Category Archives: Ocean Watch

Storm allows closer look at wildlife on reef isle

Published May 13, 2017 in the “Ocean Watch” column, Honolulu Star-Advertiser ©2017 Susan Scott

Sticky Pisonia seeds are matted in the rear feathers of this immature silver gull that appeared near the Heron Island Resort during a storm on Heron Island, off the Great Barrier Reef. The storm lent itself to the discovery of how wild animals protect themselves in harsh weather as well as ample opportunities to see such creatures in their natural habitat. ©2017 Susan Scott

HERON ISLAND, Capricorn Cays National Park, Great Barrier Reef >> After voyaging from Pancake Creek to the Gladstone Marina, where we planned to set sail for Heron Island, a gale appeared. Not only did it pack sustained winds of more than 30 mph, the storm front promised to stick around for a week.

Since sailing Honu was out of the question in that weather, I booked two nights at the Heron Island Resort, traveling the 42 miles to the island aboard the resort’s fast ferry.

Heron Island Resort, operating since 1932, is well known in Australia because it’s one of the few places, besides a boat, where people can stay out on the reef. The oval island, about a half-mile long and quarter- mile wide, also hosts the Great Barrier Reef’s first marine biology research station, built in 1951.

Coral reef encircles the island, creating a turquoise lagoon that laps onto a continuous white-sand beach, and the island’s center supports a lush tropical forest. All of the area is much loved by researchers and visitors alike because of the abundant marine animals that peacefully share their space with humans.

When the storm proved to be the edge of a cyclone that struck nearby New Caledonia, the ferry ride back to the mainland was deemed unsafe. Two nights on Heron Island became a glorious three.

Soon after we arrived, we walked the beach around the island and in one area saw a carpet of rays in the shallow water. “I stopped counting at 81,” a man said as we passed, gaping. Eagle rays, shovel-nose rays and several species of stingrays come near the island at high tide, wiggling into the sand to eat buried shrimp, crabs and snails.

The forest side of the beach contained endless craters dug months ago by female green and loggerhead turtles to lay their eggs. Walking the beach at sunset to see turtle hatchlings race to the water was a popular, if heartbreaking, activity. Silver gulls snatched the baby turtles as fast as they appeared.

Another of Heron’s harsh wildlife scenes comes from the island’s carnivorous tree, called a Pisonia, which bears sticky, branched seeds. Seabirds called noddies nest by the thousands (200,000 at peak) in the tall leafy trees. When the seeds tangle chicks’ feathers, the birds fall, and their decomposing bodies fertilize the trees.

We saw struggling wedge-tailed shearwater fledglings lethally entangled in Pisonia seeds.

Craig and I went snorkeling twice in that blowy weather, and even with wind and sand blasting our legs and rain pelting our clothes, we walked around and around the island as often as possible, watching wild animals cope with a storm.

How extraordinary is Heron Island? As we left on the ferry for the mainland, we promised we would be back.

Australian snakes keep residents on steady alert

Published May 6, 2017 in the “Ocean Watch” column, Honolulu Star-Advertiser ©2017 Susan Scott

A lace monitor lizard tasting the writer’s toes at Aircraft Beach, Eurimbula National Park. ©2017 Susan Scott

Pancake Creek, Queensland >> Australia has a national phobia about snakes.

We started our latest Australian adventure by sailing to this national park estuary that has no access by road. At Pancake Creek the beaches are huge (one is called Aircraft Beach because small planes can land there), the wildlife abundant (soldier crabs, stone curlews, friendly monitor lizards), and the hiking possibilities are nearly endless.

Pancake Creek is Australian wilderness at its best, so good I feel lucky to once again be visiting this magnificent country. So what’s the first thing several locals said when I told them we were sailing here? “Watch out for snikes.” (They mean snakes.)

The Pancake Creek region has no more snakes than anywhere else in the country, but OK, I’ll give Aussies the fact that most of the world’s venomous snakes are found in Australia. Of the country’s 172 species, 115 are venomous.

Most of the world’s pythons are Australian, the longest being the scrub python at 23 feet, as long as a two-story building is tall. I have a book aboard Honu with an amazing picture of an olive python — only about 16 feet long but bulkier than a scrub python — trying to haul a drowned wallaroo up a cliff for a meal.

In the Darwin area, homeowners have to protect their dogs, chickens and cats from olive pythons that squeeze the pets until they stop breathing, and then swallow them.

During dry spells some snakes seek out water and have been found bathing in residents’ toilets. One 7-foot-long snake worked its way through an overhead light fixture in an apartment bathroom. Roommates walked in to find the snake dangling, giving them an updated version of the “Psycho” shower scene.

My favorite Australian snake story happened in 2013 when a passenger aboard a Qantas flight pointed out a snake on the wing to a flight attendant. The scrub python bravely held on for the entire hour-and-50-minute flight. People rooted for the plucky animal, but the wind and cold were too much for it,and, sadly, the hitchhiking python died.

All snakes have forked tongues that they flick in and out to taste or smell potential food. Only Australia’s goanna lizards, called monitor lizards in other countries, share this forked tongue trait with snakes. (Goanna is the Australian version of the word iguana, a group of lizards from the Americas unrelated to monitor lizards.)

So far, we’ve encountered no snakes while hiking around Pancake Creek, but I did manage to hold still in a picnic area while a goanna (lace monitor lizard) flicked its forked tongue over my toes.

In the meantime, we Americans are looking forward to meeting some Australian snikes.

Australian yabbies draw fishers and stingrays

Published April 29, 2017 in the “Ocean Watch” column, Honolulu Star-Advertiser ©2017 Susan Scott

Freshwater crayfish, or yabbies as they are called in Australia, serve as bait for fishermen. Yabbies are also delectable to stingrays, which smash the burrowed tunnels the yabbies live in, and also to the fish that follow the stingrays. ©2017 Susan Scott

BUNDABERG PORT MARINA, QUEENSLAND, AUSTRALIA >> I’m back in Australia getting our sailboat Honu ready for another Great Barrier Reef adventure.

To answer a common question, no, we do not sail Honu back and forth between Hawaii and here. At Honu’s average speed of 5 miles per hour, it would take 50 days, minimum, to sail the 6,000 miles between Hawaii and Australia. It’s a long, hard voyage that for us is unfeasible, timewise. So, for now, the boat stays Down Under.

That means, of course, Honu is subject to cyclones. To answer another question, Cyclone Debbie did not strike this marina, and Honu survived the torrential rains unscathed.

Because Australia has marine life I don’t know, customs I’ve not seen and language I don’t always understand, during my trips here I have my own endless questions. A recent one was: Why are people sticking hand-pump suction tools into the sand at low tide?

When I asked a friendly angler, he said, “I’m pulling up yabbies.”

I’ve been in Australia enough to know that yabby is another name for edible freshwater crayfish. (Spiny and slipper lobsters are also called crayfish here.) The beach, however, was on the ocean and the suction pipe was small.

“To eat?” I said.

“No, for bait. Look here.”

He stabbed the wet sand, pulled back the plunger and came up with a cream-colored, soft-bodied creature about 3 inches long. “There’s a yabby,” he said, handing it to me. “That big claw means it’s a male. Careful, it can give you a sharp nip.”

It looked like a shrimp to me, but then that’s the problem with common names. (Latin names have their own issues — call a yabby a Callianassa australiensis and the conversation is over.)

Australia’s bait yabbies are found along its east coast where they live in the sand between the high and low tide lines. At low tide, fishers dig near telltale holes in the sand, but that’s no guarantee the creature is there. Each adult yabby has three or four holes joining its main burrow, which can be 2 feet down.

Another question I’ve had for years in Australia is why the sand on some beaches during low tide is pocked with dozens, sometimes hundreds, of perfect stingray outlines including their long tails.

It’s yabbies again. During high tide, the rays swim over the sand flats and “puddle” the sand with strong beats of their powerful pectoral flaps. This collapses yabby burrows, bringing the now-homeless creatures to the sand’s surface. Besides being meals for the rays, the uprooted yabbies also get eaten by fish freeloaders that have followed the rays.

Every time I take a walk here in Australia, I end up with so many wildlife questions, I have to write them down. And I’m still in the marina.

Snapping shrimp pop to send alert and nab food

Published April 15, 2017 in the “Ocean Watch” column, Honolulu Star-Advertiser ©2017 Susan Scott

Petroglyph shrimp channels are etched in lobe coral off Lanikai Beach. ©2017 Susan Scott

Decades ago, when Craig and I boarded a friend’s boat in the Ala Wai Boat Harbor, the crackling sound below deck made us wonder if the boat was falling apart. I later learned that the big noise comes from a small package: 1-inch-long snapping, or pistol, shrimp.

We oceangoers rarely see the little gunslingers because they live in burrows. But we hear them. The split-second closure of each shrimp’s single, oversize claw makes a popping sound. When the creatures pop by the thousands, as is often the case, it’s like snorkeling in a giant bowl of Rice Krispies.

The crackling is so loud that submarines can hide among shrimp colonies and go undetected by sonar.

The shrimp snaps for food, sending out a bubble bullet that stuns passing prey. The snaps can also be warning shots to trespassers, and perhaps a come-on to members of the opposite sex.

Most snapping shrimp dig, and live in, mud or sand burrows. We rarely see these basement apartments because they’re under rocks and rubble. One kind, though, lives in exposed sand burrows guarded by a pair of gobies. The shrimp digs while the fish keep watch. When a predator or curious snorkeler gets too close, the team dives into the hole together.

Other snappers, called petroglyph shrimp, set up housekeeping in living coral heads by making channels. No one knows how the shrimp creates the cracks. Either the animal is able to inhibit coral growth at the chosen site, or that big claw is an all-purpose tool that, in addition to firing lethal bubbles, can also dig.

Petroglyph shrimp (usually Alpheus deuteropus) create wavy, U-shaped crevices, the largest about a quarter-inch wide and 10 inches long. These are not the shrimps’ burrows, but rather boulevards lined with crops and cops.

The crops are seaweed, veggie meals for the shrimp. The cops are white hydroids, stinging jellyfish relatives that look like tiny trees. The hydroids protect the lane but might also eat the shrimps’ babies when they hatch. Security guards don’t come free. Gobies are carnivores, too.

The deepest parts of petroglyph channels bear cul-de-sacs that precisely fit each shrimp’s body. When it’s threatened, the shrimp retreats to its den, blocking the entrance with its large claw. Channels 2 inches or less usually house a single resident. Longer ones can accommodate two to four shrimp, each with its own separate burrow.

Hawaii’s petroglyph shrimp have pink eyes encircled by red dotted lines. The bodies are transparent with red surface dots.

So they say. I’ve not seen one. But I often see, and stop to admire, the shrimps’ plant-lined streets with twiggy sentries. The neighborhoods deserve a feature in Better Homes and Gardens.

A precious skeleton is found amid many birds

Published April 1, 2017 in the “Ocean Watch” column, Honolulu Star-Advertiser ©2017 Susan Scott

An aama molt is seen at Moomomi beach on Molokai. The shell of the Hawaiian black rock crab shows its true colors detached in the hot sun. The crustaceans molt their exoskeletons by separating skin from shell, then cracking a rear seam to exit from. ©2017 Susan Scott

While visiting Molokai last weekend, friends and I went to Moomomi Preserve, a 912-acre coastal area shaped by tradewinds so gusty they sandpapered our legs. It was worth the prickles.

Behind the beach stands a mile of dunes, wind-sculpted into bluffs of rippled sand. Since 1988, when the Nature Conservancy and the state’s DLNR began fencing Moomomi, several hundred wedge-tailed shearwaters have claimed the land above and behind the bluffs. Protected from predators, the seabirds dig their ground nests in peace, and the 22 native plants that grow there get their sandy soil aerated.

During our walk through this picture of ancient Hawaii, flocks of shorebirds called out over the roar of crashing waves, and turtles left behind their signature tracks.

Surprisingly, amid all this burrowing, booming and blowing, I found a fragile but intact remnant of a remarkable marine animal: the rock crab.

Hawaii’s rock crabs, also called aama, are the flat, black crabs we see hanging out on Hawaii’s basalt beaches and concrete breakwaters. When startled, the crabs skitter into cracks or jump into the water so fast you wonder what you really saw.

One Hawaii blogger calls our rock crab a “hot-rod decapod,” decapod meaning 10 legs.

Aama’s close relative is the well-named Sally Lightfoot crab, found on coasts in the eastern tropical Pacific. Sallys are easy to find because they’re bright red. Aama shells turn red, too, but never while they’re still wearing them.

Because crustaceans carry their skeletons on the outside of their skin, and those skeletons don’t expand, the creatures have to shed their shells to grow. The process resembles science fiction.

When it’s time to go up a size, the crab starts absorbing calcium carbonate from its old shell and begins secreting enzymes that separate skin from shell. The absorbing and secreting can take a few weeks.

On the big day the crab sucks seawater into its body and swells up like a balloon. This cracks the old shell along a rear seam, creating a backdoor exit. The crab pulls its body through the slit, taking its legs, eyestalks, antennae, mouth parts and gills with it.

As the crab recycles its absorbed calcium carbonate to make a new shell, it gradually replaces the inhaled seawater with protein.

When the sun hits the paper-thin molt left behind, the heat destroys the cells’ dark proteins. We then see the aama’s true colors: red and white.

We don’t see them for long. Sun and rain quickly break down the delicate molts, and soon they’re gone with the wind.

Finding a perfect, whole aama molt reminded me of the marvelous way our little hot-rod decapods grow.

Thank you, Nature Conservancy and state DLNR, for having the foresight to preserve and protect this extraordinary place.

Primordial soup brews near active volcanoes

Published March 25, 2017 in the “Ocean Watch” column, Honolulu Star-Advertiser ©2017 Susan Scott

A boat tour near Kilauea Volcano started the columnist thinking about the origins of living organisms, especially the theory that life on Earth began in the ocean, where primitive proteins evolved into cells. ©2017 Susan Scott

Last week on a Hawaii island boat tour, I watched Kilauea Volcano shoot its lava off a cliff. Liquid orange rock spurted like a fire hose from a tube 3 to 6 feet wide, plunging 60-some feet to the ocean in explosions of steam, glass particles and hydrochloric acid.

The ocean absorbed this assault with little fuss, cooling the 2,000-degree Fahrenheit lava in great green steamy swirls.

I felt like the protein in a cauldron of primordial soup.

The expression “primordial soup” was coined in 1924 when two scientists theorized that 3.7 billion years ago life on Earth began in the ocean. Chemicals there, the theory went, combined to become primitive proteins that evolved into cells.

Scientists today work with vastly more information, from genetic to cosmic, and that has led to other hypotheses about how life began on our planet. One theory maintains that life started in the ocean, but at the bottom of the bowl, in deep sea vents such as those of Kilauea’s backyard cousin, Loihi.

This active volcano lies about 20 miles off the southeast shore of Hawaii island where it rumbles and erupts 3,200 feet underwater.

Submerged volcanoes create cracks that allow seawater to percolate deep into Earth’s crust. As it descends, the water gets hot enough to absorb minerals from the rocks it passes.

When the mineral-laden water gets hot enough, it floats, rising through seafloor passageways into near-freezing water. The drastic change in temperature causes the minerals to fall out, thus forming chimneys called deep sea, or hydrothermal, vents.

The stacks, standing a few feet to a few stories tall, can be piles of gemstones, containing gold, pyrite (fool’s gold), silver and bornite, an iridescent mineral nicknamed peacock ore.

Crabs, giant clams, tubeworms, fish and more live in and near the chimneys. While life as we know it at the surface depends on sunlight and nutrients to survive, these bottom dwellers have neither. They live on Earth’s heat.

Because the chemicals of living organisms can all be made from simpler chemicals that have nothing to do with life, the theory goes that nooks in deep sea vents concentrated organic molecules and minerals, creating chemical reactions that spawned life.

Given that the hot vents host entire communities of marine animals, many still unknown, the theory makes sense. But if that hypothesis doesn’t sit right with you, there are others, ranging from RNA strands to asteroids.

My friend and I had a safe, friendly experience with a local family business, Moku Nui Lava Boat Tour. You can hike to a lava-viewing place, but I recommend seeing the spectacle by boat, too. If anything can get a person pondering life’s big question, it’s floating in a bowl of primordial soup.

Shoreline gems offer a palatable mystery

Published March 18, 2017 in the “Ocean Watch” column, Honolulu Star-Advertiser ©2017 Susan Scott

It’s still unknown how these porcupinefish palates found on the North Shore by a reader change color from white to shades of amber. ©2017 Susan Scott

Last week, reader Chris emailed a photo of some caramel-colored nuggets that she and husband Matt found along a North Shore coastline. Some of the pebblelike pieces are symmetrical, with a centerline. Others are halves of these, and all bear the markings of former ridges.

The ocean had rotated and polished the stony bits into jewels, lovely as the gemstones we call tiger’s-eye. Chris wondered if I knew what they were. I did not — and the search was on. Chris, Matt and I looked in books, queried friends and searched the internet.

The couple’s friend guessed their finds might be parts of parrotfish throats, called pharyngeal mills, that grind up coral rock. They aren’t, but it gave Chris and Matt a search subject that produced a link from Sydney’s Australian Museum. Pictured there is what the museum identified as a spiny pufferfish palate from a beach in the Gulf of Carpentaria.

Hawaii hosts a pufferfish with spines that we call a porcupinefish. The largest grows to a whopping 28 inches long and weighs 17 pounds, 12 ounces (the state record).

Chris and Matt wondered why porcupinefish mouth parts would be concentrated in one area of a long beach.

It’s possible that porcupinefish are abundant in that part of the ocean, but it’s more likely that the deposits are a result of coastal currents. The ocean sorts pebbles and shells according to flow strength, shoreline shape and objects’ weights, and that area is where the water drops off its palates.

I wondered why the roof of the mouth of the big prickly fish outlasts other parts of its skeleton, but I didn’t wonder for long. I have found dead, desiccated porcupinefish on beaches and brought them home.

When I picked one up to examine its palate, the whole thing fell apart, jaw bones included. That made clear that the fish’s upper tooth, shaped like a curved razor, is fused to a ribbed rock-hard palate. The same-shaped lower tooth is also fused to an identical hard floor, an upside-down palate. Both are bone white.

Apparently, after a pufferfish dies, ocean tumbling wears away its softer bones and teeth, leaving only the solid, durable plates. Where they get their rich color is a mystery.

Porcupinefish use their formidable teeth and rock-hard palates to crush snails, sea urchins and crabs. Be wary of a trapped porcupinefish. If caught or cornered, the fish can easily take off a finger, bone and all. Of the fresh bite I once saw, the remaining forefinger was sliced as clean across as if done with a cleaver.

Chris and Matt invited me to come see their pufferfish palates and, seeing my awe, generously gave me a few. Forget diamonds, rubies and sapphires. For us, porcupinefish palates are far more precious than stones.

White terns are at home in the trees of Honolulu

Published March 13, 2017 in the “Ocean Watch” column, Honolulu Star-Advertiser ©2017 Susan Scott

Breakfast is served. Courtesy Robert Weber.

Last week I walked into Waikiki with 11 other Oahu residents, zigzagging through tourists, street performers and pamphlet-givers. But we weren’t there to people-watch. We were there to see some of our city’s most charming marine animals: white terns.

Most people don’t think of seabirds as marine animals, but they are among the most remarkable, living entirely off the ocean without living in it.

Some don’t even get wet. In a technique called air dipping, white terns snatch fish and squid from the surface, or in midair when the prey jumps. Although the terns dive to the water, they change direction and speed so fast, they get prey without submerging.

One astonishing white tern trait is the ability to hold fish crosswise in their bills and still catch more. How they open those beaks to grab a fish while keeping hold of several others is a marvel of nature.

White terns usually catch juvenile goatfish, flying fish, flying squid and needlefish but take anything they can carry. Because the birds bring fish to their chicks intact, they have enabled biologists to discover new species. That means a person had to steal a parent tern’s fish intended for its baby.

About this, Spencer Tinker, Waikiki Aquarium director from 1940 to 1972, wrote in his book “Fishes of Hawaii,” “(Gregory’s fish) is known from but a single specimen about two inches in length from Laysan Island, which was brought to the nest of a white tern on May 12, 1923. This is an example of the extreme depravity to which scientists will descend to obtain a new species, namely, taking food from a little bird.”

Regarding humans, some terns have taken the approach of our Pacific golden plovers: If you can’t beat ’em, join ’em. The last estimate of white terns gracing our city’s trees is 2,100.

White-tern citizen scientist Rich Downs led our Waikiki walking tour, sponsored by the Hawaii Audubon Society, to show us some white terns raising chicks in the trees of Waikiki. Some of the chicks are so close to people, we bird lovers worry about vandals killing them (who can forget the Kaena Point albatross massacre?). Some of that worry eased, though, when, seeing us 12 staring up at a chick, a man emerged from a nearby building.

“You’re upsetting the parent, standing there like that,” he scolded.

Honolulu’s white terns have a growing number of friends and protectors. Kapiolani Community College biology professor Wendy Kuntz and student Katie Gipson and others set up a live chick-cam on campus, www.twitch.tv/kccmanuoku, enabling us to watch a white tern family from home. Prepare to fall in love.

For maps and information about how to help the white sprites of Honolulu, see whiteterns.org.

Weird Palau find offers a lesson in flora, fauna

Published March 4, 2017 in the “Ocean Watch” column, Honolulu Star-Advertiser ©2017 Susan Scott

More than 2,000 tunicate species are found throughout the world, with at least 45 varieties found in Hawaii. Pictured are the green barrel sea squirt variety found in waters off Palau. ©2017 Susan Scott

I’m home from my snorkeling trips to Palau and Yap, and in sorting through my pictures, I came upon a favorite: something so new, I didn’t know whether it was plant or animal. When I showed the real thing to our knowledgeable Palauan guide, he didn’t know either, but guessed it was a kind of alga.

Soft, thimble-size barrels with pores in them didn’t look like any alga I had ever seen, but then, some weird plants grow in the world’s oceans. One common one looks like a small Japanese glass float that filled up with water and sank to the bottom. Some call this one-celled seaweed bubble algae. (Singular is alga, but no one calls it that.) I prefer its more colorful common name: sailor’s eyeball.

After a few tries of describing my mystery organism, Google came up with “green barrel tunicate, scientific name, Didemnum molle” with a photo that matched mine.

Over 2,000 tunicate species are found throughout the world, with Hawaii hosting at least 45.

Years ago, in a zoology course at UH, I learned that these filter feeders have baglike bodies with two openings. One draws water in with tiny beating hairs, and the other directs water out. This human-heart-type image was the picture I had of all tunicates.

But like so many marine invertebrates, tunicates come in various forms. Some exist in colonies, where their bag bodies join at the base. The colonies can spread over coral and rocks in matlike patches with lots of inhalant and exhalant holes for sharing food. Often this spreading, combined with brilliant colors, makes some colonial tunicate species look like sponges.

The barrels in my photos are not visibly attached to one another, but runners creeping along the rock base connect individuals and give rise to new ones.

An individual green barrel sea squirt, also known as the tall urn ascidian (a class of tunicate), can grow to 4 inches in diameter in deep water. Shallow-water communities, such as those in my photos, are less than an inch wide.

The green tinge comes from a bacterium that lives in the tunicate’s tissues. Although not technically a plant, the bacteria produce oxygen, essential to the tunicate, the same way plants do, through photosynthesis. In this symbiotic relationship, the sea squirt produces a chemical sunscreen that protects its bacteria from UV radiation.

I’m not discouraged about not knowing those little barrels were sea squirts, or that I have surely incorrectly identified some tunicates as sponges. Learning new facts about the marine world is the thrill that keeps me dunking my face in water until it hurts.

Now I need to learn another fact: how one tells a tunicate from a sponge.

Yap’s gentle giants of the reef prove a bit timid, too

Published February 25, 2017 in the “Ocean Watch” column, Honolulu Star-Advertiser ©2017 Susan Scott

Manta rays are gentle giants that are plankton feeders, swimming forward with mouths open to sift the water for food. Paddlelike flaps on each side of the mouth direct plankton down the hatch. Courtesy Manta Ray Bay Resort

YAP >> Because I had never been to Yap, only a one-hour flight from Palau where I had been snorkeling, I signed up for a three-day visit here. All I knew about this South Pacific island was that it had been a major World War II battle site and that we would see manta rays.

Not exactly.

During the war, the U.S. military did not consider Japanese-occupied Yap a strategic target. American planes were sent to bomb only island airfields. Yap residents fled to the hills while 120 American pilots and crews, and an unknown (to me) number of Japanese lost their lives in aerial fighting.

My other mistaken vision of Yap was that most people come here to dive on crashed planes. That’s part of some tours but not mine. We three snorkelers joined a boat with two divers from Germany and two from Japan, all hoping to see Yap’s manta rays.

Mantas can live 50 years. At least 50 individuals call Yap home. Resident researchers identify each fish by distinct black markings on their white bellies. Workers at my top-notch hotel, the Manta Ray Bay Resort, have posted photos and names of Yap’s well-known mantas. My favorite name is Dotcom.

These rays routinely come to certain cleaning stations, where wrasses nibble parasites off the huge kite-shaped fish. Biologists think the mantas might also congregate there to socialize, perhaps males and females flirting for a future hookup.

Mantas once had hellish reputations, their enormous sizes and black backs spooking old-time sailors, who called the fish devil rays. Most mantas are about 10 feet wide, but some can grow over 15 feet wide.

Whatever their size, the fish are harmless. Manta rays have long tails like their sting- and eagle-ray cousins with one exception: Manta tails have no stingers. Nor do mantas have teeth. Like whale sharks, these gentle giants are plankton feeders, swimming forward with mouths open to sift the water for food. Paddlelike flaps on each side of the mouth direct plankton down the hatch.

On the two days that our boat dropped us off near the cleaning stations, the mantas chose to skip hanging out there. But we snorkelers weren’t disappointed. The reef was exquisite and included some magnificent manta relatives: white-tip, black-tip and gray reef sharks. Sharks and rays are related in that their bodies contain no bones, just cartilage.

I loved Yap’s super-friendly people, entwined mangrove forests and pristine reefs. It wasn’t what I expected but that’s the beauty of travel. You get to generate your own impressions.

Don’t, though, take my word for it.