Sleepless in Submersible

•June 29, 2014 • 2 Comments


At the beginning of June, Karl and I took the time to plan our dives for the rest of the summer based on my work schedule, his dive schedule, and the best days of the month for fishing, which tend to coincide with increased activity in the deep. Initially, we had planned to do a 7-8 hour dive on the 21st around 1pm. However, 1pm turned into 3pm, which turned into 4pm, which led to 7pm and a new dive plan: spending the night at 1300 feet.

The original idea was to do back-to-back dives since preparation is so time-intensive (putting extra weights in the sub, setting up the camera rig, filling air tanks, etc.). With such a late departure, we were likely going to be too exhausted to do another dive the next day. So, Karl suggested we dive from 7-11, sleep until sunrise, then film for another 4-5 hours. I was on board, but my pointed questions betrayed my apprehension about snoozing in the pitch-black ocean.

“What about oxygen?” I asked.

“Well, the regulator is set to 1.5 liters per minute which is a little too much for three people, so we’ll use that while we’re motoring but use a regular tank when we’re sleeping. We’ll just have to wake up every 2 hours to open the valve.”

Immediately I begin to imagine me and Karl in a deep sleep as the oxygen levels sank below critical levels. The air we breathe is 21% oxygen and if the concentration drops below 11%, death is likely.

“You know, you really don’t use that much oxygen when you’re sleeping,” Karl says to me, seeing my gears turning.

“Mmmmm…I just don’t think I’ll be able to sleep that much.”

“I once forgot to turn on the oxygen for the first hour of the dive. We only dropped down to 18% oxygen.”

“…..oh good.”

DCIM100GOPRO

Deep Sea Chicken

Deep Sea Chicken

An hour later, Karl was making a custom wooden board that would fit around the camera rig so we could put our heads by the viewport to sleep. He also attached a dead rooster (victim of a neighborhood dog…okay our dog – BAD Yoda!) that had been sitting in our freezer the past three weeks. After loading up on blankets, pillows, hot tea, and warm clothes, we set off a few minutes past 7. A steady rain had begun and the surface was choppy. The mangled rooster swayed in front of the window as my stomach flopped and gurgled. Not a very auspicious start. Ten minutes later, Karl cut the motors, and I waited for the lurch of the submarine that would indicate the beginning of our submergence. I kept waiting. And waiting.

“Are we submerging?”

“NO! The freaking motor died!”

This was a motor that had been giving Karl problems for the past two weeks. Luckily, the sub has a fully redundant propulsion system, so it’s not the end of the world if a motor does go out in mid-dive. Generally, though, it’s not a good idea to start a dive with one dead motor.

So we turned around. At the dock, Karl opened up the motor compartment as brown water dripped out (needless to say, this is not good). We weren’t going to dive that night.

——–

The issue with the motor was resolved by early afternoon the next day. Apparently, one of the corroded wires had been blocking the point where the air enters the motor compartment. Without air in the motor, water could easily trickle in.

By 5:15 we had pushed off from the dock and a few minutes past 6:00, we were cruising at 2000 feet. Not long after we had hit bottom, a odd spongy, fuzzy ball of an animal appeared in my viewport.

“Oh, it’s one of these things!” Karl shouted.

“What is it?” I asked while turning on the camera gear.

“I have no idea,” he replied.

dandelion siphonophore copy

Dandelion Siphonophore

After 15 years of experience in Roatán’s waters, Karl is an expert when it comes to deep sea animal identification. So it came as a surprise that he was unaware of this animal. I, too, had zero clue what it was after filming it, particularly since I could only get a remote sense of its appearance with my attention focused on a monitor screen filled with red (peak focus) and zebra stripes (overexposure). It was only after editing the footage and noticing a cluster of coordinated pumping structures that I realized its similarity to the group of nectophores used for propulsion in siphonophores. After a quick Google search using the key phrase “spongy blob siphonophore”, I found our match: the dandelion siphonophore.

Not long our siphonophore encounter, we came across a deep sea Spanish Dancer (also known less elegantly as the Flying Turkey) at 2100 feet. This Spanish Dancer, however, looked different from the one we had filmed previously: strings of reflective beads adorned this creature. Serendipitously, Claire Nouvian’s book, The Deep, helped me to explain this mystery. Upon feeling threatened, a Spanish Dancer lights up and its skin detaches, if attacked, onto the face or body of the predator, which glows vulnerably in the otherwise uniform darkness of the deep sea.

Spanish Dancer glowing in defense. Any predator that attacks will end with a layer of glowing skin - a very risky display in the dark deep sea.

Spanish Dancer glowing in defense. Any predator that attacks will end up with a layer of glowing skin – a very risky display in the dark deep sea.

Over the next few hours, we stumbled across animals every 20 minutes or so. When Karl yelled out that he had spotted a dumbo, I whooped with excitement: this would be our first shots of the dumbo with a new lens, and I was excited to see the level of detail that would come out of it. But this particular dumbo didn’t want to tango, and despite Karl’s repeated approaches with the sub, the dumbo just sank further down into the sand, clearly not in the mood for a late night dance.

And so we motored on.

Rattail Fish

Rattail Fish

One of our best finds of the night was the largest and ostensibly oldest rattail fish (also known as grenadier) that Karl has ever seen. Usually, these fish are graceful and undulating, almost hypnotic. But this grizzled grenadier was about as coordinated as a blind-folded five year-old trying to hit a pinata. In an act of aggression or more likely failing vision, the grenadier swam upside-down at full force towards the sub, crashing into the viewport. Its curiosity made for some great filming and close-up shots.

Before we called it quits around 10:30, we were able to catch a dumbo octopus in mid-water, and briefly, a dogfish swimming away from the sub.

dumbo copy

dumbo octopus copy

dumbo 2 copy

Dogfish

Dogfish

 

The criteria for a sleeping spot were not terribly complicated: we needed to find a sandy area that preferably had some rocks that could keep us from sliding down the slope. Particularly with bait attached to the bumper, a shark could move us around (a lovely thought). For most of our dive, we had come across alternating areas of steep, sloping sand and rocky debris. We happened upon a sandy area, and Karl let out some air from the ballasts tank; the back of Idabel rocked back into the sand, while my sphere still bobbed, slightly suspended in the water.

As I started to rearrange the already cramped passenger sphere, a quick stab of anxiety began to perforate my phlegmatic demeanor. Why, exactly, had I signed onto sleeping in a 4 and a half foot diameter passenger sphere with a full get-up of camera equipment and a 6-foot human? “Oh, but it’ll be such an adventure,” my 5-hour ago self had said to me, “sleeping under a sky of bioluminescence rather than stars!”

Karl laid out a thermarest pad as I arranged the pillows next to the passenger sphere window. Donned in two pairs of wool socks, a winter hat, fleece jacket, and spandex pants, I slid under the layers of cotton sheet, fleece blanket, and sleeping bag. And still…it was cold. The only way to fit ourselves through the opening of the passenger sphere comfortably was for one of us to lay on our back, both of us to lay on our sides, or one of us to lay on our side. On top of us, we also had lithium hydroxide “blankets” (the same used in the space station) to absorb carbon dioxide (in other words: to keep us alive).

So this is how the night began: a 45-minute crescendo of nervous conversation that ended with the culmination of my worst fears combined (total darkness in a tight space). Knowing that I would be completely anal-retentive about oxygen levels, Karl had  suction-cupped the oxygen level monitor directly in front of my face. After he opened the oxygen tank valve and cranked us up to 24% O2, so began the 30-minute cycle of activity that characterized our night under the sea:

Karl turns to lay flat on his back. I turn to lay on my side. Karl snores, which jolts me awake, and I frantically turn on my light and look at the oxygen levels. Shuffling of lithium hydroxide blankets. I turn to lay on my back. Karl lays on his side. I snore, which jolts me awake, and I frantically turn on my light and look at the oxygen levels. Shuffling of lithium hydroxide blankets. Repeat 10-12 times.

It was uncomfortable. But there was a moment where I opened my eyes to see the bioluminescent outline of an animal passing over the viewport. And I thought – well, here I am. There’s only so much fear you can hold on to when absolutely nothing terrifying is happening. My mind had been stuck in the elaborate “what ifs” of sleeping 1300 feet below the surface. At 5:30 am when I woke Karl up, either because my mind had come to grips with logic or it was just too fatigued to continue the endless cycle of hypothetical doomsday scenarios, I finally felt the peace of silence and the singularity of that experience.

Armored Sea Robin

Armored Sea Robin

We returned to Half Moon Bay within two hours of waking up. Footage of a catshark, tinselfish, and sea robin completed our shot list for the day, as we turned home exhausted and ready for another night’s sleep. Upon hauling the sub out of the water, we found the rooster caught between the bumper and hull of the passenger sphere – inaccessible for a hungry shark. Karl claims he felt a bump in the night – maybe a frustrated shark had tried to snatch a bite after all. I guess we’ll never know.

 

Here Fishy, Fishy: Tagging Prehistoric Sixgill Sharks

•July 6, 2014 • Leave a Comment

The sixgill shark is potentially the world’s most widely distributed large predator left on Earth today. And we hardly know anything about it.

Sixgill Shark. Photo by Lia Barrett.

Sixgill Shark. Photo by Lia Barrett.

Sightings of sixgills are rare as they tend to spend most of their time in deeper waters. Seattle, Washington, specifically Puget Sound, is one location where sixgills can be found at recreational scuba depths. Generally, young sixgills are found at these shallow depths, while adults tend to remain in deeper water farther off the coast. It’s thought that sixgills may be restricted to deeper depths due to light sensitivity and perhaps thermal sensitivity. In some parts of the world, sixgills can be found seasonally at shallower depths, usually when algae is in bloom, as the blooms tend to attenuate light penetration. In one unusual case, a sixgill was caught 30 km up a river in Tasmania!

Much of the research on sixgills and some of the only horizontal migration studies have been conducted in Puget Sound. Many studies have focused on diel vertical migration – the daily pattern of movement up and down the water column – and found that sixgills tend to vertically migrate several hundred meters into shallower water at night and return to deeper depths (the oxygen minimum zone) during the day. But no study has ever looked at the horizontal migration patterns of adult sixgills. One reason for this is that, well, they’re hard to catch. In most cases, a sixgill shark must be hauled up alongside a boat and a tagged via surgical insertion of a satellite tag underneath the skin. As you can imagine, it’s not that easy to selectively catch a deep water fish.

taggingdiagramBut what about tagging from a submersible? A graduate student at the University of Hawai’i at Manoa has just that idea. Brandon Genco is currently trying to crowd-fund his project and has also applied for a Waitt Institute grant. His main objective is to tag 3-5 adult female sixgill sharks from Idabel so we can figure out a thing or two about where these animals move and how far they swim. This will basically involve a glorified slingshot with a satellite tag attached. With a large helping of crowd-funded science and a sprinkle of renegade engineering, we plan to get it all on film, too.

Most sharks tend to migrate long distances, and these migrational movements can be extremely important for conservation efforts. For instance, studies in Puget Sound found that sub-adult sixgills stuck pretty close to home until they reached a certain size. A small home range for subadults is imperative for understanding how localized environmental effects (e.g. anthropogenic activities) could have serious consequences for these sharks. Establishing whether adults migrate long distances and congregate for mating events will be one critical to our understanding of this animal.

If you are having ANY doubts about funding this project, just take a look at when NatGeo was here a few years ago filming sixgills from Idabel. And did I mention that sixgills are prehistoric?! The majority of extant sharks today have five-gills – a hallmark of a more recent evolutionary history. Most members of the sixgill family tree no longer exist (they died off 200 million years ago), but a few aunties and sixth cousins half-removed still remain like the dogfish, greenland shark, and other six-gill and seven-gill sharks. So, if you’d like to give a hand to this unique project, please visit the crowd-funding page here!

 

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Sources

Andrews KS, Williams GD, Levin PS (2010) Seasonal and ontogenetic changes in movement patterns of sixgill sharks. PloS one 5: e12549. DOI:10.1371/journal.pone.0012549.

Barnett A, Stevens JD, Yick JL (2010). The occurrence of the bluntnose sixgill shark Hexanchus griseus (Hexanchiformes: Hexanchidae) in a river in south-eastern Tasmania. Marine Biodiversity Records, 3, e24 DOI:10.1017/S1755267210000199.

Comfort CM, Weng KC (2014) Vertical habitat and behaviour of the bluntnose sixgill shark in Hawaii. Deep Sea Research Part II: Topical Studies in Oceanography. DOI: 10.1016/j.dsr2.2014.04.005

http://psrc.mlml.calstate.edu/2008/11/featured-elasmobranch-bluntnose-sixgill-shark/

http://www.elasmo-research.org/education/topics/d_jurassic_shark.htm

Deep

•June 22, 2014 • 2 Comments

9780547985527James Nestor’s latest book, Deep, chronicles his exploration into the extreme sport of free-diving and the deepest parts of our ocean. While researching his book, Nestor took a dive in Karl’s submarine back in January of 2013, which he’s written about in what we hope is a positive light. However, from the looks of the New York Times Book Review, his descriptions may be a bit dramatic!

Deep is scheduled to be released on Tuesday, June 24th. Below is a blurb from the New York Times Sunday Book Review:

The deeper the book ventures into the ocean, the more dramatic and unusual the organisms therein and the people who observe them. Nestor takes a harrowing ride to −2,500 feet with one D.I.Y. submarine builder from New Jersey. The man operates his vessel in Honduras because “taking tourists down 70 stories in a homemade, unlicensed submarine, without insurance, was a liability nightmare,” and regulations in Honduras are “lax or nonexistent.” It adds to the drama when they reach the “midnight zone” — where light ceases to penetrate the water and some organisms have evolved into hermaphrodites to double their chance of bumping into a potential mate — and the hull of the bubble-gum-and-duct-tape sub begins creaking and fizzing.

 

 

Changing Seas: Living Fossils Episode

•June 21, 2014 • Leave a Comment

Check out Idabel‘s latest appearance on PBS Miami’s Changing Seas. This episode features the visiting crinoid scientists mentioned in the Living Fossils: Crinoids post from May.

The Sounding of the Ocean

•June 1, 2014 • Leave a Comment

Whether literally or metaphorically, you’ve no doubt heard the phrase “sounding the depths” before. “Sounding” actually comes from the Old English word sund, which means “sea”, and for many millennia, humans used archaic technologies to measure the depths of the ocean. Ironically enough, we now use sound.

History of Sounding. Way back when in 1800 B.C., the Egyptians used sounding poles and lead lines to measure the depths of ye old sea. A pole, when inserted into the ocean and hit bottom, would reveal the depth of the sea floor. Pretty straightforward method, but understandably, highly unrealistic for depths greater than 30-40 feet (aka the vast majority of the ocean).

Ancienty Egyptians using sounding poles to measure the depths. Image from http://www.history.noaa.gov/

Ancienty Egyptians using sounding poles to measure the depths. Image from http://www.history.noaa.gov/

Bathymetry, the study of ocean depths, could be nominated as arguably the slowest evolving scientific field of all time. Let’s leave 1800 B.C. and fast forward to 1838. Charles Wilkes is leading the United States Exploration Expedition and in a radical departure from his Egyptian predecessors 3500 years ago, uses copper wire (!) instead of hemp line to sound the depths. Unfortunately, the copper wire proves too pliant and Charlie becomes too impatient to explore other options. Granted, I can’t blame him because who could really tolerate letting out a line for a whole day only to get a single reading? But still. This is the same guy who decided to haul a pendulum up to measure gravity at the peak of Mauna Loa in Hawaii, employing hundreds of natives to a) drag all of his crap up the mountain and b) blaze a new path even though a well-worn trail already existed. What a kook!

Anyway, the resolute Sir James Clark Ross picked up the slack a year later and got real about the whole ocean-depth sounding idea. After failing repeatedly to obtain readings, Ross pushed onward and refused to be defeated: he ordered a 4-mile long hemp sounding line to be constructed on board his vessel. In 1840, he successfully recorded the first abyssal sounding: 2,425 fathoms (2.75 miles).

By the mid-1850s, the beginning of the sounding technology revolution had begun in response to the desire to lay a Transatlantic cable. Lord Kelvin developed a sounding machine that was modified, over the next fifty years, into several variations.kelvin machine

Using Sound to Sound the Depths. Aristotle, Leonardo da Vinci, and Francis Bacon had all, in some form or another, contributed to the idea that sound could be used to measure the depths of the ocean. But it wasn’t until 1807 that the idea was revisited, however briefly, by a French scientist. Forgoing the opportunity to embellish his Wikipedia page, Dominique Francois Jean Arago floated the idea, but did not follow through on any conceivable method or means to accomplish this objective.

 

fessenden oscillator

Fessenden and his oscillator. Image from http://www.dosits.org/

Alas, matey. We finally arrive at the last century when sounding technology really went wild. In response to the sinking of RMS Titanic in 1912, Reginald Fessenden invented an oscillator that could emit sounds underwater and receive their echoes. During an experiment which confirmed the oscillators ability to detect icebergs, Fessenden curiously noted an echo that was returned only two seconds after the outgoing pulse; that echo was the bottom of the ocean.

The discovery that the oscillator could work both horizontally and vertically set off a sounding technology revolution and a flurry of ever-improving transducers. Sonic sounding devices became the new norm and for the next fifty years, the meteoric-rise in technological innovation in the field of sounding began to help elucidate the sea floor topography. And so, the relatively nascent theories of seafloor spreading and plate tectonics were born!

Modern SONAR (SOund NAvigation and Ranging). The impetus for developing advanced sonar devices was, like all good innovations in ocean technology, defense-oriented. In the 1970’s, the Navy pushed development in order to create seafloor maps for submarine navigation. By 1977, the technology was commercially used. Over the past forty-years, improvements in multi-beam sonar devices have primarily focused on increasing the resolution of the maps (via higher frequency pulses and more beams). Today, you can take a tour through a 3-D map generated by some of these enormous transducers (and sophisticated data processing software). As compared to the leadline, SONAR is the crown jewel of oceanography. 

To give you an idea, the lead-line method represents one sounding data point. With the multi-beam sonar device used to map Roatán, each ping or sound emitted from the transducer could return up to 864 pings or echoes!

To give you an idea, the leadline method returns one sounding per survey. With the multi-beam sonar device used to map Roatán, each ping or sound emitted from the transducer returns up to 864 soundings! Image from http://celebrating200years.noaa.gov/

The ship that surveyed Roatán, the RV Falkor, used a Konsberg multibeam echosounder that was mounted to the bottom of the ship’s hull (similar to what’s pictured below). After more than a year of data processing, here is a higher resolution map that has been created, showcasing Roatán’s steep topography and an awesomely deep gully toward the west end of the island. For more maps and info, check out this poster available on the Schmidt Ocean Institute’s website.

Konsberg transducer. Image from http://www.km.kongsberg.com/

Konsberg transducer. Image from http://www.km.kongsberg.com/

 

3-D view of the west end of the island.

3-D view of the west end of the island. Map created by Matt Rittinghouse

Sources:

http://www.oceanexplorationtrust.org/#!remotely-operated-vehicles/c1lm4

http://www.schmidtocean.org/story/show/1770

http://www.history.noaa.gov/stories_tales/poletobeam.html

http://www.merriam-webster.com/dictionary/sound

Carson, Rachel (1989) The Sea Around Us. Oxford University Press, USA.

Wikipedia entries for Charles Wilkes and Sir James Clark Ross

http://www.dosits.org/people/history/early1900/

Hammer(head) Time!

•May 18, 2014 • Leave a Comment

On Thursday we were able to get back in the water for a relatively short four hour dive. It was my first experience filming with another passenger in the sphere, and to be sure, it was cramped. A few elbows and shoulders in the nose were totally worth some of the footage we were able to capture in the Lophelia Reef area though. Karl also took the opportunity to deploy a temperature and salinity recorder, as requested by last week’s visiting crinoid scientists. Some of the highlights of this dive included several tinselfish, swimming polychaete worms, spiny crabs, and a pair of strange pre-historic-looking (who knows?) fish (see pic below). Karl’s only ever seen this fish on a few dives, and usually it swims off immediately. We were able to get some jerky footage – enough to send off a still shot for species identification at least!

Rare unknown fish filmed at 1200 feet.

Rare fish at 1200 feet.

We learned a valuable lesson on this dive: never put away the camera equipment until the sub has surfaced! Usually, I begin to put away gear at 600 feet to avoid the inevitable condensation that occurs as we rapidly ascend from 50°F water to surface water temperatures around 85°F. Just as I had disconnected the Ninja field recorder and started loosening the camera from the rig, Karl yelled out, “There’s a hammerhead above us!” Cursing and feeling slightly panicked, I quickly retightened the camera, reconnected the Ninja, and turned everything on. Unfortunately, the Ninja can be temperamental as it tries to interpret the frame speed settings on the DSLR, and this, of course, is what happened. While the hammerhead cruised above us, I frantically waved my fingers in front of the camera in my usual attempt to connect the two devices. After what seemed like an eternity, but was likely only a minute or two, the Ninja finally connected, and I firmly jostled my elbow into the passenger next to me to get a good shot. “We don’t see hammerheads very often,” I explained, as if I even needed to say anything at all after my frenzied attempts to reattach the gear.

For the next few minutes, we followed the hammerhead down the wall until it disappeared into the hazy blue of the thermocline at 600 feet. At one point, we thought that the hammerhead was coming straight at us, but the low-light and symmetrical body shape created an optical illusion: the shark was actually swimming away from us, and it had gained too much distance for us to keep up once we powered up the motors at full throttle in hot pursuit. Nevertheless, it was a rare and amazing sight – only our second hammerhead sighting in 40 hours of diving, and our first where it stuck around long enough to be captured on camera! Check out the footage below.

Living Fossils: Crinoids

•May 13, 2014 • 1 Comment
Stalked Crinoid/Sea Lily/Flower Impersonator Extraordinaire

Stalked Crinoid/Sea Lily/Flower Impersonator Extraordinaire

This past week, two crinoid scientists, Charles Messing and Tomasz Baumiller, were visiting the island to continue research on the crinoid populations here in Roatán. Primarily, they were interested in the regeneration of crinoid arms after predation. A few individuals in the Lophelia Reef area have given them a sense of the relatively slow regeneration process of these creatures. If a crinoid was a land-based creature, no doubt we would already have tomes dedicated to their life histories, physiology, and genome. But, as with many deep sea creatures, there’s a lot we don’t know about crinoids. So let’s at least visit what we do know…

Crinoids are animals, not plants. Yeah, I know. These floral impostors had me tricked, too. Crinoids are echinoderms – think starfish, sand dollars, and sea urchins. All echinoderms are pentamerous, which means they are radially symmetric with five arms. In the case of crinoids, the arms are organized in patterns of five: some individuals may have more than five arms, but the number will always be a multiple of five. And yes, crinoids are damn good piano players (just take a look at the video we shot).

So in that pentamerous sea of arms, where the heck is the mouth? And how do they possibly eat with those pine needle protrusions? Good questions. Let’s take a look at crinoid anatomy for a quick sec:

crinoid anatomy

Modified from Bather, F.A. 1900. The Echinodermata. pp. 344p. IN: Lankester, E.R. (eds.) A Treatise on Zoology, Part III. Adam and Charles Black, London. © 1998 William I. Ausich

If you were to strip off the pinnules of the crinoid’s crown, you’d essentially have a mutant chicken claw. And that, my friends, is exactly what fossilized crinoids look like. If you ever find yourself in the midst of a fossil expedition, trudging through the foothills of Montana and you see something like this:

Crinoid Fossil

Crinoid Fossil. Image from http://www.fossilmuseum.net

You can impress your fellow fossil foragers: “Just your friendly Paleozoic suspension feeder, ya’ll!” But seriously, here’s how crinoids eat: the pinnules are pivotal for capturing food; each is comprised of many tube feet (you can see them juuuust barely in the photo below) that enable the crinoid to flick food into this feeding groove, which facilitates the transport of delicious blobs of mucous-covered morsels (diatoms, invertebrate larvae, etc.) to the mouth.

Tiny little tube feet protruding from the pinnules.

Tiny tube feet protruding from the pinnules. Image from http://www.nova.edu

After setting up shop on a rock, they just sway to and fro with currents and upwellings, allowing the water to push bits of morsels into their pinnules. This type of feeding behavior relegates crinoids to possibly the laziest group of animals ever: the couch potatoes of the sea!

Crinoids can crawl, fly, and boogie. There are two main types of crinoids: sea lilies, which refer to the stalked (aka stationary) variety and feather stars, which refer to the sessile (aka mobile) variety. Take a look at this Monterey Bay Research Aquarium video for an awesome shot of a dancing feather star.

Here in the deep waters off of Roatán, we see primarily sea lilies, although feather stars make an appearance every so often. The primary physical difference is the absence of a stalk in the mobile feather stars. Instead, they have cirri, which are used to grip on to hard substrate or act as feet to crawl along surfaces. Scientists speculate that the motile feather star evolved from the stalked variety some 250 million years ago in response to predation by sea urchins (Baumiller et al. 2010).

Feather start gripping a rock with its cirri. Photo by BN Sullivan (http://scienceblogs.com/photosynthesis/2009/08/12/getting-to-know-crinoids-throu/)

Feather start gripping a rock with its cirri. Photo by BN Sullivan (http://scienceblogs.com/photosynthesis/2009/08/12/getting-to-know-crinoids-throu/)

 

Crinoids are one of the oldest living fossils on Earth. Quite a few marine species hold this title, including the frilled shark, nautilus, sponge, coelacanth, and horsehoe crab. Crinoids, for some reason, don’t even make it into the honorable mention category for “oldest species on Earth” Google search websites. In fact, for quite some time people thought they had gone extinct because our access to the deep sea was so limited for so long. And it’s not like a deep sea crinoid is ever going to wash up on shore. But the 150 million year-old Frilled Shark ain’t got nothing on Crinoid’s 400 million year track record! Here’s a sweet pic of a fossilized croinoid:

Crinoid Fossil

Crinoid Fossil

We are planning to start a marathon of dives within the next two weeks, so check back soon for some fresh footage!

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Sources:

http://www.paleosoc.org/Crinoids.pdf

http://tolweb.org/Crinoidea

Baumiller et al. 2010 Post-Paleozoic crinoid radiation in response to benthic predation preceded the Mesozoic marine revolution. Proc Natl Acad Sci 107:13

doi: 10.1073/pnas.0914199107