Tag Archives: sea jellies

These jellyfish hardly sting but a snorkeler is entranced

Published November 30, 2015 in the “Ocean Watch” column, Honolulu Star-Advertiser ©2015 Susan Scott

The golden jelly has eight arms, each ending in clublike extensions that contain mild stinging cells. ©2015 Susan Scott

The golden jelly has eight arms, each ending in club like extensions that contain mild stinging cells.
©2015 Susan Scott

I’m home from Palau, but as I recall my excellent two weeks of snorkeling there, one image pops out: floating mesmerized above millions of jellyfish in a landlocked marine lake.

Called Ongeim’l Tketau (also known as Jellyfish Lake), Palau’s famous lake contains seawater that flows in and out through channels and fissures in its limestone island. As a result, the lake’s water rises and falls with the tides in the surrounding lagoon.

Jellyfish Lake is special, but not because it’s Palau’s only marine lake with jellyfish. The island nation hosts more than 50 such lakes, five containing jellyfish. All are the same species, Mastigias papua, but dissimilar enough that scientists gave them subspecies names, each honoring Palau’s five elected presidents.


Ongeim’l Tketau, however, is the only lake open to visitors. Tourists come from around the world to swim with its mass of up to 13 million golden jellyfish migrating daily across the 14-acre lake. (Waikiki’s Hilton Lagoon is 5 acres.) It’s a myth that these jellyfish have lost their sting. True, the creatures house algae in their tissues and get carbs from the plants. But the jellies also need protein and, like their coral relatives, have small tentacles that sting and kill tiny drifting animals that live in the lake.

Rocket jelly

The story that the jellyfish don’t sting comes from the fact that their stinging cells, called nematocysts, are too weak to penetrate human skin except, possibly, in sensitive places such as lips. Even then most people just get a tingle. Or nothing. When an adult golden jelly, about 4 inches across, brushed my lips, I felt nothing but joy. It was like getting kissed by a mobile marshmallow.

The jellies cluster together because they follow the sun, giving their gardens the light they need to make sugars. (The creatures’ color is their algae’s color.) At night the jellyfish rest, but come morning they’re on the move again. In Ongeim’l Tketau, the jellies travel about a half-mile per day, swimming east in the morning and west in the afternoon. By stopping where shadows hit the lake’s edges, the jellies avoid their major predator, a native white anemone that grows on fallen branches and mangrove roots along the lake’s walls. At the slightest touch, the anemone stings the jellyfish and eats it.

Susan in Jellyfish Lake

To give all their plants equal time in the sun, the pulsating creatures twirl every which way as they migrate, performing a slow-motion ballet. Watching this dance of the golden jellies while floating and breathing through a snorkel is like taking a tranquilizer. Mastigias papua etpisoni is my kind of drug.


Tiny velella sail by before stormy seas

By-the-wind sailor is a non stinging relative of jellyfish about 4 inches long and 3 inches wide. ©2014 Susan Scott

BUNDABERG, Australia » After a weeklong passage from New Caledonia, Honu is safely in a marina on Queensland’s south coast. Even so, my body thinks we’re still at sea because I have “mal de terre,” the French phrase for land sickness. This happens when the seas have been particularly rough.

The voyage didn’t start that way. For six days the wind was light, and the boat moved with a pleasant motion.

One day during those mild conditions, Craig noticed shiny disks dotting the water’s surface. They were by-the-wind sailors, the jellyfish relatives in the news recently after washing up on the U.S. West Coast by the millions.

Also known as Velella, the floating, nonstinging (to humans) creatures, about 4 inches long and 3 inches wide, bobbed on the surface as far as we could see.

I had read about enormous numbers of these creatures surrounding sailboats offshore, but this was the first time I saw it. The jelly boats ran downwind with us all day, their clear sails scooting them along while their tiny tentacles trolled for plankton. When a waved capsized them, the bottom-heavy animals popped back up and sailed on.

Because I had only seen these offshore animals dead on the beach, I wanted to see one alive in its element. Craig tied a colander to the end of the boat hook and scooped one up.

The jelly sailor was magnificent, its clear sail and blue hull radiant in the morning sun. After taking its picture, we returned the little boat to its fleet and wished it fair winds.

But none of us were that lucky. As we headed toward a 20-mile-wide pass through the Great Barrier Reef, lightning flashed ahead. With landfall only 100 miles away, we forged on. Soon thunder roared, lightning struck the water around us, and rain pounded with such force the drops felt like hailstones. We had sailed into the center of a storm.

As we breathed a sigh of relief over making it through hours of forked lightning and bellowing head winds, another thunderstorm appeared, lighting the leaping waves like a discotheque from hell.

That night we sailed through storm after exhausting storm, each time thinking it was the last. After four such tempests, the skies cleared, dawn broke and we sailed into the harbor of Bundaberg.

After friendly customs officers cleared the boat for entry into Australia, I walked to the nearby beach. There on the sand lay hundreds of Velella jellies, shipwrecked by the storms.

Even days later the ground still moves beneath my feet, and the sensation gives me a touch of nausea. But that’s OK. I’m just happy that unlike a host of our tiny fellow sailors, Honu made it safely to port.

Marine biologist Susan Scott writes the newspaper column, “Ocean
Watch”, for the Honolulu Star-Advertiser, www.staradvertiser.com

©2014 Susan Scott

Oahu’s upside-down jellyfish came in ships’ ballast water

Published September 22, 2014 in the “Ocean Watch” column, Honolulu Star-Advertiser ©2014 Susan Scott

A beached Cassiopea, or upside-down jellyfish, has frilly “arms” that face up to provide food for the animal. Courtesy Jan Dettweiler

A reader recently came across what she described as pulsating gelatinous creatures on the Kaiwi shoreline.

“Anxious to know what they are,” Jan wrote, and sent two pictures, one taken from each side of the animal.

Jan’s find was an alien creature with a cosmic name: Cassiopea. Most of us, though, call it an upside-down jellyfish.

Upside-down jellyfish live in the reverse position of most jellyfish, with bell on the seafloor and frilly arms facing up. That’s because those lovely lacy limbs contain algae that, like reef corals, contribute to the jellies’ food supply.

Like all plants, algae need sunlight to grow, and that’s what turns the world upside down for these creatures. The bell in this case works as a gentle suction cup to hold the animal in position on the bottom.

The algae give the bushy arms their color of brown, green or blue.

Upside-down jellyfish are not native to Hawaii. Oahu hosts two species (there are eight worldwide), delivered here by accident in ships’ ballast water, probably in the 1940s.

The underside of a beached Cassiopea, or upside-down jellyfish. Courtesy Jan Dettweiler

One of our species is native to the Red Sea and Atlantic Ocean. The jelly grows about 12 inches across and lives in shallow lagoons, sand flats and around mangroves (not native to Hawaii, either) on the leeward side of the island.

Years ago the Duke Kahanamoku Lagoon, adjacent to the Hilton Hawaiian Village, was a good place to watch these elegant jellyfish pulsing in the shallows like flowers with heartbeats. The pulses direct animal plankton toward stinging cells around the jellies’ hundreds of mouths tucked in folds of the frills.

When their water is disturbed, upside-down jellies release loads of free-floating stinging cells. For most people the stings are just prickles on areas of tender skin. Large numbers of stings, though, can get your attention. I paid for my snorkeling excursions in the lagoon with mild, itchy stings to my face and neck.

To me, watching those out-of-this-world jellies was worth some discomfort, but others didn’t see it that way. In 2006 the lagoon owners drained the water and installed a new circulation system. Alas, the upturned jellyfish are now gone.

Oahu’s other kind of upside-down jelly is in Kane­ohe Bay and other windward areas, including, apparently, some places on the Kaiwi Coast. DNA studies suggest that this species came from the Western Pacific, possible New Guinea.

Cassiopea may not look like much lying on a beach, but in their element, the jellies dance like the stars. See one at bit.ly/1uy4mwZ.

Marine biologist Susan Scott writes the newspaper column, “Ocean
Watch”, for the Honolulu Star-Advertiser, www.staradvertiser.com

©2014 Susan Scott

Jellyfish swarms are not of their own doing

Published September 15, 1997 in the “Ocean Watch” column, Honolulu Star-Advertiser
©1997 Susan Scott

Do Hawaii’s jellyfish swarm?

I received an E-mail earlier this summer from Pangolin Pictures in New York City. “We produce programming for National Geographic, the Discovery Channel, Audubon Society, etc.,” wrote a company researcher. “Currently, we are working on a documentary film about SWARMS and would love to ask you a few questions about jellyfish.”

I had never heard the term swarm used for these wind- and current-driven creatures. Unlike bees or locusts, jellyfish don’t cruise in a crowd. Mostly, they’re solitary individuals that occasionally become pushed together by wind and currents.

I enjoyed exchanging notes and phone calls with the people at this film company. They were pleasant, well informed and interested in getting the facts right. My only problem with their project was I didn’t think Hawaii ever had what you’d call swarms of jellyfish, and I told them so.

Several days later, thousands of jellyfish arrived in Hawaii’s bays and beaches, stinging a record number of swimmers.

For reasons unknown, on July 30, leeward beaches were inundated with box jellyfish. It was the worst invasion recorded here, so bad that lifeguards, police and volunteers walked the beaches with bullhorns, warning visitors in Japanese and English to stay out of the water. Even so, at least 800 people were stung.

The next day, Pangolin Pictures’ Eric Taylor arrived in Hawaii to interview people about jellyfish. “I looked up the word swarm in the dictionary,” he said. “I’m comfortable using the term with jellyfish here, especially after yesterday.”

A swarm, Webster says, is (among other things) “a large number of animate or inanimate things massed together and usually in motion.”

That pretty much describes what happened here in July with the box jellies. But it was interesting to me that not one of the local newspaper accounts I saw used the word swarm. Invasion, infestation and influx were the reporters’ words of choice.

Why do I care about the word swarm? I’m uneasy with its tone. Maybe I saw too many horror movies when I was young, but to me, a swarm usually means hundreds or thousands of creatures moving with a single, sinister purpose: swarms of angry bees delivering stings; locusts moving over crops and devouring everything in sight; ants or flies swarming over dead bodies.

Jellyfish don’t get together for that kind of organized carnage. The box jellies we see in Hawaii mostly drift with the currents, alone, trailing four stinging tentacles behind them to catch tiny pieces of food.

Hawaii’s box jellyfish usually show up in leeward waters 8 to 10 days after a full moon.

When the numbers get large, all hell breaks loose, both for people, who get stung by trailing tentacles, and for the jellyfish, who die in droves on the beach. And even though the sting is accidental, the creatures become animal outlaws, reviled and feared.

I’m not saying their stings don’t hurt and aren’t sometimes severe enough for an ER visit. It’s just that here in Hawaii, fear of a jellyfish sting doesn’t justify permanently staying out of the water. In spite of all the talk about allergic reactions and so-called “shock” from stings, no deaths from jellyfish or Portuguese men-of-war have been reported in Hawaii.

Heed the lifeguards’ calls and you’ll rarely get stung. If you do, the burning sensation is usually short-lived.

OK, maybe thousands of jellyfish on one side of an island constitutes a swarm. But they don’t mean to be bad. Jellyfish are victims of circumstance, just as we are when we connect with their tentacles.

Late this fall, look for “Deadly Swarms,” a one-hour special on FOX television.

Marine biologist Susan Scott writes the newspaper column, “Ocean Watch”,
for the Honolulu Star-Bulletin, www.starbulletin.com

Victims of jellyfish stings invited to join pain study

Published January 6, 1997 in the “Ocean Watch” column, Honolulu Star-Advertiser ©1997 Susan Scott

The Honolulu City and County lifeguards are launching a study on jellyfish stings this week.

This means that the next time you get a box jellyfish or Portuguese man-of-war sting and head for an orange tower for aid, you may hear the following:

“We’re studying which substances and temperatures help relieve the pain of jellyfish stings. Wanna help?”

If you agree, the lifeguard will have you sign a consent sheet explaining the study, approved medically and sanctioned by the University of Hawaii Committee on Human Studies. Then he or she will apply one of several remedies.

You are the judge, scoring your relief (or lack of it) on a scale of 1 to 10.

At the towers where liquids and pastes are used, neither the lifeguard nor the victim knows the identity of the substance being applied. This is called a double-blind study, important because both researchers’ and victims’ previous beliefs and experiences greatly influence the effectiveness of pain remedies.

Fully one-third of people given a pretend treatment (a “sugar pill”) have genuine relief of their symptoms. This is called the placebo effect and it doesn’t just happen to nut cases. It’s universal, regardless of sex, age and culture. Perhaps it’s an evolved trait that helps us humans better cope with pain.

Because of this powerful placebo effect, you can’t just slap a little meat tenderizer on a jellyfish sting, observe that the person feels better and declare success.

The treatment of jellyfish and Portuguese man-of-war stings has long been a puzzle worldwide.

Hawaii is the only place where people routinely use meat tenderizer on such stings. In other parts of the world, nearly every substance imaginable, including manure, mustard and figs, has been sprayed, laid and smeared on these stings with similar results: Some think the stuff is useless; others swear it’s the best thing since penicillin.

Few of these substances have been tested with any scientific control. The closest anyone has come are the Australians, who have a lot more to worry about than we do. Their box jellyfish, called sea wasps, occasionally kill people with one powerful sting.

Australian researchers have recently recommended dousing all box jellyfish stings (but not those of Portuguese man-of-war) with vinegar. This dousing does not relieve pain, they say. Rather, it inactivates stinging cells still on the skin, thus preventing the sting from worsening. (Vinegar fires stinging cells in some man-of-war species.)

Pain, which can be wicked, is another issue. The Australians use ice packs to ease pain. Some people in Hawaii and on the mainland, however, swear that heat, either in the form of hot packs or hot showers, works better.

And then there’s the hard core urine camp who pee on every sting, cut and puncture that comes from the ocean, believing urine relieves pain and cures wounds.

Here in Hawaii, we’re lucky. Our marine stings are usually a minor annoyance, disappearing on their own in a half-hour or so. This is one reason so many remedies seem to work so well – the sting is going away on it’s own anyway.

The down side of applying anything you happen to have handy is that some substances may do harm. In laboratory tests, urine, ammonia and alcohol cause active stinging cells to fire. Therefore, applying these things has the potential of making a minor sting major.

No such substances are included in the new study, designed by volunteers, myself included, and run by Oahu’s lifeguards as a service to the community.

If you inaugurate the new year with a Portuguese man-of-war or box jellyfish sting, take a few minutes to participate in the study. Your contribution will help replace myth with fact and make the ocean a safer place to play.