On March 2, 2018, the Museum brought together a group of scientists, oceanographers, artists, and entrepreneurs for an evening of dynamic discussion to kick off the special exhibition Unseen Oceans with illuminating conversation about marine research.
Watch talks by some of the evening’s participants.
Kelly Benoit-Bird examines animals using active acoustics (sonar) to understand the role of spatial and temporal patterns in pelagic marine ecosystems. A MacArthur Fellow in 2010, she was part of the team that received the 2016 Group Gold Medal for Scientiﬁc and Engineering Achievement.
Kelly Benoit-Bird Ocean Luminaries – March 2, 2018
KELLY BENOIT-BIRD (Senior Scientist, Monterey Bay Aquarium Research Institute):
One of the challenges to understanding life in the ocean is that this is our typical perspective on the sea. Whether we're on a boat or on the shoreline, it's difficult for us to get beneath the surface of the waves where the action is really happening: where predators are finding prey, where individuals are finding mates, where life and death are occurring.
Another challenge is that we come at this problem as terrestrial mammals. We're used to a world where plants, the base of the food web, are stationary and large. In fact, we often describe trees as landmarks. Take a left at that tree, or it's in the middle of that farm. And importantly, for the animals in these ecosystems, these trees can provide a habitat. Birds build nests, squirrels hide.
And this is really different to what it's like to live in the ocean where the plants are microscopic and free-floating. So, we can go back on a ship to the same GPS coordinates we were at yesterday and be sampling a very different ocean. And importantly for those animals there, these plants don't provide any cover. In fact, there's little cover to be had in the open sea.
So, one way that animals hide is by staying in the dark. These animals are part of the mesopelagic that you've heard a lot about tonight. There's something we call the deep scattering layer, because of how it scatters sound. These small fish, shrimp, krill, and squid up to about four or five inches in length form these extensive features that cover entire ocean basins. During the day, they stay at depths of several thousand feet to hide in the dark avoiding their predators. But they do have to access food, and food is most abundant in the surface waters where sunlight allows plants to grow. So, each and every night, these animals migrate up thousands of feet to the surface to feed under the cover of darkness.
Now, despite the huge numbers of animals in these layers—in fact, there are estimated to be 10 billion tons of mesopelagic resources in our world's oceans—we know relatively little about them. And that's in part because of our perspective from ship-based sampling. Even the name deep scattering layer tells you we know about them mostly in bulk and not much about the individual animals that make them up.
And so, I study these animals primarily using sound, and this is what the perspective we get using sound is from these deep scattering layers. At the top you see the surface, and it goes down deeper in the water column as you move down, to about 600 meters in this view. That gray area is the seafloor. And as we move along here surveying over just a few kilometers, you can see two distinct deep scattering layers shown in green. Green represents higher densities of animals at about 300 meters and around 450 meters. But again, from a surface ship, we only see these features in bulk. The only way we can ask about the individual animals, or most often the way we ask about them, is to drag a net through the water and bring the animals to us on the surface.
We've learned a lot about the species in these layers, which include animals like these lanternfish and dragonfish, which collectively make up most of the fish biomass in the ocean. And these animals are critically important for our ecosystems. They serve as an important prey resource for many top predators, including the tuna and salmon you find on your dinner plate, but also for seabirds like penguins, dolphins, whales, and seals.
And so, what I really wanted to do was to start to look at these animals in the context of their habitat and ask questions about how they were distributed and spaced and related to each other, so we could better understand how they're adapted to life in the deep.
To do that, we needed to get closer to the animals so that we could see them as individuals instead of just as layers. We did that by taking the same sound instruments that we use from a ship and developing them into an autonomous mode self-contained inside this underwater robot that can go deep into the ocean. It can dive all the way into these scattering layers and get kind of a fish eye's perspective. We call this vehicle Dory, because she thinks she could speak whale. And it really is providing us a different view.
This is an echogram here on the right taken from Dory. Now, what you might not be able to see from the back of the room is that there are a lot of individual arch-shaped marks, and each one of those is an individual animal that makes up this scattering layer that we see as a diffuse cloud from the surface. So, we can ask questions about how these animals are interacting.
And what we used to think, based on our surface sampling, was that all of these animals that were living together were just kind of jumbled. They were all looking for the same resources, the same levels of light and oxygen and food, and that they all mixed with each other by happenstance. But from Dory, we get a different view. In fact, the animals in these layers are highly organized into small groups that are made up of one kind of animal of a single size. And they're adjacent to another group of animals to form a layer. So, these are really schools in the deep; something we hadn't thought about before.
This is what it looks like if you dive into one of these schools with a video system. These are all lanternfish, as you can see, are very much about the same size, and are all swimming together. We see that these groups are typically about 100 animals in diameter, and the size of these groups can change in their physical dimension. It's really ruled by these biotic features.
So, of course the next question is, why? And this echogram gives you the answer. I want you to notice two things when you look at this, and the first is that those little arch-shaped marks, those individual animals in the deep scattering layer, change color as you move from left to right. That means that they're two different kinds of animals.
The second thing you notice are these really big, red echoes, and those are coming from dolphins feeding within this deep scattering layer. In fact, these are Risso's dolphins. They're the world's fifth largest dolphin. They're found most abundantly over slope waters and subtropical and temperate ecosystems where they forage primarily on squid. And what happens when these Risso's dolphins enter the deep scattering layer looking for squid is that the squid change their behavior. They undergo a sort of flash compression where they very rapidly form a group close together, trying to hide amongst their neighbors that look very much like them, which makes it difficult to track an individual to eat it. What's even more interesting is that the neighboring groups expand and fill in those gaps. So, they need to maintain a layer in order to protect themselves as well. So, these animals are really getting a little help from each other in order to survive in the deep.
New technologies like our underwater robot are helping us to understand the adaptations that these animals have to this really alien-to-us ecosystem. And our timing couldn't be better. For the first time, several countries have issued fishing permits for access to the mesopelagic to provide fish feed and fish oil. So, we are in a race. We have an unprecedented opportunity to design sustainable fisheries and to minimize the impact of this in a way that's never occurred before, and science has a really important role to play. Thank you.
Systematist and ichthyologist Prosanta Chakrabarty studies the evolution of both freshwater and marine ﬁshes. He has discovered more than a dozen new species, including new anglerﬁshes and caveﬁshes. He is a former program director at the National Science Foundation.
Prosanta Chakrabarty Ocean Luminaries – March 2, 2018
PROSANTA CHAKRABARTY (Associate Professor and Curator of Fishes, Louisiana State University):
This is quite the honor. It's also a bit of a homecoming. I grew up in Queens and I'd come look up at the blue whale and wonder how I'd be able to study natural history one day. And I get to do that now.
I want to talk about the power of exhibits like this one and the one that we're celebrating, but also the collections behind the scene that really lead up to these exhibits. And I want to put that in terms of the big ocean myth.
So, what's the big ocean myth? It's that the oceans are big. So, of course, the oceans are big, right? Especially if we look at our blue planet from the Pacific side. But they might not be as big as you think.
So, if we look over our world, 70 percent of our Earth is covered by ocean. But perhaps they're not the boundless, endless steppes that we think they are. Once we get off the continental shelf it's about two miles deep, on average, which is deep, but maybe not as deep as you thought. The deepest parts are about seven miles deep.
This is from the U.S. Geological Survey. All the world's water fits in this one 860-mile diameter sphere, that barely covers the Midwest. That's all the world's water. All the water in the oceans, all the fresh water, which is also represented here, but included in the bigger ball. All the water that you're drinking, all the water that's in you, all your pet's water. So, all in there.
So, this is how I think of the world's oceans. As something that is finite, something that can be destroyed, something that can be polluted.
And the reason that it seems like the world's oceans are endless is because so little of it has been explored. Most of you in here probably have a screensaver that looks something like this, but few of us have seen images like this. And it's Sylvia Earle and Jacques Cousteau that introduced us to these oceans.
And once we start talking about below 20 meters, we have to talk about these two gentlemen, William Beebe and Otis Barton, who created this Bathysphere. And this was in the 1930s, so this is the start of exploration of the deep sea. They went into this Bathysphere famously a half mile down. They would joke, only dead men had gone deeper.
So, before Barton and Beebe, this is what the deep sea looked like, a vast void of black. That's what we thought it looked like. And they introduced us to this world of light and of life, chock full of life, in fact. And even images like this, I didn't have images like this in grad school. These are new. These are from Danté Fenolio—in situ images of deep sea creatures. That's a rare thing to get, but we're getting more and more of them. So, we're still very much in the age of exploration of the deep sea.
I moved from New York 10 years ago to Louisiana, to start a curator position, and I thought, "Boy, I really hope they have a great international airport, because I am not going to discover anything new here. Everything is in Africa or in Asia, all these places far away where we've left everything undiscovered." I learned very quickly that we left undiscovered much of even the Gulf of Mexico.
On my very first expedition out into the Gulf, we collected specimens of what turned out to be new species. So, there were two new pancake batfishes right out in the Gulf, on the front steps of the U.S. So, I was shocked to discover that, but not as shocked as we were about how totally unprepared we were for the 2010 Gulf of Mexico oil spill.
We had very little baseline for what creatures were being lost or the population numbers, or anything, really, when the 2010 oil spill hit. So, what we did is use the collections behind the scenes at museums like this. Behind the scenes here are almost a million jars of fishes.
And each one is a data point. And each red fish here represents a fish in a jar at some museum. And we use those to represent the different populations relative to where the spill is, and the spill is represented in green here, the 16 weeks of that oil spill.
So, with that, we got an idea of where populations were relative to the spill. And we found an interesting fact. Half of the species that were found only in the Gulf of Mexico, the endemics, had populations in the region of the spill. So, for us, that was an incredible fact—how much of the really rare species, the endemic species, were found in the spill zone. And again, those were based on museum specimens.
And so is this exhibit, this exhibit that we called Crude Life, that we've been rolling around different museums the last few years, are based on specimens from the Gulf, from information from museums. And that's the power of what these exhibits can do. I think you've heard many of the speakers talk about that today.
We take this exhibit not just to museums, but out into the Gulf, and tell people about these other fishes that they might not know about, that aren't sport fish. These are my adorable children, by the way, and I'll just give them a shout out.
So, very telling for me about how little we know about the Gulf is, again, based on exhibits and museum specimens. This is a heat map showing one-kilometer by one-kilometer squares of different areas in the Gulf. Blue areas have no records of any vertebrate that are in any museum. Yellow is one to 10, and then you slowly get darker near the shore. But this could be a bird observation, it could be anything. Once you go below the surface, almost everything turns blue again, and not the good blue.
One small project that I've been working with is called DEEPEND, and this is Tracey Sutton here who leads this project. And they've been trying to fix this problem of how unknown the Gulf is. And they sample from zero to 1,500 meters, the mesopelagic zone that we know so little about. They've actually discovered 12 new species from these trips. They also told me that since 2011, there's been this incredible decrease in number of fish individuals that they've collected relative to pre-spill.
What really shocked me, though, is Tracey told me a few weeks ago that people are now applying for commercial permits to collect in this mesopelagic zone. And I said, what do people want? No one is going to eat these tiny little lantern fish and anglerfishes from this region. And he said, they're doing it to get cheap sources of protein for cat food, for feeding tunas, stock tunas to get them bigger. And I thought, wow, we're already getting commercial permits for this region that we barely started finding new species in. We hardly know it ourselves before we're exploiting it.
But to be honest, I don't really blame those commercial interests. It looks like a vast world, a boundless sea, with endless depths. But we know it's not. So, I like to kill this big ocean myth. Of course it's big. But it's finite. It's something that we need to protect. It's something that we need to study. And it's something we need to save. So, let's do that. Thank you.
Kakani Katija develops advanced imaging tools to measure biological-physical interactions, electronics tagging packages to deduce organism behavioral response to a changing environment, and autonomous underwater vehicles using stereo tracking to address a wide range of marine science questions.
Kakani Katija Ocean Luminaries – March 2, 2018
KAKANI KATIJA (Bioengineer, Monterey Bay Aquarium Research Institute):
So full disclosure. I'm not actually a marine scientist. I'm actually trained as an aerospace engineer. And for as long as I could remember, I've always wanted to be an astronaut. So, if you can't recognize me in this photo, I'm suspended in microgravity waiting for this very handsome mustachioed gentleman to whirl me around on the vomit comet.
And for several years now, I have stopped looking for life in outer planets, and have started instead to focus on the life that we have much closer to home in the oceans. And what you'll notice is that this footage is not actually a star field. This is what 400 meters deep in Monterey Bay might look like.
And so, what you'll also notice is, unlike our search for life in outer planets, the ocean is just teeming with life, and there's a lot that we don't know about that life. And so, a member of my lab at the Monterey Bay Aquarium Research Institute does a combination of approaches that involved innovative observation platforms, which is largely robotics-based, as well as state of the art instrumentation, particularly imaging tools. And then finally, utilizing access to novel study systems with ocean going research vessels.
And what we do is, we combine all of these things to study organisms or animals in their natural environment in the deep sea. But the reason why we do this is that ultimately, we'll want to apply these lessons learned to bio-inspired design, which is the concept of developing new tools and technology based on what we learn from deep sea animals. And a lot like how we humankind have been inspired by birds to fly, there might be something that we might be inspired to do by organisms in the deep sea that we know almost nothing about.
And so, I work in the mid-water of the ocean, and animals are weird and wacky, like this one, the angler fish. And it has a bioluminescent lure. And this is a Cystisoma, and these animals are being studied because of their transparent tissues as well as their complex visual systems, for a variety of different science and engineering applications.
This is actually a Siphonophore, and some Siphonophores can get longer than a blue whale. And they undergo these long-distance vertical migrations, and we're not sure how they do it.
And then finally, this is the Humboldt squid. And these animals are voracious predators, and their soft bodies and dual modes of propulsion are actually forcing us to rethink how we develop underwater vehicles as we study and want to continue studying the deep sea.
So, how do we do that? All of this footage was collected because of the infrastructure investments we made at our institution. Like an ocean-going research vessel, as well as large scale robots, and in this case, a remotely operated vehicle.
In addition to that, my team also developed some new imaging devices, including a laser imaging instrument called DeepPIV. And we've used that on a variety of different organisms that enables a completely new way of viewing or observing these animals.
And one of these animals are the giant larvaceans, which you see here. So, you'll notice that the animal is what's wagging or pumping its tail, and that structure around the animal is a mucus house. It's made of a mucus that the animal secretes and serves as a filtration structure to separate particles and food from the animal and the water around it. And these animals can be about 10 centimeters in length, and their houses can be up to a meter in size.
And the way we go about doing these kinds of experiments is, we go to sea on a research vessel, and that includes the science team, the ROV pilots, as well as obviously the ship's crew. And we, the science team and the ROV pilot, sit in a very fancy control room that looks a lot like a movie theater. And in order to do these kinds of measurements, an ROV pilot is maneuvering a remotely operated vehicle to an animal of interest, and the ship's crew and the ROV pilots communicate constantly to ensure that they're dealing with a different environment and the ROV isn't being pulled off the target of interest.
And once we see an animal that we're interested in studying, the ROV pilot positions the vehicle such that our laser light on our instrument, which is a millimeter thick—so a millimeter-thick laser sheet on an animal that's approximately two centimeters wide, at a depth anywhere from 50 to 400 meters. So, it's incredibly difficult.
So, what I want to show you then is a result of some of this work. This is raw footage from an ROV in MBARI. What you'll notice- and think about this as kind of an X-ray image. You can see inside the house of the larvacean as well as the larvacean.
And as the animal starts beating its tail, you'll notice that the house, that outer structure there, is inflating. And you can also see particles that are moving in and around the animal and through the house.
And so, we've actually been able to use these measurements to measure directly the filtration rates that these animals are able to process water. And in some cases, up to 80 liters per hour. And the implications of that is, in Monterey Bay, at least in their principle depth range, from 200 to 400 meters, they could fully process that principle depth range within two weeks. Which is incredibly important when you're thinking about how these organisms are interacting with their environment.
But also, we can use the DeepPIV instrument in a scanning fashion. So a lot like an MRI, where you might have a stack of images to represent different planes along the body or brain, we can do the same thing with a DeepPIV instrument where now, instead, you're seeing a scan of the larvacean house, as well as the larvacean.
And so using that image stack, what we can do and see for the first time, is not only the external structures of the house, but also what looks it like inside. So, you're getting a particle eye view of what's inside these houses. And notice all of these chambers, these finger-like chambers, where every single one of those chambers wind up going to the mouth of the animal.
So, they're incredibly beautiful, incredibly complex structures, and we really don't know much. Not only about the structure—we're just starting to scratch the surface of it—but also its function. And so, what we're hoping is, with this work and continued effort, some day we might have a new class or innovative filtration system that can filter particles on a submicronic scale.
And so, with that, I want to end on a positive note. I think what's really exciting right now is there are so many great new technologies and tools that are going to be focused on studying midwater, which is the final frontier of our planet. And with exploration, we're going to be learning things that will then inspire us to do a variety of different things, things we don't even know anything about, and potentially create innovations that will forever change our world. Thank you.
Lead funding for Unseen Oceans and its educational resources
is provided by
AN INITIATIVE OF THE DALIO FOUNDATION.
The American Museum of Natural History gratefully acknowledges the Richard and Karen LeFrak Exhibition and Education Fund.
Unseen Oceans is generously supported by