Imagine strolling along the misty shores of Seaside, Oregon, only to stumble upon a fish that looks like it swam straight off the pages of a children’s storybook—round, massive, gleaming with orange-red and grey scales, and every bit as mysterious as you’d hope. On July 14, 2021, this pre-back-to-school adventure became a reality for beachgoers and marine enthusiasts, thanks to the dramatic arrival of a rare, 45-kilogram ‘moonfish’—sending ripples of excitement through the scientific community and beyond.
An Unexpected Visitor: Meet the Opah
This particular moonfish, formally known as the royal lampris or opah (Lampris guttatus if you want to impress your next trivia night), was discovered on a quiet Seaside beach in the northwestern United States. Its vibrant coloring—orange-red with hints of grey—made for quite a spectacle, and locals weren’t the only ones baffled. The specialists at the local aquarium found themselves in awe, with The Washington Post picking up the story for curious minds everywhere. Why all the fuss? Usually, opahs prefer to keep to warmer, temperate waters, far from Oregon’s cool embrace.
Where Opahs Usually Swim: Geography of a Giant
According to France’s Institute for Ocean Research (Ifremer), opahs are ‘habitual guests of tropical and warm temperate seas.’ Lately, these fish have been making more frequent appearances in the western Mediterranean. In France, you might spot them around mainland coasts, but you’re more likely to find them off Mayotte, French Polynesia, or Reunion—making their Oregon beach cameo even stranger.
Across the Atlantic, these fish usually swim off the U.S. East Coast or around American territories in the Pacific Ocean, Hawaii included, as the U.S. National Oceanic and Atmospheric Administration (NOAA) points out. And while a lone opah was fished up in Oregon back in 2009—an eyebrow-raising occasion, according to The Oregonian—the species remains a rare find in these chilly, northern waters. Heidi Dewar, a NOAA biology researcher, confirms the oddity.
Climate Change: The Prime Suspect?
The mysterious moonfish was found in ‘good condition,’ indicating, per Tiffany Boothe of the Seaside Aquarium, that it had been close to the coast when it died. While experts hesitate to pin down a single cause for its unexpected appearance, they do have one likely culprit in their sights: climate change. Shifts in ocean temperatures may be nudging the royal lampris outside its usual playground, researchers say.
- The opah’s arrival in Oregon could be due to warming waters.
- Very little research has been conducted on the opah’s basic ecology or biology.
- NOAA adds that we have no estimates of how many opahs live in the world’s oceans.
This gap in knowledge only adds to the fascination surrounding this oddball fish. It’s a topic ripe for future study, giving marine biologists both a puzzle and a new friend to study—though good luck catching one for your home aquarium!
The Science Behind the Scales: A Fish Like No Other
In 2015, American scientists published a study in Science focused on this very species. Relying on opah specimens caught off California’s West Coast, they uncovered something remarkable: the opah is a ‘warm-blooded’ fish—the first of its kind discovered by researchers. Typically, fish have the same body temperature as the surrounding water, but opahs buck the trend, averaging a body temperature that’s about 5°C higher than their surroundings. This gives them a unique physiological edge and makes them an even greater anomaly in the Oregon chill.
The Seaside fish, soon to find itself in a deep freeze for optimal preservation, has one final role to play. Come the new school year, it’s slated for a starring appearance in dissection—local schoolchildren will have a chance to learn, scalpel in hand, about one of the ocean’s more mysterious dwellers, as shared by the aquarium on Facebook.
Final Thoughts: Fish tales are often taller than true, but this moonfish story is solid science—plus a dash of climate awareness. Next time you stroll a windswept Pacific Northwest beach, keep your eyes peeled for surprising visitors from afar. Who knows? The next scientific mystery might be waiting just beneath the waves.
William is the creative mind behind Aversa Outdoor — a lifelong outdoor enthusiast with a deep love for gardening, home design, and everything in between.
He grew up surrounded by nature, spending weekends helping in the family garden and learning the joy of building things by hand. Over time, that passion turned into a mission: helping others create spaces they love, inside and out.
With Aversa Outdoor, William shares practical tips, fresh ideas, and a laid-back approach to home and garden living. Whether you’re planting your first herbs, planning a patio makeover, or just looking for inspiration, he’s here to make it simple, rewarding, and a little bit fun.
When he’s not in the garden or sketching his next DIY project, you’ll find him exploring local nurseries, chasing the perfect sunset light, or sipping coffee on the porch with a good book.
