Saturday, February 22, 2020

How a bizarre, monster fish hoodwinked researchers and reeled in a wave of citizen scientists


A woman in Denmark has a chunk of a massive creature in her freezer, next to her peas. In New Zealand, a fisherman has pieces of the giant in a bottle of vodka. And in Alaska, a bush pilot hops in his seaplane to hunt down samples of the colossus, known to some as an enormous 4,000-pound floating head.
© National Parks South Australia, Facebook In March of 2019, an ocean sunfish washed ashore at Coorong National Park in Australia. Viral photos of the find circulated on social media.

No, it's not the Loch Ness monster. And yes, it's safe to say that the behemoth that washed up on a beach in Southern California a year ago has created a worldwide furor. Scientists were shocked to find the weird fish – known as a "hoodwinker," or Mola tecta – in North America. When photos broke of the California find, fascination mounted around the globe.


"There’s this 'mola militia' that lives underground," said Patrick Webster, social media content creator for Monterey Bay Aquarium. "But every time something goes viral with a mola, people say, 'that’s my favorite animal!'"

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Now, citizen scientists from South Africa to Japan are helping researchers find out why the weird fish ended up thousands of miles from home.

People in four corners of the Earth are hooked – the hoodwinker is reeling them in.

Photos look unreal: Huge, weird fish washes up on Australia beach
Holy Mola mola!

News spread quickly when the curious creature washed up along the beach at Coal Oil Point Reserve, a coastal nature preserve near Santa Barbara, California, on Feb. 19, 2019.

Coal Oil Point conservation specialist Jessica Nielsen promptly ventured down to the beach to investigate. She took measurements of the dead beached sunfish and posted photos to the Reserve’s Facebook page. Nielsen assumed it was an ocean sunfish (Mola mola), a common find along the west coast.

"Holy Mola mola," Nielsen said in the post. "It is even taller (fin tip to fin tip) than it is long!"

UC Santa Barbara professor Thomas Turner saw Nielsen's post and rushed down to the beach with his wife and 4-year-old son. Turner posted a series of wild photos to iNaturalist, a social platform that allows users to map and share observations.

Researchers in Australia soon hopped in the game. One researcher saw the post and wondered if it was a hoodwinker, so he flagged it to Marianne Nyegaard, a marine scientist at Murdoch University who discovered and named the hoodwinker.

"I literally nearly fell off my chair when I opened the first photo," said Nyegaard, who confirmed that it was a hoodwinker. She later verified the ID through genetic testing.
Mermen, unicorns and the hoodwinker

The hoodwinker is one of five different species of sunfish, which include the world’s heaviest bony fish. "Every tropical and temperate ocean has sunfish in it," said Tierney Thys, a freelance researcher writing a book on sunfish. "They have many world records."

Not only are sunfish heavy, but they grow rapidly, putting on up to 800 pounds in 15 months, Thys said.

"Their growth rate is something that is fascinating," said Michael Howard, senior aquarist at Monterey Bay Aquarium. "We’ve had some fish in our aquarium grow (4 inches) in one month."

They may be bony fish, but their skeletons are strange. "You can cut through them with a knife, super easily. They’re more like cartilage," Thys said.

Their skin, like white coconut meat, can be more than an inch thick. They’re also the only known example of an animal that has vertically oriented wings. They don't even have a tailfin – it's more of a rudder.

It's extremely rare to spot a hoodwinker in California, Thys said. Unlike other sunfish species, the hoodwinker doesn't have a bump on its head or chin. It doesn't have a protruding snout or swollen ridges on its body.

Nyegaard discovered the species in 2013. She was analyzing biopsies sent from fishing vessels when she stumbled across a unique genetic sequence.

Finding the fish itself was much harder: It took Nyegaard more than a year to locate it, eventually finding one on the beach in Christchurch, New Zealand. She named the fish Mola tectus – tectus meaning "hidden" or "disguised" in Latin.

The hoodwinker is likely smaller than its sister species, which can grow up to nearly 11 feet and nearly 5,000 pounds, Nyegaard said. The largest hoodwinker on record is nearly 8 feet tall and dates to the 1960s.

But that's not the first documented hoodwinker. Nyegaard poured over old texts in many languages that reference sunfish. In one 16th-century book of curious and bizarre creatures compiled by Swiss naturalist Conrad Gessner, drawings of the sunfish feature alongside images of mermen and sea monsters. Another, from 1738, describes sunfish alongside unicorns.

Nyegaard could find only one work of old literature that described the hoodwinker – a 1889 stranding on the Dutch coast. So, of course, Nyegaard tracked down that preserved specimen. All this time, it had been tucked away behind a stuffed giraffe at the Naturalis Biodiversity Center in Leiden, Netherlands.
Why the hoodwinker was in California

Most hoodwinker sightings have happened around New Zealand and Australia. Last year's Santa Barbara sighting was the first time researchers became aware of hoodwinkers in North America. But months later, in August and December, divers spotted at least two in Monterey Bay.

Scientists say it's still too early to say why the hoodwinkers are in California, but some have offered hunches.

"It is possible that Hoodwinker sunfish wander widely, and the sightings off west coast North America are of occasional strays," Nyegaard said. "But we do not know if these odd sightings are a relatively new thing – perhaps linked to warming oceans and changing ocean currents – or if the occasional straying sunfish is unrelated to climate change."

Others say the hoodwinker may have come to the northern hemisphere during "the Blob" of 2014 and 2015, when a mass of warm water spread through the Pacific Ocean.

"During the blob, there was so much disruption of oceanography, it makes sense that a bunch of these animals could have punched through the equator like shwooop!" Webster said.

More: A 'blob' of warm ocean water killed 1 million seabirds in the Pacific, study says

Myron Peck, a professor of biological oceanography at the University of Hamburg, said he's seeing changes in populations of several fish species, including anchovy, tuna and boar fish. He called the hoodwinker mystery a "very challenging topic." Changes in ocean currents that influence jellyfish, which hoodwinkers feed on, may be partly responsible, Peck said.

"It will be impossible to attribute the occurrence of a single individual to climate change, but we are hearing about this type of phenomenon – animals outside their 'normal' range – on a pretty regular basis now," said John Pinnegar, scientific adviser at the Centre for Environment, Fisheries and Aquaculture Science in the U.K.
On the hunt for the hoodwinker

Since last year's discovery in California, nearly 50 people worldwide – from the U.S., South Africa, Chile, Japan, the Philippines and across Europe – have contacted Nyegaard about potential hoodwinker sightings. While most sightings have turned out not to be hoodwinkers, people aren't deterred.

Most recently, a man from Belgium reached out to Nyegaard saying he had collected a stranded sunfish from his local beach and stashed it in his freezer.

In Christchurch, New Zealand, one man drove many miles up a beach on his quad bike to photograph and sample three stranded sunfish.

Nyegaard negotiated with the crew of one fishing vessel to give her tissue samples whenever they accidentally caught a sunfish before releasing it back into the sea. "We ended up settling on an exchange rate of a six pack of beer per sample," she said.

In California, Monterey Bay Aquarium has been helping Nyegaard and others assess photos and footage taken by locals. After the "exciting" sighting last February, Webster helped two groups who had taken video of sunfish identify their subjects as hoodwinkers. Webster shared one of the videos on the aquarium's Tumblr page.

That's when San Jose resident Lauren Wilson saw the post. An engineer and avid diver, Wilson had unknowingly photographed a hoodwinker in 2015. She was finishing up a dive with a friend when the pair spotted the huge shape nearby.

"It’s still the biggest one I’ve ever seen," Wilson said. "It was huge. I got a picture of it. We swam toward it a little bit, but they’re surprising fast. They look awkward, but they move quite quickly. That was the highlight of my month."

Wilson posted the photos on iNaturalist, but it wasn't until she saw a Facebook post from Monterey Bay Aquarium about a new sunfish species that she connected the dots. Wilson found Nyegaard's email online and sent her a link to the iNaturalist post. It was, indeed, a hoodwinker.

Nyegaard is now running a citizen science platform in Indonesia where participants identify individual sunfish based on their skin patterns. She's hoping to recover more tissue samples from hoodwinkers off the coast of the U.S. and from South America, where they have been appearing off Chile.

"Such samples are only possible to recover through the help of locals, so I am very keen to hear from anyone who sees stranded sunfish," she said. "This is where citizen science can be so powerful, as people these days can readily record what they see on their mobile phones. Over time this will build up a highly valuable database of our natural world and help us understand the changes that are occurring."

The jury's still out on why the hoodwinker is showing up in the northern hemisphere. Some say it's climate change. Some say it's natural population shifts. Others say it was there all along, hiding in plain sight, hoodwinking us.

Follow Grace Hauck on Twitter @grace_hauck.

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