Monthly Archives: December 2015

Midway’s like a dance floor for amorous albatrosses

Published December 28, 2015 in the “Ocean Watch” column, Honolulu Star-Advertiser ©2015 Susan Scott
Albies_small

Albatrosses, which mate for life, return to the same spot year after year to nest. Couples are affectionate in the nesting grounds. ©2015 David Dow

MIDWAY ATOLL >> For the holidays, Craig and I are working 16 days in sweltering sun, driving rain and gusty wind. At the end of each day, we are dirty, stinky, tired and hungry. Yet we agree that this is one of the best Christmas gifts we could give ourselves. As volunteers for the U.S. Fish and Wildlife Service, we’re counting albatrosses at Midway.

Consisting of 2.3 square miles of land, the atoll lies near the end of the Northwestern Hawaiian Islands, 1,260 miles from Honolulu. Human history here tells of shipwrecked sailors, telegraph workers, travelers, hunters and war. Today, though, Midway belongs to the birds.

Seventeen seabird species nest here, but our focus these two weeks is on albatrosses. Starting in November, about a million Laysan albatrosses return to the atoll to raise chicks, creating the largest albatross colony in the world. In addition, hundreds of thousands of single albatrosses also arrive on the atoll’s islands to find mates.

Dancing

DancingDuring the first three years of life Laysan albatrosses stay at sea, soaring over the waves and sitting on the water looking for fish, squid and flying fish eggs. Then, like sea turtles, the birds return to the island where they hatched.

The young, nonbreeding albatrosses turn the grounds into an avian rock concert as they sing and dance to attract members of the opposite sex. Usually the performance involves two birds, but sometimes a third and fourth join in, creating a circle of pure exuberance.

Albatross dance steps vary slightly with species, but they’re all similar and include beak touching, wing fanning, head bobbing and sky pointing, often while circling one another on tiptoes. At certain moments during the dance, each bird claps its bills like castanets, moos like a cow, honks like a horn, and neighs like a horse, all punctuated with the occasional owlish screech.

050_small

It can take several seasons for a young albatross to bond with a mate, but when the chemistry is right the partying is over. The quiet couples kiss, cuddle and straighten feathers in touching displays of affection.

It takes eight to nine seasons of practice before a young couple successfully raises an offspring, but once they get it right, the two will breed for decades. A bird named Wisdom, at 64 the oldest albatross known, is here sitting on yet another egg.

We volunteer bird counters pay our own considerable expenses and work long hours in all weather. But if Christmas is about sharing memorable times with friends, appreciating the extraordinary life on our planet and feeling happy to be alive, well then, Midway is the gift of a lifetime.

For volunteer information: click here

129_sm

Susan in a sea of birds. Courtesy David Dow.

Sea cucumbers in demand as both cuisine and cure-all

Published December 21, 2015 in the “Ocean Watch” column, Honolulu Star-Advertiser ©2015 Susan Scott
Sea Cucumbers

Sea cucumbers are the housekeepers of the ocean floor, playing a key role in the marine ecosystem.
©2015 Susan Scott

Hawaii’s sea cucumbers made the news last spring when untold thousands were killed off Maui and Waimanalo.

It surprised me to read that collectors export the animals to Hong Kong for medicine. I didn’t know sea cucumbers were a drug. Apparently, though, drying the creatures’ bodies, pounding them into powder and compressing it into tablets is big business.

A brief Internet search produced a staggering number of maladies sea cucumber pills are supposed to help: whooping cough, bronchitis, urinary problems, some cancers, high cholesterol, high blood pressure, impotence, stomach ulcers, diabetes and senility. One site said sea cucumbers ease joint pain in pot-bellied pigs.

Only the pills Alice took work more magic.

Sea cucumbers are also popular as food chiefly in China, Singapore, Vietnam, North and South Korea, Malaysia and Japan. Cooks add chunks of sea cucumbers to soup, stir fry and other dishes.

The Japanese name for sea cucumbers is “namako.” In Hawaiian sea cucumbers are called loli. Ancient Hawaiians ate some species and also used the creatures in love potions.

“When loli is the offering,” goes the saying, “passionate is the love.” Markets sell sea cucumbers as “beche-de-mer.” I assumed this was originally a French dish because the words sound French. It isn’t. Beche-de-mer comes from the Portuguese “bicho do mar,” meaning sea worm. Another term for the animal as food is “trepang,” from the Malaysian “teripang.”

I’m fond of sea cucumbers, not in cuisine or as a cure-all, but because they’re the housekeepers of the ocean floor. With the help of tentacles surrounding a down-turned mouth, the sea cucumber sweeps back and forth, sucking in sand and mud to eat organic pieces fallen there. The creature expels the sifted sediment through its anus in pellets or strands.

Healthy sea cucumber populations continually vacuum tons of underwater sand and mud, playing an important role in the balance of the marine ecosystem.

Besides being crackerjack cleaners, you have to love an animal that breathes through its anus. Lacking gills, a sea cucumber slowly puffs up its body to take water in through the anus. After the creature’s respiratory tree extracts the water’s oxygen, the cucumber gradually deflates, exhaling water, again through the anus.

During last spring’s alarming sea cucumber haul, the state had no limit to how many people could collect. Now aquarium collectors can legally take 3,600 sea cucumbers per year, only from Oahu waters. Because no one has studied sustainability in Hawaii’s sea cucumbers, the number is a guess. Hopefully it will leave our Hoover population healthy.

Turtles rebound in Hawaii, but most use 1 nesting site

Published December 14, 2015 in the “Ocean Watch” column, Honolulu Star-Advertiser ©2015 Susan Scott
One photo, seven turtles. Oahu’s North Shore. ©2015 Susan Scott

One photo, seven turtles. Oahu’s North Shore. ©2015 Susan Scott

‘Turtle! Turtle!”

The call came from our Palau guide during his rare turtle sightings, and usually the animal was 60 feet deep and departing. We Hawaii snorkelers in the group didn’t exactly shrug, but we’re so used to close encounters with tame turtles that seeing one disappearing in the distance was no big deal.

Turtles are so common around the main islands today that it’s reasonable to think the animals have recovered from the threat of extinction. But there’s more to recovery than head counts.

Turtles encounters in Hawaii include them coming very close to examine what you're up to. © Scott R. Davis

Turtles encounters in Hawaii include them coming very close to examine what you’re up to.
© Scott R. Davis

In a 2014 paper published in the journal Biological Conservation, workers studied Hawaii’s ancient sites, market accounts, past menus and state records to determine the history of human impact on Hawaii’s turtles. The biologists divided their findings into three stages.

The first began with Polynesian settlers in about 1250. Archaeological digs show widespread turtle use among Hawaiian societies, which surely included egg collecting. Eventually, hunting pressure from a growing population destroyed most nesting areas in the main islands.

The second decline came with European contact in 1778. During the 1800s ship crews from Europe, North America and Asia killed turtles and collected eggs throughout the Northwest Hawaiian Islands for subsistence and commercial trade. By 1950 all turtle nesting areas in the northwestern chain were obliterated except for a single island in one atoll.

The final blow began in 1946. Due to a growing tourist industry, restaurant demand for turtle meat increased, and Hawaii’s government licensed turtle hunting. Because small coastal turtles were scarce by then, fishers moved to offshore areas where large, reproductive-age turtles swam. Turtle numbers finally got so low that the animals became protected under the Endangered Species Act in 1974, ending all legal hunting.

Protection works, and today the number of greens in Hawaii’s coastal areas is (arguably) about 61,000. But whether that’s close to or far from pre-hunting numbers no one can say.

Either way, this success story has a critical glitch. More than 90 percent of Hawaii’s turtles still nest only on that one tiny island 500 miles northwest of Oahu. This unnatural concentration means that the turtles are only one calamitous weather event, or one human-driven disaster, from losing their last egg-laying haven. That problem demands continued protection.

Nowhere have sea turtle numbers increased like they have in Hawaii, nor do turtles bask on beaches anywhere else in the world.

Sometimes it takes traveling to appreciate the splendor we have in our own backyards.

A turtle basking on the North Shore of Oahu, using a rock as a pillow. © Scott R. Davis

A turtle basking on the North Shore of Oahu, using a rock as a pillow.
© Scott R. Davis

Sponges are diverse animals that pioneered filter feeding

Published December 7, 2015 in the “Ocean Watch” column, Honolulu Star-Advertiser ©2015 Susan Scott
sponge

A sponge stands tall on a reef off Palau. ©2015 Susan Scott

While sorting photos from my recent trips to the western Pacific, I enlarged several shots of sponges to look down their throats. Except they don’t have throats. Or mouths, stomachs, gills, hearts or any other body parts one might call organs.

But sponges do have holes in their bodies, and it looked like something was inside the big ones. And there is. Canals.

DSCN2129

Unlike dish washing tools and cartoon characters, real sponges aren’t square or rectangular. Living sponges are soft orange vases, squishy red barrels, slimy yellow blobs and hundreds of other colors, shapes and textures. Many are so striking that scientists are inspired. One zoology textbook author writes that sponge colors “are as vivid and varied as those of Van Gogh’s flowers.”

Although early naturalists thought sponges were plants, they are animals that strain seawater through cells in their bodies to catch bacteria and other microscopic bits of organic material. Called filter feeding, this is a way for countless marine animals to get food. But sponges invented it. They were the first creatures on Earth to eat this way, and it worked well. Over the past 600 million years, sponges evolved into at least 15,000 species and counting. Hawaii hosts more than 80.

Cool orange spongeSponges love currents. Water enters the creatures though tiny surface pores, some invisible to the naked eye. Inside are minuscule threads that whip the water through canals supported by skeletons of protein fibers and/or minerals such as silica and calcite.

From the canals, feeding cells sift out whatever the water brought in. The cleaned water is then pumped out through its larger visible holes, the ones I was peering into.

Sponges don’t have many kinds of cells, but the ones they do have are a model of teamwork. Besides skeletal cells, feeding cells and pumping cells, unemployed cells roam the body, conveniently turning into whatever type the animal needs. In this way the sponge can remold its shape to fine-tune its feeding.

SpongeIf necessary, a sponge can move to a better place. The creature walks by absorbing its skeletal cells from one side of the body and depositing them on the other. It’s slow going, but then moving the house usually is, especially when it’s an apartment building. Some species of crabs, shrimp and brittle stars (starfish relatives) live in sponge canals.

Although hawksbill turtles and some sea slugs, starfish and fish eat sponges, many species contain toxins that discourage most predators.

Living sea sponges might not have the adventures of SpongeBob SquarePants, but their colors, shapes and inner lives are just as fantastic.