12.30.2008

i am so excited



One of the many reasons I am a biologist is because the world is absolutely chock full of amazing plants, animals, ecosystems, and natural phenomena, which are unbelievably complex but overwhelmingly fragile, especially in the face of increasing pollution, expansion, and destruction by the human race. A major hurdle to reversing the effects of habitat decline all over the world is getting people to care about these fragile ecosystems and understand how local actions can have global impacts... "Why should I care about rainforests in Borneo when I live in Kentucky?"

For all the things that globalization and the internet has done, one thing that it has failed to do is truly expose those who don't have the money to the beauty of the natural world in places far from their homes. I've been fortunate enough to have traveled to the rainforests of Costa Rica, the top of a New Zealand Volcano, the ruins of Termessos in southern Greece, even the coasts of California and Maine. However, not many people have the time or money to get away from their homes to explore these wondrous places.

As a scientist and teacher consumed with wanderlust, I dream of taking everyone to see the sights, to show them the world and how amazing it all is. However, instead of leading 7 billion people through a rainforest trail or down the Yosemite valley, I could take them there with an immersive video experience, beyond National Geographic photos or a television show to a place where they can explore freely on their own time and see what they want to look at. Since almost everyone has an internet connection, why not create a website accumulating tours of amazing places around the world, guided with interactive videos that allow the user to look around as they are hiking on a trail or sailing past a fjord, clicking on things of interest like birds, plants, fish, or mountains, and learning more about them? This way, learning becomes self-driven, and people around the world can come one step closer to the natural world they may never see in person.

A company called Immersive Media has the technology to do this. They are best known for cataloging the streets of major cities for Google Street View, but they can also do 3-D video and live streaming, allowing you to look around a video world. This is the ticket to the future, and I can't wait to get started on this project.

Paddy

12.11.2008

why every city in California advertises its elevation



"Extent of flooding by rising sea level if greenhouse warming continues unabated and approximately one third of the world's volume of land-bound ice and snow melts (not sea ice). The resulting rise would place sea level about 30 m above present sea level. Dashed line shows approximate outline of the present San Francisco Bay."

Source:San Andreas Fault and Coastal Geology, from Half Moon Bay to Fort Funston-Crustal Motion, Climate Change, and Human Activity by Andersen D., Sarna-Wojcicki, A., Sedlock, R. (2001)

11.29.2008

square-dancin' cephalopods!

Howdy y'all!

Down South, home of muddin', fiddlin', noodlin', and rebellin', they have a grand old time down at the grange, square dancin' on Saturday nights.

But keep an eye on your wives and lock up your daughters, gentlemen, because there's a new dancer in town... this fella's got arms twenty feet long and enough elbows to do-se-do all of your cousins at once!

This big-eared bad boy was found pokin' around a deep-sea drilling rig in the Gulf of Mexico last week, and his name?



From National Geographic
http://news.nationalgeographic.com/news/2008/11/081124-giant-squid-magnapinna.html

6.10.2008

predicting earthquakes


Unlike most Californians (and yes, I still consider myself a Mainer), I can remember only two earthquakes in my lifetime, neither of them significant. One was in Maine, and felt very much like a truck going by, when there was none (my initial reaction was actually that my mother was cooking vigorously downstairs in our rickety old house). The other was here in California, when the house started swaying back and forth (such an event that I raced to my room to make sure that Caoimhe was okay, but she seemed more surprised by my sudden appearance).

Most earthquakes, like these, are relatively harmless. After my second, I was informed of the "Safeway Rule," which is, to those on the east coast, if the quake's national television coverage is comprised of images of cans in the aisles of grocery stores, fear not, as that is the extent of catastrophe.

Other earthquakes, however, can be disastrous. The deadliest on record was in 1556 in Shansi, China, which killed approximately 830,000 people. The Great Sumatra-Andaman earthquake in 2004 had a magnitude of 9.3, lasted 8-10 minutes, triggered other quakes all the way to Alaska, and moved the entire planet 1 centimeter (no small feat!). The resulting tsunamis killed more than 225,000 people around the Indian Ocean. The most recent shaker, in Sichaun Province, China, was an 8.3 on the Moment magnitude scale, and as of June 8, has left about 70,000 dead, 18,000 missing, and almost 375,000 injured.


The Great Sumatra-Andaman Earthquake

These tremors are devastating, and can kill hundreds of thousands of people, in addition to costing countless sums of money in damage. So what can we, as the highly intelligent species that we are, do to gain some kind of warning? Anecdotal stories of chickens or dogs going crazy and goldfish jumping out of tanks may not be reliable indicators. Our seismographs, though they be essential to the measurement of size, can only give us maybe a minute's warning, and often give false results. Surely, we can do better.

It turns out we may be able to, from space.

When the Earth was formed 6000 years ago, water molecules were churned into and captured within the rock, which was then subjected to extreme heat and pressure. This broke apart the water molecules, forming byproducts such as oxygen and hydrogen, but also crystals within the rock that conduct electricity. In the early stages of an earthquake (weeks before we feel them), increased pressure at the point of interaction causes changes in the chemical properties of these crystals, changing the electrical field surrounding them. Electric fields create magnetic fields, and this electrical field generated has such magnitude that a large magnetic field and a slight infrared (IR) glow radiate out from the Earth at the epicenter of the coming quake.


Imaging the ionosphere

Scientists have been able to detect large changes in magnetometer readings in the weeks and days leading up to a major quake, such as the one in 1989 that shook the SF bay area. However, the magnetic field also sucks in negative ions from the ionosphere, essentially creating a dimple in the atmosphere, up to 12 miles deep. This also affects communications between satellites and radio towers. Using special satellites that measure IR signatures while communicating with GPS satellites, we can detect these heat signatures and dimples, up to two weeks before a major tremor.

How do we know all this? In 1960 and 1964 in Chile and Alaska, respectively, changes in the ionosphere created radio interference in the days before major earthquakes. Prior to a cluster of quakes in Japan in the late 1960's, people reported seeing eerie lights in the sky, which could have resulted from ion movement. In 1989, after the Loma Prieta earthquake, researchers went back and examined magnetometer readings leading up to the earthquake, and found that two weeks prior, the local magnetic field began increasing, peaking at 60 times normal three hours before the tremor, and persisted in the weeks after.


Epicenter of the Sichuan Quake

The most recent evidence, however, comes from the disaster in China: on May 2, a scientist working for NASA at George Mason University noticed the telltale IR signature and changes in the ionosphere above the Sichuan Province. He sent a memo to some of his colleagues, which was only leaked to the public.

Ten days later, The Great Sichuan Earthquake, magnitude 8.3, killed 70,000 people.

Should they have gotten the memo?

Paddy

Sources:
http://news.cnet.com/Bright-lights,-big-quake/2100-11395_3-6061448.html
http://dsc.discovery.com/news/2008/06/10/earthquake-satellite.html
http://www.sunearthplan.net/5/25/3D-movies-of-the-ionosphere
Wikipedia

6.08.2008

inside the cell

Technology has come a long way. No longer are we restrained to only looking at cells under a microscope or pictures in books from expensive electron microscopes, but computer animators today can render the invisible functions of the cell in incredible detail. Below are two links you should check out. The first is an article about computer rendering technology with a teaser video, and the second is the original video, created for biology students at Harvard but available to students worldwide. It's an amazing film, and captures the nanoscopic functions of the white blood cell in captivating detail. Check it out:


http://www.studiodaily.com/main/searchlist/6850.html

http://multimedia.mcb.harvard.edu/media.html (the "Inner Life" animations at the top of the page, pick one depending on your connection speed)

Paddy

6.04.2008

what inspires you?


For some, a carefully crafted painting by Claude Monet is a subject of fascination, whether it serves to entrance, by the way light is captured with the delicacy and precision of each brush stroke. Or, it inspires, making the viewer yearn to put life to canvas in the same fashion that it was so many years ago.

Others are inspired by the steady hands of an experienced neurosurgeon, the skill of a high-speed precision air racing pilot, the intricacies of mind-blowingly complex confidence schemes, or by someone's ability to continuously burp the entire alphabet (okay, maybe not since 4th grade).

What inspires me? Apparently, the same thing that motivates Brian Greene, world famous physicist and author of The Elegant Universe, a book on String Theory which was also made into a PBS miniseries that he hosted.

On June 1, Dr. Greene wrote a letter to the New York Times about the importance of science in our lives, and how it should be (though, sadly isn't) valued in the same way that we value art, business, or language.

As Brian Greene states, we all start out our conscious lives as scientists... one of the most oft heard questions for any toddler's parents is "Why?" Why is wood fire yellow and stove fire blue? How do planes stay up in the sky? Why do bees and hornets and wasps all have black and yellow stripes?

I wonder how well a lot of parents can answer these questions, as many likely don't know the answers themselves. That's not to say they have no idea, but that the true meaning beneath a simple answer is likely lost on many people. In fact, the answers to these questions weren't really fully answered for me until I went to college and took classes in Chemistry, Physics, and Biology on my own volition.

How many of you had such memorable experiences in your high school science classes that you were driven to become lifelong scientists? I know I didn't. With the exception of an excellent and highly acclaimed high school physics teacher (Steve DeAngelis, whom I unfortunately had for only one semester of a year-long class), my high school Biology and Chemistry classes were hardly as interesting as Photography, Theater, or French (and perhaps I'm an exception when it comes to French). In fact, those basic science classes, learning about the periodic table or the organelles of a cell, turned me off of scientific pursuits. The world was much more interesting, it seemed, than the sciences could offer, especially when it came to fighting fires and chasing crooks.

After spending a few years in various forms of public service, I found myself back in school, ready for a change. My dream career had left me alternately bored and stressed out, and I needed to feed my brain some more. Moving to California, I enrolled at Cabrillo College, and started taking classes in Biology, Chemistry, and Physics.

It was here that my passion for science was ignited, quite literally, by my chemistry professor, Josh Blaustein. If you don't know him, Josh has a propensity for causing large explosions in small lecture halls, often followed by applause, if not a literally stunned silence. To this day, I remember a particular lab in that Chemistry class that involved burning various liquids containing metal ions to see what color they would be. Strontium was red, Copper was green and Potassium was a lovely shade of periwinkle. Question 1, answered. (It's also because of Josh that I know that liquid oxygen (boiling point -297 °F) is blue, and that, when poured on Corn Flakes and ignited, the combination could feasibly power a small rocket.)

Another inspiration is Joe McCullough, whose enthusiasm alone could wake up anyone in an 8AM Physics class (assuming he showed up on time). Joe can speak with the same aptitude and passion about the science behind the bowling ball-pendulum swinging perilously close to his face, the Van De Graff generator giving him frequent, painful electric shocks, and the calculations behind fluid forces as applied to an airplane wing (Question 2, answered), and he can lead informative discussions on the aforementioned String Theory.


The science that has won the majority of my fascination, however, and that to which I devote my academic pursuits, is Biology. John Carothers' knowledge base of obscure animal facts is simultaneously fascinating and humbling. Through his course in Animal Diversity and Evolutionary principles, I've learned amazing things about Hyena fetal development, why you shouldn't put a cone snail in your wet suit, and how Mullerian mimicry works for poisonous snakes of Central America (Question 3, answered). I've also developed the personal opinion that the octopus in evolutionary terms, is the most advanced animal on this planet (I didn't even tell you about the three hearts or the inverted structure of the polarity-sensing retina!).

These three professors have been an inspiration to me over the last two years, not because they know a lot or wrote fancy papers when they were grad students, but because they have spent the time since then refining their teaching techniques, figuring out the best way to get the majority of their students interested in the sciences. Whether it's designing a Rube Goldberg machine of fire to explode a balloon of oxygen propane in equal molar quantities, awarding prizes to those who can produce the most standing waves in a string, or singing obscure songs about interrelatedness and marrying one's grandmother to explain the benefits of sex, these guys have found a way to light a fire in the minds and hearts of their students and hopefully drive them on to bigger and better things.

For all the wonderful things that I've learned in the past two years, it's somewhat frustrating that it took me this long to realize how much I've been missing. This is what Brian Greene talks about in his June 1 letter. Entry level science, as it's currently taught, is less about the fascinating world that can be discovered and appreciated and more about memorizing the fundamentals, which are often quite boring. It's no wonder that so many students quickly lose interest if all they do is learn parts from a 1970 drawing of a cell or devote their homework to learning the Bohr model of the atom (which isn't even accurate, so who knows why they still teach it). If young people could be shown the most amazing, most intricate, and most beautiful parts of science first, Greene argues, then they might be more inclined to go back and say "how does that work?" In writing, it is said that the introduction should be something that captures the attention and draws the reader in. Why shouldn't science be the same way? To a novice science student, memorizing the Krebs cycle of the mitochondrion is nowhere near as fascinating an introduction as would be knowing that insects have, instead of lungs and capillaries, tiny air tubules that enter the sides of their bodies and go to each and every cell, ending right next to those same mitochondria.

Brian Greene, my aforementioned mentors and I agree that science is incredibly valuable, and should hold a place in the same high esteem as all other parts of life. I encourage you all to read his short letter, reconsider the education you tried not to sleep through in high school, and then do as my brother is and sign up for Scientific American.

You'll never know what might capture your attention.

Paddy

5.28.2008

wicked smaht

What's the fastest computer on Earth? Blue Gene? ASCI Q? The Earth Simulator? Your Compaq running Vista?

Technically speaking, while the latest supercomputers are unmatched in number-crunching ability (try calculating an exaflops), the most powerful processors are biological. Your brain can process more things simultaneously than can the best computer. For all their power, the Blue Genes of the world can't simultaneously drive a car while translating English to Portuguese over the phone, evaluating the age of a french fry found in the back seat by taste and texture, predicting the weather by looking at the sky, worrying about question 4 on the last Mammalogy exam and thinking about an itch on its butt.

Your brain, however, can. (The french fry is two weeks old. Take it out of your mouth.)

It'll be a while before a silicon computer can function as well as a human brain, but in the mean time, scientists have begun developing a computer that can potentially process information exponentially faster than anything we can build. How much will it cost? A spoonful of sugar.

Researchers (in this case, a few professors and undergrads at Davidson College) have recently developed a new method for computation, using E. coli bacteria. Instead of having one giant computer with lots of little circuits and chips calculating every possible solution to a given problem, each bacterium serves as an individual processor, calculating a portion of the problem individually. Since E. coli can grow practically anywhere (you have billions in your intestines and they help you digest your food) and the generation time is short (15-20 minutes for laboratory strains), you can grow your own supercomputer in a matter of days.

It works by taking a protein called flagellin from Salmonella and introducing it into the E. coli. In Salmonella, flagellin serves as a structural protein for the flagellum (in other words, it is the framework for the whip-like tail). Mammals can develop an immune response to these proteins, so the bacteria usually have several different genes which code for different types of flagellin to evade detection. When these genes are introduced into E. coli, they serve as an "on/off" switch. The bacterium is used to compute a problem by flipping segments of its DNA, and if it solves it correctly, the genes are activated for the protein that the antibiotic doesn't recognize, and the bacterium lives. If it can't solve the problem, the bacterium dies [there's some motivation for you].

In this case, the problem being solved is the classic burnt pancake problem, where a stack of pancakes, each with one side burned, must be sorted by a series of flips so that they are stacked according to size with the burnt side down. The number of combinations of flips increases exponentially with the number of pancakes, and so far the bacteria have only been able to sort out a stack of two pancakes. This may not seem that impressive, but the potential for this technology, once more developed, is huge, and just may allow us to grow our computers instead of mining them.

Once again, Biology rules. ;-)

Patrick

For an interesting interactive video on how these bacterial computers work, check out:
http://www.bio.davidson.edu/people/kahaynes/FAMU_talk/Living_computer.swf

5.15.2008

nudibranchs




National Geographic this month has an article with some great pictures of nudibranchs, marine invertebrates with some amazing color patterns and characteristics. Their flashy coloration and sharp contrasts have evolved as a warning to potential predators to "stay away," something called aposematic coloration. This isn't false advertising, though: Nudibranchs munch on toxic corals, hydroids and sponges, and instead of being harmed, they take the defense mechanisms of their food and excrete them from their own skin. Some are highly poisonous, while others take structures called nematocysts (the same potentially-deadly stingers found on jellyfish and hydroids) and project them out of their own skin.

With a defensive arsenal like this, they can afford to be as flashy and conspicuous as they want. Ironically, however, they can't check themselves in the mirror--they have no eyes. The sensory organs on their heads (towards the front) act sort of like our noses, in the way that they can pick up chemicals on the water.

Like other gastropods (slugs and snails, etc.), they are hermaphroditic, carrying both eggs and sperm. When they mate with each other, they share both sets of sex cells, and each carries on with fertilized eggs. Their name comes from the Latin for "naked gill", referring to the respiratory organ sticking out of their back.

Check out the article, with accompanying slideshow and photos, at http://ngm.nationalgeographic.com/2008/06/nudibranchs/holland-text

Paddy

(p.s. "Whence did these pictures come?" you may ask, "they're just gummi worms in a studio, or Photoshopped!" In fact, they were taken underwater, on the reefs where they live, using special photography apparatus (yes, that's how big they are, down in the corner there):

3.12.2008

cephalopod camouflage

I've got some really cool stuff to show you. (This time there's video!)

So, while chameleons are well-known for their ability to change the color of their skin, they don't actually do it to camouflage themselves. Each species of chameleon is naturally colored to match their surroundings, and they really only change colors to send signals to other creatures, such as their mood or their physiological state.

Cephalopods, on the other hand, have much more advanced control over their coloration, in addition to the texture of their skin. Members of the clade Cephalopoda, particularly those in the clade Coleoidea, include octopuses (yes, octopuses), squid, and cuttlefish. Members of this clade have intellects far superior to any other invertebrates', which aids in their use of camouflage.

Octopuses, considered the smartest of invertebrates, are able to change both the texture and the color of their skin, through direct neural control of the muscles connected to pigment sacs called chromatophores.
A cephalopod chromatophore
(© www.tolweb.org)

The chromatophore is one of many small organs just under the skin, with a sac called the cytoelastic sacculus, which contains tiny pigment granules. Relaxed, the compressed sacculus is opaque, hiding the pigment granules. When the muscles surrounding the sac contract, the membrane of the sacculus stretches out (with as much as 50 times the area of its relaxed state) to expose the color of the pigment within. The skin of the cephalopod contains millons of these chromatophores, containing red, yellow, orange, brown, and/or black pigments, allowing the creature to take on as many as 50 different appearances, and change its coloration very rapidly. They also have leucophores, which display white spots, and iridiophores, which refract light and make the animal seem luminescent. All of these changes in color, in addition to the shape-shifting ability, allow it to camouflage or communicate very effectively.

A cephalopod can take in the nature of its surroundings using its highly complex eyes (cuttlefish have W-shaped pupils and two foveas, for acuity looking both forward and backward), and feel and smell the things it touches with its suckered tentacles. Here, an octopus effectively mimics its surroundings, and when threatened, displays its aggressive white color (notice how the white ring around the eye makes it look bigger and more intimidating):

(© Richard T. Hanlon, Marine Biological Laboratory, Woods Hole, MA)

Here are some other examples of octopuses adapting to the colors and textures of their environments:

(© National Geographic)



(© Hanlon)

Also in Coleoidea are the squid, some of which can also change the patterns of their skin. In the case below, when two males fight, they display aggressive white spots. When a male is courting a female, however, he shows his attractive brown shade. He can also split his coloration, however, to show the sexy brown side to the female, while his other half displays the aggressive white to fend off any other males in the area. Even cooler is that when she swims to the other side of him, he instantly switches the pattern, so she only sees his non-aggressive coloration:


(© Hanlon)

The third clade in Coleoidea are the cuttlefish, who have similar abilities to change the pigmentation and texture of their skin. Some species display bright coloration to show off to the ladies or to ward off predators, while others do their absolute best to blend in:


(© Hanlon)

One of the most fascinating things they can do is display moving bands of coloration on their skin, making it appear as if rays of light are moving across their bodies. I think the only other place I've seen this is on a space ship in Star Trek (yes this is real):


(© NG)

Here's some more fascinating video from PBS' NOVA series, with guest Mark Norman, marine biologist and curator of Museum Victoria in Australia (sound on):


(© NOVA/WGBH)

(side note: British people and their colonies say Cephalopod with a "kef" instead of "sef" like we Americans.... they still ain't figured out all of the English language yet)


(© NOVA/WGBH)

When the Giant cuttlefish of Australia come together to breed, the biggest, toughest males engage in intrasexual selection, where the most impressive guy wins. They always put on a dazzling show as they duke it out for mating rights (whether or not the females actually care):


(© NOVA/WGBH)

The little guys can't compete with the machismo of the larger, stronger males, so they've developed a new tactic to get to the waiting females: pretend to be one. In an amazing display of invertebrate guile, smaller male cuttlefish will change their body size and shape to match that of a female, and slip past the fighting males:


(© NOVA/WGBH)

And finally, the Flamboyant cuttlefish, the only one known to walk around on its legs, shows a bright and complex pattern when threatened to demonstrate to predators that it is poisonous to eat (also look at these):


(© NOVA/WGBH)

These cephalopods have developed complex systems of visual and tactile information-
gathering, and have the brains and skin to match, making them some of the most impressive marine invertebrates in the world. With advanced nervous systems capable of learning and problem-solving, eyesight that rivals that of the great apes, and a system of skin control that suits any environment, they are no doubt easily comparable to some of the most advanced predators that walk on land. Without, of course, the limitations of a skeleton:


(James B. Wood, Bermuda Institute of Ocean Sciences)


Paddy



2.05.2008

mars in 3D!

This is Olympus Mons.
As far as we know, it's the largest mountain--and volcano--in the solar system. At 27,000 m (88,500 ft) high, this BAMF of igneous rock is more than three times the height from sea level of Mount Everest, and more than two and a half times taller than Mauna Kea. On Earth, it would reach well into the stratosphere. The caldera at its summit is about 85 km (53 mi) long by 60 km (37 mi) wide, and up to 3 km (1.8 mi) deep.

And now, you can check it out in 3D.

On Tuesday, the European Space Agency published photos from the Mars Express, an orbiting satellite carrying the High Resolution Stereo Camera (HRSC), which has been taking 3D pictures of the planet's surface for the past three years. Until now, images of Mars have only come from 2D cameras either orbiting or on the surface, and so scientists have had little information on the true contours of the terrain. From these new pictures, the ESA was able to produce a Digital Terrain Model, or topographical playground, to give some perspective (literally) on the proportions of things on the Red Planet.

If you want to learn more about how they obtained the pictures, check out the ESA's website on the Mars Express HRSC. One of the best places to go walk around Mars and get pictures like this one is through the HRSC page presented by the Planetology and Remote Sensing Department, Institute of Geosciences, Freie Universit├Ąt, Berlin. For tips on navigating around the maps, hit up the "How to use HRSCview" in the left hand navigation.

Paddy

1.17.2008

save the whales! from the navy!

No, they're not being hunted with torpedoes. But whales, dolphins, and all other marine mammals are in serious danger from the onslaught of another of the Navy's deadly tools: SONAR [caps for an acronym, not sensationalism].

As a species, Homo sapiens is characterized by the abilities to make tools and conduct complex communication. It is these attributes that have set us apart from all others on this planet, not because we're any better or more important than any other species, but because we have the greatest impact on all living things and the physical planet itself. Short of the evolution of oxygen-producing cyanobacteria billions of years ago that created the livable atmosphere, no other species has had such a large influence on the existence of so many other organisms.

As time progresses, the communication and tool-building abilities of the human species becomes increasingly complex, and from the days we started with the bludgeon and the cutting tool thousands of years ago, we have arrived at the advent of such things as the MacBook Air and Ununoctium (slightly different technology, I know). Essentially unchecked until recently, however, have been the effects of our creations and their byproducts on the atmosphere, land, and seas.

Ironically, one of our more advanced tools, one that is causing very damaging effects to other species, was adopted from them almost a century ago.

The members of the clade Cetacea, which includes whales, dolphins, and porpoises, live exclusively in the water, and hence have evolved special mechanisms of communication and hearing that work exceptionally well in that environment. Since water is a much better medium for transmission of sound than is air, cetacean ears are quite different from those of terrestrial mammals. In their evolution from land mammals, whales and other cetaceans have lost all external auditory anatomy, and have developed much more powerful internal ears, capable of sensing the direction of sounds up to tens of miles away. Some cetaceans, the odontoceti (toothed whales) also have developed an adaptation called echolocation, similar to that used by bats, some shrews, and cave-dwelling oilbirds.


The dolphin, for example, makes a series of rapid clicking noises (up to 600 per second!) by passing air through phonic lips, located just inside the blowhole. Sounds are transmitted through the dolphin's head, reflect off of bones in the skull, and are focused and modified by the varying-density lipids in the melon. These clicks are broadcast outward, and some sound waves are reflected off of objects in the water and return to the dolphin. The dolphin then receives the reflected waves through its jaw bone, which transmits the signal to the inner ear. The brain then processes the clicks (at 600/second) to determine the location, size, shape, trajectory, and density of the reflecting object. It is with these abilities that toothed whales can successfully navigate and hunt in low-visibility waters.


Through our advanced tool-making and communication abilities, humans have figured out how to replicate this adaptation with modern technology, called SONAR, short for SOund NAvigation and Ranging. There are two kinds: active and passive. Passive sonar consists of listening in the water to the sounds generated by other things. Active sonar works in a similar fashion to that of the dolphin's, by sending out sound waves to be reflected and returned. This is the "ping" that you often hear in movies with submarines (although modern submarines don't use active sonar very often any more because it can easily give away your position).

The first modern echolocation device was patented a month after the Titanic sank in 1912, and a similar device was demonstrated to detect the presence of icebergs up to 3 km away. Sonar technology has remained relatively consistent over the past century, with developments only in the use of computers and the power of listening devices.

Both active and passive sonar are commonly found in warships, submarines, and airplanes, and active sonar is used in some torpedoes. It's also common in fish-finders on personal and commercial fishing boats, and has several scientific uses, such as ocean-floor mapping.

The United States Navy continues to run trials and experiments with active sonar, with the goal of advancing threat-detecting abilities, using high-powered arrays with frequencies of 3-8 kHz and volumes up to 235 decibels. For comparison [PDF], standing one foot away from a jet engine as it's taking off is 180 decibels, which causes immediate inner ear tissue death, and a sonic boom, the loudest sound possible in air, is around 200 db.

Not surprisingly, with the use of these powerful sounds, the nearby marine life is being negatively affected. On several occasions, mass beachings of whales have been reported after sonar exercises in the Bahamas, Greece, and the Canary Islands and the Madeiras in the Eastern Atlantic. The stranded whales have been found with ears and eyes bleeding, and on necropsy of the heads of several after a 2000 Navy exercise in the Bahamas, scientists found massive hemorrhaging around the ears and brain due to severe sonic trauma. After a NATO test in 2002, another mass stranding of rare beaked whales gave scientists an opportunity to dissect whole whales, wherein they found the same brain hemorrhaging, but also bleeding of the vessels surrounding the liver, kidneys, and other internal organs, in addition to gas and fat bubbles, similar to "the bends." Based on this evidence, it would appear that, after being subjected to organ-crushing blasts of sound, the disoriented whales shot to the surface to try to escape the noise, incurring fatal air and fat emboli in the bloodstream.

The Navy, when confronted with this information, has consistently denied responsibility, and has been uncooperative with efforts by environmental and non-governmental panels to work toward a solution. Also problematic is the fact that a large percentage of marine mammal research in the United States is funded by the Navy, and so scientists aware of the damage being done have remained largely silent for fear of losing their funding.

In March of last year, the NRDC filed a lawsuit against the Navy to keep them from conducting dangerous sonar exercises off of the coast of southern California. In November, a US District Court judge in Los Angeles ruled that the Navy had not conducted sufficient environmental impact investigations, and ordered them to do so.

On January 16th, President Bush issued a special exemption to the Navy from provisions of the Coastal Zone Management Act, and the White House Council on Environmental Quality gave the Navy a waiver from the National Environmental Protection Act, effectively reversing the judge's ruling. The Navy is expected to resume their sonar testing activities, while lawyers for the NRDC are struggling to challenge the exemption.

Here's a dramatic yet motivating video by the NRDC on the effects of sonar on the whale populations around the world, and this is an article in the NRDC's OnEarth Magazine that provides some more information on the history and effects of sonar.

Keep tabs on this story, and to show your support you can visit the NRDC's Action Center, where you can learn about the many ways you can help them defend the environment.

Paddy