals observed on some seamounts are Psolus.

Unfortunately, the currents also carry something sinister: plastic pollution.

Bags and other trash can smother bottom-dwelling animals. Worse still, plastic trash never goes away. It breaks down into smaller and smaller pieces called microplastic. These bits of plastic are about the same size as organic material that armored sea cucumbers and their neighbors on the deep seafloor eat.

Deep-sea animals cannot distinguish plastic from food. We need to turn off plastic pollution at the tap by using less plastic and choosing reusable alternatives instead. Together, we can be the solution to ocean plastic pollution.