The Oregon Coast Aquarium reports the “blue tide” is upon us, as beaches all along the Oregon coast are strewn with an aquamarine layer of jelly-like organisms especially apparent at low tide.

These are the innumerable bodies of by-the-wind sailors, formally known as Velella velella, and their strandings are a regular, yet fascinating late spring phenomenon in coastal Oregon.

By-the-wind sailors are hydrozoans, a class of predatory animals, distantly related to corals, sea anemones and jellies. They range in size from a few millimeters across to seven centimeters and appear brilliant blue and purple when at sea or freshly washed ashore. After time in the sun, the velella dry out and lose their pigmentation. Beachgoers will often mistake the dried animals for thin, clear pieces of plastic.

By-the-wind-sailors are not singular organisms but in fact colonies of animals. Each velella is a colony of all-male or all-female individuals (called polyps), which are divided into separate groups within the colony. Some polyps specialize in feeding and reproduction, while others protect the colony and provide structural support.

Visitors walking the beaches in the next few weeks should enjoy these incredible creatures safely while their aquamarine hues last — they won’t look that good for long, and they’ll soon smell much worse.

The Oregon Coast Aquarium creates unique and engaging experiences that connect visitors to the Oregon Coast and inspire ocean conservation.