Small translucent blobs dotted the Waikiki shoreline when Angel Yanagihara set out for a sunrise swim one early July morning in 1997.
"An old woman on the beach told me, 'Don't go in. Those are box jellyfish. They are dangerous,'" recalled Yanagihara, a biochemist at the University of Hawaii. "But I looked at them and thought that was silly."
Multiple box jellyfish stings landed her in an ambulance a short while later, and she admitted regretting her quick dismissal of the advice. Yet the ordeal, which culminated in "three days of bedridden agony," redirected her research. She was determined to decode the mysterious sea creature's sting, and then find ways to protect other swimmers, fishermen and divers who might risk coming into contact with a potentially deadly jelly.
That risk may be rising, according to some experts, who hold the popular but controversial opinion that factors including discharge of sewage and plastics, overfishing and climate change are creating ideal conditions for the hardy gelatinous animals to proliferate. More than a half-billion years on Earth, they say, has provided the box jelly and its cousins with tools to handle the harshest environments and to exploit the misfortunes of other species that can't.
"Across the world, we're seeing more sinister types of jelly blooms, in oceans that have been under pressures from our own mismanagement and our own pollutants," said Yanagihara.
Regardless of whether jellyfish are taking over our oceans -- a point of intense scientific debate -- researchers agree that the sea animals are worthy of more attention, research funding and public education.
"Jellyfish blooms are a problem that needs to be dealt with, pronto," writes Lisa-ann Gershwin in her new book, Stung! On Jellyfish Blooms and the Future of the Ocean.
"We are more frequently using the oceans, putting our bodies and industries into the pathways of jellyfish blooms," Gershwin adds. "But despite our increasing use of the sea, we have surprisingly few datasets about jellyfish."
Every year, some 150 million people are exposed to jellyﬁsh around the world, according to the National Science Foundation. Most jellyfish stings are minor, but rare tentacle swipes from some types, such as the box jelly can inject life-threatening doses of poison. In fact, certain species of box jellies have been known to stop the heart of a healthy adult in less than three minutes.
Yanagihara described the pain as the "sensation of thousands of burning needles."
She was fortunate to survive. An estimated 20 to 50 people annually are not so lucky in the Philippines, with the actual number likely to be far higher due to unreliable data, according to Gershwin. More locals and tourists lose their lives on the tropical coastlines in Australia, Thailand, India, China and Papua New Guinea, among other countries.
Deaths from Irukandji box jellies are particularly difficult to track. The sting itself often goes unnoticed and rarely leaves a mark. But about a half-hour later, a constellation of symptoms may develop, including muscle cramps, vomiting and hypertension. In severe cases that end in heart attack or drowning, a jellyfish may never be suspected.
The effects of jellyfish extend far beyond their sting, of course. Blooms have capsized fishing vessels, shut down nuclear reactors, clogged desalination plants, threatened an Olympic triathlon and devastated fisheries. Since the 1980s, according to the National Science Foundation, blooms of jellies have cost the world's fishing and tourism industries billions of dollars. Many fear the worst is yet to come.
Jellyfish are more common than they used to be in many places, noted Mark Gibbons, a jellyfish expert at the University of Western Cape in South Africa. While we can't point a finger at any one culprit, he said, the "coincidence is too great to be anything other than anthropogenic for most of those systems."
Perhaps nowhere are box jellies more recognized than the coasts of northern Australia, which entered box jellyfish high season in October. Here, blooms of box jellies have long been an annual occurrence. But a 2012 study suggests rising sea surface temperatures mean an earlier arrival and later departure, and thus a longer season of danger for public health.
Robert Condon, a marine biologist at the University of North Carolina Wilmington, led a separate study in 2012 that concluded the apparent rise in swarms of jellies may simply be an artifact of natural waxing and waning of global jellyfish populations on cycles of about 20 years. His teams's analysis of data since the 1970s did show a slight increase over time, he said, but more waxing than waning phases were also represented in that time period.
The studies call for more monitoring in order to get a better grip on what to expect of the slimy creatures in the decades ahead.
"In a lot of respects, issues of blooms are kind of irrelevant," said Condon. "We know we go through rise and fall periods, so we should prepare for that what's happening during future rise periods."
Some South Korean scientists envision that preparation in the form of jelly-slaying robots. They are currently testing prototypes. But critics such as Condon warn that such a technology may actually have the potential to enhance a jellyfish bloom -- releasing the eggs and sperm and creating even more jellies. He recommends a thorough environmental impact study before any robots are set loose on the seas.
Condon calls Yanagihara's new technology, meanwhile, "really clever."
Yanagihara has developed a dual-acting agent that blocks tentacles from shooting their toxic venom into the skin, while also providing treatment for stings -- just in case. The technology is the first that's designed for prevention, Yanagihara said, which is crucial in the case of fast-acting box jellyfish venom.
"It's been effective for every species we've tested so far," said Yanagihara.
The concoction is currently in the pipeline for U.S. Food and Drug Administration approval. Yanagihara said she ultimately hopes to have various versions, including sunscreen-like lotions and IV therapeutics, available to the public and out on the beaches for lifeguards and emergency care-givers. U.S. Army Special Forces, fisheries and others have already expressed interest, she added.
World-renowned long-distance swimmer Diana Nyad used the salve during her record-breaking open water swim from Cuba to Florida in September. She suffered box jellyfish stings three times during earlier, unsuccessful attempts at the crossing.
Yanagihara, like other experts, emphasized the importance of basic research and surveillance to help predict when and where dangerous jellies may appear. She has a study coming out soon based on 16 years of data from Hawaii, which she said finds that while waxing and waning, the overall trend has been of an increase in jellies. And she has started field surveys of jellyfish in the Northern Mariana Islands and the Caribbean.
"Systems need to be in place to detect these things early," said Gibbons of the University of Western Cape. suggesting the benefits of someday being able to predict the pending presence of jellies based on, for example, wind patterns. "But, at the moment, we're in a very poor position to be able to understand enough of the biology and the way jellyfish interact with the environment to build good models."
Citizens can help by reporting any jellyfish stings or sitings at JellyWatch.org. Cell phone apps are available. On Sept. 12, one beachgoer reported being stung by box jellyfish 10 days prior in Key West.
"Wounds are still healing," wrote the contributor.
CLARIFICATION: Some changes were made to this story to better differentiate between box jellyfish and Irukandji.