Hello Reddit.

I'm a deep-sea biologist that also helps oversee a research center focused on evolutionary biology at Duke University (craigmcclain.com). I've participated in dozens of oceanographic expeditions taking me to the Antarctic and the most remote regions of the Pacific and Atlantic. I've been to the bottom of the ocean at 1 mile deep and have worked with remotely operated vehicles at 2.5 miles deep. I am a connoisseur and contributor of research on the body size of animals, including the Giant Isopod and Giant Squid (storyofsize.com). But my favorite research topic is the diversity of deep-sea invertebrates, especially snails, and the range of their often bizarre adaptations to the environmental extremes of the deep oceans.

Currently I'm researching wood falls in the deep oceans; logs and whole trees that saturate with water and sink to the deep-sea floor. These wooden carcasses bring a rare commodity to the deep sea devoid of light and plants—food. On the seafloor these wood falls are covered in unique marine invertebrates wholly adapted to eating wood. I'm so passionate about this work I'm crowd sourcing the project. If you are interested check out this sweet deep-sea video with a sick dub step audio track at tinyurl.com/gotwoodfall

I am also the founder and chief editor of Deep-Sea News (deepseanews.com), a highly popular ocean themed blog written by seven marine scientists.

Looking forward to your questions on a life of science, being crammed in a submersible, body size of marine animals, wood falls, crazy deep-sea creatures, and anything else you can think of. Ask Me Anything!

Proof: https://twitter.com/DrCraigMc/status/431914107043086336 http://deepseanews.com/2014/02/i-am-a-deep-sea-biologist-and-visit-the-oceans-depths-in-a-submersible-a-reddit-ama/

UPDATE: Thanks everyone for an amazing AMA. I enjoyed answering everyone's questions. Don't hesitate to continue to post further questions and I'll try to answer them when can.

Comments: 206 • Responses: 79  • Date: 

PuffsPlusArmada30 karma

Are there gatherings or convention type meetings for the Deep Sea Biology community? If so does James Cameron show up half way through and steal away the attention of all the women leaving the rest of you pissed and muttering "god I fucking hate Cameron..."

DrCraigMc30 karma

Why do I have a feeling you may know the answer to this ;-) Every three years there is a Deep-Sea Biology Meeting. In 2012 this occurred in New Zealand and Cameron showed up half way through...late. The rest of us don't get jealous. Most of us have been into the deep more times than him.

PuffsPlusArmada20 karma

Dude I swear to you I just made all of that up. Are you seriously telling me that happened?

DrCraigMc26 karma

Yep. Not the lady part but all the other parts yes.

Whysharksmatter15 karma

Would you rather fight 100 hydrothermal vent shrimp sized horses, or one horse sized hydrothermal vent shrimp?

DrCraigMc40 karma

100 vent shrimp sized horses. I would gather them all up and put tiny harnesses on them. I would make them pull me around in a Red Flyer Wagon.

On the other hand a horse sized hydrothermal vent shrimp would go well with some Cajun seasoning. So it might be worth the fight. But then again they accumulate sulfur and toxic metals in their tissues so the taste by be a little zesty. But then again Cajun spice does cover up the taste of almost anything.

kingcarter310 karma

You from Louisianan bro?

DrCraigMc3 karma


zzanna15 karma


  1. Do you have any advice for a second year marine biology university student? As in what kind of information would you have found useful at this stage in your education? Or just general words of encouragement...
  2. Do you have a favourite deep sea creature?
  3. What do you consider the best part of your job and what is the worst?
  4. What is the scariest thing you have seen, if anything, and what was the most bizarre?
  5. How do you locate the woodfalls? Just by chance or are they planted and then revisited?

P.S. If you happen to be looking for an intern I would be very interested.

edits: I keep thinking of more questions!

DrCraigMc14 karma

  1. The greatest advice I can give is be passionate about what you do. The first and last thing you think about should be the ocean. Don't tell my spouse I just said that. But a genuine love of what you are doing will pull you through the hurdles you might face. I wish I had taken more math, programming, and statistics. Modern science in any field is heavily dependent on these things. It would have been easier to acquire these skills when you are younger.

  2. Tough one. Giant Isopod, Giant Squid, Carnivorous sponges, and the scaly foot snail. The last one is definitely the most amazing. It's a snail with iron pyrite plates across its foot http://deepseanews.com/2010/01/the-evolution-of-iron-clad-samurai-snails-with-gold-feet/

  3. The best parts of my job are being at sea, working with and seeing bizarre deep-sea creatures, and interacting with the public and sharing with them my passion. Worse part? Constantly trying to find money to support those activities. Did I mention that I am trying to raise funds for some of my research through crowd funding? ;-) https://experiment.com/projects/wood-is-it-what-s-for-dinner

  4. Nothing really scary but seeing the most bizarre has to be either the carnivorous sponges or a hermit crab that doesn't use a shell but rather a bunch of anemones that form a sort of soft shell. The hermit crabs are so deep that the snails there are too small and brittle for them to use as homes. Likewise under extreme pressure and cold temperatures calcium carbonate, snail shell material, dissolves. So old snail shells don't last very long with out a snail actively maintaining and repairing the shell.

  5. We deploy logs ourselves. If you watch the video here you can see us with an ROV pulling mesh wrapped logs out of basket we sent to the seafloor. https://experiment.com/projects/wood-is-it-what-s-for-dinner

rejectedbanana12 karma

Have you ever pet a live giant isopod?

DrCraigMc16 karma

Absolutely! The Shedd Aquarium in Chicago has an aquarium full of them for the public to see. They let me touch one. Otherwise I just poked at dead ones I've caught.

rejectedbanana9 karma

I am fascinated yet creeped out at the same time.

DrCraigMc13 karma

I think that is a valid response.

karma41510 karma

have you ever had the opportunity to investigate any under water ruins, ancient or recent ?

DrCraigMc35 karma

The secret society of underwater scientists don't allow biologists to do archaeology

Keith_Creeper9 karma

How many times have you got it on, in the submersible. Be honest. Its for science.

DrCraigMc15 karma

For science! I have never had relations in a submersible. Impure thoughts yes. There is not a lot of room in there to maneuver and as a large guy my moves require a lot of room.

Keith_Creeper7 karma

As a large guy myself, I too have yet to find a submersible with sufficient "relations", room.

DrCraigMc3 karma

Independent confirmation!

Thereminz8 karma

how many new species have you found?

if you find some new species that looks like the reddit alien you should call it Snooidae

DrCraigMc17 karma

Every sample I've taken from the deep sea, or time I visited in a submersible, or live video from a ROV I've watched as come with a new species. In some of my wood fall samples 50% of the species are completely new to science. In some of my mud samples 75% are new.

AFrikkenPuppy6 karma

Even considering you travel far beyond where most humans have access, do you still see signs of us at such depths? For example trash such as beer cans or bottles

And also what is the strangest thing you've observed at the bottom of the sea?

DrCraigMc8 karma

Every deep-sea dive I encounter some form of trash. Cans, bottles, random pieces of metal...even shipping containers have been seen http://www.mbari.org/news/news_releases/2011/containers/containers-release.html

The deep oceans are by far the least impacted by human activities but that is quickly changing.

In the comments I have mentioned some of the strange things but there has been so many I can provide a bunch of different examples. Deep-sea corals can be very cool. My favorite is the bubblegum corals that look like huge masses of chewed up bubblegum. On top of seamounts bubblegum corals can reach heights of 10 feet. Hundreds of these will cover the peak of a seamount.



surfinspacegirl6 karma

Have you seen the giant trash island floating in the middle of the Pacific Ocean and if so, what are your ideas on how to clean it up?

DrCraigMc6 karma

I have not. But most of the plastic in the ocean is microscopic bits. My friend Dr. Goldstein has some great information at her website http://seaplexscience.com/faq/

cayal36 karma

Good day Doctor,

I have a couple of questions. I got into Scuba Diving big time and became fascinated with the underwater world. As such I would love to get into that line of work. My questions are:

  1. Most interesting/astounding thing you've ever seen deep water? Something that most people are never going to see.

  2. Are there a lot of fall logs and trees underwater?

  3. How did you get into the field? What did you study?

  4. How long do you spend in a submersible, how does it feel? How many people can it hold and is there a cabin fever-like feeling towards the end?

  5. Are you paranoid about the ocean crushing you and your submersible?

  6. Need an assistant. Don't care if it's to get you coffee ;)

Look forward to your answers.

DrCraigMc8 karma

  1. On my very first dive I say a giant isopod. Imagine a roly poly the size of size 13 shoe. That experience confirmed that I had to deep-sea biology and study the size of animals.

For reference: http://upload.wikimedia.org/wikipedia/commons/1/18/Giant_isopod.jpg

  1. In mud samples from the ocean floor we often recover small bits of wood. Only rarely do see a tree or log in the deep sea. I have never seen one myself but have seen video from other submersible and ROV dives. The deep ocean is a very big place and finding anything specific can be very difficult.

  2. See my comment above

  3. The dive was 8 hours. Two hours down, two hours up, and only 4 hours on the bottom. It feels cold and very, very cramped. The sphere that holds 2-3 people depending on the sub is only a little over 6 feet in diameter. Definitely toward the end of the dive you are ready for a good walk and a bathroom break. I can never convince myself to go pee into a container in front of the others.

  4. I am actually claustrophobic but I get so excited about seeing everything I quickly forget the small capsule I'm in.

  5. Fantastic! I love coffee!

koreanknife5 karma

What's the scariest moment you've had while in the submersible?

Also - is there a reliable way to quickly evacuate or abort mission if something terribly wrong happens while a mile deep in the water?

DrCraigMc12 karma

No scary moments. Lots of checks, double checks, and triple checks by engineers and submersible crews to make sure nothing goes wrong.

There is really not a reliable way to escape if something goes wrong. In case of emergency there is a pull handle at the bottom of the sphere that ejects the crew sphere from the submersible. This sphere would then shoot up through the water column. I don't think this has ever been used and I'm not sure anybody knows what would really happen.

dguv221 karma

Is your submersible like a bathoscath similar to ALVIN? (Probably incorrect spelling)

DrCraigMc1 karma

All modern submersible pretty much follow the same design plans as the Alvin. Basically a titanium crew sphere with lots of extra stuff attached to the outside.

neoncactus4775 karma

As a young scientist, what sort of work did you take to gain experience in the field? Also, weirdest deep-sea creature?

DrCraigMc15 karma

The contest for the weirdest deep-sea creatures is a very tough competition indeed. I got to go with carnivorous sponges. 99% of sponges are filter feeders. However, in the deep sea are these crazy sponges that capture tiny crustaceans with sheets of little hooks. Something like velcro. The crustaceans get stuck and then sponge cells mobilize and envelop the crustacean. The cells secrete enzymes and then slurp up the crustacean juices. It is the equivalent of a mosquito getting trapped in your arm hair. Then you grow a sheet of skin over it quickly. You then digest and absorb the trapped mosquito.

Even weirder is that some of these carnivorous sponges look like lollipop displays at the store.


DrCraigMc11 karma

I started off with an undergraduate degree in biology...and religion. The later was probably not necessary ;-) I knew I wanted to be a marine biologist so I volunteered one summer in a marine lab in Louisiana. The next summer I spent the summer in Boston as part of Research Experience for Undergraduates Program. That by chance was working with deep-sea snails. I liked it so much I asked the professor if I could be his Ph.d. student. Thankfully he said yes.

meterspersecond5 karma

I'd like to say, I really enjoy the stuff Deep Sea News puts out, so keep doing a great job with that!

Also, I've been interested in what lies beneath the oceans surface since I read a book on William Beebe's bathysphere dives.

~What vehicle did you do your 1 mile dive in?

~What about the underwater world do find the most fascinating?

~What research have you done on Giant Squids/what did that research entail?

Thanks for doing this AMA!

DrCraigMc4 karma

  1. I have been in both the Alvin and the old SeaLinks that were at Harbor Branch Oceanographic Institute http://admin.collegepublisher.com/preview/polopoly_fs/1.2328660!/image/3456667645.jpg The SeaLink was actually my first dive.
  2. That is a great question. Everything!? I am constantly amazed by the unusual behaviors and features of deep-sea animals to deal with extreme pressures, freezing temperatures, no light, and little food. How messed up is it that there are animals miles deep that are totally adapted to eating wood. Nothing else just wood. Something that occurs randomly and rarely in the deep sea. I mean how do larvae actually find the wood to settle on it? Do they just hang around waiting for random piece of wood? I seriously cannot figure a biologically feasible way that this could ever work or be evolutionary successful strategy but yet it does.
  3. I am mainly interested in the evolution of size in mollusks including squids. My research with squids is no more complicated than measuring them with a tape measure! But man it rocks.

DrCraigMc3 karma

Also thank for reading Deep-Sea News

baldkat5 karma

I don't know if this applies, but I've been really interested in the effects from Fukushima on deep-sea creatures. Can you tell us a little about this?

DrCraigMc3 karma

So far we know of know impacts of Fukushima on deep-sea creatures. Also the story going around about the sea floor being littered with dead animals is also wrong.


Also see the posts here


The_Write_Stuff5 karma

As someone who is claustrophobic, I admire anyone who can work at depths where the tiniest mistake could mean being instantly crushed under the weight of thousands of pounds of pressure or trapped in a dark metal box to die of hypothermia and lack of oxygen.

Given that, have you ever been really scared on a dive?

DrCraigMc4 karma

I have never been scared to dive. In fact I wish I could do it more. In the last several years I have only used remotely operated vehicles (basically underwater robots on a tether). ROVs allow for longer bottom times and greater flexibility in what a scientist can accomplish. And while the dive is being conducted I can step out for coffee or a bathroom break...usually in that order.

solanumtuberosum4 karma

  1. Why do some deep sea creatures have color, like this octopus here?

  2. What kind of adaptations do deep sea creatures have for such high pressures? Any special bones/exoskeletons?

Thanks a lot for doing this AMA!

DrCraigMc9 karma

The main adaptations to pressure are biochemical.

As you may remember from high school or college biology, a cellular membrane consists of lipid bilayer. The major membrane lipid is a phospholipid. One end of this molecule is polarized consisting of both a negatively charged oxygen attached to the phosphate and a positively charged nitrogen group. To this ‘head’ is attached to two noncharged fatty acid ‘tails’. The polarized end is thus hydrophilic (i.e. water ‘loving’ because of the charges on a water molecule) and the fatty acid tails are hydrophobic. The polar regions of the phospholipids are oriented toward the surfaces of the membrane as result of their attraction to the polar water molecules in the fluid both inside and outside the cell. The important thing to remember is no chemical bond connects adjacent phospholipids. The structure is entirely maintained by the interaction of charges (or lack of) between water and the phospholipids. This makes the membrane semipermeable much like a layer of oil on water.

But wait… Pressure increases 1atm for every 10m, so deep-sea organism can experience a range of pressures from 20atm at the shallowest point to 1100atm in the deepest. This results in a tighter packing of the phospholipids which lower the permeability of the membrane.

But wait it gets worse…Temperatures in the deep are typically near 4 degrees C and near the poles water can become supercooled to -1 degree C. This also decreases the permeability of the cell membrane.

One adaptation to increase cellular permeability is to increase the percentage of unsaturated fatty acids. In a saturated fatty acid all the carbons in the chain are lined by a single covalent bond. As you recall, a carbon can take four chemical bonds. If all these bonds are covalent (single) then a carbon could potentially attach to 4 other atoms. Thus the saturated comes from the fact that the carbon chain is loaded with hydrogens. If a carbon forms a double bond with another atom then the carbon would have to bond with one less hydrogen. Thus an unsaturated fatty acid is one with double bonds and not ‘saturated’ with hydrogens. The double covalent bond between adjacent carbons in an unsaturated fatty acid leads to a ‘kink’ in the tails of the molecule. Thus increasing their concentration in membrane leads to a looser packing.

At the basic level, temperatures and pressures would also select for enzymes with different temperature sensitivities and pressure resistances. Changes in protein structure can influence their cellular function. Thus selection for rigidity is needed to counteract pressure. Proteins contain hydrogen and disulfide bonds between different subunits and parts of the amino acid chain that both dictate structure. A selection for proteins with increased bonding would minimize changes in shape to do pressure.

DrCraigMc5 karma

Thanks for coming and posting a question! 1. A host of deep-sea animals are red. Red light does not reach down deep so the red color in deep-sea animals is actually black. This makes them less visible to predators or prey. These are mainly in the water. Sediment deep-sea animals are are white to cream to brown colored. Because they can hide in the mud. The dumbo octopus you mention is yellow to red. I think the green color may be artificial lighting.

Napkin-Man4 karma

What was your inspiration to become a deep-sea biologist? How would inspire the future to enter this career?

DrCraigMc7 karma

It all sort of happened by chance. When I was an undergraduate I applied to work with a coral reef biologist to work in St. Croix as part of undergraduate program. So did everybody else. As part of the program you had to pick a second choice. I picked the only other "marine" project. Counting and measuring tiny snails in a windowless lab all summer. The person I worked for was a deep-sea biologist and those snails were from a very famous collection of deep-sea samples. The questions and intrigue of the deep oceans, even though I never stepped foot on to ship or submersible that summer, completely overtook me. I asked if I could come back and work on the same project for a Ph.D.

Napkin-Man2 karma

For someone who is still undecided on what career to choose, this is great! Thank you so much for doing the AMA.

DrCraigMc1 karma

My pleasure.

gillyman104 karma

What discovery have you made that has surprised you the most?

DrCraigMc8 karma

That the evolution of body size in deep-sea invertebrates may occur under a very similar process as what occurs to mammals on islands.

On islands and in the oceans, we've found that large organisms evolve toward smaller sizes and small organisms toward larger sizes, both heading toward a medium size. This pattern occurs with such frequency on islands that it’s often referred to as the “island rule.” As shallow-water species colonized the deep, small species evolved larger and large species evolved smaller, both heading toward a size that is just right.

It's interesting that the Earth's largest environment, the oceans, and its smallest, the islands, operate under similar processes. But the fact that the two environments share so little in common was a bonus that has allowed us to refine and eliminate hypotheses.

Despite all its area, what the deep sea lacks is food. The lack of sunlight precludes plants, meaning that for the majority of organisms, the food chain starts with plankton, dead organisms, and other organic debris that falls from the ocean surface above. But less than 5% of the total food available at the surface reaches the deep, leading to an extremely food-limited environment. On islands, less food occurs because the small island area supports fewer plants at the base of the food chain.

In both cases, animals need to be efficient and creative about acquiring food. There is not enough food in the deep ocean to support a whole population of giants. On the other hand, tiny animals cannot travel long distances looking for food and do not have the body volume to store surplus food when it does become available. Thus, conditions in the deep sea favor a medium-sized organism, causing some species to evolve toward giantism and others toward miniaturization to reach this optimum size.

Bathynomus giganteus, a deep sea pill-bug the size of a large shoe, is an extreme example of gigantism among crustaceans, making it something like the Komodo Dragon among island lizards. These giant isopods have developed larger in response to food limitation. They are scavengers, utilizing a variety of food sources. When you put a dead fish on the seafloor, swarms of them attack in a few hours. Their great size gives them the ability to traverse distances quicker than smaller relatives, getting them to the spoils first. Then their large size allows them to store a great quantity of fat, giving them the potential to survive up to two months without food, in an aquarium at least

guitarnoir3 karma

A couple of decades ago I saw some PBS show on the oceans and they showed the open-ocean harvesting of shrimp, via large nets. These nets seemed to pull-in all many of creatures and although I loves me some shrimp, it seemed like a ecologically ham-fisted way of getting the shrimp. Did I over-react, or was as this as bad for the seas as it looked? Have we gone to farm-raising these shrimp, or is the ocean-harvesting the current preferred method?

DrCraigMc1 karma

Your assessment is pretty accurate most shrimp fisheries are bad. However, like you, I don't want to avoid those tastey little buggers. The Monterey Bay Aquarium has a great resource for seafood. Here is a link to the shrimp page http://www.seafoodwatch.org/cr/SeafoodWatch/web/sfw_search.aspx?s=shrimp

This lists some options for eating shrimp that you don't have to feel guilty about.

angrypotato13 karma

Did you have to come over any anxiety going deep under?

DrCraigMc3 karma

No. I get so excited about the submersible dive and the cool stuff I see that is all I can think about. Most of my anxiety is whether I can go the length of the dive without going to the bathroom.

vianeyleos3 karma

How do you decide which areas to explore in the submersible?

DrCraigMc2 karma

A lot of things determine this.
1. Where do I want to actually go and do science.
2. Where will ship be near. If the Alvin is in the Pacific and I want to work in the Atlantic then that might be problem. 3. Do any of my deep-sea science friends have funded ship time that I can piggy back a project on? 4. How far away from a port is it? Sounds odd but you pay for every day the ship is at sea including transit days. 5. See number 3

_clio3 karma

Will climate change affect deep sea ecosystems? Have you seen any of the effects?

DrCraigMc10 karma

If energy is the currency of life then deep-sea organisms are in a long-term recession.

Energy comes in three major forms important for life: solar radiation in the form of photons, thermal kinetic energy as indexed by temperature, and chemical potential energy stored in carbon compounds. In the deep sea, these three forms are either absent or minuscule. Except in a few rare places, the temperature of the deep oceans is near or below freezing. In the dark depths, kilometers down, the sun does not visit. Without the sun’s rays, photosynthesis and plant life, the carbon base of the food web in most habitats, are absent. The chemical energy that sustains most deep-sea organisms is sequestered from sinking particulate organic carbon, marine snow, derived from dead organisms and feces from the ocean surface above. However, of the total food at the surface less than 1% makes it to the abyss.

This limited energy, of any type, makes the deep sea one of the most energy deprived habitats on earth.

The deep sea’s future? Even more recession and its likely to be worse. The oceans are and will continue to produce less phytoplankton, i.e. chemical energy. Indeed, global phytoplankton production has declined at a rate of ~1% over the last century, meaning less marine snow and dinner sinking to seafloor. In some places, the oceans have seen ~50% reductions over the last decade. Whereas chemical energy is decreasing, thermal energy is increasing. The deep Mediterranean Sea has warmed by 0.12°C since the middle of the last century. Deep oceans now store 16-89% more heat. However, this increase in thermal energy will make the recession worse not better.

In a paper of mine in PNAS http://www.pnas.org/content/early/2012/08/30/1208976109.abstract I and other tried address how the deep-sea biome across scales of complexity will respond to energy limitation and how they might respond to continued changes in the oceans. In terms of the analogy, how will the recession impact individuals and families to communities and eventually up to the global economy?

Temperature impacted individuals, including their respiration and growth. Deep-sea animals, like any other animal, living in warmer temperatures have faster metabolisms. Food impacted communities much more than temperature. Less food meant fewer individuals could be supported and less diversity as well. Interestingly, we also found hints that a restricted caloric intake, a harsh reality of life in the deep sea, led to longer lifespans in some fish.

However, the story is complicated by body size. Body size impacted all of these relationships. For example, larger animals have longer lifespans and higher respiratory rates. The greatest predictor of body size in the deep sea is the amount of food available. So food even impacts individuals by controlling their size.

Our findings, add to a growing body of research, indicating that the deep sea, once thought remote and buffered against climatic change, is greatly tied to changes in the ocean’s surface. As the oceans continue to change, the deep-sea may function quite differently in the future. For example, increasing ocean temperatures will increase the metabolism of organisms. This in turn will require larger meals, an item even scarcer in the future abyss.

As my coauthor Michael Rex stated, “The news is not good. Changes in temperature and food availability associated with climate change could cause widespread extinction in the deep ocean if environmental changes occur faster than deep-sea organisms can respond by shifting their ranges or adapting to new conditions.”

_clio2 karma

Thank you for the in-depth answer!

DrCraigMc1 karma

No problem. It's one I have thought about a lot.

EvilTech51503 karma

Which came first, life that lives around hydro thermal vents, or standard sea life/ krebs cycle life? ;)

DrCraigMc5 karma

What’s the current take on a deep-sea origin of life? I just finished reading Genesis by Robert Hazen where he discusses some of the hypothesis’ pros and cons and how there is something of a divide between the “ventists” and the “Millerites” . Deep-sea scientists naturally and wishfully fall into the “ventist” camp.

First some background, in Origin of Life Circles you can either be a Ventist or Millerite. Millerites are disciples of Stanley Miller, who created an early earth analog in the laboratory that produced organic molecules from water, methane, ammonia, hydrogen, and shot of electricity. Miller and Urey’s experiments in 1952, although quite distant from demonstrating how life evolved, pointed to the possibility that the conditions on the young earth’s surface could produce the basic building blocks of life. They operate under the Oparin-Haldane hypothesis or the organic soup (or primordial ooze) hypothesis. The problem is that the early atmosphere would have to be reducing for these reactions to work. Recent evidence suggests this may not be the case. As well, some argue that CO2 and/or CO would reduce organic material by chemosynthesis. So if the earth as a whole was not reducing, then you would need particular environments to be.

Fast forward to the 1970′s and the discovery of hydrothermal vents, a reducing environment, which spawns a new line of thinking. The interface of cold and hot waters allow for unique reactions to occur. Moreover, the extreme pressure, protection from UV radiation, abundant geothermal energy, and both methane and sulfide provide the necessary conditions to serve as a cradle of life in the deep depths of the ocean.

But to be a ventist is blasphemy, guilty of desertion of the very principles of Miller and Urey!

Hazen claims, “Miller and his scientific cohort had staked their claim to a surface origin of life, and they seemed determined to systematically head off dissenting opinions.” The Millerites attack the theory that life could have begun at ocean vents, saying high temperatures would have destroyed amino acids. Van Dover in her book on vents, points to both empirical and laboratory evidence indicating this is not the case. Van Dover also presents an excellent figure of phylogentic tree of Bacteria, Eucarya, and Archaea, that point to the hyperthermophilic nature of the basal taxa.

Add to this a recent study from Geology that types of clay mineral can convert simple carbon molecules to complex ones in conditions similar to the hot and wet environment of hydrothermal vents. The group simulated a vent in the laboratory by immersing various types of clay in pressurized water at 300 °C for several weeks and looking at the fate of methanol, a compound formed readily formed at vents. Having helped such delicate molecules to form, the clays can also protect them from getting broken down in the piping hot water issuing from the vents.” Not to mention the ultimate buffering from meterorite impacts that occurred on the early earth.

On the other hand. Miller, himself, called the vent hypothesis “a real loser.”

preddevils63 karma

I saw you have discovered many new species! How do you go about naming them? Are there any Dr. Craig snails wandering around the ocean floor??

DrCraigMc6 karma

There is a governing body for naming new species. One of the rules is you can't name a species after yourself. So unfortunately no Craig snails crawling around. A friend of my who studies starfish told me would name a deep-sea starfish after me. I'm still waiting ;-)

captain_guestbook3 karma

Is it possible for a normal person (like me) to go on one of these trips with you?

DrCraigMc8 karma

I'm just a normal person too!

Space on these trips is pretty limited and often its just scientists and their students allowed.

For years I've wanted to have a program that would allow people to apply and go out for a week or two to do deep-sea science aboard a ship. We would cover your travel and everything. You could do it on your vacation. Factory workers, business people, fast food cooks, it wouldn't matter what your day job was. Everybody could join in, help with the science, and be marine scientists.

captain_guestbook1 karma

I like your optimism. I just wish the person driving (flying? controlling?) the submarine is that optimistic too. :D On a more serious note... if you really do have any directions (or websites) on how to approach this, please share... I will be eternally grateful! :)

DrCraigMc2 karma

I don't have anything now but I will look around further.

apeshitgravy1 karma

You should totally do that. People would pay good money for trips to the deep sea.

DrCraigMc3 karma

The idea would be not to charge. Why should people from the working class not be able to join in?

fstop5702 karma

I'm a photographer and I'm wondering what your most brilliant image ever captured in the deep was.

DrCraigMc5 karma

My favorite deep-sea images are the amazing photographs that my friend Jason Bradley took. He has a series where he photographs long dead specimens that have been in jars for years. He has an amazing techniques that seems to breathe life back into these amazing creatures.


DrCraigMc3 karma

The most brilliant image I have is this of a carnivorous sponge http://blogs.discovery.com/photos/uncategorized/2008/10/29/chondrocladia_spmcclain.jpg

fstop5701 karma

This is great!! What's it's specific function down there. (I know that might read as elementary but I know nothing about marine life)

DrCraigMc1 karma

To eat and reproduce

Plasticheka2 karma

Do you never worry that if you're sub fails..........you're fucked

DrCraigMc5 karma

I'm actually most terrified of being lost overboard in the middle of the night to never be found. Being alone in a dark ocean is a hell I don't want to experience.

akesh451 karma


DrCraigMc3 karma

Nothing rational I just can't think of anything worse.

jimanri2 karma

so, here we love the creepy animals of the deep-sea, and you are a biologist. so,can you give us some creepy animal photos?

DrCraigMc3 karma

Mantraa2 karma

What are thoughts on intelligent life existing in the deep sea?

DrCraigMc2 karma

Depends on how you define intelligence. The animals in the deep oceans solve the problems of pressure, complete darkness, cold temperatures, and a lack of food every day. Seems pretty impressive to me.

PelicanElection2 karma

Have you ever eaten anything from the depths that most of us never will, say a Giant Isopod? What was it like? I find the breadth of the crustacean group a little off-putting when I think about wood lice while eating lobster.

DrCraigMc8 karma

When I was sorting through the wood from the wood fall experiments http://deepseanews.com/2014/02/wood-falls-chemicals-dubstep/ I accidentally swallowed some invertebrates. Splitting the logs requires a chisel and mallet to break them apart and get to the things have bored into it. I hit the wood just right and bunch flicked up into my face including a small wood boring snail. In my shock I inhaled and the snail was lost down my trap. I pray to god it wasn't a new species and that was the only specimen.

captain_guestbook2 karma

I just wanted to say, I love your IAmA. I'd love to read more from you! (coming from a naval architect, who knows nothing about biology)

DrCraigMc3 karma

You can visit http://deepseanews.com/ where I write regurally with 6 other great marine scientists.

j_bob11 karma

Hi. I'm currently doing a research masters in marine and freshwater ecology. I am undertaking projects on aquatic bio-acoustics using passive acoustic techniques. It's a area that i have become increasingly interested in. I'm having ideas about carrying this research through for a PhD. Do you think there would be benefits of carrying out bio-acoustic studies on these isolated deep sea communities. I'm aware that there would be difficulties using and maintaining the equipment at such depths. Thanks

DrCraigMc2 karma

Interesting idea. What would your question/hypothesis be? But keeping in mind testing scientific ideas in shallow water is logistically and financially easier!

crimsoncustom1 karma

  1. You have been going to many expeditions, do you have a region/ an ocean you want to explore but haven't yet?
  2. Your most memorable expedition?
  3. How many people involved in one diving session? Are all people in the submersible biologists or there is mechanic or such?

DrCraigMc3 karma

  1. I have always wanted to do due deep-sea research in the Arctic Ocean below the polar cap. Nobody has really explored that area of the deep sea. There is also a large area in the South Pacific that get's little to no marine snow. Marine snow is the dead plankton, bacteria, and feces that sinks from the overhead waters. This is the source of carbon for everything at the bottom of the ocean. Without any food can deep-sea life exist there?
  2. As a graduate student I did work in the Weddell Sea of Antarctica. We would trawl for deep-sea creatures during the day as icebergs floated by. It was amazing experience.
  3. Depending on the sub 2-4. One of those is pilot and there may be a sub tech as well. The others are scientists.

Yearlaren1 karma

Is the bottom of the sea as blue as seen or TV? Because I think what you see on TV looks too blue, like they use a filter or something.

DrCraigMc3 karma

The bottom of the ocean is pitch black. When lit with a submersible it can range in color from blue to green.

sovelong11 karma

I've been thinking of going back to school for either Atmospheric Sciences or Marine biology - hopefully ending up in a field similar to yours if I go that route. You wouldn't be able to compare career paths or give pros/cons over one or the other would you? Thanks for doing this AMA! Definitely some interesting stuff in here I wouldn't have known otherwise.

DrCraigMc2 karma

I don't know much about Atmospheric Sciences but it seems like there may be more jobs available to someone who knows weather.

shark_zeus1 karma


I know this is crazy late, but it's really important to me to get some academic opinion:

You've been down in submersibles (super jelly :) ), and you've piloted ROVs. Do you see any advantage to using manned submersibles over ROVs that would help convince modern institutions to invest in them again?

It is my fear that the future is just going to be more and more robots and prevent the construction of new submersibles to allow manned exploration of the deep sea. And I also happen to very much dislike the monopoly that WHOI has on national academic deep sea submersibles.

DrCraigMc1 karma

I think the future requires both. I wrote about the very topic in the past and it is one I still struggle with.


shark_zeus2 karma

Thank you. Your posts - I'm a fan of DeepSeaNews - are both informative and heartfelt for the future of ocean exploration. Happy diving.

DrCraigMc1 karma

Thanks for being a reader.

403redditor1 karma

I'm a fan of ocean depths and its deepness! Do you think that there is a lot to be discovered? It seems we're putting little time in exploring ocean depths than we do in space.

DrCraigMc2 karma

There is still so much to discover. Every time I sample or visit the deep sea I find new species. You are right that ocean exploration, at least by U.S. scientists, is way on the decline. Al Dove and I have advocated for the creation of Ocean NASA called OSEA (Ocean Science and Exploration Agency)


Rigabear1 karma

Do you know Colleen Cavanaugh? She's my aunt! My question: does life without light actually exist? If so, how?

DrCraigMc3 karma

I do know Colleen. Tell her I said hello.

DrCraigMc3 karma

Life does exist without light. The deep oceans contain some of the highest diversity of animals in the world. The main issue is how do animals actually eat with photosynthetic life to support. In the deep this happens two ways. 1. Most deep-sea animals rely on food sinking from above. This can be dead whales, logs, dead plankton, feces, anything that is carbon. 2. At hydrothermal vents and methane seeps, carbon is produced by chemosynthesis http://en.wikipedia.org/wiki/Chemosynthesis


When you're deep down in the ocean do you ever get worried or hopeful that you'll find something terrible or incredible? Something like encountering deep sea intelligent life? Or sunken ruins, vessels or alien structures? Something with deep ramifications?

DrCraigMc2 karma

I always have wanted to see a Giant Squid in its own habitat. Still hasn't happened for me. But my friend Steve O'Shea with others caught the first live footage of a Giant Squid a few years ago. I was so jealous.

scubahana1 karma

I have been obsessed with the deep ocean ever since I learned about Dr. Ballard discovering the hydrothermal vents back in the '70s.

I have taken some oceanography courses and would like to eventually get a degree in marine science and get out in the deep ocean to do some primary research (I think the biological and chemical relations that make the deep sea ecosystem possible are of particular interest) and would like to know if there are any programs or courses I should consider over and above the 'standard' elective courses that would cover my education and specialisation?

Thanks for helping to unmask the final frontier!

DrCraigMc1 karma

It would be hard for an undergraduate to specialize in deep-sea science or get that opportunity unless you had a deep-sea biologist at your university. I would look for deep-sea scientists and email them about potential summer opportunities. Other than that take lots of biology, math, computer science, and statistics. At touch of engineering wouldn't hurt either

scubahana1 karma

Thank you immensely for this; I would eventually like to get into a Masters and PhD program where I know I will have greater opportunities but knowing the recommended basis for it is good.

Dr. Ballard (half) jokingly said that unless I knew how to work ROVs I would be useless on his team so having a confirmation of this is also quite useful :).

DrCraigMc2 karma

I have no idea how to run an ROV or submersible. Pilots and engineers take care of that. Both are excellent ways to get into this work and absolutely vital to what I do. However, if you want to set the mission objectives and conduct the science then choose the scientist route.

KrazyPhox1 karma

Hello! I'm a senior in high school and was seriously considering going into marine biology, but when I did some research I found that the funding for projects is mostly done by grants. This kind of turned me off from marine biology because it seems like the pay is unstable and a lot of time will be spent on grant searching. Is this true? Or is it better than what I am imagining. Thank you so much for doing this AMA and I hope you have a great day! :)

DrCraigMc1 karma

Unfortunately you have it about right. But struggling with funding is common among scientists and worth it even it means I don't get to go down in sub every year.

DrCraigMc1 karma

And of course money is something is something that is always in short demand which is why I am currenlty trying to get people to help me crowd fund some cool deep-sea science


microsatviper1 karma

Do you see any differences in species diversity between wood falls and whale falls (or other animal carcasses)? Do totally different communities form on these two kinds of debris? Or is the deep sea benthos just so generalist that there are no differences in community composition?


DrCraigMc1 karma

There are huge differences in community composition among the sediment, wood falls, and whale falls. Wood and whales falls share species that are closely evolutionary related. The sediment species are only distantly related.

microsatviper1 karma

That's really cool! I'm surprised that wood and whale fall communities are so different, that organisms have evolved to fill those two specific niches!. Thank you so much! Have you ever looked at the microbial community structure or composition of wood and whale falls?

DrCraigMc2 karma

We have microbial samples but are still working on them up. BTW did I mention I have a project on wood falls that I am trying to crowdsource ;-)


MOREBLOCKS1231 karma

Hello! I want to be an oceanologist when I'm older. What are the ideal courses I should take?

DrCraigMc1 karma

College? High school?

MOREBLOCKS1231 karma

High school. Thank you for replying by the way! I was worried I was too late.

DrCraigMc1 karma

In a comment along this thread I gave another high school student advice.

kryptonik_1 karma

How can I go down there?

DrCraigMc2 karma

Lots of schooling, passion, and drive

kryptonik_1 karma

I'm almost thirty. Can't I just pay?

DrCraigMc1 karma

I don't know of option for that yet. Unless you pull a Branson and build your own sub.

tmurg3751 karma

Seeing the most extreme environments, do you feel there is a statistically feasible chance that there is life at the bottoms of oceans located on the moons of Jupiter and Saturn? What would be necessary for sustainable life at extreme depths?

DrCraigMc1 karma

I think the more we learn about how different life is in the deep sea it greatly opens up the possibility of life on other planets. I wrote about this a while ago


apeshitgravy1 karma

Do you have any advice for a young amateur biologist?

DrCraigMc1 karma

See by comments in thread to others.

DingDog1 karma

My sister has a friend who is a marine biologist and goes to the bottom of the ocean some times. He draws on styofoam cups and then takes them down and they shrink to tiny little cups. He gave one to my sister. Do you do this or anything like this?

DrCraigMc1 karma

All the time. I consider it to be part of my good luck ritual to ensure there are no problems with the gear and I get good samples. My favorite is my shrunken Cup O Noodles cup that is now the size of thimble.

[deleted]1 karma


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avogadros_number1 karma

Hello, thank you for doing this AMA, it's a fascinating area of research (great video btw).

  • I'm interested in how far out these deep sea samples have been taken from. Do you have a map of the sample locations (shallow coastal settings, continental shelf, slope, rise, abyssal plain)?

  • In the video you mention about the link to the global carbon cycle, have you done any calculations as to what the suspected carbon input from organic burial of trees is?

  • Have you been able to date any of the wood, and if so what are the oldest samples you have recovered?

  • Is there typically a lot of sediment being deposited around sample locations?

  • What is the percentage of organic debris brought in from turbidity flows, versus other methods of input such as ice rafted debris, etc.?

  • Typically what are the thickest sediment packages you sample looking for wood samples? Are there any outliers?

  • From most common to least common, what are the types of wood samples you come across, is there a reason for the observational differences between woods (if any), and which woods tend to provide the most food for all those funky critters deep down?

PS - That carnivorous sponge... O_O

Keep up the amazing work, thank you for your contribution to science, all the best and stay safe ;)

EDIT: Noticed that the song used in the video is Medium Troy - Space Tree and figured you might like another 'tree' song - Carbon Based Lifeforms - Photosynthesis. The audio samples are from the 1972 environmental sci-fi film Silent Running.

DrCraigMc2 karma

  1. This paper http://archimer.ifremer.fr/doc/2008/publication-6091.pdf has a great figure in it of all known deep-sea samples (taken at that time). For natural wood falls there are very few.
  2. I have not done in calculations but am hoping to when I have some more accurate measurements from my wood falls. A great paper found that the amount of tree carbon input during a typhoon can equal about 25% of the total carbon an ocean basin sees during a given year.
  3. No dating of the wood yet, my samples were down 5 years. In shallower water ~1500m a wood fall may only last a year or so.
  4. In the areas where I did my experiments the sedimentation are quite low. The amount of carbon the wood fall brings to the deep is several orders of magnitude larger than the background.
  5. Great question but not one I have an answer for.
  6. Not sure I understand the question
  7. We really don't know much about how different types of wood provide different habitats or have unique species on them. We are trying to test this experimentally.

akesh451 karma

What's the pay like?

DrCraigMc1 karma

Depends on position. If it is a typical faculty position then new faculty make around $50-70,000 a year depending on the state and university/college. Full professors with lots seniority usually make over $100,000

sbarrett161 karma

Have you been to any basketball games at Duke?

DrCraigMc1 karma

Basketball isn't really my game. I have been to a football game and few local rugby matches.

nosaJ42971 karma

Any advice for a high school freshman who wants to become a marine biologist? I want to focus nainly on marine mammals such as whales

DrCraigMc3 karma

It is very competitive especially if you want to work with marine mammals. You will need to have good grades and excellent test scores. Also try to find opportunities for hs students during the summer to do marine biology. Try to attend a university that has a marine mammalogist (or hopefully more) as part of the faculty. Your first day on campus go their office and tell them you will volunteer to do anything. Copy, get coffee, actually marine mammal work... You will need to earn your place and with enough time you might actually get to do some cool stuff. They can guide you the rest of the way.

MrEugeneKrabs1 karma

Do you think the Loch Ness monster could exist? If yes do you think it does?

DrCraigMc2 karma

Not likely. Pretty sure if there was Loch Ness in a small lake we would have seen it. We see larger creatures in bigger bodies of water all the time, e.g. blue whales in the Pacific Ocean.

Noologist1 karma

Hi DrCraigMc! I was wondering if you were also measuring connectivity and fragmentation between wood falls across the deep-sea floor? Be very interested to hear more!

DrCraigMc1 karma

The research is still new. However, this is exactly one of the questions we hope to answer over the next few years.

rbcarol1 karma

Hi, super cool AMA! I have a kindergarten-aged son who is obsessed with becoming a marine biologist. What do you think are the most important things to expose him to, at such a young age, to keep his interest in marine biology and possibly help him get a head start on learning the science as he gets a little older?

DrCraigMc2 karma

We have a few kids books at the DSN library that we (a bunch of marine scientists) love http://deepseanews.com/resources/the-essential-dsn-library/

For me trips to the aquarium and the beach were the best times of my childhood. I grew up in a landlocked state.

Depending on where you live there may be some summer programs that offer young children a chance to interact with the oceans and ocean life. I'll look around and try find some links.

rbcarol1 karma

Thanks so much for replying! We actually live near the beach and near a National Seashore. I think that is probably a big part of what inspired him in the first place. I will definitely check out the books.

DrCraigMc1 karma

Perfect! PADI, the scuba diving organization, offers courses for children. These would be a great opportunity for your son to see the ocean from a new perspective and pick up some useful skills for the future.