Monthly Archives: August 2014

Bright colors and designs give fish a flashy disguise

Published August 25, 2014 in the “Ocean Watch” column, Honolulu Star-Advertiser ©2014 Susan Scott

In 1981 I rented mask, snorkel and fins and, for the first time, gazed upon a coral reef. My impression: Such color! The swirling yellow, green, pink and blue fish looked like an underwater confetti toss.

My awe over the colors of reef fish has never faded. To this day, seeing their gaudy colors displayed in such eye-popping patterns makes me happy to be alive.

But how do the fish survive? In the fish-eat-fish world of the ocean, those colors and designs look like neon signs saying, “EAT HERE!” It seems a miracle that any make it to adulthood.

When it comes to being flashy, the pros have to outweigh the cons.

Although countless colorful reef fish do get eaten, being bright isn’t as dangerous as it looks. Those horizontal stripes, vertical bars, frilly fins and diffuse polka dots break up a fish’s shape so that some predators don’t immediately see it as a fish. This form of camouflage is called disruptive coloration.

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Another common countermeasure to reef fishes’ conspicuous attire is the Lone Ranger strategy: They wear a mask. Because a fish’s head and eyes are primary targets for an attack, black bars running across the eyes of many species make a predator unable to tell heads from tails.

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To add to the confusion, many reef fish have a false eyespot or two on their back or rear fins. A bite to a fin gives the prey a fighting chance to escape and recover. And it works. It’s common to see a ragged fin on an otherwise healthy fish.

On a reef teeming with hundreds of species, sporting yellow stripes, pink spots or blue-lined fins has a huge advantage: Distinct colors and markings enable fish to find their own kind. Such fellowship is crucial for an individual to romance the right species, join the best school and link up with a successful security team.

Good examples of color and design helping fish get it right are members of the flamboyant butterflyfish family, named for their resemblance to butterfly wings.

Raccoon Butterfly Fish - Courtesy Russell Gilbert

Raccoon Butterfly Fish – Courtesy Russell Gilbert

On the reef, we often see butterflyfish swimming in tight pairs. These are the coral eaters, and the couple is a male and female that stick together year after year. The standout markings of each species help the butterflyfish partner up with the right kind, and then keep track of that partner for mating and guard duty.

Coral-eating butterflyfish don’t wipe out coral colonies because the fish take tiny bites from large territories that the couple defends together. In ousting trespassers from a sprawling estate, two fish are better than one.

Other butterflyfish species graze on tiny animals drifting in the water, settled on the seafloor or stuck to rocks in the form of eggs. These butterflyfish often band together in gangs, all the better to overpower a damselfish dad guarding his eggs or to scout for food in a vast ocean.

That first snorkeling experience I mentioned was in Mexico’s Garrafon Natural Reef Park, a marine preserve that will always be close to my heart. I had a wonderful experience that day, but the sanctuary gave me more than colorful fish: It painted a picture that remains forever bright.

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Marine biologist Susan Scott writes the newspaper column, “Ocean
Watch”, for the Honolulu Star-Advertiser, www.staradvertiser.com

©2014 Susan Scott

Koleas return after a busy season of laying huge eggs

Published August 18, 2014 in the “Ocean Watch” column, Honolulu Star-Advertiser ©2014 Susan Scott

Enormous eggs: Each one is about a quarter of the length of a female kolea. Courtesy Wally Johnson

A couple weeks ago, I had one of those days when my brain felt like an iPod shuffle stuck on fast forward. Deadlines, chores, errands, family and a hundred other things raced through my head until I finally gave up trying to work. Turning off the computer, I went for a walk in a nearby park.

It was a hot, still day and I soon stopped to sit in the shade of a monkeypod tree. And at that exact moment, a Pacific golden plover dropped from the sky and landed in the grass not 20 feet away.

I had just witnessed the arrival of my first kolea of the season.

She was not, however, the first plover to return to Oahu this summer. Nor am I the first person to look up to see a plover descend from the heavens.

Earlier this month a fellow plover lover emailed that her kolea arrived in her yard July 31.

“It landed just as I looked outside, about 6 p.m.” Cindy wrote. “Pretty early this year?”

Yes, July 31 is a bit early, but not extraordinary. The early birds are usually females needing a long tropical vacation from their summer job of laying their enormous eggs.

Each kolea egg is about a quarter the length of the bird and weighs just under an ounce. That may not sound very heavy (an AA battery weighs about an ounce), but it means that a freshly laid clutch of four eggs weighs about the same as the fat-free female, about 3.5 ounces.

She’s bone thin, of course, having used the fat she gained in Hawaii first to fly 3,000 nonstop miles to Alaska, and soon after to develop her eggs. Because the female lays each egg about a day and a half apart, it takes six to seven days to produce a typical nest of four.

But that’s not always the end of her procreative push. If an owl, hawk or other predator eats a plover’s eggs, or a caribou breaks them while tramping through a colony, these formidable females, keeping the same nest and mate, start over. The first egg of the replacement batch appears, amazingly, within a week of the loss.

Lost clutches are common. At one study site from 1993 to 2002, 50 to 100 percent of kolea eggs were crushed or eaten.

No wonder that when their chicks get near fledging, the worn-out moms beat it back to Hawaii, leaving dad and the kids to follow.

I watched my first kolea of the season for 20 minutes, thinking about her miles flown, eggs laid and chicks raised, as well as how these busy bundles of feathers brighten the days of so many people in Hawaii.

Being one of those people, I walked home at peace.


Airborne to avoid predators, flyingfish get eaten by birds

Published August 11, 2014 in the “Ocean Watch” column, Honolulu Star-Advertiser ©2014 Susan Scott

Two weeks ago Craig and I, with about 40 others, attended our friends’ wedding. We got ready for the ceremony and reception by dressing in shorts and slippers, donning hats and applying sunscreen. The event took place on a boat.

As we left Kewalo Basin, white terns hovered ahead, and off Waikiki a school of black durgons surrounded the catamaran like a party of best men in blue-edged tuxedos. But the animals that caused the group to gasp were marvelous creatures that straddle the worlds of air and ocean: flyingfish, known in Hawaii as malolo.

Lots of marine animals jump from the water into the air. Flyingfish are the only ones that can stay there.

But not for long.

Glides average 10 to 30 seconds, with occasional exceptions. In 2008 a Japanese ferry rider filmed a flyingfish gliding for 45 seconds, the longest airborne time recorded.

Baby flyingfish, called smurfs, look so different from adults that over the years people named about 150 species. Today researchers agree that the worldwide number is between 60 and 70.

The longest grow to 20 inches, but most are between 6 and 12 inches.

The flyingfish family name, Exocoetidae, comes from a Latin word meaning “sleeping outside,” a label resulting from ancient sailors’ belief that flyingfish came ashore at night to sleep.

They don’t, of course, but if fish could wish, this might be high on their list. Just about every predator in the ocean eats flyingfish day and night.

And their glides over water at 30-some mph for up to 300 feet don’t guarantee a getaway. When flying fish leap from tunas below, they’re meals for seabirds above.

Without a boat, flyingfish are nearly impossible to see, and even from a boat, their speed and size make it difficult to determine colors, patterns and behaviors.image

Now, though, we can all see the fantastic fish in vivid detail. For years, author, photographer and bird tour leader Steve N.G. Howell captured flying fish on camera, and shares his stunning photos in a new book called “The Amazing World of Flyingfish” (Princeton University Press, $12.95, 64 pages).

The photos show colorful wings in exquisite patterns. These are reflected in the informal names Howell and friends call the fish: Big Raspberry, Violaceous Rainmaker, Black-eyed Blushwing, Ornate Goldwing and Purple Haze, among others. Howell also includes hard-to-find flyingfish facts.

The close-up pictures of fish gliding and seabirds catching them, as well as the compiled information, are exceptional.

As the wedding catamaran sailed along the Honolulu shoreline, the sparkling school of turquoise malolo bursting from below was such an elegant performance, it brought tears to my eyes.

As did the marriage vows. How privileged I felt to be on a boat surrounded by exquisite marine creatures, off the world’s most beautiful city, in a state where everyone in love and committed to one another can get married.

Congratulations, John and Ed. Your special day was special for us all.


Marine biologist Susan Scott writes the newspaper column, “Ocean
Watch”, for the Honolulu Star-Advertiser, www.staradvertiser.com

©2014 Susan Scott

Hawaiian sergeant males perform duties with zeal

Published August 4, 2014 in the “Ocean Watch” column, Honolulu Star-Advertiser ©2014 Susan Scott

The Hawaiian sergeant is Hawaii’s version of the Caribbean’s sergeant major, the Indo-Pacific sergeant and other sergeant species, totaling 20 worldwide. Courtesy Russel Gilbert

During a recent snorkeling excursion at Electric (Kahe) Point, my friend and I stopped to watch a fish fight. Even though we floated in clear water 20 feet above the artificial reef (the outflow pipe), the sparring was so fast and furious, it was hard to make out what was happening. But when I spotted a purple splotch spread out on a rock like so much plum jam, I knew: A male Hawaiian sergeant was protecting his eggs.

The Hawaiian sergeant is Hawaii’s version of the Caribbean’s sergeant major, the Indo-Pacific sergeant and other sergeant species, totaling 20 worldwide. All are about 8 or 9 inches long and have black stripes on yellowish bodies.

When a male sergeant is ready to mate, he prepares a site on a rock, fanning away sediment and eating algae and small invertebrates growing on the chosen spot. Once he’s got his house in order, the male turns pale blue and performs a dance of loops, zigzags and head-down hovers to get a female’s attention.

If a female likes what she sees, the two swim side by side in an upward rush and return to the site of the future nursery.

Egg laying and fertilization take about 20 minutes but can last up to two hours, depending on distractions. Besides circling the female and spraying her eggs with sperm, the male drives off other males attempting to sneak in and spew their sperm without the bother of making a nest.

Sergeant males must also chase away countless reef fish trying to eat the exposed eggs, 20,000 or so for each female.

After the female lays her eggs, she’s done. Off she goes to graze on plankton and algae. The male’s job, however, has just begun.

As both guard and gardener, he drives off predators, removes dead eggs and picks out debris that settles on them.

As busy as these males are, they still take time to woo passing females. A lucky sergeant might spawn with 11 females in one to three days, resulting in 11 clutches of eggs all in one nest.

Because the eggs change color as they mature, these nurseries can be various shades of red and purple. When the eggs hatch in five to nine days, parenting is over.

During all this chasing, weeding and courting, male sergeants have no time to graze, and occasionally eat some of their own eggs. Such cannibalism may seem counterproductive, but it’s better to eat a few of the kids than lose them all to wrasses or butterflyfish because dad got woozy.

Sergeant males don’t hesitate to charge and nip snorkelers and divers who get too close to their eggs. The pecks don’t hurt, but even so, that day at Kahe Point, I was glad we were 20 feet above the fray.

Those bold little fathers have enough to do without wasting energy on humans.


Marine biologist Susan Scott writes the newspaper column, “Ocean
Watch”, for the Honolulu Star-Advertiser, www.staradvertiser.com

©2014 Susan Scott