Whale Fall – More than just a hilarious existential crisis

Whale fall. It may sound like the rejected title of a James Bond movie or a Douglas Adams reference, but it is actually a surprisingly important and relatively little known concept in the study of the world’s oceans. It all begins with one of the saddest moments in the story of any whale family. Grandpa whale, let’s call him Moby, after a long a fulfilling life of eating ship captains’ legs, dies. 

As sad as this is for the rest of the whale family, odds are that if Old Moby died from natural causes he lived a pretty long life. Research beginning in the 1990’s revealed that a significant portion of the population of many whale species is over 100 years old. Questions started being asked when whale carcasses were pulled from the ocean containing stone harpoon heads, which fell out of fashion around 1860. Tissue samples from a group of Bowhead whales subsequently revealed that several were in their mid-100’s and one male was pushing 200. The point is whales can live a long time.

When a whale dies without human intervention its body either washes up on shore, occasionally with hilarious consequences, or it sinks to the bottom of the ocean. The latter is much more common and the result is something pretty remarkable.

When a whale fall, as these things are known, touches down the animals that live on the sea floor throw a party. The deep ocean is a surprisingly poor environment in terms of available food and energy with animals living mostly on small particles of so-called “marine snow” that drift down from above or by eating each other. A whale carcass, as you can imagine, is a welcome break from this kind of life.

The first phase of a whale fall food chain involves getting all that delicious, rancid flesh off the bones. That job is taken care of by animals like ratfish, sharks, crabs, and hagfish. The work goes surprisingly quickly. These scavengers can liberate up to 60 kg (132 lbs) of meat in a day. After a few short months (whales are big animals) only a skeleton remains. At first glance it would seem like the show is over, but in reality things are just heating up.

As the crabs and sharks pack up and move on to greener pastures, worms move in. Lots of worms. Polychaete worms, to be precise. Up to 45,000 worms per square meter blanket the sea floor about one year after the whale buffet opens its doors. They, along with a few other species of invertebrates, feast on the organic material in the whale bones. Although this stage of whale decay brings huge numbers of animals, they represent only a few species. The real fun begins when the microbes arrive on the scene.

Somewhere between one and two years into the show, most of the low hanging fruit (to use a more pleasant sounding metaphor) has been harvested. At this point sulphur-reducing bacteria arrive to feed on the fats and oils left in the skeleton. As they do this they release sulphur into the surrounding water, which attracts sulphophilic (sulphur-loving) bacteria. These bacteria, remarkable, form the basis for a very unique food web.

Most food webs on Earth begin with photosynthesis as plants turn sunlight into food. The web around this stage of a whale fall by comparison is chemosynthetic, meaning that it’s basis is chemical reactions by bacteria. Larger and larger animals feed on the bacteria and on the creatures that feed on the bacteria until eventually you have a booming community that includes up to 190 different species of visible animals. The only other place where this type of system exists is around deep sea vents where the energy comes from within the Earth itself.

These Stage Three whale fall communities can last a surprisingly long time. We're talking decades. Research has shown that some whale falls can sustain an ecosystem for over 50 years! And these are not rare systems. Given the number of whales alive today and the length of time that these communities last, scientists estimate that there may be a whale fall every 5 to 16 km (3 to 10 miles) along the sea floor, meaning that when the nutrients finally do run dry, the creatures that depended on them don’t have far to travel until they find their next home.

Whale falls are islands of biodiversity in one of Earth’s least bountiful places. Yet another reason why humans should do our part not only to protect whales, but to protect the fish and oceans that they depend on. 

Ice Fishing in Space: Two new oceans discovered in our solar system

During the last week of August in 1835 readers of the New York Sun were treated to one of the great scientific discoveries of all time. A series of articles reported that British astronomer Sir John Herschel had developed a ridiculous new telescope that had given him glimpses of planets in other solar systems, close views of comets and – just to put a nice bow on things – he had discovered life on the moon. Of course, this all turned out to be a hoax (John Herschel had no part in it), but it got people thinking about life on the worlds that orbit other worlds and we call moons. Now, in the second week of March 2015, a couple major discoveries could reignite that curiosity.

On March 11th and 12th two teams of scientists reported in the journal Nature and in a NASA teleconference respectively that they had serious reason to believe that they had discovered two brand new oceans right here in our own solar system. The first on Enceladus, an icy moon orbiting Saturn, and the second on Ganymede, the largest moon in our solar system (it’s almost the size of Mars) which orbits Jupiter. Along with Europa, another Jovian (Jupiter-orbiting) satellite, these icy encrusted water worlds are the best candidates we’ve so far discovered for alien life.

Europa has long been a hot topic at astronomical dinner parties. Back in the 70’s when Pioneer spacecraft 11 and 12 flew by Jupiter they took the first pictures Europa’s surface and shocked the world when they revealed long dark channels on an otherwise smooth icy surface along with a stunning lack of craters. A lack of craters is interesting because it suggests that some force exists on the moon that can erase surface features. The Earth doesn’t have many craters because they erode. Our moon has lots, because not a lot happens up there.

When the Galileo mission returned to Jupiter in the 90’s, photos revealed that Europa’s surface channels appeared to be the result of the cracking that was later filled in by some flowing material (warmer ice or liquid water). Analysis of Jupiter’s magnetic field around Europa also provided evidence that some conductive material (probably salt water) exists beneath the ice.

If you’re wondering how moons so far out in the solar system could have liquid water beneath thick, sun-blocking ice, the answer is a process called tidal heating. See, as moons orbit planets the gravity of their hosts stretches them every which way, producing heat. If you’ve ever played squash or messed around with modeling clay you’ve seen similar forced at work. As a material gets stretched (be it clay, rubber or moon) it generates heat and becomes more elastic. On the scale of moons the heating can be kind of nuts. The ocean on Saturn’s moon Enceladus is thought to be as hot as 90 degrees Celsius (200 F)!

That heat is actually what led to its discovery. Back in 2005 the spacecraft Cassini saw massive plumes of water vapor shooting out of the moon’s south pole. Analysis of particles found in the vapor revealed silicon, which on Earth is generally created around hot ocean vents. That means that Enceladus is geologically active, and that is thought to be a prerequisite for life.

The ocean on Ganymede (back in the Jupiter system) is equally interesting but less likely to be home to any freaky fish-type things. That is because the liquid water probably doesn’t touch a rocky surface like on Enceladus. If you were to start digging on Ganymede you would burrow through 100 miles of ice before hitting water. When you sunk to the bottom of the ocean you would find yourself on more ice beneath which lies the rocky mantle and finally the moon’s iron core. The only reason we know there is water down there is because the auroras around the moon’s magnetic poles (caused by its iron core, just like Earth) are more stable than they would be if there was no water.

To sum things up, it has been a pretty crazy week in space exploration. It seems that will our focus on all the planets outside the solar system that may harbour life, we might have missed some supremely weird ice-fishing opportunities closer to home.

Giant Boat-Knives and Other Bad Decisions: The Tale of the Basking Shark

Our friends at The Starfish asked us to drop some knowledge on basking sharks for Shark Week. Ask and you shall receive:

The ocean is full of monsters. That is a pretty well established fact. Any parent who has ever told an insomniac child, awake and trembling at 3AM, that there is no such thing has clearly never seen a picture of a giant squid or an angler fish. Sea monsters range from the very small (jellies) to the unfathomably enormous, but few are as impressive as the basking shark (known to science by the delightfully gladiatorial name of Certorhinus maximus).

Basking sharks fall into the “sea monsters” camp mainly because of their size. They are the second largest fish in the ocean (after whale sharks), reaching lengths of up to 33 feet and weighing as much as 8,000 pounds (3,600 kg). They also look unmistakably ferocious in that classic sharky way. They have dorsal fins that stick high out of the surface of the water, streamlined bodies, and (scariest of all) enormous mouths. You could swim into a basking sharks mouth pretty easily without ever touching the edges.

The thing about basking sharks though, is that they aren’t ferocious at all. Like so many of the biggest things in the ocean, they are almost comically gentle. They cruise around at around 3 mph (5 km/h) with their mouths agape, swallowing tiny plankton and filtering out massive amounts of water. They love to hang out in the sun right at the surface of the water, hence their name.

Unfortunately, this affinity for sunshine and their ridiculous size has caused some trouble between us and them, but not for the reasons you might think. Whereas humans normally hunt things as impressive as basking sharks for trophies or meat, these lumbering beasts are actually pretty useless as a commodity (unless you’re one of the 3 people alive who enjoy Icelandic hakarl).

The problem with basking sharks is that back in the 1940’s and 50’s they routinely got caught in fishermen’s gill nets by mistake. You may think that a basking shark would make a good catch for a humble fisherman, but the only sellable part of the great fish is its liver. I say “sellable” instead of “valuable” because in the mid 20^th century basking shark livers sold for 3 cents a pound (about $35 per shark) whereas the nets they destroyed with their massive bodies cost roughly ten times that much.

This inevitably led to fishermen hating basking sharks and complaining to the government. In 1949 the Canadian government gave in and labeled basking sharks marine pests and set to work at killing them. The method of choice was either ramming them with boats or slicing them in half with a huge makeshift blade mounted on the bow of a boat. In the 1950’s a giant boat-knife was an impressive thing, at least impressive enough to be featured in the November 1956 issue of Popular Mechanics magazine.

The giant knives proved remarkably effective and in a matter of decades basking sharks were nowhere to be found. Nowadays there is about one sighting per year off the British Columbia coast. Ask someone at the Department of Fisheries and Oceans where they went, and you will likely get a sheepish, embarrassed look in return.

However, the news isn’t all bad. In 2010, Canada followed the lead of countries like Ireland and Great Britain and declared the basking shark endangered. A recovery strategy was finalized in July 2011 and the people who once drove the knife-boats have since been at work mashing the ocean’s CTRL+Z key. Only time will tell if they’ve changed their minds in time.

A Methane Mix-Up: Losing Yourself in The Bermuda Triangle

Special thanks to Veronica in Ottawa, Ontario, Canada for this week’s topic. Veronica was kind enough to send us this link and on the ball enough to ask “Seriously?”

To understand the Bermuda Triangle it helps to first get our bearings on this big old planet of ours. If you connect the dots formed by the country of Bermuda; Miami, Florida; and San Juan, Puerto Rico on a map you will have created a triangle covering about 1.3 million square kilometers (500,000 square miles) of the North Atlantic Ocean. Some people argue that based on historical data of plane and ship wrecks, this is most dangerous area of all the world’s oceans.  

Before we dive into possible explanations for the Bermuda Triangle, it is pertinent to stop and make the most popular demand in all of science: show me the evidence! Aficionados of the triangle claim that in the past 100 years, about 100 ships/planes have vanished within its borders, claiming 1,000 lives. That right there should set of your suspicion-o-meter. The numbers are too neat. Nature doesn’t work with many zeros.

When you have a question about shipwrecks, you are best off asking the folks at Lloyd’s of London. As the world’s top insurer of all things nautical, Lloyds has a vested interest (in the order of billions of dollars) in knowing where the dangerous parts of the ocean are. They recorded 428 sunken vessels between 1955 and 1975 and when asked about rates of disappearance in the Bermuda Triangle they have been quoted as saying “It doesn’t exist.” Yes indeed, insurance rates for ships in the Bermuda Triangle are no higher than for anywhere else in the ocean.

That kind of takes the wind out of our sails, right out of the gate. But there is hope! Lloyd’s of London deals mostly in massive cargo ships and not so much in personal air and watercraft, so let’s just pretend we didn’t read that last paragraph… And let’s ignore the US coast guard when they reassure us that the rate of disappearances in the so-called Bermuda Triangle is no higher than anywhere else. Instead we can cling to the alleged reports from the National Transportation and Safety Board that indicate that only 10 private planes have disappeared off the coast of New England in the last 50 years, while 30 have gone off the radar in the triangle.

Okay, so what might be causing this string of definitely not-made-up disappearances? As you would expect for this sort of things, there are more theories than there are confirmed missing persons. The most note-worthy are aliens, wormholes to other dimensions, and government bomb testing. But this is a science blog, so let’s set aside the nonsense right now.

One of the more interesting theories still in the far-fetched category involves something called electric fog. Bruce Gernon and Rob MacGregor, two experienced pilots, have written a book called The Fog: A Never Before Published Theory of the Bermuda Triangle Phenomenon. In it, they describe eerily round clouds they have each encountered on flights in the area. Gernon, on one flight, attempted to fly through a tunnel in one of these clouds only to have his instruments malfunction and observe a strange electric disturbance on the walls of this plane. He also reports emerging from the fog to find himself flying over Miami after flying for 47 minutes. His route that day was scheduled to take 75 minutes.

Spooky time-travelling fog aside, the more realistic explanations for the Bermuda Triangle (which is totally a real thing, in case you forgot) centre around weather, ocean topography, and human error. The east coast of North America is not only a magnet for hurricanes, it has some of the deepest ocean trenches on the planet as well as a large number of amateur pilots and seamen. Those are all components in a bad equation.

But what about the link that started off this article? What about these supposed Methane Vents? Well, it turns out that the internet may be on to something. The area off the east coast of the United States contains methane deposits in enough quantity to meet the country’s current natural gas output for 16,000 years. These deposits form as dead, decomposing plants and animals at the bottom of the very deep ocean release gases, namely methane. Since the temperature is so low and the pressure is so high, these gases get trapped in the sediment.

Researchers Elchin Bagirov and Ian Lerche have studied similar “Methane Hydrates” (methane trapped in ice instead of sediment) in the Caspian Sea and deemed them to be a serious hazard to oil drilling in the area, because of their instability. When these methane deposits rupture they can release gas so violently that the entire water column above them becomes less dense. Theoretically a ship directly above a methane eruption could be sunk. There is no record of this ever actually happening, but if your ship goes down in a vortex of bubbling methane you aren’t likely to survive to tell the people who record such things.

It is kind of a one in a million shot. The equivalent of lightning from below. And it still doesn’t explain all the alleged plane disappearances, but as far as cool science goes, it is high on the list of possible explanations. And we really do need explanations because, as we have seen, the Bermuda Triangle is definitely a totally real thing that actually exists.

Garbage Island: Floating Fun with the North Pacific Gyre

Last year we at Sketchy Science were fortunate enough to find ourselves on the Hawaiian island of Oahu for 10 days of fun in the sun. We explored every corner of the island looking for fun stories to share and were not disappointed, from extinct volcanic craters, to epic surf, to amazing wildlife, Hawaii proved to be a hot bed (if you’ll pardon the pun) of science gold. However, one of the things we discovered was bigger than all the rest. We never actually saw it because, as you will read, it’s not easily detectable for land-dwellers; but we did spend the better part of 5 hours flying over it.

The Northern Pacific ocean is home to one of humanity’s great shames. Due to the collision of currents and the durability of certain man-made detritus, there now exists a floating patch of garbage twice the size of the continental United States stretching from 500 nautical miles off the California coast nearly to Japan. It goes by several names, but we like to call it Garbage Island.

Garbage Island is a joint creation of human wastefulness and the clockwise-spinning network of currents call the North Pacific Gyre. This massive area in the world’s most massive body of water is an oceanic desert, home to few large fish but brimming with microscopic phytoplankton. The rotating nature of the Gyre causes any drifting material to get caught up in the middle of the ocean for what can turn into an immense amount of time. Fortunately most natural materials break down in a few years. Unfortunately, humans have invented plastics, which basically last forever.

Give anything on Earth enough time and it will eventually find its way into the ocean. That is just how things work. The problem with plastic is that no natural process exists to break it down into simpler compounds. Instead of biodegrading, plastic photodegrades; slowly fracturing into hundreds or thousands of smaller and smaller pieces. These tiny bits of plastic are called nurdles, or (if you are the poetic type) mermaid tears. Roughly 70% of nurdles sink, the rest get caught up in surface currents and float around for an indeterminate amount of time. What this all means is that garbage island isn’t actually an island. It is more of a conceptual blob of sparsely packed filth in a vast expanse of water, which is way less fun.

It may not seem like such a big deal. After all, there isn’t much wildlife in an oceanic desert. Unfortunately, large animals like whales, sea turtles, and birds travel through the North Pacific looking for food. They end up swallowing garbage which clogs up their innards and eventually kills them. If that isn’t enough, there is another indefatigable law of nature: Whatever ends up in the ocean eventually ends up on your plate. As plastics float about, they absorb chemicals like mercury and pesticides like DDT that people continue to dump into the oceans. Those compounds get more and more concentrated as they work their way up the food chain. Humans are at the top of every food chain there is, so this bioaccumulation is bad news for us if we plan to keep eating fish.

This is all pretty upsetting, I am aware. So what can be done to fix it? Fortunately, many countries around the world are taking steps to reduce unnecessary consumption of plastic. You may have noticed that your local grocery store now makes you pay for plastic bags, or, at the very least, encourages you to use reusable ones. Many restaurants are also moving away from plastic forks and knives in favour of metal utensils that are actually capable of spearing and cutting food.

Cleaning up the Pacific is something that we still need to figure out. Collecting billions of tiny pieces of plastic without hauling up a heap of plants and animals along with them is a daunting task. Until engineers solve that problem, we will have to rely on common sense to avoid making the problem worse. Do your part to recycle and to produce as little waste as you can. It’s the least you can do to help eliminate the world’s biggest landfill. At worst, just aim to be better than the countless tourists we encountered on Oahu who watched in stunned disbelief as their air mattresses blew out into the ocean without making the slightest attempt to retrieve them.  If a simple lack of idleness isn’t enough for you, grab a snorkel and a biodegradable trash bag, then meet us in Hawaii.

Mahalo