Tag Archives: Great Barrier Reef

Mesmerizing sea ‘squash’ part of reef mod squad

Published November 19, 2016 in the “Ocean Watch” column, Honolulu Star-Advertiser ©2016 Susan Scott
The baler snail lives in small communities, never traveling very far from the area in which it is born, quite often in isolated areas in Black Island, Great Barrier Reef Marine Park. ©2016 Susan Scott

The baler snail lives in small communities, never traveling very far from the area in which it is born, quite often in isolated areas in Black Island, Great Barrier Reef Marine Park. ©2016 Susan Scott

Black Island, Great Barrier Reef Marine Park >> While anchored off this small, round, wooded islet, Craig and I started snorkeling on its leeward coral side and later emerged to walk the sand beach on its windward rocky side. As time passed, the tide rose so high we had to abandon the beach walk and swim over the rock bottom.

Thank heaven for big tides.

Craig touched my arm and jabbed his finger below us. “Wait,” he said, raising his head. “I lost it.”

We peered down and saw only gray rocks. And then there it was, a spaghetti squash creeping along on a black-and-white carpet. Its leading organ resembled an elephant trunk. It was hard to keep track of the animal because its appearance changed depending on viewing angle. One side of the creature’s bulbous oval shell was yellow, but the other was a rocklike gray.

The animal was a big, breathtaking snail, but what kind I did not know.

Thank heaven for field guides.

Our crawling beauty was a baler snail. “Baler” is a misspelling of the word “bailer,” dating to when Europeans first saw islanders use the shells to bail water from their canoes. The scientific name for this snail family of over 50 species is Volutidae, shortened to the common name volute.

Volutes are famous for their dramatically patterned shells, feet and tentacles, each different from one another. One endemic species here on the Great Barrier Reef is described as “a carnival of colour, the stripes and spots of its shell pale in comparison to its luridly painted foot and tentacles.”

Volutes are also famous here for species being isolated, each found on only one reef or a small group of reefs. That’s because these snails, as opposed to most others, have no planktonic stage. Their eggs hatch on the bottom as crawling juveniles that stay in the neighborhood where they were born. Being a species in only one small area makes volutes exceptionally vulnerable to extinction through pollution, cylcones and over-collecting.

Each volute walks around the ocean floor on its large muscular foot looking for clams and other snails to dig up and eat. The photos of our volute clearly show a digging claw on each side of its carpetlike foot. Its “trunk” is a water siphon through which the animal circulates water over its gills, extracting oxygen and releasing carbon dioxide.

For half an hour we watched the 12-inch-long creature slide gracefully among the rocks of its own little island.

The experience of seeing and learning about this rare creature was a highlight of our exploration of the Great Barrier Reef.

Thank heaven for baler snails.

Corals’ outer beauty belies fierce battles over territory

Published October 29, 2016 in the “Ocean Watch” column, Honolulu Star-Advertiser ©2016 Susan Scott
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A coral micro atoll is formed due to encroachment by several species of clams. ©2016 Susan Scott.

Whitsunday Islands, Australia >> Among these famous islands, fish of every color, shape and size swim among corals of every color, shape and size. And squeezed into virtually every nook and cranny of these underwater gardens are sponges, clams, seaweed and countless other plants and animals.

Floating above this riot of life on a calm sunny day makes me feel totally at peace. But the creatures below me aren’t at peace. They live in a constant state of war.

As with nearly all living organisms on Earth, the fighting is about territory. Millions of offspring of thousands of species must settle down where they can get food, mature and make babies. But space in clear shallow water is mostly taken, making competition fierce.

Stony corals often hold prime spots, and are under constant attack by other coral species trying to get a foothold. Corals, however, can fight. Some use long stinging tentacles that sweep surrounding areas to kill early settlers. Others use guerrilla warfare at night, extending filaments that digest their new neighbors’ soft bodies.

While hard corals defend themselves with strings and strands, soft corals use chemical weapons called terpenoids to hold their borders. Some soft corals are particularly aggressive, growing right over hard corals and smothering them.

One bay here consists nearly entirely of such single-minded softies, mostly rubber and leather corals that are flexible to the touch. Between them are other soft corals, some with fluttering tentacles resembling dust mops and palm fronds. Others look like spilled pancake batter, lace doilies and pink pansies, all swaying in the current.

The pretty pastels and slow movements are so serene, it’s hard to remember that these creatures have knocked off an entire bay of stony corals to live there.

Stony corals are also under constant assault from noncoral organisms. Christmas tree worms, clams, sponges and snails set up housekeeping on hard corals. Starfish, butterflyfish and parrotfish eat them, and seaweeds grow over them.

As much as stony polyps fight back, the colony gradually loses ground over time and becomes what’s called a micro atoll. The original coral species struggles around the edges, but a mixed community thrives in its center. Eventually, a new species dominates, becomes king of the hill, and the cycle starts all over again.

Such winning and losing of space creates the diversity we see on coral reefs as well as on the entire planet.

Recalling that fighting for territory is a natural part of life on Earth helps me cope. Perhaps the end result of human warring will be something as beautiful as the Great Barrier Reef.

‘Pompom’ corals create a colorful ocean delight

Published October 22, 2016 in the “Ocean Watch” column, Honolulu Star-Advertiser ©2016 Susan Scott
This soft coral contains no symbiotic algae to help feed it, as other corals do. The red polyps catch and eat animal plankton adrift in the current. ©2016 Susan Scott

This soft coral contains no symbiotic algae to help feed it, as other corals do. The red polyps catch and eat animal plankton adrift in the current. ©2016 Susan Scott

Orpheus Island National Park, Australia >> When a local sailor heard we were sailing to the Palm Island Group, he kindly fetched his cruising guide to show us the best places to go. The anchoring spots were fairly straightforward, but he added a gem. “There’s a channel between Orpheus and Fantome Islands that has a strong current always running the same direction. It’s a good place to take the dinghy for a drift snorkel.”

A good place? It was snorkeling heaven. As our 2-horsepower outboard slowly carried us up-current in our rubber dinghy, we donned masks and fins, ready to jump off the boat as soon as the motor stopped. “How does one check for salties?” I said to Craig, remembering last week’s advice to keep an eye out. Orpheus Island’s park sign also posted a crocodile warning.

“You go in first and look,” Craig joked.

Hands on our masks, we backflipped into the water and instantly forgot about crocs. The flow, going about 3 mph, sent us zipping down-current, an exhilarating sensation that felt like flying. More exhilarating, though, was the sight 5 feet below: a strip of soft coral bushes so red and fluffy it made me feel like shouting, “Thank you! I love you!” The highway-wide gap separating the islands has exactly what this soft coral species loves: a stretch of sparsely populated (with coral) water with swift, plankton-rich current. How the tiny drifting larvae got anchored in the white sand to start their eye-popping colonies is a mystery of the marine world.

The current was so strong I could not get a good look at the exquisite red corals, but that’s the beauty of pictures — if you can get close enough and hold the camera still. Kicking as hard as possible, I could stay over a red bush for only about one second before losing ground.

Craig saw me struggling and pushed me forward, no small favor given that he was towing the dinghy. The brief boost allowed me to get off a few snaps. Seawater and visible white needles of calcium carbonate support the clear flexible stems of this soft coral that also comes in pink, purple and yellow. It has no common name, but since its genus name, Dendronephthya, is so unfriendly and clumsy, I call it pompom coral.

The genus has several species, so similar that scientists can identify them only by examining the supporting calcium bits.

During our fourth pass over the crimson coral clusters, the current swept us over a slightly different spot, and we found another pompom garden we hadn’t seen before.

What a wonderful world.

Heading Down Under again, this time like the bird flies

Published October 8, 2016 in the “Ocean Watch” column, Honolulu Star-Advertiser
©2016 Susan Scott
A wild sulfur-crested cockatoo pays a visit to the Honu at anchor off Hook Island, Whitsunday Islands National Park. ©2016 Susan Scott

A wild sulfur-crested cockatoo pays a visit to the Honu at anchor off Hook Island, Whitsunday Islands National Park. ©2016 Susan Scott

As you read this, Craig and I are on our way to Australia once again to explore the Great Barrier Reef Marine Park on our sailboat, Honu. People assume we’re setting sail when I say that and ask, “How long will it take to get there?” As the bird flies, Australia is about 5,600 miles southwest of Hawaii. Because Honu averages 5 mph, a voyage from here to there nonstop would take six to seven weeks.

In our dreams. At 64 million square miles, the poorly named Pacific Ocean generates endless variations of tradewinds, doldrums, currents and storms that can add weeks to a long offshore voyage.

But few skippers sail directly from Hawaii to Australia, or vice versa. We do it in hops. For my first voyage Down Under, I sailed via Palmyra Atoll, Tahiti, the Cook Islands, Tonga, Fiji and New Caledonia. The second time I added the Marquesas, the Tuamotus and Niue to the westward run. Because I took my time visiting those South Pacific islands and flew home during cyclone seasons, my answer to how long it took to sail to Australia is, “Ten years.”

Now Honu is in Australia to stay. The decision to keep the boat there was made easy by the Great Barrier Reef Marine Park Authority, or GBRMPA. For sailing, snorkeling, diving, beachcombing and hiking among friendly hosts who make great food (meat pies, yes!), it’s as good as it gets.

That coral wall we all picture when we mention the GBR is superb, but getting out there in a 37-foot sailboat can be a challenge.

Usually we must leave the night before so we arrive in high sun, critical for dodging coral heads. And because the submerged reefs offer little protection from the open ocean’s wind and waves, flat, calm water is essential. That means motoring, which is fine as long as we have plenty of diesel fuel. And if the wind and swells start up while we’re out there, we hightail it back.

But not going to the outer reefs is an excellent option because the more user-friendly parts of the park — atolls, islands and mainland rivers — offer calm anchorages, drop-dead scenery, astonishing marine life and charming avian visitors.

Honu waits for us now in a marina in Townsville, the headquarters of GBRMPA. The lovely town is visitor-friendly and so close to coral reefs that I highly recommend a visit.

After 10 years of sailing Honu across the South Pacific, the fact that I can leave Honolulu this morning and sleep on the boat tonight feels nothing short of a miracle. This time when someone asks how long it took to get to Australia, I’m very happy to say, “Twelve hours.”

Lone sea pen makes mark during shallow-water swim

Published August 13, 2015 in the “Ocean Watch” column,
Honolulu Star-Advertiser ©2016 Susan Scott
A sea pen is found in Australia’s Great Barrier Reef Marine Park. ©2016 Susan Scott

A sea pen is found in Australia’s Great Barrier Reef Marine Park. ©2016 Susan Scott

Craig and I don’t often snorkel side by side. He thinks that swimming fast in deep water is best, because that’s where the big jacks, sharks and manta rays hang out. I, however, like to float quietly in a few feet of water. Not only do some astonishing creatures live there, but I get to see them up close and take their pictures.

During a recent swim off a tiny island in Australia’s Great Barrier Reef Marine Park, Craig, as usual, headed out and I headed in. And sure enough, confirming my theory that shallow is good, there stood, like a lone sentry, the biggest, most beautiful sea pen I’ve ever seen.

I’ve not seen many — this discovery was No. 3. Sea pens belong to the soft coral clan and aren’t particularly rare, living from shallow water to deep. But the animals like to set up housekeeping in calm water and that usually means deep. Down around 150 feet, one researcher in Puget Sound found an average of 23 sea pens per square yard for miles on end.

Several sea pen species range from tropical to temperate waters around the world, growing 6 inches to 2 feet. One species in Scotland grows to 6 feet tall. Its witty name: the tall sea pen.

Sea pens were so named because the upper parts of their bodies look like the fluffy feather quills people once used for writing. The animal’s bottoms, however, look like tulip bulbs buried in sand or mud.

From the bulbous base, a central stalk rises with delicate branches extending from each side like a feather. The branches bear hundreds to thousands of tiny mouths, each surrounded by eight tentacles (that’s the octo in octocorals, the scientific name for soft corals).

The sea pen orients itself into gentle currents with its branches stretched out. Unlucky plankton animals that drift through the branches get stung and eaten.

On the sides of the sea pen’s central stalk are holes lined with beating hairs, some drawing water in and others pushing it out through countless channels. Muscle contractions of the body also assist with this circulation system.

It would seem that these delicate feathery animals are rooted to their spots, but no. If disturbed, a sea pen can pull up its orbed anchor, inflate its body with water and drift like a balloon in the current to a new home.

Vast plains of fleshy, slow-moving animals are easy targets for carnivores. Nudibranchs (snails without shells) eat small sea pens. Starfish target adults.

I couldn’t resist lightly touching my 6-inch-tall pen, and that was that. A sea pen’s defense is to exhale its water and sink into the sand.

When Craig and I reunited, he told me he had seen a shark. Big deal. I had made an Australian pen pal.

‘Mermaid bracelets’ ashore a curious find Down Under

Published July 9, 2016 in the “Ocean Watch” column, Honolulu Star-Advertiser ©2016 Susan Scott

wormsOne of the joys of snorkeling or beach walking in Australia is finding marine animals new to me. It’s also frustrating because being on my sailboat, I often don’t have internet access or the right books on board to look up what I’ve found.

The creature that stumped me on my recent trip appeared on Whitehaven Beach during an extremely low tide. At first glance the thing looked like a line of white seashells tangled up in brown and green seaweed. But when a small wave rolled over the clump, it stayed in place, fixed to the spot.

Down the beach, a longer string of shells and seaweed appeared, then another and another, all streaming behind the receding water like glistening ornaments. Mermaid bracelets, I named them, because a few of the shells in the strands were the forams I wrote about called mermaid pennies (May 28).

I gently scooped sand from around one of the shell ropes and found it anchored a few inches down in the sand. I laid my strand above the break to examine it, and out from the end popped a pair of rust-colored antennae and behind them several fuzzy legs. I had found a bristle worm that collects shells. I’m home now, and, as usual, Google found my mystery worm first try, even with the lame search words “polychete (bristle worms’ scientific name) that makes tubes from shells.” My worm’s name is Diopatra (rhymes with Cleopatra). Members of this group live in self-made tubes of thin, paperlike material onto which they glue small shells, bits of algae and pieces of coral. The worm lives with the lower part of its tube body buried vertically in the sand and the top part drooping head-down over the seafloor, like a candy cane.

Diopatra shell jackets look decorative to us, but for these ambush predators they’re camouflage. When a small invertebrate wanders close to the worm-in-shell-clothing, the worm darts partially from its tube and grabs its prey with sharp jaws. When fresh meat is scarce, the worms eat dead plant and animal tissue.

Hawaii hosts at least two species of Diopatra. These little cross-species-dressers extend a third or more of their length from their tubes to feed in an arc around their anchored base. In some areas the worms’ dense presence between reef and beach stabilizes sand, preventing beach erosion.

These shell-dressed worms are exposed at very low tides, during which times the worms are in danger of drying out and/or getting eaten. I’ve not seen them before, but I’ll now be on the lookout.

I like the rather regal name Diopatra, and found it means “divine habitat” in Greek. For those of us who love walking beaches during low tide at first light, these worms are well named.

When it comes to coral, the story is complicated

Published July 2, 2016 in the “Ocean Watch” column, Honolulu Star-Advertiser ©2016 Susan Scott

DSCN3313News reports about the demise of the Great Barrier Reef are so pervasive that before I left Hawaii to sail there, several people asked me why I wanted to go.

Then I arrived and for six weeks enjoyed the most glorious corals I’ve ever seen.

So what’s the story? It’s complicated.

It’s true that warmer-than-normal water due to El Nino and climate change is seriously stressing the Great Barrier Reef’s corals. It’s not true, however, that over 90 percent of them are dead.

False impressions come from coral bleaching studies with startling titles, confusing statistics and locations that mean little to those unfamiliar with Australia.

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In April, for instance, the Australian Research Council’s Centre of Excellence for Coral Reef Studies issued a media release with the headline, “Only 7 percent of the Great Barrier Reef has avoided coral bleaching.” From this the Huffington Post ran the headline: “93 Percent of the Great Barrier Reef’s Coral is Practically Dead.”

Not so. I sailed and snorkeled in the central section of the reef and saw only one bleached coral patch about 2 feet square.

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Part of the confusion is the term bleaching, the name of a phenomenon involving corals’ embedded algae. Corals host about 10 species of algae, the source of corals’ lovely colors.

Several events occur when ocean temperatures rise, one being that the corals’ algae produce more oxygen, consequently breaking down the creatures’ chemical sunscreen. And so to prevent death from sunburn, the corals oust their algae. Coral colonies look white then because the transparent animals sit in white calcium carbonate cups of their own making. Hence the word bleached.

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Bleaching doesn’t always mean death. Corals also get food by stinging passing animal plankton and can survive on that for some time depending on species and conditions. When the water cools, the colorless corals still alive catch the algae they need from surrounding water. Surviving corals might grow slower after a bleaching event or not reproduce well for a while, but they’re alive.

Coral bleaching and its rapid increase worldwide is a dire warning to the world that the oceans’ plants and animals are in trouble and, therefore, so is every living thing on Earth. As to how many of the Global Barrier Reef’s bleached corals will recover, how many will not and how to best help them get growing again, no one knows for sure. We have no previous experience with what happens when we heat up the entire planet.

The areas in the northern Great Barrier Reef have been hit hardest with bleaching, but all is not lost. I’ve seen some of the central area’s healthy, breathtaking corals. And that’s why I go.

Huge sea life of great reef is too incredible to see solo

Published June 18, 2016 in the “Ocean Watch” column, Honolulu Star-Advertiser ©2016 Susan Scott
A giant clam about 4 feet long was just one of the oversize specimens spotted in Australia’s Great Barrier Reef Marine Park. ©2016 Susan Scott

A giant clam about 4 feet long was just one of the oversize specimens spotted in Australia’s Great Barrier Reef Marine Park. ©2016 Susan Scott

BOWEN, Queensland, Australia >> Where fishing is prohibited here in the Great Barrier Reef Marine Park, I can describe the animals in one word: big.

I’ve seen turtles, invertebrates and fish so large I was happy I had Craig beside me as a witness or I would have doubted my own eyes.

One day off a Haslewood Island beach, Craig and I saw in the distance a mound of charcoal-black coral. We had never seen such a coral color and swam toward it. Then the hulk rose up and disappeared into deep water. As the enormous creature departed, we saw, to our astonishment, a pair of giant flippers. We both believe our “coral head” was a leatherback turtle.

Although leatherback turtles swim off most of Australia’s coasts, no nests have been found here since 1996. Maybe biologists will find a leatherback nest on a Haslewood beach.

In another area of the massive reef in Waite Bay, Craig and I each followed our own marvels and got separated. When I looked up he was barely visible in the distance, but I could see him motioning for me to come see what he found.

This had better be good, I thought, as I swam and swam, because I was passing some eye-popping-beautiful giant clams nestled in beds of corals as stunning as the most exquisite flower gardens.

We later laughed about my worry of missing the clams, because Craig had found the biggest giant clam either of us had ever seen, so old it had its own coral reef growing on its shells. The gaping mother of all clams was, we guessed, 4 feet long. We weren’t far off. The record shell size here is 3.7 feet long.

On another reef we spotted the father of all stingrays (clams seem female; stingrays, male) resting on a sandy patch in a shallow cave of corals. Stingrays aren’t aggressive, but seeing that the ray could escape its space only by swimming toward us, we slowly back-paddled. Never startle a snoozing stingray, especially one as big as an area rug.

And, oh dear, the fish. Schools of huge, rainbow-colored parrotfish roam the reefs. I’ve seen three 3-foot-long humphead wrasses and once found a giant black trevally hanging out under the boat. Even the squirrelfish are supersized, their dark eyes set like jewels against their brilliant red-and-white striped skin.

The weather has been so calm for snorkeling most of the past five weeks that my mask has given me face-ache. But now we’re having a different kind of adventure: knock-down wind. Honu is holed up at the friendly North Queensland Cruising Yacht Club as we wait out rain and impressive blasts of 30-35 knots. But I’m not complaining. On the Great Barrier Reef, even the tradewinds are big.

Great reef’s coral array, sea castles still awe explorers

Published June 11, 2016 in the “Ocean Watch” column, Honolulu Star-Advertiser ©2016 Susan Scott

coral1HOOK ISLAND, GREAT BARRIER REEF MARINE PARK >> While snorkeling here this week, I found myself thinking that there’s too much coral.

Capt. Cook thought so, too, in 1770, and he didn’t even know that the lagoon he was exploring was a vast channel paralleling the Australian mainland.

The concept of a barrier reef forming a passage came later. The open stretches of this so-called passage are about 100 feet deep. But sprinkled among them are coral-rimmed islands, free-standing reefs, atolls and peaks. Some reefs are visible, but many lie just below the surface.

Today we have GPS charts that point out most of them. But not all. Last week I came within yards of crashing Honu, at speed, into a tiny, uncharted pinnacle.

“Turn right!” Craig shouted from the bow. We avoided disaster only because he was securing the anchor and saw waves breaking ahead.

Today, corals are much loved and a frequent topic in discussions of global warming. But in the early years of exploration, no one knew what they were. Eng-lish Capt. Mathew Flinders speculated that corals were “animalcules” that lived on the ocean floor. When they died, other animalcules (love that word) grew atop, and so on, thus building “a monument of their wonderful labors.” The creatures’ care in building their walls vertically was to Flinders a “surprising instinct.”

What he didn’t know was that stony corals grow upright because they host algae that need sunshine to survive. That fact came to light 30 years later from another explorer, Charles Darwin.

My problem with the corals here isn’t running the boat into one of their “monuments” (although I’m more watchful now), but that I can’t take them all in.

The corals on these reefs look like mushrooms, wheat fields, brain tissue, antlers, cabbage leaves, chicken skin, grassy knolls and endless other shapes, colors and textures.

Some corals are hard; some are soft. Many cover their space like rugs; others wave greetings like anemones.

Among all the coral splendor here, one in particular stands out for me. On a white-sand beach I found pieces of a bright red structure of tubes known as organ pipe coral. In admiring the tiny pipes, which remind me of fairy castles, I’m in good company. Capt. Cook’s naturalist, Joseph Banks, wrote about being overwhelmed by the variety of corals, too, especially one he called Tubipora musica. That’s the scientific name of my organ pipes.

It’s clear to us modern sailors that this labyrinth of coral shoals must have been a nightmare to early explorers. It’s also clear why mariners, past and present, admire them so. What other animalcules build monuments?

Whitsundays offer preview of outer reef, more to come

Published June 4, 2016 in the “Ocean Watch” column, Honolulu Star-Advertiser ©2016 Susan Scott

CoralWHITSUNDAY ISLANDS, Australia >> Our cruising guide calls these 74 islands “a tropical paradise in the heart of Australia’s Great Barrier Reef Marine Park.”

It’s no exaggeration.

The Whitsunday Islands, so named by Capt. James Cook because he arrived here the seventh Sunday after Easter, or Whit Sunday, are two mountain ranges cut off from the mainland by ancient geologic events. The teeming coral reefs that now surround the islands can keep a snorkeler busy for months. But beyond the Whitsundays lie the platform reefs most people picture when you mention the Great Barrier Reef. The islands, therefore, are a leg up for sailors who want to visit the outer reef. The nearest, called Bait Reef, is about 20 miles east of the easternmost island, a three- to four-hour voyage for our 37-foot ketch, Honu.

Bait Reef hosts the famous Stepping Stones, 18 flat-topped coral pinnacles lining the southwest side of the reef. Each round tower rises 50 to 80 feet from the ocean floor and stops 3 to 6 feet below the surface.

It’s easy to swim from one backyard-size coral head to the next, and each is a snorkeler’s dream. Confetti parades of tropical fish swim at the pillar tops, and enormous fish such as giant trevally and Napoleon wrasse hang near the drop-offs.

The Great Barrier Reef hosts about 350 species of light-loving coral, making competition for space fierce. When coral-eating fish and invertebrates leave bite scars, the larvae of sponges, worms, crustaceans, clams and corals quickly claim the space.

Every imaginable shape and color of stony corals cover the flat column tops, with soft corals and giant clams elbowing their way between.

An Australian researcher recently surveyed an area of coral reef off Port Douglas, about 300 miles north of the Whitsundays, and reported that 90 percent of the corals he observed have bleached (turned white). I’ve seen no bleaching here, but the study is a stark reminder that this largest living organism on Earth is at risk from climate change.

At the outer reefs, weather is everything. Being submerged and patchy, the coral heads offer no protection from wind and waves. Skippers head out when the wind is light, and keep an escape plan in mind should the weather change.

So, fingers crossed, out we sailed. Soon after our arrival the wind stopped completely, leaving the water so flat and glassy, we were able to spend the night. As we sailed back the next day, two humpback whales, up from Antarctica for the winter, put on a show of breaching.

Our cruising guide for this area is called “100 Magic Miles of the Great Barrier Reef.” I couldn’t imagine a better title.