Video and Text Passages
Part of the Giants of the Sea Curriculum Collection.
In four parts, these videos and text passages with discussion questions provide a case study of the Stanford University scientists at work—out at sea and in their labs.
Part 1: How did blue whales get so big?
An introduction to the largest animal that ever lived.
How Did Blue Whales Get So Big?
Giants of the Sea, Part 1
A blue whale swims near the surface of clear, sparkling ocean water. The Museum’s logo unfolds across the screen, reading “150 Years | American Museum of Natural History.” It fades away. The whale spouts.
JEREMY GOLDBOGEN (Assistant Professor of Biology, Hopkins Marine Station of Stanford University): Blue whales are absolutely awe-inspiring. By all standards they are the largest animals of all time.
A two- or three-person inflatable boat, running between two blue whales is shown from overhead.
The camera pans over large skeletons in the Museum’s Hall of Primitive Mammals.
GOLDBOGEN: There's all these examples of giants in the fossil record. We have giant rodents. We have huge dinosaurs.
A model of a Xiongguanlong baimoensis, a tyrannosauroid dinosaur.
Jeremy Goldbogen interviewed in an office space, with computer monitors behind. Text animates on screen, identifying him as Jeremy Goldbogen, Assistant Professor of Biology, Hopkins Marine Station of Stanford University.
GOLDBOGEN: We don't have the opportunity to study those animals in the way that we can study the modern giants.
A blue whale surfaces and spouts, before diving back under. An animated title reads “Giants of the Sea, Part 1: How did blue whales get so big?”
GOLDBOGEN: Today we have the largest animals of all time, throughout the entire history of life on Earth. By better studying these ocean giants we can ensure that these species will persist for future generations.
David Cade interviewed in an office space. Images of whales decorate the walls. Text animates on screen, identifying him as David Cade, Postdoctoral Researcher, Institute of Marine Sciences, UC Santa Cruz.
DAVID CADE (Postdoctoral Researcher, Institute of Marine Sciences, UC Santa Cruz): The defining characteristic of a blue whale is that it's the biggest animal that's ever lived, certainly by mass—up to 140 tons of whale in one animal. When you're up next to one of these things, you really see that. This whale surfaces and then goes and goes and goes and goes and goes and goes and goes and then you see the flukes and the flukes are 10 or 12 feet across.
Goldbogen speaks in his office.
GOLDBOGEN: It's widely recognized that body size is one of the most important determinants of how you function and how you interact with your environment.
A hippo munches on a grassy field.
GOLDBOGEN: When you get bigger your metabolism becomes much more efficient.
Giraffes, zebras, and wildebeests roam over a broad savannah.
GOLDBOGEN: So, that means you can fast for longer periods of time and you can put on lipid stores very, very rapidly.
A blue whale swims near the surface. A rhinoceros strolls in an area with trees.
Cade speaks in his office.
CADE: You can avoid predators better. You have a lower cost of transport—it's easier to walk or move long distances.
A herd of elephants crosses a plain with a mountain looming in the background.
CADE: You can potentially have longer lifespans because of that.
Cade speaks in his office.
CADE: But the downside is that it can take more energy and that on land…
An Indian elephant chews grassy plants and moves its trunk around.
CADE: …there's a kind of a limit to how much mass you can actually hold on your legs.
A blue whale breaches the surface, spouts, and goes back under.
GOLDBOGEN: If you're in water you don't have to deal with gravity in the same way. You have the support of the aquatic medium.
Goldbogen speaks in his office.
GOLDBOGEN: And that might allow you to evolve much larger size and you don't have to bear that weight with limbs as you would on land.
A blue whale is seen from above, moving only slightly, near the surface of the ocean.
CADE: The blue whale is essentially neutrally buoyant, meaning that they can just kind of float there.
Cade speaks in his office.
CADE: No matter how big you are, if your tissue is about the same density as water, you don't have that same mass of gravity laying on you. So, the ocean allows for these big animals to exist.
A blue whale floats near the surface, spouting.
CADE: And what are the procedures and mechanics that allow them to get that big? It’s been pretty well unknown until now.
Shirel Kahane-Rapport is interviewed in an office setting. A whiteboard with equations is in the background. Animated text identifies her as Shirel Kahane-Rapport, Ph.D. student, Hopkins Marine Station of Stanford University.
SHIREL KAHANE-RAPPORT (Ph.D. student, Hopkins Marine Station of Stanford University): One of my research questions is how whales got to be so big and I'm choosing to answer that question using basic physical principles, one of which is called scaling.
Kahane-Rapport indicates a diagram on a monitor. Text reads “10 x Length > 100 x Skin > 1000 x Volume.” Beneath the text a small circle on the left and a much larger circle on the right are separated by an arrow pointing to the larger circle.
KAHANE-RAPPORT: And so, scaling is how something grows proportionally as its length increases.
An animation demonstrates how as length increases, surface area and volume increase proportionately, by showing a spheroid object growing in size. As it grows, numbers next to text reading “Length,” “Surface Area,” and “Volume” increase. E.g., as Length goes from 11.1 to 18.7, Surface Area increases from 388 to 1,100, and Volume increases from 719 to 3,431.
KAHANE-RAPPORT: When the length of an object increases, the surface area squares and the volume cubes. So, that's a basic thing that holds in sizes of circles and sizes of cubes,
Drone footage of San Francisco’s famous Golden Gate suspension bridge.
KAHANE-RAPPORT: …but it also is true for things like bridges or bones.
A paleontologist lies next to a huge, single dinosaur bone for scale. The bone is longer than the person.
A blue whale swims near the surface.
KAHANE-RAPPORT: And so, in this case we apply it to an animal like a whale.
An animated graphic shows a whale with an enlarged throat. Text reads “expected engulfment capacity: length3.”
KAHANE-RAPPORT: We have found their body mass and their engulfment capacity—which are volumes—do not cube.
An additional line of text appears, reading, “actual engulfment capacity: length3.8”, and the outline of the whale’s throat is expanded beyond the original illustration.
KAHANE-RAPPORT: So, they engulf more than we expected and that's what allows them, we think, to get so large.
A large whale propels itself forward with an open mouth, taking in a huge volume of water as its throat expands.
Goldbogen speaks in his office.
GOLDBOGEN: There are about 80 to 90 species of whales.
An evolutionary cladogram shows the relationships between various whales. They are divided into two categories: porpoises, dolphins, beaked whales, sperm whales are identified as “toothed whales,” while rorqual and gray whales, and right and bowhead whales are classified as “baleen whales.”
GOLDBOGEN: There are two major groups of what we call the great whales. We have toothed whales and baleen whales. So, toothed whales are well known for using echolocation to target single prey, whereas baleen whales are obligate filter feeders and they target patches of small-bodied prey.
Another evolutionary cladogram zooms into the rorqual whales, where several types are listed: sei whale, Bryde’s whale, blue whale, fin whale, humpback whale, and minke whale.
GOLDBOGEN: Blue whales are rorqual whales and rorquals are characterized by their unique lunge filter-feeding mechanism.
Goldbogen speaks in his office.
GOLDBOGEN: So, in contrast to other vertebrate filter feeders, which swim slowly forward and filter at really low, steady speeds, rorqual whales have this dynamic lunge filter-feeding mechanism,
In dramatic footage, a whale powers to the surface with its mouth agape. It breaches, its throat expands to a huge, bulging sac to take in a massive amount of water, and then turns below.
GOLDBOGEN: …where they open their mouth to tremendous gape angles and they have this huge expandable throat sac that basically engulfs the water and prey.
Goldbogen speaks in his office.
GOLDBOGEN: Then once the mouth closes around that prey-laden water,
An illustration of a rorqual whale shows water streaming out between the feathery slats of baleen.
GOLDBOGEN: …it pushes that water past the baleen plates that hang down from the top of the mouth, leaving the tremendous amount of prey inside the mouth.
CADE: Blue whales are migratory animals.
Near the surface, a young blue whale nudges at its mother’s side.
CADE: So, they're born in warmer tropical waters where they're with their mothers, learning how to feed in these waters.
A whale breaches, spouting. Its tail flicks above water before diving back beneath the surface.
CADE: So, up in the Northern Hemisphere where you have big dense patches of krill, in the summertime that's an ideal time for a blue whale to travel north and start feeding on these krill patches.
Cade speaks in his office.
CADE: They'll feed for three or four months and during that time they are building up energy. They're sometimes increasing their body mass by 40 or 50 percent,
Drone footage shows a mother blue whale and her calf swimming near the surface. Both come up to spout.
CADE: …and then the whale will use that energy throughout the rest of the year when the food is not as good.
GOLDBOGEN: Studying blue whales is interesting because they're so mysterious, in a way.
Goldbogen speaks in his office.
GOLDBOGEN: There's still so much that we don't know and just their sheer size inspires this sense of awe.
A blue whale swims near the surface and then vanishes out of view into deeper waters.
GOLDBOGEN: So, it's an animal that we see just for a few seconds at a time at the surface. Most of the time it's at depth. So, what is it doing down there and how can we figure that out?
Credits roll:
The “Marine Biology” Seminars on Science is made possible by OceanX, an initiative of the Dalio Foundation, as a part of its generous support of the special exhibition Unseen Oceans and its related educational activities.
Director / Producer
Karen Taber
Producer / Editor
Ben Tudhope
Post Producer
Kate Walker
Title Design
Timothy J. Lee
Illustrations
Alex Boersma
Special Thanks
The Goldbogen Lab at Hopkins Marine Station of Stanford University.
All footage & images taken under permit NMFS 16111/21678.
© American Museum of Natural History
Part 2: What happens underwater?
The history of whale tagging and modern methods of data collection
What Are Blue Whales Doing Underwater?
Giants of the Sea, Part 2
Shots of people standing at the prow of small rubber motorboats, moving quickly through the ocean. They wear helmets and hold long poles.
JEREMY GOLDBOGEN (Assistant Professor of Biology, Hopkins Marine Station of Stanford University): The first couple of times you tag a blue whale your legs are shaking, and you're trying to just focus and make sure you get that tag in just the right spot.
In an aerial view, a boat comes up behind two large blue whales, swimming close to the surface.
DAVID CADE (Postdoctoral Researcher, Institute of Marine Sciences, UC Santa Cruz): So, you're on this boat and you have about a 20-foot pole…
Various shots of people at prow reaching out poles to breaching whales’ backs and attaching a device via suction cup.
CADE: …and you're trying to get as close as you can to this animal, and you have a four-second window in which to get the boat close enough to put it on the animal and then get out of the way.
Animated title text appears: Giants of the Sea, Part 2: What happens under water?
Jeremy Goldbogen walks down a hallway in research offices. A dog plays beside him.
GOLDBOGEN: I run the whale biomechanics lab here at Stanford University's Hopkins Marine Station in Pacific Grove, California.
Large wooden sign reads, “Hopkins Marine Station of Stanford University.” An exterior wide shot of Hopkins Marine Station buildings, sited on a rocky coast with waves breaking in the foreground.
Goldbogen speaks in his office. Text identifies him as Jeremy Goldbogen, Assistant Professor of Biology, Hopkins Marine Station of Stanford University.
GOLDBOGEN: Our specialty is using suction cup-attached tags that allow us to track and study whales underwater.
Goldbogen and Cade hold and adjust whale tags with suction cups. The tags are a little larger than the size of their hands.
GOLDBOGEN: So, we use new tag technology to pry into the intimate daily diaries, is what we call it, of whales as they're swimming and foraging underwater.
A man and boy look out at a pod of whales from the deck of a ship.
CADE: People have been fascinated by whales for thousands of years.
Waves break over a large beached whale carcass.
CADE: They wash up on beaches and people are like, “What is this thing? What is going on?”
Aerial view of a whale swimming near the surface.
CADE: They're this massive animal that lives in the ocean and you can only see it at the surface.
Cade speaks from his office. Text identifies him as David Cade, Postdoctoral Researcher, Institute of Marine Sciences, UC Santa Cruz.
CADE: And for thousands of years that's kind of how people studied them.
Faded archival film footage of a large whale hauled aboard a whaling ship.
CADE: They could study specimens that were killed on whaling operations…
Drone footage of two distant whales spouting.
CADE: …and they could study the surface behavior. For that brief moment in time they could study what the animal's doing.
Cade speaks from his office.
CADE: For the most part, at the surface, these whales are just breathing.
Overhead view of a whale spouting at the ocean’s surface, then diving below.
CADE: So, for most of the life cycle they're not really observable. They're going down to very deep depths very quickly and doing something.
Goldbogen speaks in his office.
GOLDBOGEN: So, we take our tags and tagging pole with us as far south as the Antarctic, and as far north as Norway.
People unmoor a rubber motor boat from a dock and head out into the ocean.
GOLDBOGEN: But we do a lot of our work right here off the coast of California where in Monterey Bay we're really lucky to have one of the densest concentrations of blue whales in the world.
Researchers in the small boat motor across the open ocean. One person stands in the bow with the tagging pole.
GOLDBOGEN: So, in just an hour's cruise from a nearby port here, you can be surrounded by blue whales in the summer months of July, August, and September.
Drone footage reveals a wide shot of two blue whales followed by two small boats.
The exterior of an academic building. A sign reads, “De Nault Family Research Building.”
GOLDBOGEN: Since we started in 2014,
Close-up of a suction-cup tag on a workbench. Researchers make adjustments to tags.
GOLDBOGEN: …we have collaborated with a small company to build over 50 of these tags and we've now tagged several hundred whales.
Cade stands in front of computer monitors, displaying a suction-cup tag a little larger than his hand.
CADE: This is one of my favorites. It's got the forward-facing and the backward-facing camera here.
Diagram of the tag shows its placement area on a whale’s back—just behind and a little lower than the dorsal fin. An image of the tag indicates locations of front and back cameras, as well as a small, square GPS sensor near the front camera.
CADE: It's got a GPS sensor here. GPS is a little bit challenging on a whale. So, you can't get GPS signals under water,
Cade holds tag in office space.
CADE: …so, you actually only get the signal for that three-second period…
Aerial drone footage of two whales swimming near the surface.
CADE: …where you're supposed to find every satellite in the sky for that three second period as the whale surfaces and then goes back underwater.
Cade indicates features on a tag.
CADE: It's got the sensor package up here in the front.
A diagram illustrates the location of a small circuit board near the GPS sensor and front camera on the tag. An inset shows a close-up of the circuit board and text reads, “accelerometer, magnetometer, gyrometer.”
CADE: It's just this little circuit board, is actually all the accelerometer, magnetometer.
Cade speaks in his office, holding the tag.
CADE: The reason that we've been able to do some of this work over the last 10 years is largely because cell phone technology has driven these sensors so small that there's a market for that and then we can take advantage of that.
The researchers’ small rubber boat pulls up behind a whale swimming close to the surface, and tags the animal as it breaches.
CADE: But what's cool about these tags is that they are all suction cup based.
Cade speaks in his office, holding the tag.
CADE: So, it doesn't actually hurt the whale at all. It doesn't puncture any skin or anything like that.
Cade demonstrates the suction cups by slapping the tag down onto the desk.
CADE: And it basically just sticks on to the whale's back and just stays on there for six to 24 hours. Then eventually the suction fails and then the tag will float to the surface.
Cade pries the suction cups off the desk and indicates a flexible antenna on the back of the tag.
CADE: And then we'll recover it with this antenna that's sticking up out of the back there.
A researcher stands at the prow of a rubber boat speeding through the ocean, while two researchers film and photograph in the middle of the boat.
CADE: So, we have this long pole and a boat and what you'll see out here on the side is this whale start to surface up…
Cut to Cade watching this same footage on his office computer monitor.
CADE: …and we're basically timing it so we can do an approach from his side, so we don't bother him.
Back in the original footage, a large whale surfaces just in front of the boat and the researcher reaches out with the pole to attach the tag to the animal’s back.
CADE: And then right when he's committed to surfacing, we're going to accelerate right up to him and on the end of this pole, which is about 20 feet long, we'll drop this tag onto his back.
Cade speaks in his office.
CADE: Huge team effort, right? Like you have to work with the driver, you have to work with the other people on the boat to actually take pictures, you have to work with the spotters. You usually have about six or seven people out in the water actually working to get this this data on these animals.
Split screen shows the views from the front and rear tag cameras. The tag is still attached to the researcher’s pole at this point, so the front view shows the ocean and the rear camera shows the antenna and the trailing boat.
CADE: So, if I was going to show you what that same process looked like from the tags’ perspective, on the left-hand side you have this forward-facing part of the camera and on the right-hand side you have the backward-facing cameras.
Cade speaks while watching the footage on his computer monitor.
CADE: Basically, the whale's going to approach here, come up on the left-hand side. We're going to accelerate up there.
Split screen of front and rear tag cameras..
CADE: We're moving faster and now there's the whale and now we're on the back of a whale.
The whale’s back appears suddenly in the front camera and shortly after the tag is attached, water fills the screen as the whale goes below.
Cade indicates footage on his computer monitor as he talks.
CADE: Up here on the left-hand side is going to be the whale's head and back here is the tail.
The original footage shows the massive body of the whale on the bottom half of each split screen—head in the front camera, and rear in the back camera. The flexible antenna can be seen in the rear view.
CADE: And this right here is the antenna from the tag that we actually use to recover the tag.
Goldbogen and a man with a camera examine one of the suction-cup tags on the deck of a boat.
GOLDBOGEN: They're sampling at really high resolution. So, for example, the whale's movement is measured at several hundred times a second.
Cade leans overboard to pull up a tag floating on the ocean’s surface.
CADE: As technology's improved and our sensors have gotten smaller and smaller and smaller, that's easier and easier to do,
Goldbogen and others examine a suction-cup tag onboard a boat.
CADE: …and to get more and more data over a longer time span with more resolution.
Cade speaks from his office.
CADE: So, we can finally now start to interpret and determine what are these whales doing when they go underwater.
Credits roll:
The “Marine Biology” Seminars on Science is made possible by OceanX, an initiative of the Dalio Foundation, as a part of its generous support of the special exhibition Unseen Oceans and its related educational activities.
Director / Producer
Karen Taber
Producer / Editor
Ben Tudhope
Post Producer
Kate Walker
Title Design
Timothy J. Lee
Special Thanks
The Goldbogen Lab at Hopkins Marine Station of Stanford University.
All footage & images taken under permit NMFS 16111/21678.
© American Museum of Natural History
Analyze Blue Whale Data: Student Worksheet
Part 3: How does a blue whale feed?
How blue whales have adapted by evolving extremely efficient lunge-feeding behaviors in order to live throughout the world’s oceans.
How Does a Blue Whale Feed?
Giants of the Sea, Part 3
A baleen whale opens its mouth wide in a huge feeding lunge near the surface of the ocean. The Museum’s logo unfolds across the screen, reading “150 Years | American Museum of Natural History.” The whale closes its mouth on an enormous amount of water and dives back below.
JEREMY GOLDBOGEN (Assistant Professor of Biology, Hopkins Marine Station of Stanford University): The first time I saw a blue whale lunge feeding event, I almost couldn't believe it. It is absolutely a crazy feeding mechanism. The whale literally doubles in size as it's feeding, so it's inflating at this really capacious ventral feeding sac on the underside of the animal. So, it's literally inflating with water and food.
An animated title reads, “Giants of the Sea, Part 3: How does a blue whale feed?
Goldbogen speaks from his office. Text identifies him as Jeremy Goldbogen, Assistant Professor of Biology, Hopkins Marine Station of Stanford University.
GOLDBOGEN: These questions come to mind—how does that work? how does that evolve? and how does such a large whale feed on very, very small prey?—and these must be linked in some way.
Researcher David Cade speaks from his office, standing in front of two computer monitors. One shows aerial footage of a whale. Text identifies him as David Cade, Postdoctoral Researcher, Institute of Marine Sciences, UC Santa Cruz.
DAVID CADE (Postdoctoral Researcher, Institute of Marine Sciences, UC Santa Cruz): So, this is actually a fin whale which is very closely related to a blue whale.
Aerial footage of a fin whale, swimming close to the ocean’s surface. It has a long, relatively thin body shape—almost like a pencil with flippers.
CADE: A fin whale is the second largest animal, probably, to have ever lived by mass.
Cade speaks in front of the footage playing on his computer monitor.
CADE: So, it has that nice, streamlined shape and it's really easy for this whale to accelerate to high speed.
The fin whale swims through the water, rolling onto its side, and opening its mouth. The pouch below its lower jaw balloons to an enormous size, inflated by a large mass of water. It closes its mouth and turns to dive.
CADE: And as it does that, it rolls onto its side, it opens its mouth right at the krill patch, and then as it engulfs this water you can see its pouch totally engulf all that huge amount of water. And then it spends about 30 seconds to a minute or so actually filtering out all that water.
Cade speaks in front of the computer monitors.
CADE: So, every rorqual lunge has those three phases.
A diagram illustrates the three phases of rorqual whale feeding. An animated rorqual whale swims vertically toward the surface. Text reads, “Acceleration (7.4 ± 3.6 seconds).”
CADE: It has an acceleration phase where it goes up to about three or four meters per second.
The animated whale turns on its side and opens its mouth in front of a patch of krill. Its pouch inflates with water. Text reads, “Engulfment (5.1 ± 1.0 seconds).”
CADE: It has an engulfment phase which lasts about five seconds.
The animated whale closes its mount around the krill patch, its pouch still inflated. It rolls back upright. Text reads, “Filtering (79.4 ± 18.0 seconds).”
CADE: And then it has that filtering phase. It does this over and over and over and over again, sometimes a hundred times a day.
A split screen shows the front and rear cameras of a tag attached to a whale’s back as it swims, breaches the surface, then dives back below. The whale’s long body is visible in the lower half of each camera angle.
CADE: So, what's unique about our tags is that we were able to integrate not just the sensor data, but also video. So, now we can see what the whale is actually doing from its own perspective.
Cade reviews the split screen tag footage on a computer monitor.
CADE: Now this whale's out looking for food, so he's going to do one long breath and he's going to dive down. So, he's going to dive down to about 100 meters here.
In the original tag camera view, the footage has become grainy and dark as the whale dives deeper below the surface. The rear view captures the whale’s tail and some of the light from the surface.
CADE: So, he's diving down, it's getting darker. And he’s gonna come up from below this prey patch.
Cade speaks from his office, in front of the computer monitors.
CADE: He's gonna start maneuvering his body up towards this prey patch,
Split screen of the whale tag cameras. Now the rear angle (with the tail) is dark and the front camera heads towards the lighter surface waters. As the whale arcs upward, its head and front flukes come into view.
CADE: …accelerating up to about four meters a second. A couple of big fluke strokes, and then right when he gets up to that prey patch he's gonna open his mouth and engulf all that water and then, basically, start that filtering process. So, you can tell that the whale's opening its mouth because you can see its normal head motions…
Cade speaks from his office, in front of the computer monitors. He indicates the whale’s mouth in the tag footage.
CADE: and then you'll see the jaw actually separate.
The split screen view shows the moment where the whale opens its mouth. An arrow indicates a protrusion (the lower jaw) that can be seen momentarily as the whale lunges upwards.
CADE: You can actually see the whale's mouth the bottom of its jaw over there on the left-hand side.
Cade speaks in his office and uses his hands to imitate the shape of the whale’s mouth. His index fingers hook forward, facing one another, while the rest of his hand makes a loose fist.
CADE: The rotation of these jaws is amazing. These jaws are about- some of them on a big blue whale they can be up to 12 or 13 feet long and it'll be just the jaws there.
A diagram of a whale skeleton is superimposed on the footage of Cade speaking in his office. Arrows indicate the motion of the two lower jaw bones—a short of skinny U-shape, turning outwards as the mouth hinges open.
CADE: They sit in the whale's mouth, kind of arched up like this, and then as that whale feeds it opens it up, basically doubling the area that it can engulf. And so it's like- imagine, like, a whole wall of this room coming at you. It's engulfing all that water.
The diagram illustrates the jaw bones rotating back inwards, as the mouth closes.
CADE: And then as it starts to close its mouth, those jaws will rotate back up, so you have a minimal area around the edge for the water to actually come back out.
Goldbogen speaks from his office.
GOLDBOGEN: The interesting thing about blue whales is that they evolved from much smaller ancestors.
An illustration of a torpedo-shaped blue whale. The animal is long and slender, very streamlined. A much smaller whale—about 1/6th the size of the blue whale—is shown in comparison. Text identifies it as Maiabalaena nesbittae.
GOLDBOGEN: So, about three to five million years ago. whales were really dolphin sized.
Goldbogen speaks in his office.
GOLDBOGEN: And the oceans went through a rapid series of changes.
Thousands of small invertebrate organisms swarm through ocean waters.
GOLDBOGEN: The effect of those changes creates a lot of whale food and,
Goldbogen speaks in his office.
GOLDBOGEN: …really, these enormous patches—super, super dense—and that's what makes their filter feeding mechanism so efficient and allows them to evolve massive body sizes incredibly rapidly in just a small amount of geological time.
A diagram shows a blue whale with fully inflated pouch. Text reads, “Two-quarter Ellipsoid Engulfment Model.” Mathematical formulas indicate the volume of the rear portion and the front portion of the pouch.
SHIREL KAHANE-RAPPORT (Ph.D. student, Hopkins Marine Station of Stanford University): This diagram shows a blue whale with its pouch, the engulfment capacity, fully expanded and it shows the model that we have created to measure how much water it can swallow in one gulp.
Kahane-Rapport stands in front of a computer monitor displaying the engulfment diagram. Animated text identifies her as Shirel Kahane-Rapport, Ph.D. student, Hopkins Marine Station of Stanford University.
KAHANE-RAPPORT: And whales, when they engulf water like this, they're also engulfing prey. So, the more prey you can engulf at once, the more efficient you are,
Underwater camera tag footage shows a whale swimming off to the side of the tagged whale. The whale off to the side opens its mouth for a feeding lunge and its pouch expands tremendously.
KAHANE-RAPPORT: …and you get so much more energy for that singular effort. And so, we think that whales have gotten so big because they're able to engulf huge amounts of energy in a really efficient way.
Cade organizes equipment on board a rubber boat.
CADE: Last week we put out 14 different types of tags.
Researchers on a boat hold a reception antenna. Cade examines a whale tag.
CADE: If you're putting a camera on a whale, you can only tell so much.
A researcher stands in the prow of a rubber boat and stretches a long pole out over the water. The camera tag is at its tip and the researcher slaps it on a whale’s side as it momentarily surfaces.
CADE: You have to have the context, the interpretation of what's actually happening here.
Cade speaks from his office.
CADE: The most common whale behavior is just gliding, just hanging out.
Split screen footage shows the front and back views of a whale camera tag.
CADE: And if you have to just watch this video with no context, you could spend your whole career just basically watching whales do nothing, right.
Below the split screen footage, there is now a color-coded graph showing variables (like depth, speed, pitch, and roll) over time.
CADE: So, one of the things that's really important in the work that we do is do the interpretation.
An arrow indicates a blue line that begins at zero then dips lower as time progresses.
CADE: The blue line here is the depth sensor of the whale. So, that's a pressure sensor that measures how much pressure is being applied to that whale.
Cade speaks in front of his computer monitor, as it plays the footage of the whale tag cameras.
CADE: And so, then you can interpret that as depth and how deep that whale actually is.
An arrow now indicates an orange line that oscillates up and down fairly rapidly.
CADE: The orange line here is the animal's speed. When the animal is going faster that line is a little bit higher.
Cade speaks from his office.
CADE: This red line here is where we are in the video.
The arrow now indicates a vertical red line, moving horizontally across the graph as the video plays. Above the graph, the footage shows the whale approaching the ocean’s surface and then breaching.
CADE; So, right now the whale is coming back up towards the surface. It's about to break the surface here. And then goes back down. You can see that it's going to do about one, two, three, four, five breaths…
Cade speaks in his office.
CADE: …and then go back down.
An arrow indicates a spiky pink line, running the length of the graph’s x-axis.
CADE: The pink line here is a measurement- we call it the animal's jerk. Jerk is the rate of change of acceleration.
Cade speaks in his office.
CADE: In addition to the video we can use all those sensors to actually construct a model of what that whale is doing in space and time.
In a computer-generated 3D graphic, a simulated whale goes through the motions of the actual whale, as recorded by the tag’s sensors.
CADE: How is it actually oriented in relation to the surface, in relation to everything else?
Cade speaks in his office.
CADE: So, if I'm looking for interesting areas of this whale's behavior, I’m looking at this graph and saying, like, “Okay, well, what's interesting? What's unique? What's actually going on here in interesting environments?”
In a close-up of the graph displayed on his computer monitor, Cade’s finger indicates a spike in the graph.
CADE: And the first thing that catches my eye is this peak and speed here with a rapid deceleration phase.
Cade speaks in his office.
CADE: So, I know that something's going on there. I know that you have a big event going on at that moment.
Split screen footage of the front and rear whale tag cameras is shown above the graph indicating time, speed, depth, etc. The whale is heading back towards the surface at great speed.
CADE: And that is the feeding event. So, the whale here is doing its acceleration phase—really pumping its tail, accelerating up there, opening its mouth, and then feeding as it decelerates.
In the split screen footage, the whale’s jaw opens wide.
CADE: There's that pouch. It inflates with water and it slows that whale down from all that drag. Imagine, like, trying to force equal to your body weight amount of water.
Cade speaks from his office.
CADE: That whale is using its momentum and then forcing that water forward as it then starts to filter that water out.
Credits roll:
The “Marine Biology” Seminars on Science is made possible by OceanX, an initiative of the Dalio Foundation, as a part of its generous support of the special exhibition Unseen Oceans and its related educational activities.
Director / Producer
Karen Taber
Producer / Editor
Ben Tudhope
Post Producer
Kate Walker
Title Design
Timothy J. Lee
Illustrations
Alex Boersma
Special Thanks
The Goldbogen Lab at Hopkins Marine Station of Stanford University.
All footage & images taken under permit NMFS 16111/21678.
© American Museum of Natural History
Part 4: Why does a whale’s feeding behavior matter?
The threats to blue whales and how the research on feeding behaviors could be used in conservation efforts.
Why Does Whale Feeding Behavior Matter?
Giants of the Sea, Part 4
An aerial view of a blue whale gliding near the ocean’s surface. The Museum’s logo unfolds across the screen, reading “150 Years | American Museum of Natural History.” It fades away. A title animates in, reading, “Giants of the Sea, Part 4: Why does a whale’s feeding behavior matter?”
DAVID CADE (Postdoctoral Researcher, Institute of Marine Sciences, UC Santa Cruz): The whale behavior is only half the story if you want to study feeding, right. You also want to look at the context of how much prey there is and where is it located.
Researchers on a small boat in icy waters are captured by the rear camera of a tag attached to a whale’s back as it dives below the surface. As the camera passes the bottom of the boat, a box-like electronic device can be seen jutting below the propeller.
CADE: The way we do that is we've rigged up a system on the back of our boats that actually has these echosounders on there that allow us to determine the density and distribution of prey in the water column.
Jeremy Goldbogen interviewed in an office space, with computer monitors behind. Text animates on screen, identifying him as Jeremy Goldbogen, Assistant Professor of Biology, Hopkins Marine Station of Stanford University.
JEREMY GOLDBOGEN (Assistant Professor of Biology, Hopkins Marine Station of Stanford University): So, there's a saying on the California coast called “wind to whales.”
Gulls fly over a beach at sunset, as waves crash to shore. An illustrated cutaway of the California coast shows the beach sloping down to the sea floor and a floating blue whale.
GOLDBOGEN: And so, every spring we get really, really high winds and that creates upwelling.
Two arrows appear, pointing in a parallel direction to the sandy beach. Text on them reads, “surface winds.”
GOLDBOGEN: So, those winds basically take the surface waters away from the coast…
J-shaped arrows curve along the coastline and then turn perpendicular from the surface winds, out towards sea.
GOLDBOGEN: …and that's replaced with really nutrient rich deep water.
Blue arrows, indicating colder temperatures, curve up from the sea floor towards the coastline. As they turn up the slope, they become red (warmer), and turn back out to sea.
Goldbogen speaks from his office.
GOLDBOGEN: And so, that in turn causes a trophic cascade—
The arrows representing winds and currents in the illustrated diagram move in animated loops. An inset of microscopic ocean organisms pops out.
GOLDBOGEN: …all of those rich nutrients will allow the phytoplankton to bloom. It also, in turn, allows the zooplankton and the krill to bloom.
Goldbogen speaks from his office.
GOLDBOGEN: So, that's why it's a very seasonal pattern of krill going boom and bust throughout the foraging season for blue whales.
David Cade interviewed in an office space. Text animates on screen, identifying him as David Cade, Postdoctoral Researcher, Institute of Marine Sciences, UC Santa Cruz.
DAVID CADE (Postdoctoral Researcher, Institute of Marine Sciences, UC Santa Cruz): So, what the echosounder allows us to do is actually determine the density and distribution of prey in the water column.
Cade indicates a graph on his computer monitor. Labels on the y-axis read “75m, 100m, 125m, 150m,” and on the x-axis read, “1km, 2km,” etc.
CADE: So, if you look at this graph, on the vertical axis you have the depth. On the horizontal axis you have, essentially, time or distance.
Cade speaks in his office, indicating the graph on the computer monitor.
CADE: The ship moves across the surface of the water. It's actually mapping—each one of these vertical lines is one individual ping where it's listening for the return echo.
An animated rubber boat moves through the ocean. Curved lines expand out into the water from an echosounder positioned on the bottom of the boat. As it passes over a patch of krill, the curved lines are reflected back towards the boat.
CADE: How strongly that signal bounces off of an object in the water tells you how much of it there is and how far away it is.
Cade speaks in his office.
CADE: If that click [MAKES A CLICKING NOISE] takes longer for it to come back that means that the object it's bouncing off of is further away.
The echosounding graph is shown in full. A spiky shape indicates the signals received as the boat travels. A significant amount of red can be seen throughout, indicating high density in the water column.
CADE: The louder it comes back, the more stuff there is in the water. So, what this is, is then a map of the loudness of the return signal and the red areas are areas of high intensity. That's an area where you have a lot of stuff in the water column.
Cade speaks in his office.
CADE: In this case, it's krill. The white areas mean that that sound just traveled through there without bouncing off of anything. The blue areas are areas where there's a little bit of stuff in the water but not so much in there. So, then because we've done, then, these finely calibrated experiments, we can actually tell you how much krill that actually corresponds to.
Cade, Goldbogen, and other researchers confer over a laptop.
GOLDBOGEN: So, we think that krill will migrate deep into the ocean during the day to avoid predation from other predators,
Goldbogen speaks in his office.
GOLDBOGEN: …but also because they're deep and aggregated, trying to avoid predators, blue whales appear to have evolved foraging strategies that take advantage of that dense patchiness at depth.
Goldbogen confers with Cade, as the two review images on a computer monitor.
GOLDBOGEN: Understanding the vital rates of an animal, such as how an animal feeds and its feeding rate, is really fundamental to the conservation and management of these animals. Because blue whales are specialists on a very specific resource, we have very good studies and models…
Goldbogen speaks in his office.
GOLDBOGEN: …that can tell us exactly what the energetic efficiencies are of blue whales, especially how it relates to changes in their food supply.
Cade speaks in his office.
CADE: One of the things that we have to monitor and think about and predict into the future is as the oceans warm and if they continue to warm at the current rate how that might affect those oceanographic processes,
Animated diagram of the ocean winds and current patterns along the California coastline.
CADE: …how that might affect upwelling which leads to these big blooms, which lead to these krill hot spots.
Cade speaks in his office.
CADE: As the ocean warms, those processes might change and how those are going to be changed is a matter of a big scientific debate. Like, is there going to be increased upwelling or is there going to be- or will warmer surface waters lead to increased stratification that inhibits that cold, cold bottom water, that nutrient-rich bottom water from coming up to the surface and providing nutrients to the phytoplankton that everything in the ocean thrives on.
A field of bubbles rises up through the ocean. A blue whale swims underwater.
CADE: So, how climate change is going to affect these blue whale populations is unknown, but it will probably have a big effect one way or the other.
Goldbogen speaks in his office.
GOLDBOGEN: Blue whales face a number of different threats due to our increasingly urbanized oceans.
Still image of a whale’s tale flapping above the ocean’s surface, while in the background, a large commercial ship looms on the horizon.
GOLDBOGEN: One specific threat relates to ship strikes.
Goldbogen and Cade confer at a computer workstation.
GOLDBOGEN: Our tags give us a really detailed view of where these foraging hot spots intersect with the shipping lanes.
A graphic indicating the locations of documented ship passages to blue whales’ feeding areas off the coast of southern California. Lines indicating shipping lanes pass very close or directly over whale locations.
GOLDBOGEN: And if those foraging hotspots change, hopefully in the future we can have a dynamic management solution where we can say,
Goldbogen speaks in his office.
GOLDBOGEN: “Hey, we're predicting that the foraging hotspot is actually going to move west and perhaps if we just move the shipping lanes a little bit to this side or a little bit to this side,
Still image of a whale’s back breaching above the surface with a large commercial ship in the background.
GOLDBOGEN: …we can significantly decrease the amount of ship strikes that occur.”
Goldbogen speaks in his lab.
GOLDBOGEN: Because blue whales are such tremendous filter feeders—they process vast amounts of the ocean—we think that they might be susceptible to ingesting microplastics…
Goldbogen and other researchers handle equipment on a boat.
GOLDBOGEN: …and they might be sentinels for ocean pollution, specifically microplastics.
MATT SAVOCA (Postdoctoral Research Fellow, Hopkins Marine Station of Stanford University): One of the ways to determine what you're eating is to look at what you're pooping out.
Close-up of a hand holding a mason jar with a frosty red substance inside.
SAVOCA: And so, what we have here is a fecal sample from a blue whale…
Savoca speaks to camera in an equipment room, holding the whale poop. Text identifies him as Matt Savoca, Postdoctoral Research Fellow, Hopkins Marine Station of Stanford University.
SAVOCA: …that we collected in Monterey Bay last summer. The reason why it's deep red like that is because they eat krill. Blue whales, especially, eat only krill and krill are this dark, you know, deep orange and red color.
Goldbogen and other researchers operate equipment on a boat, pumping up water from the ocean.
SAVOCA: And what we intend to do is analyze these samples to look for plastics within the fecal sample.
Cade speaks over a CB radio on a boat.
CADE: Martin, Musculus.
Drone footage of a research vessel in the ocean. On board, Cade operates equipment and plugs in a laptop.
CADE: Blue whales are coming back from centuries of exploitation. These new devices have really, like, opened up a whole new world for studying these animals that we really know so little about.
Close-up of a computer monitor showing a research paper by Goldbogen, et al., entitled, “Why whales are big but not bigger: Physiological drivers and ecological limits in the age of ocean giants.” Camera pulls back to reveal Goldbogen at his desk.
GOLDBOGEN: Every time we’ve learned something, there's actually 10 more questions that pop up.
Goldbogen speaks in his office.
GOLDBOGEN: How blue whales migrate across the ocean from their breeding grounds to their feeding grounds…
A rubber motorboat pulls behind a blue whale. A researcher with a long tagging pole stands in the bow.
GOLDBOGEN: …and how they impact the resources that the entire ocean ecosystems rely on is really interesting and important.
The researcher successfully tags the whale as it spouts and then dives below.
GOLDBOGEN: And that's why we should try to better understand these ocean giants.
[EXCITED YELL]
Credits roll:
The “Marine Biology” Seminars on Science is made possible by OceanX, an initiative of the Dalio Foundation, as a part of its generous support of the special exhibition Unseen Oceans and its related educational activities.
Director / Producer
Karen Taber
Producer / Editor
Ben Tudhope
Post Producer
Kate Walker
Title Design
Timothy J. Lee
Illustrations
Alex Boersma
Special Thanks
The Goldbogen Lab at Hopkins Marine Station of Stanford University.
All footage & images taken under permit NMFS 16111/21678.
© American Museum of Natural History