Thousands of blue sea creatures wash up on California beaches, intriguing but harmless to humans.

Thousands of glittering blue Velella velella, known as by-the-wind sailors, have washed up on California beaches. These creatures, related to sea anemones and jellyfish, cannot swim and are blown ashore by shifting spring winds. Though they have stinging cells, they are harmless to humans. Once on the beach, they decompose quickly, leaving behind colorful, crunchy remains. Researchers suggest a link between their strandings and rising ocean temperatures.