Velella live for months and travel widely around the Pacific gyre, says Julia Parrish, a marine biologist at the University of Washington. Typically they travel down the coast of California to Central America, then shoot out past Hawaii to Japan and return again, skimming along the surface like a kite surfer.<\/p>\n
The creatures go through boom-and-bust cycles during this journey, experiencing many different life stages, \u201cwhich are all quite different from each other\u201d, says Parrish. When there is a lot of food in the water column for them, their population explodes and they wash to shore together, which often happens in the spring and sometimes in the fall.<\/p>\n
Despite people encountering them often, velella are actually not widely studied in science \u2013 partly because of how they live. Marine biologists have been very successful in figuring out how to raise jellyfish in tanks, for scientific research and for the public to see up close. But velella live on the ocean\u2019s surface and have many forms through their lifespan, and scientists haven\u2019t quite solved the problem of how to create the conditions to raise them in captivity. That means we know less about them than we do about most jellyfish that live underwater, far from human eyes.<\/p>\n
One current area of study is the relationship between velella and ocean temperatures. In 2021, Parrish used data collected from 20 years of citizen scientists\u2019 observations to uncover the patterns in the mass strandings of velella, and found that the events were more likely to happen when winters were warmer than usual.<\/p>\n
The reasons why are still being investigated, but Parrish thinks it has something to do with rough winter seas. \u201cIn really stormy winters with very high waves sustained over multiple days, as in storm events, those colonies that are just small and just starting to develop are going to be torn apart,\u201d Parrish says. \u201cBut in a milder winter, they\u2019re going to have a higher chance of survival, leaving more of the colonies towards the end of the winter to really grow up.<\/p>\n
\u201cThat\u2019s our hypothesis,\u201d she adds, but proving it would take a major effort to study the organisms out at the continental shelf.<\/p>\n Since the little sailors are ephemeral in nature, they don\u2019t follow the same patterns every year. But when they do show up in mass numbers, it usually happens in multiple places at the same time, Parrish says.<\/p>\n When they come ashore, the blanket of shiny blue creatures creates a magnificent tableau for photographers and beachcombers \u2013 but as they dry out, the creatures lose their color and become \u201clike crunchy potato chips or candy wrappers\u201d, Stajner says. They also play a role in bringing carbon and nutrients that would otherwise have been in the ocean to the shores where they are blown.<\/p>\n Beachgoers love them because they are cute, shiny and instantly recognizable, and because they come in such huge numbers. But admirers may not realize they are actually looking at colonies of creatures that are struggling and dying, Parrish says. \u201cInstead, what you see is something that is beautifully colored, small enough to be harmless and it\u2019s just so odd and interesting,\u201d she adds.<\/p>\n As the world\u2019s oceans continue to warm as part of the climate crisis, it\u2019s likely that more velella colonies will come to shore, and also thrive out at sea. It makes scientists such as Parrish wonder if these charismatic little blue-hatted creatures could have a more complex impact on the oceans than we realize. For instance, since velella eat zooplankton, fish larvae and especially fish eggs, they may begin to negatively affect fish species.<\/p>\n \u201cThere\u2019s some evidence that collectively there are enough hungry velella out there that they can actually change the population dynamics of some of the forage fish like anchovies that are also found in the California current system,\u201d Parrish says.<\/p>\n