Monthly Archives: December 2014

Emails reveal shared love of sea creatures worldwide

Published December 29, 2014 in the “Ocean Watch” column, Honolulu Star-Advertiser ©2014 Susan Scott

You’ll never hear me complaining about email. It used to be that writing this column was a lonely job. Now each day I get to drink my morning coffee with people who share my love of the ocean and its remarkable inhabitants.

Some readers write to tell me about their own experiences with a subject I’ve written about, and others offer kind corrections or clarifications. Countless people just want me to know how much my articles brighten their Mondays and that brightens the hours I spend at my computer.

Every message has its charm, but a few from 2014 stand out.

Cutest story: Jennifer from Kualoa wrote that she gives the ghost crabs on her beach peanuts. “The big dudes take one in each claw and shuffle another around like a soccer ball … Sometimes they share, as with an apple core that washed in.” Another day, she wrote that her crabs “hold the peanut in one claw and nip off bits to eat with the other. But what about the ones with no claws? I know they will grow back, but in the meantime, what will they do?”

I loved learning that ghost crabs share apples and play soccer with peanuts. The fact that Jennifer worries about injured crabs tells me that we are kindred spirits.

The shortest and sweetest: In this era of information overload, I loved this reader’s economy.

Subject box: “Upside-down jellyfish.”

Message: “Thanks — Really Good.”

Appreciation noted.

Most alarming question: On Feb. 12, Paul wrote, “Aloha Susan, Could the invasive algae be responsible for the missing Honu in the Ala Moana Lagoon? We have only seen one Honu in 4+ months.”

Happiest ending: On Feb. 19, Paul wrote: “Aloha Susan! Had to avoid a large Honu at Ala Moana Lagoon today so that makes 3 in 2 days. A welcome return after many months absence (for whatever reason.)”

Question with the easiest answer: While watching manta rays at night, a Big Island reader, Chris, met a woman who “claimed that there is a day, one time a year, when the world’s oceans all get super excited, and the water is effervescent and the tides change color and sea life large and small all becomes super animated … perhaps tied to a lunar event. Was this gal off her rocker?”

Um. Yes.

Best message from a distant land: Emails arrived from readers in Australia, South Korea, Pakistan and the Czech Republic. These were all fun starts to my day (Wow, Pakistan?) but the one that touched my heart came from the CR. “Hello madam,” Jan wrote. “I’d like to run away from Europe and live a spiritual life. It would be possible to settle in such a paradise? Good luck.”

I already had my good luck. I wished Jan equally good luck in finding his or her paradise.

Favorite video: My neighbor Joanne sent this link — bit.ly/1zad8WG — with the note, “In case you haven’t already seen this 46 times.” I had not seen it even once, but I’m now close to 46.

All my messages this year were positive, entertaining and inspiring. Thank you, dear readers, for making this column so much more than a job. See you in 2015.


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

©2014 Susan Scott

Turtle-cleaning station raises islander’s spirits

Published December 22, 2014 in the “Ocean Watch” column, Honolulu Star-Advertiser ©2014 Susan Scott

Sea turtles are protected in Hawaii and have lost their fear of people. Courtesy David Schrichte

The surf is up. The water is murky. It’s windy, rainy and cold. I’m not complaining — Hawaii winters have their own splendor.

But blustery conditions have been keeping me out of the ocean, and when that happens I get gloomy. Global warming, political gridlock, endless war, robot spy tunas (bit.ly/13dshbR). The world of my species overwhelms me.

Then a visitor helped put me right.

Friends called asking me to join them snorkeling because their California guest wanted to swim with turtles. What? Get wet? Oh, OK, I sighed. We met on the North Shore, pulled on wet-suit tops and took the plunge.

As I expected, the current was strong, the water chilly (77 degrees compared with summer’s 81) and the visibility poor. As we swam to a place where honu hang out to have fish pick algae and parasites off their necks, flippers and shells, I wondered whether the turtles would even be there.

Oh, yes. Six big, fat turtles floated trancelike inside a curved coral wall, their heads down and limbs limp as convict tangs nibbled them clean. The surge pushed the turtles into each other in their crowded spa, and once, I had to back-paddle fast to keep two drifters from bumping into me.

Turtle 127

Turtle 204_smallTurtles at a North Shore cleaning station – Susan Scott

The turtles ignored us, not a bit concerned about four humans gawking and occasionally getting in the way.

Turtles are like that in Hawaii, where they’ve been protected for so long (since 1978) they’ve lost their fear of people. This is not so around other tropical islands.

I once visited a seaside hotel on the Tahitian island of Tahaa where the owner bought live turtles from anglers aiming to sell them at fish markets. The proprietor fed and nursed his reptile lodgers, and when the turtles were healthy, guests got to release them.

The encounter moved some to tears. A Tahitian woman told me she spent money she could not afford for airfare and a hotel room so her 8-year-old daughter could set a turtle free.

releaseTurtle being released on Tahaa. -Susan Scott

I’ve now sailed twice across the South Pacific, and spotting a turtle is a rare event. And once a turtle spots you, it’s gone in a flash.

I love Hawaii’s turtles, and our tourists as well. People’s excitement over what we take for granted reminds me how lucky I am to live on Oahu. Nowhere else in the world can I, at any time, drop in on turtles grazing, resting or getting a massage, and the animals don’t consider me a predator.

Swimming with turtles on a Hawaii winter day didn’t solve the problems of the world, but it sure lifted my spirits. It also helped me believe that there’s hope for the future.

Have a happy honu holiday.


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

©2014 Susan Scott

 

Blossomlike zoanthids join to form colorful mats

A Palau zoanthid with tentacles tightly closed. ©2014 Susan Scott

I don’t write the headlines to my columns, but when I email one to the newspaper, I title it with a common name so the editors know what the piece is about. This week my subject gave me pause because it’s known only by its scientific order, Zoanthid, a name that doesn’t exactly roll off the tongue. When I looked up the word’s meaning, though, it painted a picture as pretty as the creatures themselves. “Zoanthid” is Greek for “flower animal.”A Palau zoanthid with tentacles tightly closed.

I don’t write the headlines to my columns, but when I email one to the newspaper, I title it with a common name so the editors know what the piece is about. This week my subject gave me pause because it’s known only by its scientific order, Zoanthid, a name that doesn’t exactly roll off the tongue. When I looked up the word’s meaning, though, it painted a picture as pretty as the creatures themselves. “Zoanthid” is Greek for “flower animal.”

An individual zoanthid body is leathery and round, about a half-inch across. Encircling the body are two rows of tiny waving tentacles that sting animals unfortunate enough to drift close. The tentacles drop their paralyzed catch into the creature’s mouth at the center.

Zoanthids don’t live alone like their solitary cousins the anemones. Like reef corals, zoanthids create colonies, expanding their communities by budding off each other. (Brand-new colonies start when mature bodies release eggs and sperm into the water.)

Some zoanthid bodies lie flat, like buttons, and others sit atop stumps or stems, like flowers. In most species the walls of the round bodies contain grains of sand that probably give some heft to the animals’ build.

A mat of rubbery tissue connects zoanthids’ bodies, making large colonies look like floral-patterned carpets draped over rocks. Channels inside the mats connect the individuals’ digestive systems, allowing zoanthids to share food.

Like their coral and anemone relatives, zoanthids host algae in their tissues that add veggies to the diet.

The color combinations and designs of zoanthids and their algae rival the world’s most famous summer gardens, making these creatures jewels of both reefs and aquariums. You can see some of these eye-popping animal flower beds at bit.ly/1ywm0EB.

Hawaii might — or might not — host eight species of zoanthids. Their appearances are so varied that Great Barrier Reef studies showed several so-called species are genetically identical. Conversely, several distinct species look remarkably alike, even when dissected.

We know for sure, however, that one rare kind of Hawaii zoanthid, called “limu-make-o-Hana” (“deadly seaweed of Hana”), can kill you. Its stingers aren’t potent enough to hurt humans, but the body contains a potent toxin.

Ancient Hawaiian warriors rubbed mucus from this Maui zoanthid on their spear tips, causing wounds to be fatal.

The poison might also save lives. Researchers have discovered that the palytoxin produced by algae or bacteria in the zoanthid has anti-cancer properties.

The sight of zoanthids blossoming on the reef or in an aquarium is memorable even if their name is not. But then, it’s hard to improve on “flower animal.”


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

©2014 Susan Scott

Equine fate in question when encountering eels

Published December 15, 2014 in the “Ocean Watch” column, Honolulu Star-Advertiser ©2014 Susan Scott

Can an electric eel kill a horse? The question came to me last week after a Vanderbilt University researcher published details about how South American river eels catch fish. The nearly sightless eel sends out two electric pulses that cause a hiding, motionless fish to twitch, revealing its location. The eel then zaps the shuddering fish with 600 volts, killing it for an easy meal.

An excellent short video shows this hunting technique at bit.ly/1vFsrzd.

The report about this odd eel got me wondering how electric eels are related to ocean eels, and that investigation brought me to a website stating that an electric eel can kill a horse.

Really? Any science to that? My search just got longer.

In describing a typical eel, my favorite fish book lists five qualities, and follows it with a whole paragraph of exceptions. That, of course, is the beauty of biology. Species adapt in their own ways to their surroundings, and that often makes lists of characteristic useless.

This is especially true of eels, for which exceptions are the rule. The only thing all eels have in common is that they’re fish with long, snakelike bodies.

To give some order to the wide world of eels, researchers divide them into four families. Three of those — morays, congers and snake eels — are common saltwater species.

Members of the fourth family are called “true” eels. (This statement makes me smile because it sounds as if our eels are lying about their heritage.) These live in fresh water and spawn in the sea.

Depending on the species, lake and stream eels spend six to 12 years in their freshwater homes and then migrate to sea.

To reach their spawning grounds, true eels swim and ride ocean currents, some for more than 3,000 miles. After spawning, they die. Their tiny offspring drift for one to three years before finally reaching coastal waters.

Males prefer to live in estuaries and rivers; females like lakes.

The electric eel is a grand exception to all of the above. Not only is this freshwater fish wired, it breathes air, an adaptation to the muddy, oxygen-poor creeks and rivers the fish calls home.

An electric eel must break the surface every minute or so to take a breath or it drowns.

Only the front one-fifth of an electric eel contains vital organs. The rest of the 7 foot long body is a container for the fish’s battery bank, charged by about 6,000 special cells.

The eel uses low power, about 10 volts, like radar to move around its murky environments.

Electric eels have a category of their own shared with their cousins, South America’s knifefish, also snaky and electric, but much smaller and packing far less voltage.

As I looked for reliable confirmation that an electric eel can kill a horse, I found in another of my textbooks a detailed black-and-white drawing, source anonymous, of several wild-eyed horses flailing in a river loaded with electric eels.

The caption says, “An accurate rendering of electric eels, Electophorus electricus, in an otherwise dramatized setting.”

No mention of the horses.


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

©2014 Susan Scott

Acid-making tissue helps giant clams thrive on reefs

Published December 1, 2014 in the “Ocean Watch” column, Honolulu Star-Advertiser ©2014 Susan Scott

A giant clam lives on its coral home in Palau. ©2014 Susan Scott

Why don’t giant clams growing deep inside living coral heads get squished by growing coral?

My friend asked me that in Palau as we snorkeled over brilliantly colored clams sunbathing in all their glory from their coral head homes.

Good question. I did not know.

Then last week Mary sent me a link to a marine aquarist magazine article that explained how giant clams bore. It was a well-written piece, with references, but I wondered: Why do people who keep home aquariums want to know about giant clams?

Giant clams, I learned, are suitable for the home aquarium trade because despite their family name, some of the eight giant clam species are small. Six of the little ones, as gorgeous as their colossal cousins, are sold as saltwater pets. Besides enjoying the clams’ unique colors and patterns (no two clams are alike), aquarists like giant clams because they’re hardy, grow fast and need little care.

clams

This is good because people also like to eat giant clams of all sizes, and as a result, they’re scarce or absent in most unprotected areas of the tropical Indian and Pacific oceans. Today most species are on the International Union for Conservation of Nature red list of threatened species.

But there’s hope. Because the clams do well in tanks, aquaculture farmers grow giant clams throughout the Pacific. Some of the young clams go to the aquarium industry, but the clams grown in state-sponsored farms get transplanted in their native habitat.

clams

Giant clams being farmed in Aitutaki, Cook Islands. Courtesy Scott R. Davis

Tank-grown clams never bore into coral heads after release, but remain free-standing. If born on the reef, however, baby clams often dig in. After drifting in currents for about 10 days, a larval clam drops hinge-side down onto a coral head, anchoring itself with threads protruding from a hole where the clam’s two shells meet.

Also protruding from the hole is a flap of tissue that excretes a weak acid, killing the coral bodies beneath it and weakening the limestone below. (Only the top layer of a coral head is alive. The bulk below consists of the living coral’s long-dead ancestors.) Meanwhile, topside, the clam’s lovely “lips” release a chemical that keeps budding coral polys at bay.

The exposed lips also contain algae that feed the clam and iridescent color cells that act as sunscreen to protect the clam’s soft parts from burning. The resulting color combinations make giant clams of all sizes look like brilliant smiles lighting up the face of the reef.

Thanks, Mary, for the question and link. The expression “happy as a clam” finally makes sense.


clam


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

©2014 Susan Scott