New Discoveries in Deep-Sea Biodiversity
IRA FLATOW, host:
Up next, 30,000 species under the sea. A few years ago, marine biologists working off the coast of Oregon collected samples of seawater from the very deepest parts of the ocean there at two sites near an active ocean floor volcano. And once the samples are brought to the surface, biologists on the other side of the country, in Massachusetts, analyzed the samples to find out what kinds of microbes were living at the bottom of the ocean. And what they found was astonishing. An amazing array of microbes, more than 30,000 species many, which were never - have never been seen before. They are new to science. The results of that analysis were published earlier this month in the journal Science.
Joining me now to talk more about what they found is my guest, Julie Huber is assistant scientist at the Marine Biological Laboratory in Woods Hole Massachusetts.
Welcome to SCIENCE FRIDAY.
Dr. JULIE HUBER (Assistant Scientist, Marine Biological Laboratory): Thanks, Ira.
FLATOW: Tell us. Were you really shocked by what you saw?
Dr. HUBER: We were genuinely shocked with what we saw. This was the deepest sampling to date of any environment in the ocean of looking at the types of microbes there. And we sequenced - we used DNA sequencing technology and looked at almost a million different sequences. And we thought we would actually be able to sample all the diversity there. And we discovered we hadn't. And so we are very surprised at these results.
FLATOW: Mm-hmm. Why should they be so different than everywhere else?
Dr. HUBER: Well, it's not necessarily that they're more different than everywhere else; it's simply that we haven't sampled enough in the ocean to even know what's really there. So under sampling is kind of fact of life in oceanography especially in the deep sea. You know, we know more about the surface of Mars than we do the surface of Earth because it's covered in water. So we simply haven't gone out there and sampled enough environments and sampled them deeply enough.
And so what we did is developed a technology that allowed us to sample thousands and thousands of organisms in one environment and begin to make some strong statistical conclusions about who's actually there.
FLATOW: And you collected these at an active underwater volcano?
Dr. HUBER: Yes.
FLATOW: It sounds fascinating in itself.
Dr. HUBER: Yes. They're from a volcano called Axial Volcano and it's located on the Juan de Fuca Ridge, which is only about 300 miles off the coast of Oregon. So it's one of the best-studied seafloor systems in the world because that's only about a 24-hour ship ride from land.
And for about the last decade, scientists from NOAA and the Pacific Marine Environmental Labs have been going out there every year to monitor the system.
And it erupted in January of 1998. So it was extremely active and we've been collecting samples every year and trying to follow the changes in that system.
FLATOW: And how did you actually collect the samples?
Dr. HUBER: So we used something called a remotely operated vehicle or an ROV. So it's a big floatation device with a bunch of arms and collection devices and cameras and lights. And it's tethered to the ship. And we have a group of pilots and engineers on the ship that control it, and we use monitors to see the seafloor, and we collect their samples that way.
FLATOW: Sort of like the remote controlled robots that went down to the Titanic.
Dr. HUBER: It's exactly like those, yes.
FLATOW: Yeah. Do you think robots can do that as well as people?
(Soundbite of laughter)
Dr. HUBER: Well, the wonderful thing about being tethered to the ship is you can stay down for days and days and days. You don't have to worry about people, you don't have to worry about batteries or oxygen or anything like that. So you can do a lot of very efficient science on the seafloor that way.
FLATOW: Mm-hmm. You've found 37,000 different kinds of bacteria, but you also found these archaea.
Dr. HUBER: Yes. So we looked at two domains of life, both the bacteria and the archaea - these are both microscopic forms of life. And we found that we were able to pretty well sample the archaeal diversity. And so a lot of people might be familiar with archaea because there's - kind of known as these extreme organisms that live at really high temperatures or really low pH, things like that. And we found that we are actually able to sample that diversity.
But with the bacteria, we've only gotten about halfway there. And that's the sampling over 600,000 sequences from this environment. So we still have a ways to go.
FLATOW: And that's really a hostile environment down there, is it?
Dr. HUBER: Well, you know, there are a lot of different environments at a hydrothermal vent. And the specific samples that we looked at sort of represent a mixture. So it's where, you know, you've seen those images of black smokers with a hot, hot fluid gushing out of the seafloor.
FLATOW: Right, right.
Dr. HUBER: And these samples were actually warm fluids that mix with seawater. So they're actually a bit cooler. They're only about 100 degrees Fahrenheit, and they have - they sort of have all the good things, from seawater like oxygen and all the good things from hydrothermal fluids, like hydrogen and sulfur compounds. So it allows a lot of different organisms to exploit those energy sources.
FLATOW: 1-800-989-8255 is our number. But they don't have any sunlight down there.
Dr. HUBER: There's no sunlight. This is a chemosynthetic-driven system. So the reason you see all those beautiful tube worms and clams and things is because of microbes that are fixing carbon dioxide that's coming from the vent fluid, and they're combining that with chemical energy like sulfur and methane to make carbon for these big animals.
FLATOW: Is this part of a larger effort to try to catalogue all the life on Earth, and if you want to find that life, you got to go down to the bottom of the ocean, too?
(Soundbite of laughter)
Dr. HUBER: Well this is definitely part of a much bigger effort through the International Census of Marine Microbes, which is part of the Census of Marine Life. And we are trying to understand, discover and catalogue all of the microbial diversity in the world's ocean. So we're not just looking in the deep sea. We're looking at the sunlit surface ocean. We're looking in marine sediments. We're looking at methane hydrates. We're looking at cold deep. We're looking at estuaries.
So we're trying to use this sampling technology to really begin to understand what microbes are out there, what is their distribution, what are their patterns, and how are they changing.
FLATOW: It's just a fascinating place, is it not? I mean…
Dr. HUBER: Yes it is. The ocean is a great place to do microbiology, especially the deep sea.
FLATOW: And you can expect them to find lots more life since we haven't census it yet - they were taken at census - to know what's down there.
Dr. HUBER: I absolutely agree. And the more places we can explore, the more we're going to discover, I have no doubt.
FLATOW: We talked to Craig Venter a few years ago about his efforts to catalogue a lot of this stuff in the ocean on the surface. Is that part of the same effort?
Dr. HUBER: Well the difference between what Craig and other scientists are doing is they're looking at all the genes in the ocean. So they're just sort of - they're going in and they're randomly sequencing all - the whole genome of all the different microbes in the ocean. We targeted one specific gene. And so in some - in one sense, it's even more remarkable because just by looking at one gene, we still can't catalogue the diversity. So you can imagine if you're looking at all the genes from all the microbes, how challenging that effort is going to be.
FLATOW: Mm-hmm. We were up in Alaska - we were talking with their efforts to talk about the Arctic Circle for the first time. They were looking in parts of the ocean that had never been looked at.
Dr. HUBER: That's right.
FLATOW: Is this the same area in Oregon that was never looked at before?
Dr. HUBER: Well we've - like I said, we've been going to Axial from quite some time, but certainly, if we discover hydrothermal systems in the Arctic Ocean or down near the Antarctic - I mean, we have a lot of mid-ocean ridge that's unexplored. We've only explored about 20 percent of it. So any new site we're certainly going to be interested in examining.
FLATOW: Mm-hmm. This is TALK OF THE NATION: SCIENCE FRIDAY from NPR News. I'm Ira Flatow, talking with Julie Huber.
So are you going back?
Dr. HUBER: We are going back. We try to go back to Axial every year, like I said, because it's one of the few places on the seafloor that we can actually monitor. And so we're going to go back and we're going to keep collecting samples and we're hoping it's going to erupt again very, very soon. Like I said it erupted in 1998 and we're trying to follow the changes in the community.
FLATOW: Here's a question from Tam(ph) in "Second Life," which I think a lot of people wonder about.
Are the bacteria in the lab - how do you keep them alive while they're bringing them up, and in the laboratory, if they're so used to being way down there?
Dr. HUBER: Right. Well, this particular sampling technology - you don't need to keep any organisms alive. We're simply filtering hydrothermal vent fluids, extracting the DNA and going from there. But I have cultured lots of interesting organisms from the deep sea and the pressure change doesn't really seem to bother them.
What you do, instead, when you get them on land is you try to mimic the conditions that they have on the seafloor. So if you're trying to culture and organism without oxygen, you create that environment in the lab, you put it at high temperature, you try to give it the same food that it had, and you can also give it high pressure just like it has at the seafloor, but microbes are incredibly resilient. They've been around for three and a half billion years. So they've figured things out.
FLATOW: So you're saying you have a little laboratory down there at the bottom of the ocean that just does a DNA analysis immediately?
Dr. HUBER: No. It does - that doesn't happen on the bottom of the ocean.
(Soundbite of laughter)
FLATOW: Oh, I see.
Dr. HUBER: That would be great.
(Soundbite of laughter)
FLATOW: Not yet.
Dr. HUBER: Not yet. No. We filter the fluids on the seafloor then bring them up and process them in the lab.
FLATOW: I see.
Dr. HUBER: Yeah.
FLATOW: And how many - how many samples does it take? You have 37,000 different discoveries. How many samples do you have to take for that kind of discovery?
Dr. HUBER: Well that was only two samples.
Dr. HUBER: That represents a couple liters of vent fluid, so not much.
Dr. HUBER: Yeah.
FLATOW: Do you and your colleagues talk a lot - compared notes between different sites in the different parts of the oceans?
Dr. HUBER: Definitely. And as part of the census, the marine microbes were collecting the samples from collaborators around the world. And we're trying to put together this big database of who is there and environmental conditions and parameters that we can begin to get an idea of what the distribution of these organisms are, like I said how they're changing, how they're - you know, what is low abundance in one environment might be very dominant in another. And sort of what's controlling their distribution.
Dr. HUBER: I think it's important to note that things are changing a lot in the world's oceans. And we still don't have a really good sense of what the baseline is. And so this type of technology and these types of studies will help us establish that.
FLATOW: Well, we talk about a lot about loss of biodiversity, for example, in the rainforest…
Dr. HUBER: Right.
FLATOW: …as they're disappearing is there - is that your worry down there at the bottom of the ocean, too?
Dr. HUBER: Well, there is really no good evidence that microbes can go extinct the way we think of a tiger going extinct, for example. We don't know much about their resilience or even what a dead microbe means. And so what is sort of hopeful about this type of study is it shows that there's a huge amount of genomic information out there. And that these organisms have a lot of different diversity to draw upon under different environmental conditions, and that if things change or when things change, different organisms can take over and sustain an ecosystem.
FLATOW: Mm-hmm. Sounds fascinating. And sounds like you can't wait to get back.
(Soundbite of laughter)
Dr. HUBER: I'm very excited.
FLATOW: Yeah. Is it very difficult on the ship out there or is it…
Dr. HUBER: It's a lot of fun. It's kind of like camp for grownups and you have to work.
(Soundbite of laughter)
Dr. HUBER: It's a lot of fun.
FLATOW: Well, good luck to you.
Dr. HUBER: Thank you.
FLATOW: Thanks for taking time to be with us.
Dr. HUBER: Great.
FLATOW: Julie Huber is an assistant scientist at the Marine Biological Laboratory in Woods Hole, Massachusetts, talking with us about an active volcano. Imagine, an active volcano underwater off the coast of Oregon. And the oceans have even higher mountains underwater than they do here on land.