December 17 – Clam Bake

Today’s factismal: An adult giant clam can get 75% of its food from algae living inside its skin.

One of the staples of Saturday afternoon movies is the deadly giant clam. As our hero swims fearlessly underwater through the coral reef surrounded by colorful fish and fierce pirates, suddenly his foot is caught by a giant clam. He struggles fiercely and is only able to free his foot and head for the surface after stabbing the clam to death with his handy bowie knife. But how realistic is that?

This man-eating clam is waiting for its next victim (My camera)

This man-eating clam is waiting for its next victim
(My camera)

It turns out that there is some truth in that scene, but there’s a lot more fiction. Let’s start with the true part: in coral reefs from the shores of Australia to the Philippines lives a giant bivalve that was once known as the man-eating clam; today, we call it by the less evocative name of giant clam. And the giant clam certainly deserves its name; this enormous bivalve can grow to be more than four feet across and can weigh as much as 700 pounds!

A three-foot long giant clam (My camera)

A three-foot long giant clam
(My camera)

But tales of men being captured and eaten by the clams are far more fiction than fact. The giant clam closes very slowly and would be unlikely to catch any but the least wary swimmer in its grasp. In addition, the larger clams can’t even close completely, allowing swimmers to wriggle free with no trouble. Finally, the giant clam is a filter feeder, with no way to digest any large prey that might accidentally get caught when it closes its shell.

However, that last statement isn’t completely true. The giant clam starts its life as a filter feeder, pumping water across its gills using a siphon and living off of the sediment and other goodies that get trapped inside. But by the time it has settled down for a life as a responsible adult clam (when it is about a tenth of an inch long), the clam has started to play host to a type of algae known as zooxanthellae (“little yellow critters”). These algae live inside the clam’s skin in special sacs surrounded by blood vessels. The giant clam will open up and spread its mantle to let the algae get the sunlight as it feeds them waste products that the algae use as food; the algae in turn will combine those waste products with sunlight to make food for the giant clam. A large giant clam will get as much as 75% of its energy from the algae and only about 25% from the goo it filters out of the water.

The zooxanthellae live in the colorful spots on the giant clam's mantle (My camera)

The zooxanthellae live in the colorful spots on the giant clam’s mantle
(My camera)

These giant clams are an amazing example of symbiosis and form an important part of the reef system where they live. Unfortunately, their reputation (and large closing muscle) have made them a popular target for poachers who can sell them for several thousand dollars each. And that’s why the Reef Environmental Education Foundation would like you to report any giant clams (or any other reef critters) that you’ve seen. If you’ve seen them alive, then they want to hear from you. And if you’ve seen them dead and being sold in the market, then they really want to hear from you. To learn more about their mission to save the giant clam and other reef animals, swim on over to:
http://www.reef.org/

November 26 – Aloha!

Today’s factismal: Mauna Kea means “white mountain”.

There’s no doubt that Hawaii is a beautiful place. It is covered with rainforests, surrounded by colorful reefs, and filled with brightly colored animals, plants, and tourists. But perhaps the most beautiful part of Hawaii is Mauna Kea, the 33,100 ft tall mountain that is both the base for the state’s largest island (the eponymous Hawai’i) and the world’s tallest mountain. (Everest is a mere 15,260 ft when measured from its base to its summit; if Everest were placed beside Mauna Kea, it wouldn’t even reach the sea surface!)

Mauna Kea covered with snow (Image courtesy of USGS)

Mauna Kea covered with snow
(Image courtesy of USGS)

And that marvelous mountain is a wonder in many ways. Formed from a shield volcano, it started life a million years ago as a mere seamount. Fed a steady diet of basalt lava by a mantle plume, it grew quickly into the massive presence that we know and love today. Though its last major eruption was more than 200,000 years ago, it could still erupt and add a few more feet to its impressive total. But even more exciting than the possibility of a future eruption is the reality of its peak. The top of Mauna Kea rises an impressive 13,803 ft above sea level, which is tall enough to put the peak into a freeze cold enough to create a permafrost zone at the very summit! And if that’s not enough, for about nine months out of every year, Manua Kea is topped by a white blanket of snow that can be several feet thick. And it was that white coating of snow that gave the peak its name; in Hawai’ian, “Mauna Kea” means “white mountain”.

Of course, you don’t have to live in Hawaii to get snow (as most of the US can attest this week). And that’s where you come in! All you have to do is go outside when it snows, measure the depth of the snow, and let the folks at CoCORAHS know how deep it got. To learn more, sled on over to:
http://www.cocorahs.org/

November 12 – Snowbody’s Business

Today’s factismal: Meteorologists have more terms for snow than Eskimos do.

One fact that everyone knows is that Eskimos have lots of words for snow. It only makes sense that they would; after all, every year the Arctic is covered with the stuff for the better part of six months. But what many people don’t know is that meteorologists have even more terms for snow than the Eskimos do!

“Snow on water”
(My camera)

Of course, that does depend a little on how you define “words related to snow” and “Eskimo” (we’re pretty sure on what folks mean by “meteorologist”). There isn’t one group of Eskimo any more than there is one group of people in Europe. There are at least twenty-six distinct languages spoken by “Eskimos” (that is, indigenous people living in the Arctic Circle); though the languages all share a common ancestor (much as English and German and Afrikaans do), they differ in how many words they have for any given topic including snow.

And then there is the problem of defining words related to snow. Is “snowing” different from “snow”? Is “snowstorm” different from “blizzard”? Fortunately for us, linguists have been arguing over questions like this for the better part of a century. Based on one influential dictionary for the Yup’ik people, many people say that the Eskimos (or at least the Yup’ik) have fifteen distinct words for snow. They include snowflake (qanuk), frost (kaneq), fine snow/rain particles (kanevvluk), drifting snow (natquik), clinging snow (nevluk ‘clinging debris’, nevlugte- ‘have clinging debris’), fallen snow on the ground (aniu), soft, deep fallen snow on the ground (muruaneq), the crust on fallen snow (qetrar), freshly fallen snow on the ground (nutaryuk), snow floating on water (qanisqineq), snow bank (qengaruk), a block of snow (utvak), a snow cornice (navcaq), a blizzard or snowstorm (pirta), and a severe blizzard (cellallir).

The Hubbard glacier (My camera)

The Hubbard glacier
(My camera)

What about meteorologists? They worry about all types of weather, snow included, and have developed a very exacting terminology for snow and ice. Their lexicon includes snow ablation (snow removal by erosion), avalanche (snow rushing downslope in a mass), blizzard (a winter storm with sustained winds in excess of 35 mph that causes drifting and blowing snow and limited visibility), blowing snow (snow that is being blown by the wind and limits visibility), depth hoar (large crystals that form in snowbanks due to strong temperature gradients), diamond dust (tiny snowflakes too small to branch), drifting snow (snow moved around by the wind that doesn’t limit visibility), flurries (light snowfalls for short time periods), freshet (the increase in river flow caused by melting snow and ice), frost (small ice crystals formed on the surface of cold objects), frozen dew (what it sounds like), glacier (a packed mass of snow and ice), graupel (snowflakes that are coated with ice), heavy snow (more than four inches of snow accumulation in twelve hours), ice pellets (just what they sound like), ice storm (precipitation that falls as rain but freezes on contact with the ground), lake effect snow (the enhanced snowfall that happens on the down wind side of a lake), polycrystalline snow (several snowflakes fused together), quality of snow (the percent by weight of a snow sample that is ice), sleet (snow that melts and refreezes on the way down), snow (duh), snow depth (how deep the frozen precipitation is on the ground), snow flurries (light snow showers), snow grains (very small, white, opaque grains of ice), snow pellets (large white, opaque grains of ice), snow shower (snow falling for brief periods), snow squalls (intense but short periods of moderate to heavy snowfall and strong, gusty winds), snowburst (a very intense shower of snow), snowfall (how much snow has fallen), snowflake (duh), water equivalent (how much water you’d get if you melted the snow), whiteout (blowing snow that reduces the visibility to zero), and winter storm (a heavy snowfall event). If you were keeping score, that’s thirty-three terms or more than twice the number that the Eskimos use!

Hoar on leaves and plants in Oklahoma (My camera)

Hoar on leaves and plants in Oklahoma
(My camera)

Of course, all of that terminology is useless without some data to back it up. And that’s where you come in! All you have to do is go outside when it snows, measure the depth of the snow, and let the folks at CoCORAHS know how deep it got. To learn more, sled on over to:
http://www.cocorahs.org/

November 5 – Nice Ice, Baby!

Today’s factismal: Antarctica is losing ice at record levels. Antarctica is also gaining ice at record levels.

If there is one thing that everyone is willing to agree on, it is that climate is complex. (If there is another, it is that the media inevitably gets science wrong.) On a globe with as much topography and as large an ocean as ours has, it is entirely possible to have droughts, floods, record high temperatures, and record low temperatures all at the same time. As an example of the complexity our climate creates, let’s consider Antarctica.

Though Antarctica is covered with ice, it is really a desert (My camera)

Though Antarctica is covered with ice, it is really a desert
(My camera)

Located on top of the world at the South Pole (the Australians made me say that), Antarctica is about twice as large as Australia, making it the second smallest continent. Antarctica is unique in that it is circled by a current that helps shield it from some of the vagaries of weather in the rest of the globe. The Antarctic Circumpolar Current also blocks off moisture and helps keep Antarctica a dry, cold desert. But that is changing as the climate changes.

This is is the accumulation of eons worth of snowfall (My camera)

This is is the accumulation of eons worth of snowfall
(My camera)

About 30 years ago, several groups of climatologists pointed out that warmer air could carry more moisture. Now this may seem obvious, but the implications aren’t. The climatologists then pointed out that having more moisture in the air would lead to more precipitation especially in areas where the land rose up quickly. That’s because when the land rises up, it forces the moisture-laden warm air to go up as well. And as the moisture-laden warm air goes up, it cools thanks to adiabatic expansion (the same thing that makes a spray can feel cool in use). And once the moisture-laden warm air turns into moisture-laden cool air, the moisture would come out as precipitation. That’s what happens on the Cascade Mountains, which is why Seattle is lush and green where Spokane is dry and brown. So on the parts of Antarctica where the land rises up quickly from the sea, they expected to see more precipitation, which would lead to more snow which would lead to increasing ice levels.

Ice on the west side of Antarctica, where it is being lost in record amounts (My camera)

Ice on the west side of Antarctica, where it is being lost in record amounts
(My camera)

But Antarctica isn’t the same everywhere. On the eastern side of the continent, things do indeed rise steeply up from the ocean. But on the Western side, there are a series of small islands that cast a wind shadow on the mainland, robbing it of ice. As a result, the ice packs on the eastern side of Antarctica are growing faster than ever before while the warmer waters are causing the ice on the western side to retreat faster than ever before. So Antarctica is both losing and gaining ice at record levels!

Snow capped mountains in Antarctica are more common than ever - but they may not last (My camera)

Snow capped mountains in Antarctica are more common than ever – but they may not last
(My camera)

Now the way we know this is thanks to NASA satellites that measure the ice cover on Antarctica. Those satellites don’t stop there; they also orbit over your home and measure the ice and snow cover when you get it. And that’s where you can help NASA improve their data! The S’COOL project (which makes a great school project!) is looking for folks to go outside and look at the clouds when a satellite passes overhead. All you have to do is enter your location on the website and then go outside and tell NASA how cloudy the area is. They’ll use that to help ground truth the satellites and we’ll all get better climate and weather data thanks to you. To learn more, slide on over to:
http://scool.larc.nasa.gov/groundtruth.html

October 29 – The Light-House

Today’s Factismal: At 177 ft, the bootlace worm (Lineus longissimus) is the world’s longest animal.

Imagine, if you will, a piece of licorice that is nearly twice as long as a basketball court but only about half an inch across. Now imagine that the “licorice” is writhing about and exuding a smelly, toxic goo. Paint your writhing mass of poisonous licorice brown with light brown racing stripes, and you’ve got a bootlace worm, the world’s longest animal.

A Bootlace Worm offshore England (Image courtesy Gordon Lang)

A Bootlace Worm offshore England (Image courtesy Gordon Lang)

Also known as the giant ribbon worm or the ribbon worm (though that is more of a generic name), the bootlace worm is a member of the sea-going worms known as the Nermerteans. These critters all have a rudimentary “brain” consisting of four nerve clusters, up to twenty pairs of light-sensitive “eyes”, a gut that runs the length of the animal, and (most amazing of all) a nose that they poke in and out as they stab at their prey. Nermerteans are found in all oceans and a few species even live on land, but the bootlace worm is limited to the North Sea, where they are plentiful.

A bootlace worm offshore Norway (Image courtesy XX)

A bootlace worm offshore Norway (Image courtesy Sor-Trondelag)

Amazingly, the 177 ft measured for the bootlace worm may not be the longest it can get – many Nermertean species can extend themselves by as much as ten times their normal length! Of course, even for the bootlace worm, 177 ft is exceptional; most specimens are a mere thirty feet long. That length serves the bootlace worm well as it searches for prey to grab with the “fingers” at the end of its “nose”. These stretchy scavengers live in tide pools, along rocky shores and mud flats. Though they can reproduce sexually, cutting them into pieces (for example, when a fish tries to turn one into dinner) will also make new bootlace worms from each piece.

Though the bootlace worm may seem icky or gross, it is a vital part of the local ecology and can tell us much about the local ocean health. If you’d like to help monitor your local ocean, then why not join a Beach Watch program like this one in Texas?
http://texasbeachwatch.com/

October 22 – The Narrative of Arthur Gordon Pym of Nantucket

Today’s Factismal: in October of 1871, Dr D. Mackenzie of Balnain reported seeing a monster in Loch Ness.

The good thing about science is that we are always discovering new and interesting things.  When we see something odd, like possible signals from a little green man, ripples in the very fabric of the universe, or faster-than-light neutrinos,  we sit down and take a good look because life is about to get interesting and we’re about to discover something interesting. The bad thing about science is that there are lots of people who like to take advantage of our drive to discover.

A photograph of Nessie, taken by Hugh Grey in 1933

A photograph of Nessie, taken by Hugh Grey in 1933

Perhaps the best example of this is the infamous “Surgeon’s Photograph” of the Loch Ness Monster. Nessie, as she is affectionately known, had been identified in the press and folklore for centuries. She’d been seen by Saint Columba around 650 CE, and by Dr D. Mackenzie of Balnain in 1871. And a flurry of sightings in 1933 led to someone actually getting a photo – but it was so blurry that it could have been anything. So a race to capture fame and glory by capturing Nessie (or at least her image) began.

The

The “Surgeon’s Photograph” of Nessie, published in the Daily Mail on April 21, 1934

And in 1934, it looked like the race had been won. A photograph attributed to Colonel Robert Wilson was published in the Daily Mail, showing the head and neck of a monster swimming in the loch. Because he was a prominent surgeon and asked that he not be identified, it became known as “the Surgeon’s Photograph” and because he had such a sterling reputation, its provenance was without question. Case closed – Nessie was real.

The complete image of the

The complete image of the “Surgeon’s Photograph”

Except that wasn’t the whole story. Some experts questioned the photo because of the wildly different behavior of the rings around Nessie and the waves in the background; the differences were visible in the cropped photograph and even more obvious in the full image. They suggested that perhaps, thanks to mist, darkness, and distance, Wilson had mistaken a bird for a monster. But it would turn out that their alternative explanation was wrong, simply because they trusted the surgeon’s veracity.

It wasn’t until 1994 that the truth came out. Wilson and two other people had conspired to create a fake image by gluing the head of a monster onto a toy submarine and taking its photograph. Their motive was revenge; one of the conspirators was a noted big game hunter who had mistaken tracks made with a hippo-leg umbrella stand for Nessie’s real tracks. When the truth had come out about his error, he was furious and decided to make fools of those who had made a fool of him.

Despite the revelation that the photograph was faked, people still go to Loch Ness to look for the monster. They want to discover what, if anything lives in the waters (witness the recent furor over the “Nessie from space” image). If you’d like to do some searching for monsters of your own without going all the way to Scotland, then why not join the SERC Marine Invasions Research Lab? They are trying to find out how much progress invasive species like the mitten crab, the green crab, and algae plates have made, and if efforts to counter these real-life monsters have had any effect.
http://www.serc.si.edu/labs/marine_invasions/citizen_science/index.aspx

October 15 – A Descent into the Maelström

Today’s factismal: Basking shark corpses are sometimes mistaken for sea monsters.

Have you ever seen a sea monster? If you’ve seen a basking shark, then you have. The basking shark or Cetorhinus maximus (that’s “big critter with a sea monster nose” in science-speak) is one of the world’s largest fish; at 40 ft long and 40 tons, it outweighs every other fish but its near relative, the whale shark. And much like its cousin, the basking shark is a filter feeder that swims about looking for tasty, tasty plankton to nibble on.

A basking shark hunting for plankton (Image courtesy New England Basking Shark & Ocean Sunfish Project)

A basking shark hunting for plankton
(Image courtesy New England Basking Shark & Ocean Sunfish Project)

These amazing sharks are seen everywhere from the Bay of Fundy in Canada to the Florida shores. They are known to pine for the fjords of Finland and to cavort in the Mediterranean as they swim down to the Ivory Coast. They are also seen from Argentina to South America, and from Australia to Chile. Basking sharks have been sighted in the California surf and the Alaskan ice, and are popular visitors to Hawai’i. In short, these guys get around! And no wonder – when you are as long as a bus and weigh as much as three full-grown elephants, you have to keep on the move just to find enough food to eat. Some scientists estimate that a basking shark will spend 10 to 15 hours a day looking for the microscopic plankton that is its primary food source.

The basking shark is born alive from an egg that hatches in its mother’s oviduct; they then spend a few months maturing before being born again into the salty ocean water. Since they have no placentas, during the last part of their maturation the baby sharks eat their mother’s eggs to survive! (That’s oophagy to all true shark nerds.) After being born, the baby basking shark is a cute and cuddly little four foot long bundle of joy. It immediately begins to hunt for plankton and sets about growing large enough to make more baby basking sharks, a feat which takes about six years to accomplish. Every couple of years thereafter, the females will bear more young while the males look for a good paternity test. After about fifty years, the basking shark dies of old age – and that’s when the weirdness begins.

Three images of basking sharks (Image courtesy New England Basking Shark & Ocean Sunfish Project)

Three images of basking sharks
(Image courtesy New England Basking Shark & Ocean Sunfish Project)

Because basking sharks are sharks, their corpses can float. And those corpses are usually scavenged of the gooshier bits first: the head, the belly, and the fins. That leaves behind a long, sinuous spinal column with a bulb on one end where the head used to be and a ratty tail where the tail used to be and little flaps where the fins used to be. Squint at it in the right light, and the thirty-foot long “globster” looks more than a little like a sea monster. And that’s how they’ve been reported in cases such as the Zuiyo Maru “plesiosaur” (warning: gory!).

Perhaps it was this sea monster-like appearance that caused the Canadian government ot put a bounty on the basking shark from 1945 to 1970. Or maybe it was the mistaken idea that they would eat all of the fish. But, whatever the reason, the basking shark was hunted nearly to extinction and is only now starting to recover. Which makes a sighting of one a rare occurrence and of great scientific interest. If you happen to see one, then please head over to the New England Basking Shark & Ocean Sunfish Project and let them know!
http://www.nebshark.org/