Jellyfish Scourge: For Whom The Bells Toll

In the Sherlock Holmes tale "The Adventure of the Lion's Mane," Sir Arthur Conan Doyle left no doubt as to the pernicious nature of the jellyfish (although the clever title would mislead anyone unfamiliar with them).

Aside from the Lion's Mane Jellyfish (Cyanea capillata), other non-human culprits unmasked by the world's best-known sleuth include a "swamp adder" and, of course, a big dog. But Doyle attributed signally excruciating potency to the giant cnidarian (whose nematocyst-laced tentacles can outstretch a Blue Whale):

As he fell over, his Burberry, which had been simply thrown round his shoulders, slipped off, exposing his trunk. We stared at it in amazement. His back was covered with dark red lines as though he had been terribly flogged by a thin wire scourge. The instrument with which this punishment had been inflicted was clearly flexible, for the long, angry weals curved round his shoulders and ribs. There was blood dripping down his chin, for he had bitten through his lower lip in the paroxysm of his agony. His drawn and distorted face told how terrible that agony had been.

That was 1907, with Sir Arthur's bell-topped killer vaguely foreshadowing the kind of panic that Peter Benchley and Steven Spielberg's classic "Jaws" would spawn more than a half-century later.

Don't look now; but the narrative of the ravenous beasts is back. Unpopular anyways outside of Asian salads, the deceptively beautiful medusa is experiencing a return to scurrilousness.

It's more serious than just that rampaging zombie jellyfish that stung 100 or so New Hampshire bathers in late July. (Even in death, they're locked and loaded, as Kevin Zelnio at Deep-Sea News explains in connection with that incident.)

So Smithsonian.com has revisited the question of a jellyfish scourge. In addition to offering an engaging boilerplate description of the animals that alone makes the piece worth reading, Abigail Tucker explores how many ill-tempered jellyfish is too many jellyfish:

All around the world, jellyfish are behaving badly—reproducing in astonishing numbers and congregating where they’ve supposedly never been seen before. Jellyfish have halted seafloor diamond mining off the coast of Namibia by gumming up sediment-removal systems. Jellies scarf so much food in the Caspian Sea they’re contributing to the commercial extinction of beluga sturgeon—the source of fine caviar. In 2007, mauve stinger jellyfish stung and asphyxiated more than 100,000 farmed salmon off the coast of Ireland as aquaculturists on a boat watched in horror. The jelly swarm reportedly was 35 feet deep and covered ten square miles.

Nightmarish accounts of “Jellyfish Gone Wild,” as a 2008 National Science Foundation report called the phenomenon, stretch from the fjords of Norway to the resorts of Thailand. By clogging cooling equipment, jellies have shut down nuclear power plants in several countries; they partially disabled the aircraft carrier USS Ronald Reagan four years ago. In 2005, jellies struck the Philippines again, this time incapacitating 127 police officers who had waded chest-deep in seawater during a counterterrorism exercise, apparently oblivious to the more imminent threat. (Dozens were hospitalized.) This past fall, a ten-ton fishing trawler off the coast of Japan capsized and sank while hauling in a netful of 450-pound Nomura’s jellies.

So there's a lot of anecdotal and circumstantial evidence of mounting jelly hell. But disabling and overturning ships? Not even Spielberg depicted his Great White Antihero crippling an aircraft carrier. (That wouldn't come until "Jaws 2.")

But before you go get a bigger boat, Mr. Mundus, it's important to read on. Tucker is quick to quote experts who say the jury is still out on this possible pestilence and its likely causes, which predictably include human encroachment on their habitat and devastation of the jellyfish's natural enemies (like swordfish, anchovies, bearded gobies, and some sea turtles).

Steven Haddock, a zooplankton scientist at the Monterey Bay Aquarium Research Institute (MBARI), is concerned that researchers and the news media may be overreacting to a few isolated jelly outbreaks. Not enough is known about historical jelly abundances to distinguish between natural fluctuation and long-term change, he says. Are there really more of the creatures, or are people simply more prone to notice and report them? Are the jellyfish changing, or is our perspective? A self-described “jelly hugger,” Haddock worries that jellyfish are taking the blame for messing up the seas when we’re the ones causing the damage. “I just wish that people had the perception that jellyfish are not the enemy here,” Haddock says.

Purcell, who sports jellyfish earrings the day I meet her in Monterey, says she is disgusted by what she sees as humanity’s efforts to exploit the ocean, filling it with fish farms and oil wells and fertilizer. Compared with fish, jellies are “better feeders, better growers, more tolerant of all kinds of things,” she told me, adding of the marine environment: “I think it’s entirely possible we’ve made things better for jellyfish.” Part of her likes the idea of unruly jellies causing a commotion and foiling our plans. She’s cheering for them, almost.

So it's not a direct link, but generally, it looks like the worse damage we inflict on our seas, the more we can expect jellyfish to come back and sting us. A GlobalPost headlined "The New Ocean Predator: Jellyfish?" articulated the problem this way:

Unlike sharks, orcas and other aggressive carnivores, jellyfish thrive in ecosystems damaged by human activity. From the Gulf of Mexico to the Sea of Japan, oceanographers have found a common symptom among places where overfishing, chemical pollution and rising sea temperatures have killed off other species: more jellyfish.

Jellyfish are hardy indeed. Their fossil remains date back some 500-700 million years. As polyps, they can "sit dormant for a decade or more, biding (their) time," Tucker tells us. Their sting, at 1 microsecond to hit its target, is one of the fastest animal actions in the world. When turtles or other predators chomp off hunks of jellyfish, the animals simply regenerate. The arctic Lion's Mane "continues to pulsate when half its bell is imprisoned in ice, and may revive even after being solidly frozen for hours," Rachel Carson tells us. And on and on.

While technically speaking they're sophonophores rather than "true jellies," the Portuguese Man-of-War (Physalia physalis) is a jellyfish in most people's minds. And Carson suggested after one encounter that it demonstrated a "strong illusion of sentience":

The sail, or float, of a Portuguese man-of-war is filled with gas secreted by the so-called gas gland. The gas is largely nitrogen (85 to 91 per cent) with a small amount of oxygen and a trace of argon. Although some siphonophores can deflate the air sac and sink into deep water if the surface is rough, Physalia apparently cannot. However, it does have some control over the position and degree of expansion of the sac. I once had a graphic demonstration of this when I found a medium-size man-of-war stranded on a South Carolina beach. After keeping it overnight in a bucket of salt water, I attempted to return it to the sea. The tide was ebbing; I waded out into the chilly March water, keeping the Physalia in its bucket out of respect for its stinging abilities, then hurled it as far into the sea as I could. Over and over, the incoming waves caught it and returned it to the shallows. Sometimes with my help, sometimes without, it would manage to take off again, visibly adjusting the shape and position of the sail as it scudded along before the wind, which was blowing out of the south, straight up the beach. Sometimes it could successfully ride over an incoming wave; sometimes it would be caught and hustled and bumped along through thinning waters. But whether in difficulty or enjoying momentary success, there was nothing passive in the attitude of the creature. There was, instead, a strong illusion of sentience. This was no helpless bit of flotsam, but a living creature exerting every means at its disposal to control its fate. When I last saw it, a small blue sail far up the beach, it was pointed out to sea, waiting for the moment it could take off again. (p. 150 "The Edge of the Sea")

Now, she's not claiming that Portuguese Man-of-Wars would recognize themselves in a mirror or blush at buying their clothes off the rack. However, it's not an inconceivable leap from setting a course in the wind to stinging a bather just to watch him die.

Maybe Sherlock Holmes was onto something. A jellyfish strikes again in that story, after all. But no one's saying it's the same Lion's Mane, right? Right!?

Dem Bones, Dem Bones, Dem Jawbones

A new study points to an adaptation that allows rorquals, the pleat-throated whales, to engorge huge amounts of food-filled sea water without snapping off their lower jaws.

When Blue Whales (Balaenoptera musculus) open their mouths to filter-feed, one keen whale observer and author noted in her recent book, it is "the biggest biomechanical event to happen on the planet." And quote possibly the biggest ever to have happened.

The subject of the study cited by Live Science was Humpback Whales (Megaptera novaeangliae), lunge-feed thousands of times a year if they're lucky.

The research involved a type of X-ray technology called quantitative computed tomography, or QCT. Writes Live Science's Clara Moskowitz:

The scientists discovered that humpback whale mandibles are shaped in a unique way, different from the mandibles of humans and right whales -- the only other species for which QCT data is available.

In particular, the scientists measured a feature called flexural rigidity -- a combination of high bone density and large cross-sectional area that allows a bone to resist bending. The researchers found that humpback whales' jaws are formed with a unique pattern of flexural rigidity -- highest at the edges attached to the skull, and lowest at the center -- that is optimized to resist the strain from lunge feeding.

It's like a high-performance tennis racquet, in a way. With a sweet spot for krill.

Don't It Make My Brown Sea Blue?

BP had already demonstrated that it's spectacularly incompetent and irresponsible. Now "Wired Science" shows its latest foray into cartoon-villain territory.

Video: A Killer Whale's Best Friend

This blew my mind. It's not new, but it's new to me. Friends? Or was that Killer Whale just thinking this was the loudest, ugliest seal he'd ever hunted? (Hat tip: SharkDivers)

Video: Shark Eats Seal Off Catalina

And unfortunately the world's worst videographers just happen to be there to witness it. But it's morbidly compelling viewing, in part because of the languidly methodical movements of the shark. And heartbreaking at the 15 second mark, when the wounded and doomed seal peers up at the onlookers.

The boat's passengers say it looks like a Mako Shark, and that looks about right. I think both Makos and Great Whites attack hard and then wait for their prey to bleed sufficiently to make them easy pickings. There are other videos from other passengers aboard the same boat here and here. (It was a whole boatload of fisherdudes, after all.)

Calling them shark "attacks" reminds me of the story, by Jacques Cousteau co-writer Susan Schiefelbein in "The Human, the Orchid, and the Octopus," of him asking her whether she'd describe herself as "attacking" an egg on her plate. They're just eating, he noted.

If you decide to watch, note that another seal darts by at one point, seemingly putting itself in some danger and contrary to the flight instinct that one might expect, even if it's a mate getting devoured. One of the boat passengers wonders aloud, "What's that other seal doing there?"

CAUTION: Graphic scenes.

If you're into the grisly, here's how BBC recorded a Great White attack on a seal.

And if it makes you feel any better, here's one where a Great White Shark is out-apexed atop the food chain:

Glorious Deepwater Squid Vid

Some gorgeous high-definition glimpses of deepwater squid from Monterey Bay Aquarium Research Institute. (If you want to see it with the various species of squid identified beneath the video, go straight to the same video on MBARI's website. Here's the Monterey Bay Aquarium page with quick descriptions of each species.)

You're hardly human if don't emerge with a soft spot in your heart for the Cockatoo Squid.

Paul The Octopus: Out Of The Paella Pan And Into The Fire

Octopus just can't seem to get a break. Even cephalopod successes somehow morph into tragedy.

First there was the wild success of eight-armed prognosticator Paul correctly picking every World Cup football game he tipped. That feat alone should have ensured that Paul could jet off in a cloud of ink to wild cheers.

But soccer is the hooligan sport, after all, so it can't be that simple.

And, sure enough, fans of losing soccer clubs like Argentina and Germany were soon calling for the head on a platter of Oberhausen Aquarium Sea Life Center's most storied resident.

Now an "axis of edible" has heaped saltwater on the octopus's wounds. RIA Novosti says Paul's "brethren" (presumably octopus or its ancestral kin and fellow cephalopod, squid) was served to German Chancellor Angela Merkel and President Dmitry Medvedev over talk of World Cup action at dinner this week.

The choice must have gone over well with Merkel, whose countrymen's appetites were whetted when Paul correctly picked Spain to beat Germany in the semifinals.

But the Russians had better change the menu when Spanish Prime Minister Jose Luis Rodriguez Zapatero comes calling.

Paul is understandably treated with greater respect by victorious Spain, where the township of Carballino even tried to rent him to be the guest of honor at their annual party.

Even that invitation is hardly what it seems, however. Carballino is renowned for its annual Octopus Festival, where Paul's "brethren" are the main course. Polbo a feira, anyone?

Provided it's done sustainably, I have little beef with other folks' eating habits. And I loves me a piece of freshly grilled octopus.

But I've given up eating octopus ever since I started encountering them on dives and regularly being dazzled by their intelligence. I just can't bring myself to eat them anymore.

Diving A 'Sinkhole' In A Mayan Lake

In this National Geographic video, it feels like these divers should be following a white rabbit with a pocketwatch down into this "hole" in a Belize lake.

It takes some fortitude to launch yourself under the bottom like that.

Surprising Life Under Northern Ice

CNN carries a brief video report on underwater photographer Gavin Newman's astonishment at the abundance, appearance and variety of life in the frigid waters of the Arctic.

The "CNN report" looks like a fig leaf for Greenpeace activism, but that's OK by me. (It's a product of Greenpeace's "Arctic Under Pressure" expedition.) After all, polar areas like this risk being devastated by the Klondike mentality as ice recedes at a breakneck pace and mankind races to exploit what's left behind. (Remember when "glacial pace" used to mean slow? No more, as ice caps and glaciers vanish before our eyes.)

CNN:

The receding polar ice is also tempting fishing trawlers into the Arctic's international waters, Greenpeace says.

"There are some Norwegian and Russian trawlers out here. We asked to go on board one of the Norwegian trawlers to talk to them about where they were fishing, but they declined our offer," Newman said.

Greenpeace also claims these fishing trawlers are causing damage to ecosystems on the seabed.

"We've found trawlers are ripping up huge amounts of coral and other important habitat on the seabed. It's like someone's ploughed a field," Newman said.

Greenpeace found the trawl marks on the seabed at varying depths of between 200 and 400 meters.

The environmental group has called for an international moratorium on all industrial activities, including bottom trawling in the Arctic Ocean.

Ode To The Goody Bag

I remember when I got my first goody bag, the soft nylon mesh bag that was all the rage back when I was learning to snorkel and then scuba in the late '70s and early '80s.

I felt like we were unwrapping "Certified Collector" badges when my best friend and fellow underwater enthusiast at the time, Brad K., and I got our hands on ours.

I also recall the temptation that gripped Brad when "slurp gun" ads hit "Skin Diver" magazine, and how badly he wanted to order one of those bazooka-like plexiglass contraptions that suck in unwitting fish.

I was less committal on the Slurp Gun, perhaps because it looked so ungainly. But more likely, it was because it was so highly specialized. It did one thing, and one thing only. The instructions must have read: Find fish. Aim. Click. Slurp. Repeat.

And we could only use so many fish, since we had just one 100-gallon, saltwater aquarium between us (technically speaking, it was Brad's, since his parents had bought it, it was at his house, and he did everything to maintain it). Besides, the greatest prize -- the bright orange damselfish known as the Garibaldi, which was even more arresting as an electric-blue-and-orange juvenile -- was California's state fish and therefore off-limits.

The goody bag presented no such problem. No task was beneath its dignity. Need to cushion your mask en route to a dive spot? Slip it into the goody bag. Don't feel like tucking a pencil and slate with the dive tables on it into the crotch strap of your wetsuit? (And who would?) The goody bag! Happen across a mother lode of abalone? Start prying, because you've got a goody bag.

It could hold stuff. And the very best stuff that it could hold -- in a 12-year-old's estimation -- was the stuff you found during your dive. And therein lay the problem, the feature that put the goody bag on a collision course with All That Is Good In The World. It was on the wrong side of history, if you will. Now more than ever.

To survive at all, goody-bag manufacturers had to adapt. And they did. Now they're specialized. You can get a goody bag that shows how big a crab must be in order to keep it. This one's actually turned utility on its head, serving primarily as a gear bag but "doubling" as a goody bag. Another could safely hold the headless corpse of the Creature from the Black Lagoon in it.

But the reality is that the goody bag's reputation is in shreds until mankind adopts sustainable ways to harvest the ocean's bounty. If it ever does.

With so-called factory ships filled to the gills, countless tons of "bycatch" heaved off decks and into death spirals, bottom trawlers scarring our seabeds, cyanide and dynamite replacing rod and reel, and drift nets killing everything in their paths for hundreds of kilometers, the thrill of a freshly stocked goody bag is gone. In its place, guilt and regret. With humans having taken so much out of the seas already, what self-respecting diver wants to take anything but photographs now?

The crew of the "Calypso" could feast on all the fresh lobster and seafood it could gather, and even harpoon dolphins to film frenzied sharks, it's just less cool these days for undersea documentarists to eat their way through their subjects at the end of the day. It seemed way cool 30 years ago when a camp counselor on Santa Catalina Island poached the occasional abalone; now, no respectable campers should put up with it.

No, the mystique of goody bags has been ghost-netted and left to drown by my generation. Don't get me wrong; I know they still have some important "adult" uses.

But I desperately hope their salad days return for my children and grandchildren. Because I aspired to learn a lot about those shells, plants and, yes, even animals that I proudly towed behind me as I emerged from the Southern California surf. And those kids should get a chance to do the same.

She-Whale Companionship

Since my last post was dedicated exclusively to male genitalia, a link to this item at Carin Bondar's biology blog that sounds straight out of "Sex and the City" is in order.

A New Milton Berle Of The Undersea Kingdom

Blushing scientists say the male deepwater Greater Hooked Squid (variously known as the Moroteuthis ingens or the Onykia ingens because of a taxonomic squabble) has a giant penis that he proudly shows off at even the most awkward of moments. BBC's Earth News crew explains:

The male squid's sexual organ is almost as long as its whole body, including the squid's mantle, head and arms.

Turns out an individual actually got erect and ejaculated after a dissection had begun. So they're kinda twisted, too.

BBC goes on to quote Dr. Alexander Arkhipkin of the Falkland Islands Government Fisheries Department, one of those who made the discovery and reported it in the "Journal of Molluscan Studies" (that's his photo, above, of The Beast unleashed; the penis is at bottom):

"When the mantle of the squid was opened for maturity assessment, we witnessed an unusual event.

"The penis of the squid, which had extended only slightly over the mantle margin, suddenly started to erect, and elongated quickly to 67cm total length, almost the same length as the whole animal."

But there's more to the story than schlong envy. With protective mantles covering much of their bodies, it's been a bit of a mystery how male deepwater squid inseminate females (shallow-water species just, um -- I'll let urbandictionary.com explain). Well, if the Greater Hooked Squid is indicative (no puerile pun intended) of other deepwater species, we have our answer:

That shows how male deep-sea squid inseminate females; they use their huge penis to shoot out packages of sperm, injecting them into the female's body.

The discovery may also help explain how giant squid mate in the ocean depths.

I should add that it might also explain how they attract the ladies at depth in the first place.

Aside from almost inevitably spawning a bustling Chinese trade in squid penises, the discovery earns these prodigiously endowed cephalopods the honor of best-hung moving creatures in the animal kingdom.

"Moving?" you ask. That's right, because, well, have you ever wondered why barnacles just pick any old spot and then stay there for the rest of their lives (like the guys reclining on the banquettes in the back of the dance club)? To be fair, evolutionarily speaking, I guess barnacles' penises were actually lengthening in response to their sessile lifestyles, rather than vice-versa (unlike the guys on the banquettes).

But whichever the case, ugly, shrimp-like recluses that they are, barnacles are the true Milton Berles of the animal world. There's an amusing passage about it in Rebecca Stott's riveting book about Charles Darwin's efforts to cut his scientific teeth through extensive work with barnacles, called "Darwin and the Barnacle" (p. 220):

The minute Arthrobalanus males also had quite the largest genitalia he had ever seen in the barnacle world, he wrote in the manuscript, allowing himself a rarely used exclamation mark:

the probosciformed penis is wonderfully developed, so that in Cryptophialus, when fully extended, it must equal between eight and nine times the entire length of the animal! These males...consist of a mere bag, lined by a few muscles, enclosing an eye, and attached at the lower end by the pupal antennae, it has an orifice at its upper end, and within it there lies coiled up, like a great worm, the probosciformed penis...

Talk about the descent of man.

HAT TIP: Not Exactly Rocket Science

Smell-Shocked

The suspected risks to fish of climbing ocean acidity keep escalating. First, the suggestion was just that anemonefish and others might not get home, although many broader implications of that study (published in the "Proceedings of the National Academy of Sciences") were left for others to pursue. Now, wiredscience points to more dramatic conclusions from a new, related study in the same journal that suggests, only slightly hyperbolically, that the actual effect is tantamount to a death wish:

Researchers discovered the potentially deadly problem through a series of experiments on common reef-dwelling fish that were raised in seawater with acidity levels resembling what’s expected by the century’s middle and end.

“Instead of avoiding the odor of a predator, they’re attracted to it,” said biologist Douglas Chivers of the University of Saskatchewan. “When you take them into the wild, their behavior has changed. We ended up with huge mortality.”

Five to nine times the mortality, actually! Here's the "Proceedings of the National Academy of Sciences" executive-style summary:

As atmospheric carbon dioxide increases, dissolved CO2 in seawater will increase, and lower the surface ocean’s pH. Previous studies have examined how ocean acidification may impact species that depend on seawater pH to create skeletons and shells, but the consequences for noncalcifying species such as fishes are less well understood. Philip Munday et al. examined the effect of acidification on clownfish and damselfish larvae, at values that could occur this century if atmospheric CO2 continues to increase at the current rate above the present-day concentration of nearly 390 ppm. The authors placed larvae in seawater at 700 and 850 ppm, and observed the fishes’ response to the odor of a predator. According to the authors, half of the larvae that initially avoided the odor were less able to detect it after 4 days in seawater at 700 ppm CO2, and at 850 ppm all of the larvae appeared to become attracted to the scent. When transplanted to a natural coral reef habitat, larvae that had been exposed to the elevated CO2 levels spent more time near predators, and had five to nine times the mortality rate of controls. The authors suggest that by the end of the century, ocean acidification could threaten the sustainability of some fish populations.

And here's the money shot from that abstract:

Our results show that additional CO2 absorbed into the ocean will reduce recruitment success and have far-reaching consequences for the sustainability of fish populations.

On a slightly related note, I stumbled across a factoid not long ago that didn't exactly surprise me but rather fazed me because it was one of those things I simply hadn't pondered. It was this: In all mammals, marine and terrestrial, the sense of hearing was evolved in order to hear sounds in an airborne environment. But it's tempting to flip that point on its head for olfactory abilities: Isn't it the case that olfaction was evolved long before our ancestors wriggled out of the water and thus was tailored to sensing water-borne smells? (I'd put a sperm's ability to smell its way to an egg in its liquid environment pretty darned high on my list of Darwinian "do's.")

I don't know the answer, but I resolve to find out more about what adaptations the move to land precipitated (pun intended!).

Of Whale Sharks And Oilmen

Grrlscientist has a worthwhile post at scienceblogs.com on Whale Sharks and how they're faring as BP tries its damnedest to replace the Gulf of Mexico's seawater with crude oil.

In addition to the near-miraculous (100 Whale Sharks feeding en masse in what might be a relatively -- and our standards are pretty low at this point -- untainted area) and the heart-wrenching (three of them swimming right in the thick of the spill), there's this thought-provoking detail from a piece by Ben Raines of the Press-Register:

"Our worst fears are realized. They are not avoiding the spill area," said Eric Hoffmayer, the University of Southern Mississippi scientist who found the large aggregation last week. "Those animals are going to succumb. Taking mouthfuls of oil is not good. It is not the toxicity that will kill them. It's that oil is going to be sticking to their gills and everything else."

Whale sharks, the largest fish on earth, feed by filtering plankton and tiny fish from the water through sieve-like mechanisms in their mouths.

"Based on all the information I'm getting, they are doing the normal things regardless of the oil. The idea that sharks have these evolved senses that will protect them -- well, they haven't evolved to detect oil," Hoffmayer said.

Now, I got inadvertently doused with gasoline pretty good by an attendant at a Stuckey's gas station outside Denver, Colorado once. And given that unpleasant episode, I'd never really contemplated the notion that any creature could be anything but acutely aware of being immersed in something like crude oil or its byproducts. But that could be the case here.

Dog Days Of Summer

If nobody minds, I'll stay away from that Boniface the scuba-diving dog story. I know Russians tend to be thrillseekers underwater. Or attention hounds, I guess.

Tuning In To Whale Sounds

Interesting news from the world of cetacean science, where researchers are homing in on why specific sounds come from specific Sperm Whales (not pictured!), physically and perhaps socially.

Courtesy of Wired Science:

“The whales communicate by patterns of clicks. The clicks reverberate in the head. If you listen to it carefully, there are these pulses. The time between pulses reflects the time it takes for sounds to reverberate, to go from one end of the head and back. Because the heads are all different length, they have different reverberation times,” study co-author Hal Whitehead, also a Dalhousie University biologist. Until now, “just figuring out who makes which sound underwater was tough,” he said.

That's the physiological bit. Now for the behavioral part:

...While the whales tended to possess the same basic repertoire of “codas” — the technical name for each distinctive series of clicks — one female had a completely different set. She happened to be a mother. The distinctive sounds could be what she used to communicate with her calf.

Apart from the mom, the researchers found that half of each individuals’ vocalizations followed one of two patterns.

One pattern is formed by two consecutive, slowly-paced clicks, followed by three faster clicks. It has been found only in the Caribbean. While the pattern varies slightly between groups, this study suggests that it’s consistent within the group. According to Gero, it could function as a family identifier, letting other whales know who is around. “It says, I belong to this family, I belong to this vocal clan,” he said.

The other common pattern is composed of five regularly-spaced clicks, and has been heard in sperm whales all over the world. Preliminary research suggests that the pattern may vary slightly between each individual, said Gero. If so, the pattern could function as an individual identifier — or, from another perspective, a name.

There was another, unrelated great contribution to the topic of cetacean sound recently, when TED invited Woods Hole Oceanographic Institution's Peter Tyack to talk about marine mammal sounds and humans' inability to shut up.

Tyack talks about dolphins imitating trainers' whistles. OK, parrots can mimic sounds, too. But the complexity and functionality of "vocal" art in cetaceans goes so much further. (Here's a great interactive sampler of whale "Voices in the Sea" courtesy of UC San Diego.)

In one example, Tyack points out that Humpback Whale populations each have their own distinct sounds; but songs are regularly transferred, with individuals on the move introducing a song that catches on and displaces the new group's old song. Tyack (see from around the 10-minute mark in the video) uses the example of Australian east-coast whales adopting a west-coast whales' song -- and completely, to an individual, abandoning their old song. (But you might also think of The Beatles' famous propagation of their sound across the Atlantic and beyond, releasing "Sergeant Pepper's Lonely Hearts Club Band" and utterly transforming the musical landscape.)

Something in Tyack's lecture -- maybe it was the implied fragility of cetacean songs and sound -- made me think of a "meeting" I'd read of somewhere. Turns out it was a description by David Powell, the Californian diving pioneer and aquarist extraordinaire, of dives in the Revillagigedos off the southernmost tip of Baja California (probably in the 1970s or 1980s, though chronology is an afterthought in his excellent memoirs "A Fascination for Fish"). He describes a "mysterious moaning sound" during night dives that a Mexican fisherman had once laughingly described as the "cry of the hungry tiger shark."

The morning after one such dive at Isla Socorro, Powell says:

"[W]e looked out from our cove and were astonished to see a humpback whale leap from the water and come crashing back down with a giant splash. All of a sudden the strange sounds made sense: they must have been the song of the male humpback! We were familiar with the recordings Roger Payne made in the late 1960s in the Caribbean, but what we'd heard underwater didn't sound anything like Payne's record. One striking feature that was missing was the echo of the whale song from the bottom of the deep ocean. Since we were in shallow water next to an island, we must have received the sound directly from the whale, without an echo....

We later learned that the Revillagigedo Islands are the winter home for a large number of humpbacks, a little-known fact, mainly because of the islands' remoteness. (pp. 136-137)

Tyack's talking about the potential damage of oceanic noise pollution, for the most part. But it's a fascinating window on the world of marine mammal communication (he deals more with communication than echolocation, which is present among whales only in the so-called toothed whales, as far as scientists can tell).

It also brings to mind a recent claim that Blue Whales are sliding down the musical scale. The jury's still out on whether it's somehow to escape our deafening racket, keep up with the way sound travels in ever-warmer waters, grab attention among growing populations of whales, get the girl, or for an entirely different reason.

There are reasons for optimism on the issue of noise from commercial shipping, although there's also a great counterweight in the form of public indifference and obstacles to international cooperation. Tyack points out (at around 15 minutes) that the UN's International Maritime Organization is tasked with issuing standards for commercial shipping noise levels and, hopefully, "quieting down ships."

Here's some of what the U.S. National Oceanic and Atmospheric Administration has to say about it:

Interference with (or "masking" of) such communications could have significant impacts on marine life. As a result of the potential significance of incidental noise to commercial shipping interests and the marine environment, the International Maritime Organization (IMO) has charged its Marine Environment Protection Committee (MEPC) with investigating and developing papers on these issues. GCIL worked with the National Marine Fisheries Service Offices of Ocean Acoustics Program and Protected Resources, NOAA's Office of International Affairs, as well as other federal agencies in developing the U.S. Noise and Marine Mammals Information Paper (MEPC 57/INF.4). The paper notes the ongoing work of NOAA on this issue and invites participation in NOAA’s ongoing dialogue regarding identification of potential adverse impacts associated with incidental vessel noise and the potential mitigation of those impacts.

Tyack does some of the reasoning for us, and notes that two easy improvements that might even be cost neutral are slightly adjusting shipping lanes and easing up on the throttle. But it's far from a no-brainer.

"They've already found that by being more intelligent about propeller design, you can reduce that (propeller) noise by 90 percent," Tyack says. "If you actually insulate and isolate the machinery of a ship from the hull, you can reduce that noise by 99 percent. So at this point it's primarily an issue of cost and standards."

We humans aren't the greatest of neighbors to begin with; and even if we started implementing dramatic changes, the improvements would come only gradually. But alas, it's hard to imagine this particular topic getting its due at the best of times, much less amid the current (and overdue) hue and cry over global warming.

But the next time one of your dives is spoiled by the liquid-jelly grind of a passing motorboat, put yourself in the flukes of marine mammals trying to doze, woo, croon, mingle, coddle or hunt with the human cacophony blasting away from above.