Monthly Archives: October 2016

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.

Australians have learned to coexist with crocodiles

Published October 15, 2016 in the “Ocean Watch” column, Honolulu Star-Advertiser ©2016 Susan Scott
A crocodile gives a hitchhiker a ride at the Australia Zoo. ©2016 Susan Scott

A crocodile gives a hitchhiker a ride at the Australia Zoo. ©2016 Susan Scott

TOWNSVILLE, AUSTRALIA >> We arrived in the Townsville marina to find a notice from the Queensland government. On the gate of Honu’s pier, a sign read, “WARNING! ACHTUNG! Recent crocodile sighting in this area. Crocodile attack can cause serious injury or death. Keep out of the water and well away from the water’s edge.”

Craig’s reaction: “Why write ‘attention’ in German?” I wondered what triggered the notice since crocodiles are native to the area, and the sign wasn’t here when we left. As it happens, a 15-foot-long crocodile was sighted about 150 feet off the city’s popular beach and walkway called The Strand. Because crocodiles have been a protected species in Australia since the 1970s, if a croc is over 6 feet long and in a high-use area, rangers don’t kill the animal, but rather relocate it.

State rangers were called to catch the Townsville salty, so called because although crocodiles usually live in rivers and estuaries, they swim from one to another via the ocean. And sometimes, if the fishing is good, a croc will stick around a particular island. We once anchored off Hope Island, where a large sign said, “Crocodiles inhabit this area. Do not enter the water.”

We skipped snorkeling. People here call Australia’s second croc species “freshies,” but this and “salties” are misleading names. Both can live in either fresh or salt water. They go where the food is.

Males are larger than females, reaching about 20 feet long and weighing over a ton. Females grow to about 9 feet. The male off Townsville — estimated to be age 50 — had lived a hard life fighting other males for territory. He had lost an eye and all but a few teeth.

Saltwater Crocodile. Courtesy Scott R. Davis

Saltwater Crocodile. Courtesy Scott R. Davis

But the geriatric titan got a break. After a period of rest to get over the stress of capture, the grand old croc went to a zoo or farm to live the rest of his days in peace.

The day after our Townsville arrival, a friendly local sailor showed us the best anchoring sites off Townsville’s nearby islands.

“Here’s a lovely reef,” she said, pointing at the chart. “And here, and here.”

“Is it safe to swim there?” Craig asked.

“People swim there all the time,” she said.

“What about the crocodile warnings?”

“Oh, we just keep an eye out while we’re in the water,” she replied. Such tolerance for an apex predator is the result of Queensland’s “Croc Wise Education Campaign,” developed to inform the public about the value of crocodiles and how to live with them. It’s working. In discussions of crocs here, “No worries” is the general attitude. So, OK. We’ll go snorkeling, pay attention, and if we see a salty we’ll call out, “Achtung!”

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.”

Opae ula are hardy critters, but treat them with respect

Published October 1, 2016 in the “Ocean Watch” column, Honolulu Star-Advertiser
©2016 Susan Scott

If you dig it, they will come. Not the ghosts of baseball past, but equally enchanting, the shrimp of Hawaii present: opae ula.

Also called anchialine (AN-key-ah-lin) shrimp, opae ula are half-inch-long creatures that live in underground cracks and pukas containing a mixture of fresh and sea water

When a nearshore opening, natural or human dug, appears above the shrimp’s tunnels and forms a pool, the creatures emerge from below, eat whatever is available and multiply. Mostly the shrimp live on algae that grows on their rocks, but they also eat dead insects that fall into their pools and bacteria that grow in their water.

The hardy shrimp tolerate variable degrees of salinity and can live up to 20 years with little care. The little crustaceans are usually red but can be pink, orange, yellow, white or clear. DNA studies today show that Hawaii’s opae ula consist of at least eight genetically different populations.

p1030957I’ve written about anchialine shrimp before but information about the charming native creatures and their pools was hard to find. No more. Now we can read facts about our opae ula in a $13.95 paperback titled “Hawaiian Anchialine Pools, Windows to a Hidden World” (Mutual Publishing, 2015).

The book contains just about everything everyone knows about our little shrimp, including references for those who want more details. Clearly written by Hawaii researchers — Mike Yamamoto, Thomas Iwai and Annette Tagawa — the book also has great photos.

Most people don’t see these remarkable shrimp in pools, but rather in jars, vases and other clear containers sold in Hawaii shops and online. As for buying the shrimp, the authors don’t advocate it but acknowledge that opae ula make fascinating pets and are for sale locally and on the internet.

It’s researchers’ hope that keeping opae ula at home or the office raises awareness of the importance of preserving Hawaii’s anchialine pools. Due to coastline development and thoughtless people tossing trash and fish into these special bodies of water, Hawaii’s anchialine pools and their famous native inhabitants have dwindled in number.

If you decide to host some opae ula, buy them. Collecting your own is prohibited. When buying, confirm that the shrimp have either been raised through aquaculture or come from a state permit holder with permission to collect in a particular pool.

Of the 700 or so anchialine pools left today, about 650 are on the Big Island. Maui and Oahu have a few, some listed in the book. At least one business and one research team I know have created anchialine pools by digging holes in porous seaside rock. And as if by magic, the shrimp appeared.

When you visit a Hawaii pool of dreams, prepare to be awed.