Issue 18.2: April/May 2015

Mollusk Man

Amateur malacologist Mike Severns' decades-long quest to find and document every land and sea shell in the Islands
Story by David Thompson. Photos by Dana Edmunds.

Given the chance, Mike Severns will talk your ear off about Hawaiian shells. And with more than two thousand shell species calling the Islands home, he can go on for hours. He gets excited about things like whether the whorls of a certain population of Maui tree snail turn clockwise or counterclockwise, even though he knows most people couldn’t care less. “If you ever want to put the person in the airplane seat next to you to sleep fast, try talking about snails,” he says, undoubtedly speaking from experience.

But there are people who share Severns’ passion for such things. Mostly they are either shell collectors or malacologists, the scientists who study mollusks. These are Severns’ people, despite the fact he is much more than a mere hobbyist but not really a professional scientist. The niche he created for himself is that of the guy who undertook the monumental task of cataloging every known Hawaiian shell species—from mountaintops to freshwater streams to the bottom of the sea—photographing them and publishing them in a hefty two-volume set of books called Shells of the Hawaiian Islands.

“He’s really done a fabulous job,” says Jerry Harasewych, former curator of invertebrate zoology at the Smithsonian Institution’s National Museum of Natural History, one of many molluscan authorities who encouraged Severns along the way. “If you find a shell in Hawai‘i, whether it’s a land shell or seashell, and you’ve got these two books, you can probably figure out what it is.”

Severns’ twin tomes—The Land Shells and The Sea Shells—are not going to help you stock up on amusing bits of natural history trivia. They’re meant as serious science. So the little Hawai‘i Island snail known as Catinella rotundata, for instance, is identified solely by its Latin name, not by its popular monikers, “snot with a hat,” “snot that walks” and “snot on the half-shell.” The curious way a harp snail has of turning the tables on a crab trying to eat it—by self-amputating a piece of its foot as a distraction, then smothering the crab in mucus and sand and then eating it!—is not the kind of thing Severns delves into. “It’s not the animal I’m interested in at all,” he admits. “It’s the structure of the shell. The beauty in the shell.”

That’s where Shells of the Hawaiian Islands shines. With the scientific names of 1,566 seashells and 750-plus land species attached to high-quality, close-up color photos shot from two angles, top and bottom, the books are as exhaustive as they are beautiful.

Severns regards the them as snapshots in time, an inventory of all the Hawaiian species known to science from the day the Native Hawaiians offered the first shell lei to Captain Cook in 1778 until the moment Severns ran out of shells to photograph in December 2010. Virtually every known Hawaiian species of shelled mollusk, plus a few hundred that science hasn’t gotten around to identifying, fill more than one thousand pages. “I grabbed everything,” Severns says. “If I knew it was from Hawai‘i, it went into the book. I got to the murky edge of science, the fuzzy edge of what is known.”

Severns' extensive shell collection includes some common varieties of Hawaiian cone shell (above left) as well as a recently discovered species of Hawaiian sea snail, Fusinus michaelrogersi (pictured in the center at left).

At his hillside home in Wailea, Maui, Severns keeps a twenty-seven-foot dive boat in his carport and a giant tortoise from the Seychelle Islands in his backyard. He bought the tortoise in Paris in 2003 but still hasn’t figured out its gender. “It’s named either Simon or Simone,” he quips. “They say you can’t tell the sex of those things for years.” The dive boat has many nautical miles on it. Severns is a professional scuba diver who, at 64, estimates he’s racked up twenty thousand hours of bottom time. He’s an accomplished underwater photographer, and for many years he earned a living running dive tours, a business his ex-wife wound up with after an amicable divorce.

Alongside Severns’ garage is the “man cave” where he did most of the work on The Shells of the Hawaiian Islands. It looks like the office of an adventuresome academic. Scientific illustrations of fish and color photos from exotic places he’s visited cover the walls. Thousands of shell specimens are stashed on shelves and in cabinets. Stone sinkers, bone hooks and other Hawaiian fishing artifacts Severns has found underwater fill a glass display case. Severns sees himself as a naturalist in the tradition of the great eighteenth-century scientist/explorers who mixed data collection with high adventure. When he wants to get into the deepest reaches of the West Maui Mountains to hunt for snails, his ideal is to arrive by helicopter, preferably rappelling to the ground. “Why waste time hiking when you could be looking for snails?” he says. When rebreathers, which the US military developed for bubbleless combat missions, hit the consumer market in the 1990s, Severns was an early adopter. Freed by the rebreather from the depth limits of conventional scuba tanks, Severns began making solo dives to three hundred feet in search of rare shells. He prefers to dive alone, in defiance of scuba diving’s cardinal safety rule behind the buddy system. “When I’m diving, I don’t want to worry about anyone else but me,” he says.

Severns likes working with scientists, and he’s had a hand in the discovery of several new species by either collecting the actual specimens or tipping off scientists to their whereabouts. Six species have been named in his honor. Two (Vexillum severnsi and Fusinus severnsi) are seashells. The others are an extinct Hawaiian bird (Porzana severnsi), an extinct Hawaiian land crab (Geograpsus severnsi), an Indonesian fish (Pseudojuloides severnsi) and a South Pacific pygmy seahorse (Hippocampus severnsi).

Severns has a slight build and an intense gaze, and he’s partial to wearing blue jeans and chambray shirts. His uniform is reminiscent of the undersea explorer Jacques Cousteau’s, but that’s just a coincidence, Severns says. As a teenager in the early 1960s, however, he did meet the great Cousteau after a lecture. “I wanted to be a diver for him so badly I couldn’t stand it,” Severns recalls. “He said to me, ‘It’s easier to train a biologist how to dive than it is to train a diver to be a biologist.’” Severns took the words to heart, and he graduated in 1978 from the University of Hawai‘i at Hilo with a bachelor’s degree in biology.

Long before Severns took on the colossal challenge of putting all of Hawai‘i’s known shells into print, he did a brief stint in graduate school at UH Mānoa. There he met the renowned malacologist E. Alison Kay, now deceased. Kay’s Hawaiian Marine Shells, published in 1979, has long been considered the bible of Hawaiian malacology. It took account of every Hawaiian seashell species known at the time, 966 in all. Two decades later, in an effort that foreshadowed Shells of the Hawaiian Islands, Severns put out a small identification guide called Hawaiian Seashells. He based it on Kay’s work, but where Kay had black-and-white photos and detailed scientific data on each species, Severns offered high-quality color photos and brief descriptions of select species. His was a sort of unauthorized greatest-hits version of Kay’s original.

But there was a problem. Since Kay’s book had come out, advances in genetics had shaken up taxonomy, the way science identifies and classifies organisms. By the time Severns published Hawaiian Seashells, some of Kay’s classifications were out of date. Severns hadn’t realized this, nor was he aware that some of the names in Kay’s book had become obsolete. Severns considered Kay his mentor; the two had always been on friendly terms. But when Kay saw the errors in Severns’ book, she chastised him for not having his manuscript reviewed by scientists before publication. “She told me, ‘I cannot recommend your book,’” he says. “That really hurt.”

Life went on, but in the back of Severns’ mind, he knew he needed to someday right the wrongs in Hawaiian Seashells. His interest in marine shells, however, always took a back seat to his interest in land shells. He was especially fixated on a genus of Hawaiian tree snail called Partulina. They were once very common. Nineteenth-century collectors plucked them off trees by the thousands, but nobody had seen a live specimen for a long time. Some experts suspected Partulina had gone extinct, but Severns believed that it could still be found. The historic record described Partulina as a forest dweller, but it offered no other clues about its habitat. Over the years Severns made several journeys deep into forests on Hawai‘i Island and Maui to find one, but he came back empty-handed.

Then one day, after a typically fruitless Partulina hunt in the woods of the West Maui Mountains, Severns returned to his Jeep (this was before he made friends with a helicopter pilot), popped open a beer and noticed something shiny on an ‘ōhi‘a tree. Partulina, it turns out, don’t live in the forest; they live at the edge of the forest. “I had been parking beside this thing the whole time!” he says. Severns gets credit for both proving Partulina still exist and for more completely describing their habitat. He spent years after that perusing the forest edge, searching for Partulina and carefully noting how the color patterns of their shells vary distinctly and predictably from one ridgeline to the next.

Meanwhile, the seashell project inched ahead. Initially all Severns intended to do was update his small book. But hundreds of previously unidentified shell species had been added to the list of endemic Hawaiian fauna since Kay’s Hawaiian Marine Shells. Eventually it occurred to Severns that simply revisiting the greatest hits wasn’t enough. So much of the nomenclature had changed, so many new species had been named, it seemed like the only thing for him to do was to record them all—with, of course, beautiful photos.

Severns tenaciously sought specimens to photograph. He befriended members of the Hawaiian Malacological Society and gained access to historic private collections. He tracked down collections of rare species hauled up during deep-sea dredging operations. He befriended crab fishermen, who provided him with shells taken as bycatch. He dove for shells himself, and he persuaded a retiree with a microscope to spend hundreds of hours sorting through sand samples to pluck out tiny shells barely visible to the eye.

He also cultivated contacts with malacologists and museum curators all over the world. It was a phone call to the curator of invertebrate zoology at the Smithsonian, Jerry Harasewych, that led Severns to expand the massive project he’d taken on. Harasewych knew Severns was interested in Hawaiian land shells and that he had a substantial personal collection of his own. Why not do land shells, too? Harasewych asked. “If he was going to go most of the way, why not just go the rest of the way?” Harasewych says. With those simple words of encouragement, Severns extended his project beyond the sea and into the mountains, streams, fields and trees of the Hawaiian Islands.

The genus Partulina represents a fraction of the overall diversity of Hawaiian snails, of which an estimated three-quarters are extinct. Introduced predators, shell collectors and habitat destruction have taken a terrible toll. But Hawaiian snails were once so abundant that hundreds could be plucked from a single tree. One nineteenth-century account describes Hawai‘i Island cowboys gathering thousands of the creatures in an afternoon without getting off their horses.

Almost all the Hawaiian land snails are endemic to the Islands, with unique species evolving on each island. Even little Nihoa, that sixty-three-acre speck of rock in the Northwestern Hawaiian Islands, has a species found nowhere else. In the mountains of the larger islands, a single ridgeline—or even a single cluster of trees—might have once had species found nowhere else. In the giant mixing pot of the ocean, on the other hand, only around 20 percent of the shell species are unique to the Islands. And unlike their terrestrial and freshwater cousins, most of Hawai‘i’s endemic seashells are found throughout the island chain.

Both land and seashells have an important place in Hawaiian culture. They turn up in folklore and song, in arts and crafts and even in meals. Pūpū, the Hawaiian word for hors d’oeuvres, is also the general word for shells.

The first Hawaiian shell specimens to wind up in the hands of Western science were strung into the shell lei presented to members of Captain James Cook’s expedition. Severns devotes two full pages to photos of two such artifacts. One, from London’s British Museum, is an eight-strand Ni‘ihau lei made of four seashell species. The other, from the Bern Historical Museum in Switzerland, is strung with the shells of two species of large, conical, now-extinct land snails. For years that lei was misidentified as an artifact from Cook’s visit to Tonga. Then a sharp-eyed shell collector from Līhu‘e spotted a picture of it in a book and realized it must have come from Hawai‘i because the two snail species were unique to Kaua‘i.

Severns can be brash, and even his friends say he sometimes rubs people the wrong way. Sometimes, in fact, he rubs entire institutions the wrong way. After his relationship with the Bishop Museum soured, Severns was effectively shut out of its malacology collection, which contains specimens of extinct Hawaiian land shells no other museum has. He struck back in print, noting sharply in his introduction to the section on a land shell family called Achatinellidae (which includes the genus Partulina) that all known species are represented except for two, “which I was not permitted to photograph for this book by the staff at the Bernice P. Bishop Museum.”

Fortunately for Severns, there are collections of Hawaiian shells in museums around the world. One of the best is in France, at the National Museum of Natural History in Paris. As it turns out, Severns had met a Frenchwoman while scuba diving in Indonesia, and he began spending a lot of time visiting her in Paris. Naturally, the museum’s vast shell collection drew him and his camera like a magnet. He became such a regular there that the head of the malacology department, Phillippe Bouchet, gave him an electronic badge to access the building and a little table to work at. He also offered Severns the museum’s address to receive specimens on loan from other museums. “I have always felt it is part of my role as a museum professor to foster, encourage, mentor people who are not professionals, who are not academics,” says Bouchet, one of the world’s foremost experts on molluscan taxonomy. “I opened the door to Mike. I think he was not used to it. He’s a little lonely wolf.”

In addition to writing the section on marine biota for Shells of the Hawaiian Islands, Bouchet introduced Severns to the head of ConchBooks, a German publishing house specializing in mollusks. ConchBooks became Severns’ publisher and brought in some of the world’s leading authorities to review the material. Molluscan taxonomy has changed greatly over the last few decades as DNA testing has flooded the field with information. In Kay’s day, taxonomists tended to be generalists who specialized in entire phyla or broad classes of species. Nowadays taxonomists tend to be specialists in a single family or even sub-family. The incredible diversity of mollusks has opened the door for non-scientists—amateur experts—to rise to the top. “The world’s best expert on the family Buccinidae, the whelks, is a bus driver in Antwerp,” Bouchet says. The experts that ConchBooks brought in helped Severns sort out long-standing taxonomic messes, correct historic misidentifications and bring the nomenclature of Hawai‘i’s shells up to date. “This one is named A, but that one is also called A because nobody knew this one had been called A,” Severns says. “It went on and on like that. It seemed like it would never end.”

For four long, laborious years Severns was engrossed in the project, often working until the wee hours of the night, waking up on the floor of his man cave and getting right back to it. Along the way Severns lost his mother, lost his dog, lost his French girlfriend and had to sell his Jeep. “I was losing everything,” he says. “It was like a country-and-western song.” But ultimately he accomplished what he set out to do. And this time the work was thoroughly reviewed. E. Alison Kay, he likes to think, would have been pleased.

Shells of the Hawaiian Islands was introduced to the mollusk-loving public in 2011 at the annual international shell show of the Belgian Society of Conchology, the world’s largest shell show. ConchBooks prominently displayed the volumes for thousands of people to see. Severns himself had only recently laid eyes on the books, which until that point had been an abstraction, existing for him as a staggering collection of digital files, folders and databases. But now it was real, a hefty 12.6 pounds of ink and paper that could be set on a table with an imposing thump. He met for the first time many of the reviewers who had contributed to the book, the French, the Russians, the Germans, the bus driver from Antwerp. There were handshakes and toasts, dinners and many bottles of wine. “I had made myself the focal point of the world of malacology at the moment,” he says. “I’ve never been so proud, really, honestly.”

And then people pointed out a few errors, or errata as Severns prefers to say. Severns wasn’t discouraged, though. In a work of such magnitude, with so many people involved, there were bound to be some mess-ups. And in a way, that’s how science works. You put yourself out there, someone knocks you down and knowledge advances because of it.

Shells of the Hawaiian Islands sells on for a walloping $325 for the full set. It certainly wasn’t cheap to make. To finance the production, Severns got a $20,000 grant from the Harold K.L. Castle Foundation, and he took out a home equity loan on his house, ulti-mately winding up $50,000 in the hole. But if ConchBooks ever pays off its printing costs and decides to do a second edition, Severns would jump at the opportunity to correct the errata. And to add new species.

He estimates that another two hundred Hawaiian seashell species and perhaps three hundred Hawaiian land shell species have yet to be identified by science. Recently one of them turned up right under his nose—or rather under the concrete walkway in his yard. He had never given much thought to the little black snails that emerged from beneath the concrete when it rained. “I always walked right by,” he says. “Crunch, crunch, crunch.” Then one of the reviewers of The Land Shells paid him a visit, a zoologist from Germany named Ira Richling. She bent down, picked up one of the tiny animals and realized it was a species not yet described by science. “You have no idea how embarrassing it was to be living in the house—to be, like, the snail guy—and have some German lady walk down your sidewalk and pick up an undescribed species of snail,” Severns says.

He laughs about the discovery. Of course, Shells of the Hawaiian Islands is not the final word on the shells of the Hawaiian Islands, but it is an incredible inventory of what had been found up to the time the work was completed.

“It was like reaching the edge of the flat Earth,” he says. “If you go in one direction far enough, you reach the edge of man’s knowledge. I went to the edge of what is known.” HH