- Small nudibranchs, known as blue sea dragons, feast on blue buttons and man o’ wars, using their winglike cerata to grab and hold onto their tentacled prey. There are sea anemones, barnacles, copepods, color-changing crabs, specialized bacteria, even bugs, all living in this inverted reef in the middle of the open ocean. (Organisms that live exclusively by floating at the surface of the water are called pleuston, while neuston is a broader term, referring generally to the sea-surface ecosystem, which is why I chose to use it here.)
Just like reefs on the seafloor, this ecosystem does not stand apart from the open ocean around it. The neuston is a nursery for multiple species of larval fish and a hunting ground for paper nautilus octopuses. It supports sunfish, leatherback turtles, and diverse ocean grazers, which frequent these islands, relying on them as a food source. At night, soft-bodied jellies rise up to join the neuston, sparkling like fireflies. But all of this, from the blue sea dragons to the by-the-wind sailors, is in peril.
When I learned about the Ocean Cleanup project’s 600-meter-long barrier with a three-meter-deep net, a wall being placed in the open ocean, ostensibly to collect plastic passively as the currents push water through the net, I thought immediately of the neuston. How will it be compacted ? But in the 146 pages of the Ocean Cleanup’s environmental-impact assessment, this ecosystem isn’t mentioned once.