September 17, 2013
“Call me Migaloo,” would start the memoir of the most famous white humpback whale out there. He’s not quite from the pages of Moby Dick—Herman Melville’s white whale was a sperm whale and not entirely white—but Migaloo still makes quite a splash when he lifts his head or tail above the waves.
First spotted in 1991, he’s been seen more than 50 times since, including a few times around the Great Barrier Reef this summer. But the probable-but-unconfirmed spotting by Jenny Dean, a Queensland, Australia native, takes the cake. A few weeks ago, she captured Migaloo breaching in a spectacular photo, showcasing the whale’s bright whiteness that nearly looks photoshopped.
But what’s the deal with Migaloo and white whales? Let us ocean enthusiasts from the Smithsonian Ocean Portal answer your questions.
What do we know about Migaloo?
In the past 22 years since whale watchers first spotted the exceedingly social Migaloo—so-called after the Aboriginal word for “white fella”—scientists have been able to learn a bit about him. They think he was around 3-5 years old when first spotted, which makes him 25-27 now. Barring an unfortunate accident, he may have another 50 years ahead of him, although scientists don’t know for sure how long humpback whales live because they don’t have teeth—like tree rings, analyzing concentric layers in teeth is a common way to measure age in mammals.
They know he’s a male from his song. While both male and female humpback whales produce sound, only males sing the melodic humpback songs that long ago captured our imaginations. In 1998, researchers first recorded Migaloo singing—and his knack for melody gave it away.
His maleness was further confirmed by DNA after researchers from Lismore, Australia’s Southern Cross University, collected skin samples from Migaloo in 2004.
Are white humpbacks rare?
As far as we know, exceedingly so. Besides Migaloo, there are three other known white humpbacks. Willow lives up in the Arctic and was spotted along the coast of Norway in 2012. Meanwhile, Bahloo lurks in Migaloo’s territory in the Great Barrier reef, first seen in 2008. But these two are not as gregarious as Migaloo, rarely showing their faces.
The other known white humpback is a calf first seen swimming around the Great Barrier Reef in 2011. Unofficially named “Migaloo, Jr.,” the calf is not known to be the child of Migaloo—in fact, the two whales may not even be related. If a DNA sample from the calf is obtained someday, they could compare it with Migaloo’s genetic profile to find out.
There probably are more white whales out there, however. These are just the ones that have surfaced near people with cameras. Two years ago, an unknown white whale washed up on a beach, and if you dig around on the web, you can find even more.
How do we know these aren’t the same white whale?
In the case of Migaloo, Jr., it’s pretty obvious: he’s much smaller than the Migaloo Australians are so familiar with.
Bahloo and Migaloo hang out in the same area and, because Bahloo rarely shows its face, you could argue that the two are actually the same whale. But photos taken in 2010 showed a few black spots on Bahloo’s head and tail, differentiating it from Migaloo. Willow also has black patterns on the underside of its tail, making Migaloo the only documented all-white whale. These patterns and markings are distinct for each whale, white or otherwise, allowing researchers to track the creatures through detailed observations.
Why is he white anyway?
Many articles describe Migaloo and the other white whales as albino. But making that diagnosis is easier said than done.
Albinism is a genetic disorder in which the protein tyrosinase, which helps to produce the pigment melanin, is completely absent or damaged by a variety of possible mutations. Fully albino animals and people have no melanin whatsoever; they are white or pink from head to toe, including their eyes.
Willow and Bahloo are not albino: they have black spots or patches on their bodies. It’s more likely that they have leucism, a condition where all pigment types are lost in patches of cells.
Even though Migaloo is all white, scientists are skeptical that he is albino because he doesn’t have red or pink eyes—like other humpbacks, he has brown eyes. Instead, he’s considered the more conservative “hypo-pigmented,” describing a generic loss of skin color. It’s also possible that Migaloo is leucistic.
The Southern Cross University researchers could analyze his DNA for different genetic variants associated with pigment disorders to pinpoint the exact form. But there are many variants and, as Megan Anderson, who originally tested Migaloo’s DNA, said in a press release, “It’s going to be a long and complex process to test for albinism in this humpback whale as it has not ever been done before.”
And what about the calf? There isn’t enough known about it to be sure.
Are there other white whales that aren’t humpbacks?
Yes! These skin disorders are not exclusive to humpbacks. There have been several other wild spottings of white whales recently.
A white right whale calf (incorrectly described as albino) was filmed last year off the coast of Chile by a group of surfers. Last April, researchers spotted a white killer whale off the coast of Alaska, and they named it “Iceberg.” And a truly albino pink dolphin has been seen around Florida and the Gulf of Mexico repeatedly over the years.
In fact, whales aren’t the only creatures that can lack pigment. A plethora of other all-white examples—such as koalas, penguins, and gorillas—can be found throughout the animal kingdom.
August 30, 2013
You’re at the beach for a weekend with family or friends. Splashing and jumping, dunking your head beneath the waves, you start to cool off. Then you feel something soft brush against your leg—and suddenly, the coolness is replaced by a hot, shooting pain. You’ve been stung by a jellyfish. But what do you do now?
First let’s take a look at exactly what’s happening to your leg. Jellyfish have special cells along their tentacles called cnidocytes. Within these cells are harpoon-like structures full of venom, called nematocysts. The nematocysts shoot out when triggered by touch and can penetrate human skin in less time than it takes you to blink.
Once the venom is injected into your skin, the pain, redness and blistering begin. One of the main causes of this discomfort is a type of protein called a porin found in the venom of all jellyfish—and in all their relatives, including corals and anemones, which together form a group of creatures collectively known as cnidarians. Angel Yanagihara, a research professor studying box jellyfish venom at the Pacific Biosciences Research Center at the University of Hawaii, explains that the porins in box jellyfish are fast-acting and “promiscuous:” they are indiscriminate and “will punch holes in all types of cells” including blood, skin and nerve cells. The complex concoction of these proteins varies (along with the stinging cell mechanism) from species to species, which is why we might only feel a small sticky sensation when we come in contact with some anemones, while a box jelly sting may cause a trip to the emergency room or even kill you.
So after you’re stung, you should pee on it, right? Or get someone else to? That’s what you’ve seen on TV—maybe you’re thinking of a certain incident from Friends. But don’t pull those board shorts off too quickly—urine can do a lot of things, but it doesn’t help the sting. It may actually make it worse.
That’s because pouring freshwater—or urine—on the area will change the composition of the solution surrounding the remaining cells and may actually trigger the release of more nematocysts and venom. Instead, experts suggest rinsing the area with saltwater to help reduce discomfort. Before you do any rinsing, however, remove any jellyfish tentacles that remain on the skin, as nematocysts on loose tentacles can continue to sting even after they are detached from the jelly. Making sure that sand stays clear of the wound is also an important task, but likely a difficult one while on the beach. In the case of a box jelly sting, it would be helpful to have Yanagihara nearby with the two treatments she has developed—or even better would be to make use of her preventive ointment before going in the water. Because these aren’t yet available to the public, putting vinegar on the affected area and seeking medical attention are the suggested treatments.
It’s good to have this information in-hand when you go to the beach just in case—though it’s unlikely that you’ll be stung. But that possibility could be on the rise if, as has been suggested, jellyfish numbers are increasing. A study from April 2012 in Hydrobiologia found increasing jellyfish populations in 62 percent of the regions analyzed, including coastal areas of Asia, the Black Sea and the Mediterranean Sea. “Our study confirms these observations scientifically after analysis of available information from 1950 to the present for more than 138 different jellyfish populations around the world,” said Lucas
Brotze Brotz, the lead author of the study in a press release.
However, jellyfish are a difficult species to study: their life cycles aren’t well understood, and catching them by net is not a good option due to their fragile, gelatinous bodies. Because of this, sweeping claims about global changes in jellyfish populations are up for debate. Their historical numbers are largely unknown, making it hard to be sure whether jellyfish populations are increasing over the long term, or whether the increases we see are a part of natural population fluctuations or an artifact of more people reporting sightings. And there is evidence for these caveats: a different 2012 study found that the perceived rise in the number of jellyfish is actually the peak of a normal 20-year boom and bust cycle.
But if jellyfish are increasing globally, it is likely that human influences are the cause. Overfishing has reduced some jellies’ competition for food; increased nutrients running into the ocean create oxygen-depleted environments that jellies can tolerate better than other animals; and warmer water can help some species of jellyfish larvae to grow more quickly. Even jellies without a nasty sting can cause problems, clogging up pipes in nuclear power plants that use seawater to cool their reactors and pushing fish out of the ecosystem.
There still is much to learn about the fascinating and pulsing lives of jellyfish that can help to determine if their populations are increasing long-term. Scientists are making use of observant beachgoers, with websites where you can input your jelly sightings onto a map to generate global data on jelly populations. So if you do have the bad luck to get stung by a jellyfish, remember: wash it with salt water, not pee, and maybe pop your location into the map to help us all learn something from the experience.
Learn more about the ocean from the Smithsonian’s Ocean Portal.
June 7, 2013
Ocean plants produce some 50% of the planet’s oxygen. Seawater absorbs a quarter of the carbon dioxide we pump into the atmosphere. Ocean currents distribute heat around the globe, regulating weather patterns and climate. And, for those who take pleasure in life’s simple rewards, a seaweed extract keeps your peanut butter and ice cream at the right consistency!
Nonetheless, those of us who can’t see the ocean from our window still feel a disconnect—because the ocean feels far away, it’s easy to forget the critical role the ocean plays in human life and to think that problems concerning the ocean will only harm those people that fish or make their living directly from the sea. But this isn’t true: the sea is far more important than that.
Every year, scientists learn more about the top threats to the ocean and what we can do to counter them. So for tomorrow’s World Oceans Day, here’s a run-down of what we’ve learned just in the past 12 months.
This year, we got the news that the apparent “slow down” in global warming may just be the ocean shouldering the load by absorbing more heat than usual. But this is no cause to celebrate: the extra heat may be out of sight, but it shouldn’t be out of mind. Ocean surface temperatures have been rising incrementally since the early 20th century, and the past three decades have been warmer than we’ve ever observed before. In fact, waters off the U.S. East Coast were hotter in 2012 than the past 150 years. This increase is already affecting wildlife. For example, fish are shifting their ranges globally to stay in the cooler water they prefer, altering ecosystems and fisheries’ harvests.
Coral reefs are highly susceptible to warming: warm water (and other environmental changes) drives away the symbiotic algae that live inside coral animals and provide them food. This process, called bleaching, can kill corals outright by causing them to starve to death, or make it more likely that they will succumb to disease. A study out this year found that even if we reduce our emissions and stop warming the planet beyond 2°C, the number considered to be safe for most ecosystems, around 70% of corals will degrade and die by 2030.
Although coral reefs can be quite resilient and can survive unimaginable disturbances, we need to get moving on reducing carbon dioxide emissions and creating protected areas where other stressors such as environmental pollutants are reduced.
More than a hit of acid
The ocean doesn’t just absorb heat from the atmosphere: it also absorbs carbon dioxide directly, which breaks down into carbonic acid and makes seawater more acidic. Since preindustrial times, the ocean has become 30% more acidic and scientists are just starting to unravel the diverse responses ecosystems and organisms have to acidification.
And it really is a variety: some organisms (the “winners”) may not be harmed by acidification at all. Sea urchin larvae, for instance, develop just fine, despite having calcium carbonate skeletons that are susceptible to dissolving. Sponges that drill into shells and corals show an ability to drill faster in acidic seawater, but to the detriment of the organisms they’re boring into.
Nonetheless, there will be plenty of losers. This year saw the first physical evidence of acidification in the wild: the shells of swimming snails called pteropods showed signs of dissolution in Antarctica. Researchers previously found that oyster larvae fail under acidic conditions, potentially explaining recent oyster hatchery collapses and smaller oysters. Acidification may also harm other fisheries.
Plastic, plastic, everywhere
Americans produced 31 million tons of plastic trash in 2010, and only eight percent of that was recycled. Where does the remaining plastic go? A lot of it ends up in the ocean.
Since last World Oceans Day, trash has reached the deep-sea and the remote Southern Ocean, two of the most pristine areas on Earth. Most of the plastic trash in the ocean is small—a few centimeters or less—and can easily be consumed by animals, with damaging consequences. Some animals get hit on two fronts: when already dangerous plastic degrades in their stomachs it leaches toxic chemicals into their systems. Laysan albatross chicks are fed the bits of plastic by their parents in lieu of their typical diet and one-third of fish in the English Channel have nibbled on plastic.
Where have all the fish gone?
A perennial problem for the ocean, overfishing has only gotten worse with the advent of highly advanced gear. Despite fishing fleets going farther and deeper, the fishing gains are not keeping up with the increased effort.
Our brains can’t keep up either: even as we catch fewer fish, we acclimate to the new normal, adjust to the shifting baseline, and forget the boon that used to be, despite the fact that our memories are long enough to realize that most of the world’s fisheries (especially the small ones that aren’t regulated) are in decline.
Thankfully, those responsible for managing our fisheries are aware of what’s at stake. New knowledge about fish populations and their role in ecosystems can lead to recovery. A report from March 2013 shows that two-thirds of U.S. fish species that are closely managed due to their earlier declines are now considered rebuilt, or on their way.
Learn more about the ocean from the Smithsonian’s Ocean Portal. This post was co-authored by Emily Frost and Hannah Waters.
February 8, 2013
Invertebrates close-up never fail to please: with their bright colors and strange structures, they begin to take on patterns that are more art than animal.
So is true of this series of close-up photographs of starfish taken by researcher and photographer Alexander Semenov. But it isn’t enough to call them art: why are all those finger-like appendages waving around? And what are those bulbous spikes (or floral bouquets, if you’re feeling romantic)?
Lucky for us, two floors up from the Ocean Portal office sits Dr. Chris Mah, an expert on echinoderms (a group of ocean animals that includes starfish, sea urchins and brittle stars) at the Smithsonian National Museum of Natural History. He helped us to fill in some of the details.
The Worm-Like Soft Bits: The vast garden of waving worms isn’t a starfish experiment in cultivation, but how they breathe on the seafloor. Sea stars breathe passively, letting oxygen-rich seawater flow over those finger-like sacs, called papulae, which peek through the cracks in their protective plates. Like fish gills, papulae absorb the oxygen in seawater.
Such fleshy little fingers would make an excellent snack for a passing shrimp or another small predator. To defend themselves, starfish can retract their papulae to make them less obvious targets, as this Mithrodia clavigera, pictured below, has done.
The Bald, Grooved Patches: Starfish are powered by plumbing: a series of pipes carry food and oxygen through their bodies. Water pressure builds up in these pipes, which helps to support their bodies. It was long-thought that this water pressure also created suction, allowing starfish’s hundreds of tiny tube feet to attach to surfaces and slowly creep across the seafloor. But recent research has suggested that tube feet are more like sticky pads than suction cups.
How does water get in and out of this plumbing system? It goes through the sieve plate (also called a madreporite), a small bald patch on the starfish that, close up, looks like a tiny, grooved maze. While it’s not the only way that water can enter the plumbing, it’s a major intake valve for starfish.
Most starfish only have one sieve plate, but larger ones with many arms can have far more. For example, the coral-devouring crown of thorns starfish can have up to 15 to power its many arms. And starfish that reproduce asexually by splitting their bodies in half sometimes end up with more than one.
The Spiked Clubs: Humans aren’t the only species that came up with the mace as weaponry. Instead of being offensive tools, starfish spines (as they’re known) protect them from the smothering force of mud and debris. It’s likely that they also protect against predators, but a starfish’s first line of defense is stinky and poisonous chemicals.
Not all starfish spines are spiky. These purple spines of Evasterias retifera (below) in a field of orange papulae are low and stubby with lovely white notches. Other species have more architectural spines shaped like pyramids or tall spires.
The Tiny, Bitey Mouths: A slow-moving lifestyle puts starfish in danger of becoming overgrown with algae or other encrusting organisms. As a defense, many starfish are speckled with small, extendable “claws” called pedicellariae, which you can see in the photo below. In some species, the pedicellariae surround the spines and, if the starfish is threatened, will extend out to the spine’s full height! In other species, they are flat and spread out over the starfish’s skin. “They can look like a pair of lips or small jaws,” said Mah. “They probably look like monsters if you’re small enough to appreciate them.”
January 10, 2013
Whenever anyone talks about ocean acidification, they discuss vanishing corals and other shelled organisms. But these aren’t the only organisms affected—the organisms that interact with these vulnerable species will also change along with them.
These changes won’t necessarily be for the good of the shell and skeleton builders. New research published in Marine Biology shows that boring sponges eroded scallop shells twice as fast under the more acidic conditions projected for the year 2100. This makes bad news for the scallops even worse: not only will they have to cope with weakened shells from acidification alone, but their shells will crumble even more quickly after their cohabiters move in.
Boring sponges aren’t named thus because they’re mundane; rather, they make their homes by boring holes into the calcium carbonate shells and skeletons of animals like scallops, oysters and corals. Using chemicals, they etch into the shell and then mechanically wash away the tiny shell chips, slowly spreading holes within the skeleton or shell and sometimes across its surface. Eventually, these holes and tunnels can kill their host, but the sponge will continue to live there until the entire shell has eroded away.
Alan Duckworth of the Australian Institute of Marine Science and Bradley Peterson of Stony Brook University in New York brought boring sponges (Cliona celata) and scallops (Argopecten irradians) into the lab to examine the effects of temperature and acidity (measured through pH) on drilling behavior. They set up a series of saltwater tanks to compare how much damage sponges did to scallops under current temperature and ocean conditions (26°C and pH 8.1), projected conditions for 2100 (31°C and pH 7.8), and each 2100 treatment alone (31°C or pH 7.8).
Under higher acidity (lower pH), boring sponges drilled into scallop shells twice as fast, boring twice as many holes and removing twice as much shell over the course of the 133-day study. The lower pH alone weakened the shells, but after the boring sponges did their work, the scallop shells were an additional 28% weaker, making them more vulnerable to predation and collapse from the sponges’ structural damage.
The sponges weren’t entirely thrilled by the water’s higher acidity, which killed 20% of the them (although the researchers aren’t sure why). Despite this loss, 80% of the sponges doing twice as much drilling meant more damage to shelled organisms in total. Temperature did not affect sponge behavior at all.
This study illustrates a classic positive feedback loop, where weakness in the shells leads to more weakness. And not through the sponge-drilled holes alone: the addition of sponge-drilled holes creates more surface area for acidification to further erode the shells, hastening each scallop’s inevitable collapse. It’s tempting to speculate out to the rest of the system—that the sponges are destroying their own habitat more quickly than scallops can produce it—but we don’t really know whether in the long run this is also bad news for the sponges.
Though a small and specific example, this study illustrates how a seemingly small change—more acid and weaker shells—can ripple out and affect other organisms and the rest of the ecosystem.