TINY TUVALU RUNS DRY

Funafuti Atoll, Tuvalu. Credit: Stefan Lins via Wikimedia Commons.

 

The tiny Pacific nation of Tuvalu—already suffering from rising sea levels—has declared a state of emergency as water supplies on some islands ran dry today. 

The Telegraph reports that Tuvalu's state of emergency was declared after existing desalination plants broke, exacerbating an already dire drought:

The Tuvalu Red Cross said it had not rained properly in the country for more than six months. Meteorologists have forecast a lack of run until December. Typically it gets between 200mm to 400mm [~8 to 16 inches] of rainfall per month... [New Zealand] was working with the Red Cross to deliver aid workers and supplies as quickly as possible.  

  

Location of the Pacific island nation of Tuvalu. Credit: TUBS via Wikimedia Commons, modified by Julia Whitty.

 

I wrote about the troubles facing Tuvalu's nine tiny islands in my 2003 Mother Jones article All the Disappearing Islands. At that time Tuvalu was threatening to sue Earth's gassiest nations for emitting enough CO2 to sink Tuvalu for good:

Tuvalu is among the smallest and most remote countries on Earth, with a total land mass comprising only 10 square miles/26 square kilometers, less than half the size of Manhattan and scattered over 347,400 square miles/899,000 sq km of ocean—an area larger than California, Oregon, and Washington combined... At no point is the sandy island of Funafuti higher than 13 feet above sea level, as is the case throughout the nine coral atolls of this South Pacific nation of Tuvalu. Surrounded by the sea, the people here have been shaped by it as few others on earth. Every afternoon, rain or shine, Tuvaluan children romp in its unsupervised playground... Inescapably, this is a nation of waterfront property; even the plywood and corrugated-tin houses standing 'inland' a block or two enjoy the ambiance of the ocean. No one here has ever lived a moment without hearing the thunder of surf.

Credit: © Julia Whitty.

Now Tuvalu's freshwater aquifers may be contaminated, reports the BBC:

Secretary General Tataua Pefe advised people against drinking water from wells. "It's not safe for consumption," he told Radio Australia. "Some animals have died recently and we think it's because of subterranean water."

In The Fragile Edge I wrote how Tuvalu's problem with freshwater contamination could render its islands uninhabitable long before rising sea levels irrevocably sink them:

Floods and rogue waves raise the saltwater table underlying the atolls, poisoning the Tuvaluans' staple crops. Already some farmers have been forced to grow their [crops] in tin containers, and already some of the smaller motus [islands] have lost their coconut palms to saltwater intrusion. Nor are storms a prerequisite for disaster. "Last August," Prime Minister Saufatu Sopoanga tells me, "on a clear, calm day, a sudden wave surge rolled in from the sea and washed across Funafuti into the lagoon, flooding houses." There was no apparent reason for it, and during my stay on the atoll, I find the sensation of threat to be ever present—the sea on both sides, the constant drumroll of surf, a thin strip of land between—like living on a liquid fault line.

Funafuti Atoll, Tuvalu. Credit: Davidarfonjones via Wikimedia Commons.

   
Meanwhile 3 News New Zealand reports the drought is affecting other Pacific islands too:

The latest place to declare a state of emergency is Tokelau, a New Zealand territory of fewer than 1,500 people on three coral atolls in the central Pacific.

And The Taiwan News reports a possible cholera outbreak in Tuvalu.

A wedding party on Funafuti. Credit: © Julia Whitty.

  
Inundated by ills from afar, more and more Tuvaluans are leaving their home islands—and not because they want to. From All the Disappearing Islands:

Within the coming decades, the atolls of Tuvalu and elsewhere will almost certainly revert to sandbars and then nothing. Although the people themselves will not go extinct, without their home islands to anchor them, their beliefs and identity probably will, scattered person by person across the rising waters... until, like Atlantis, the name of Tuvalu fades into myth.

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GOOD FISH, BAD FISH

(Two cleaner wrasses, Labroides dimidiatus, working a sweetlips. Photo by Nhobgood, courtesy Wikimedia Commons.)

New research out on one of my favorite subjects—cleaner fish and their mimics.

For starters, here's a smart video showing the world of cleaners—fish and shrimp—and their clients in the seagrass beds and coral reefs off Papua New Guinea.


Symbiosis: Cleaner shrimp and Fish Clients from Lucy Marcus on Vimeo.

Although half the animals waiting in line at a cleaning station are menu items for the other half, peace mostly prevails. That's because everyone needs the ministrations of those who eat parasites and clean messy wounds. One researcher, Redouan Bshary, has been investigating the relationship between cleaners and their clients for some years. Here's some of what I wrote about his findings in The Fragile Edge:

Cleaners do occasionally bite their clients too hard (some actually sneak a forbidden fish scale now and again), which can lead to them being chased away by the angry client. If the injured client returns later to this same cleaning station, the cleaner will spend the first few moments backing gently into him and massaging him with undulating caudal fins. The client appears to enjoy this, and the researchers conclude that it is an attempt at reconciliation—an apology, if you will, and the first of its kind seen in anything other than mammals on the order of primates, dolphins, sheep, goats, and hyenas. Bshary also discovered that cleaners are more likely to use caresses to mollify carnivorous fish who might eat them. But what of the nonpredatory client species, the vegetarians who can’t wield the ultimate threat? What is to stop the cleaners from nibbling their fish scales, or nipping a little muscle tissue, or slurping an energy-rich slick of mucus? Another study revealed that market forces shape the cleaner-client relationship. Curbing what might otherwise be an overwhelming temptation to imbibe some of the client’s protective mucus is the pressure of competition. Clients are less likely to visit cleaning stations where they have previously been cheated by the cleaner’s nibbling, or where they have had to wait in line. So even nonpredatory clients wield the big stick of consumer choice.

(A dragon wrasse, Novaculichthys taeniourus, getting cleaned by rainbow cleaner wrasses, Labroides phthirophagus, on a Hawaiian reef. Photo by Mila Zinkova, courtesy Wikimedia Commons.)

Of course all good things come with their attendant thieves and con-fish. Some fish mimic cleaner wrasses—and not for the benefit of the clients. Again, from The Fragile Edge:

If you spend long enough in the company of cleaners on the reef you might find yourself a victim of one of the inevitable opportunists: the false cleaners, or mimic blennies, small fishes who make their living as cleaner mimics (some only in their juvenile phase). These little predators look uncannily like cleaner fishes, with blue stripes and long, narrow bodies. They even abandon their wriggly blenny swimming style for the cleaners’ characteristic rowing with the pectoral fins. Even more remarkable, some false cleaners have stolen the barbershop-pole display, the trademark of the cleaner wrasses, to lure the unsuspecting and the disheveled close by. When a victim falls for the ruse, the false cleaner charges, bites off a hunk of flesh with fangs hidden in its underslung lower jaw, then runs to hide in a cranny. The scale-eating blenny is renowned for darting up from the substrate and nipping at passing divers.

I like the Twilight Zone aura of this video from the golden age of wildlife melodramas. At any rate, it's a good illustration of the ways of the mimic blennies—even if it is a total set-up in a tank. (Question: Who cleans the mimics?)

Now Andrea Bshary and Redouan Bshary have a new paper out in Cell Biology describing how some victims of parasitic saber-tooth blennies spend valuable time and energy punishing their attackers by chasing them or biting them—even though there's no getting back that lost flesh.

So when does it make sense to punish, given that punishment has immediate energetic costs to both the punisher and the punished?

Well, according to the Bshary's experiments, the vengeful victims of blenny attacks serve themselves. That's because in future attacks blennies are more likely to go after different individuals than those who took the time and expended the energy to punish them. Yet the vengeful victims also serve other member of their own species. That's because, given a choice, blennies are more apt to switch to a different species of fish for their next attack if their previous victim punished them. Thus the vengeful victim creates a "public good."

A third tier of research showed that at least some blennies can tell the difference between look-alike pairs of victims in which one punished them and the other did not, and will selectively bite the nonpunishers. From the paper's abstract:

A key challenge for evolutionary biologists is to determine conditions under which individuals benefit from a contribution to public goods. For humans, it has been observed that punishment of free riders may promote contributions, but the conditions that lead to stable cooperation based on punishment remain hotly debated. Here we present empirical evidence that public goods may emerge as a by-product of self-serving punishment in interactions between coral reef fishes and parasitic saber-tooth blennies that stealthily attack their fish victims from behind to take a bite. We first show that chasing the blenny functions as punishment, because it decreases the probability of future attacks. We then provide evidence that in female scalefin anthias, a shoaling species, punishment creates a public good because it increases the probability that the parasite switches to another species for the next attack. A final experiment suggests that punishment is nevertheless self-serving because blennies appear to be able to discriminate between look-alike punishers and nonpunishers. Thus, individuals that do [not?] contribute to the public good may risk being identified by the parasite as easy targets for future attacks.

[I'm assuming the "not" was left out of that final sentence...?]

'Cleaner' Pt. 2 from MORPHOLOGIC on Vimeo.

Finally, here's another memorably intimate video from Morphologic showing a Periclemenes pedersoni shrimp cleaning its host sea anemone, a fluorescent orange Ricordea florida corallimorphs.

The paper:

• Andrea Bshary, Redouan Bshary. Self-Serving Punishment of a Common Enemy Creates a Public Good in Reef Fishes. Current Biology. DOI: 10.1016/j.cub.2010.10.027

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HOW TO CATCH A MULLET

This short video is an excerpt from the BBC Life series showing the amazing cooperative hunting technique of bottlenose dolphins working Florida Bay in pursuit of mullet. This video was published on their new website, Life Is, which will release monthly embeddable videos from the entire BBC catalogue of nature programming. I'm glad to hear it.

The research behind this film was published in a 2005 paper: A division of labour with role specialization in group–hunting bottlenose dolphins (Tursiops truncatus) off Cedar Key, Florida. DOI: 10.1098/rspb.2004.2937 Proc. R. Soc. B 22 January 2005 vol. 272 no. 1559 135-140. 

From the abstract:

Individual role specialization during group hunting is extremely rare in mammals. Observations on two groups of bottlenose dolphins (Tursiops truncatus) in Cedar Key, Florida revealed distinctive behavioural roles during group feeding. In each group, one individual was consistently the ‘driver’, herding the fishes in a circle toward the remaining ‘barrier’ dolphins. Aerial fish–capture rates differed between groups, as well as between the driver and barrier dolphins, in one group but not in the other. These differences between the two groups may reflect differences in group stability or in prey school size.

(Mullet from here.)

I wrote about mullet living in the waters around the atoll of Rangiroa—and a different way of catching them—in my book The Fragile Edge. Here's an excerpt:

The littlest fish are less than six inches long, and their schools are sleek and whippy as cat-o’-nine-tails. They are behaviorally circumspect, skittering only through the protected water around the dock’s pilings. In contrast, the schools of the larger mullets, with individuals reaching more than a foot in length, parade aggressively under the dock, around the pilings, and out into the open water, their pectoral fins flipping open and closed like golden fans
as they root out the diatomaceous and detrital scum of the sandy bottom. As one of the few species of fish that feed almost exclusively on single-celled plants—diatoms, dinoflagellates, and phytoplankton—vegetarian mullet have a taste unlike any other fish, or so I’m told. 

Sucré et huileux (sweet and oily), says the Tahitian woman who has joined me on the dock with her hand-fishing line. She has settled onto the pier not far from me, her bare legs and feet dangling over the edge, the sunset square in front of her, where all sunsets always seem to be in Rangiroa. Like many Tahitian women, her hair reaches past her waist, blue-black and shiny as the inside of a mussel shell, the long plait unfastened at the bottom, the hair holding the shape from habit alone. 

She cooks the mullet whole in a pan with just salt, no oil, she says, since the fish are oily enough. Sometimes she adds milk. I recognize her from the hotel, where she works as a maid, and this dock is apparently one of the perks of her job because I’ve seen her fishing here most evenings. She seems relaxed and happy at the end of her workday, carrying nothing of the emotional and psychic exhaustion of a Western worker at shift’s end—and this is one of the many miracles not only of Polynesia but of French Polynesia, where the Gallic embrace of the sensual allows time for the enjoyment of life as it comes.

It's possible this video (the Oprah-Winfrey-narrated version) will stream only on computers based in the US. Sorry if that's true. Copyright Is, too.

(Photo by Endless Vacation on Flickr)  

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RANDOM EXCERPT: BIOLUMINESCENCE

Photo by Phil Hart. And, by the way, well worth a visit to his website for his explanation of the complex factors that led to this photograph. Plus more really beautiful images of bioluminescence.

I wrote about bioluminescence, the brilliant aurora stirred by motion in the nighttime sea, in THE FRAGILE EDGE. Here's an excerpt:

The light show we observe near the surface, at least as we understand it, is produced largely by the dinoflagellates—those unicellular plants possessing microscopic whiplike tails that enable them to move, however slightly, this way and that. Large creatures such as you or me or a spinner dolphin will activate billions of these bioluminescent plants as we move through the surface layer of the nighttime waters. Even small zooplankton, for instance, the predatory krill traveling on their swimmerets, will find themselves spotlighted.

As to why plants in the sea produce bioluminescence, a hypothesis known as the burglar alarm theory postulates that the chemical production of light acts as a visual siren: the plants turn on their lights when their predators (for example, krill) are in motion, illuminating them so that their predators (for example, lanternfish) can catch the krill and eat them first.

Tricksy.

You can read a classic science paper on the phenomenon: 
Mark V. Abrahams and Linda D. Townsend. Bioluminescence in Dinoflagellates: A Test of the Burglar Alarm Hypothesis (pdf). Ecology, Vol. 74, No. 1 (Jan., 1993), pp. 258-260

Photo from here.

More about bioluminescence from THE FRAGILE EDGE, an excerpt about sailing the Pacific one stormy winter:

In the trough between the swells, an incandescent waterfall of radiance tumbled from the wave breaking directly ahead. Time and again, we sailed into this cascade, which outlined the bow of the sailboat in a vibrating aura of electric blue and electric green. Behind us, our wake writhed like an aquamarine serpent before fading from view over the precipice of the receding wave.

Most nights schools of dolphins—generally common dolphins (Delphinus delphis)—arrived seemingly out of nowhere to ride our bow-wave. Alone on watch in the open-air cockpit, I would glimpse a streak of blueish-green heading towards the bow, looking for all the world like a torpedo until it porpoised through the surface to breathe. The first streak was invariably followed by others, sometimes dozens, all racing across the beam, carving glowing turns before settling into bow-riding position: on their sides, tail flukes nearly touching the bow as it hobby-horsed through the swells. No matter how violent the action of the bow, the dolphins held fast in their position, their bodies outlined in the pulsing blue light of an underwater St. Elmo’s fire. 

Common dolphins were not the only cetaceans we encountered in the course of these bioluminescent nights. We also came upon migrating gray whales headed for their breeding lagoons on the western coast of the Baja Peninsula. Their bioluminescent wakes mimicked the wakes of boats. If conditions were right, when the whales blew, the plugs of water covering their blowholes flared into faint, blue-green mists of luminous organisms, as if the behemoths were exhaling pixie dust.

Photo by Jed Sundwall, courtesy Wikimedia Commons.

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SWARMING, SCHOOLING, FLOCKING, CROWDING

Swarm Mentality is an excellent short film from Scienceline parsing the collective decisions made as the sum of individual choices, which manifest in behaviors we call swarming, schooling, and flocking.

I wrote about schooling and flocking in some detail in my book The Fragile Edge. Here's an except:  

Meanwhile, out on the lagoon, a juvenile bigeye trevally caught by a black noddy falls back to the surface to be reingested by the ocean. Sometimes, with a big enough flock of noddies and an armada of aggressive frigatebirds, the little fish fall like rain, their reentry points marking the surface with the bulls-eye targets of ripples. If you happen to be snorkeling or diving in the vicinity of a feeding frenzy while this is going on, you can see the little fish streaking like lightening bolts for the company of the school. With a homing sense as true as any bird’s, they dash towards their beleaguered fellows, gathering until they form a subschool of survivors. If the subschool grows large enough, it may temporarily abandon the mother school, particularly if the battle is not going well for the latter. 

Watching, you think it must be hopeless: that every last living creature in the sea or in the air above desires these little fish as bright as newly-minted silver coins. Tossed cruelly into the hordes of the greedy, hounded day and night, they live lives of unending terror under conditions of perpetual warfare. Yet they survive, many of them, somehow.

Photo of a school of goldband fusiliers, Pterocaesio chrysozona, by Mila Zinkova, courtesy of Wikimedia Commons.

Back to the excerpt:

A school of predatory jacks, which the Tahitians calls paaihere, are dogging their heels from below. The noddies are skipping across their spines from above. The frigatebirds lurk in the shadows of clouds. Bunching together, the juvenile trevallies spill and pool and reunite like loose mercury. When the paaihere launch an attack, the little fish perform a defensive maneuver known as the fountain effect: the school instantaneously splitting into two, each subschool reversing direction and circling behind their attackers on opposite sides. This behavior awards the trevallies a running headstart from their enemies.

Capitalizing on the momentary advantage, the little fish dive, trying to escape the reach of the birds above. But the paaihere are relentless hunters with big appetites and phenomenal accelerating abilities. They wheel around and come at the trevallies from below, herding them towards the sunlight, where the reflections of their newly-minted bodies sparkle in the irises of the dancing noddies.

Trapped, the little fish unloose another defensive stratagem known as the flash expansion. Without warning or any apparent means of coordination, the school explodes, and members scatter shrapnellike out from an imaginary center. The whole reaction takes place in as little as twenty milliseconds, as each fish accelerates to speeds of twenty bodylengths per second. Amazingly, the trajectory of each trevally carries it away from the center and away from its neighbors, and is accomplished without any collisions—which would surely prove fatal under the circumstances. More astounding is the fact that the entirety of the flash expansion occurs at speeds faster than the rate of nerve impulses travelling from the little fishes’ eyes to their brains and back to their muscles. In other words, this defensive play has nothing to do with sight, and the little fish are as good as blind throughout it.

Here's a video showing flash expansion in whirligig beetles.

Again, more of the excerpt:

Curiously, computerized fish programmed to behave like a school of a fish cannot perform as well as the real thing unless they are subject to a field, which is itself influenced by all the individuals in the school, and which in turn links them together. For living fish, sight alone is not enough to maintain tight schooling. Neither are the lateral line systems that enable them to sense minute pressure changes in the water. Real fish that have been temporarily blinded with opaque contact lenses and others have had the nerves to their lateral lines cut still manage to school effortlessly.

—from The Fragile Edge: Diving & Other Adventures in the 
South Pacific, Chapter 12, The Infinity Pool

 

Photo of schooling bannerfish by Jon Hanson, courtesy of Wikimedia Commons.

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OUTTAKES: CANNIBALS

This outtake is actually from my earlier book, THE FRAGILE EDGE. A scene with the crown jellyfish made it into the final cut. The shipwreck musings did not.

"As always when underemployed at sea, I imagine which of my boat mates would make the best eating if we suddenly found ourselves adrift and starving, only to conclude the crown jellies would be tastier than any of us. As succulent as cactus. Though light on nutrition."

The fantastical painting above is by Julie Speed, whose work I discovered serendipitously online. I'm now a devoted fan. She's also got a delightfully subversive show opening April 1st at the Gerald Peters Gallery, 24 E 78th St, New York, NY, that's up for a month. Check it out.

 

The moon jellyfish below (relatives of crown jellies) are from here.

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