Sant Ocean Hall Visual Description Highlights Tour

Welcome to the Sant Ocean Hall, where you can explore how the ocean is a global system essential to all life—including yours. This permanent gallery is located on the first floor of the museum, in one of the wings branching off the central rotunda.

It presents fossils, biological specimens, anthropological items, and models of marine organisms. The exhibit panels and platforms feature many different shades of blue, with darker hues for deeper waters. Some displays are behind glass, while others are out in the open on raised platforms.

A skylight spans the entire central atrium, which runs from the rotunda entry to the “deep ocean” area near the back of the gallery. Projections on the upper back wall of the atrium show footage of marine ecosystems, from undulating kelp forests to busy coral reefs. The atrium itself contains displays about currents, biodiversity, whale evolution, the North Atlantic right whale, and the different zones of the open ocean.

Three smaller wings run along the left, right, and back end of the gallery. The left wing explores the fossil history of the ancient ocean and contains the Ocean Explorer theater. The right wing includes the Science on a Sphere theater and showcases eight coastal ecosystems (including a live coral reef tank), explores the importance of natural history collections, and highlights the polar oceans. The rear wing deals with humans living on an ocean planet, and the human activities that threaten and protect this global system.

This visual description tour was developed to make the exhibition’s key messages, images, and objects more accessible to visitors who are blind or have low vision.    

The tour divides the exhibit gallery into 10 thematic sections and takes you through them one by one. Each thematic section includes a description of the space, a summary of the content, and detailed descriptions of several key objects or tactile elements in that section. The titles of these thematic sections are typically the same as the titles on large text panels throughout the hall. You can follow the tour in order or skip around to get to a different section.

Ready to start the tour? Let’s dive in!

This section introduces the staggering variety of life in the ocean, as well as the currents, oxygen production, and temperature regulation that make life on Earth possible.

To orient yourself, stand at the central doorway with your back to the rotunda, facing into the hall. A series of rectangular archways act as portals to the Ocean Hall. Beyond the portals are three curving glass cases in the middle of the hall, which are filled with specimens, models, and images. To either side of these central cases, walls of content feature touchable fossils, tactile models, and video screens.

You can continue with this overview for more information on each of these areas, starting with the entry archways.

Or for detailed descriptions of the touchable fossils, touchable seafloor model, and key specimens and models, skip ahead to the next header.

Just inside the rotunda doorways, four towers connected by crossbeams form rectangular arches that welcome you to the museum and to the Ocean Hall. Display cases embedded in each tower preview the types of objects and stories you’ll encounter at the museum, exploring evolution, biodiversity, cultural heritage, and planetary history. The introductory text of the ocean hall, repeated on each tower, reads: “The ocean is a global system essential to all life — including yours. We depend on a healthy ocean. But the health of the ocean is in crisis. This productive global system is perilously threatened by human activities. You can take action. Everyone has a role: at home, in your community, and in the world.”

Enter this first section by passing between the two middle towers. The crossbeam above reads “Earth is an ocean planet.”

Turn to the left side of the gallery, where a long wall flanks an escalator that leads up to the Ocean Hall. A photo collage to the left of the escalator landing says: “we are all connected to the ocean.” The long wall to the right of the escalator landing is actually made up of seven staggered walls that explain how the ocean is essential to all life — past, present, and future.

On the segment closest to the rotunda, a video screen shows footage of marine ecosystems and people living near water. There’s no sound, but captions outline the importance of the ocean to humans and marine life. Further down, the fifth segment of the wall introduces how life began in the ocean, and includes fossils in a display case and four touchable fossils nearby. Text and graphics on the other walls explain that not only does the ocean produce half the oxygen we breathe, but its huge volume of water also regulates temperatures and drives weather systems, keeping Earth livable.

The right side of the gallery mirrors the left: there’s another set of staggered walls, an escalator, and a video monitor playing the same synchronized content as the other screen.

To the right of the escalator (which leads down to the Constitution Avenue lobby), a photo collage says: “We can all be ocean stewards.” The five staggered walls explore the ocean as an active, ever-changing, and complex system made up of interconnected basins. The first wall features the video monitor, and the remaining walls include maps explaining that while the Arctic, Southern, Indian, Pacific, and Atlantic Ocean basins each have distinct characteristics, they’re connected by currents that distribute heat, nutrients, and organisms. This constant mixing helps moderate the climate and shapes our weather. Meanwhile, underneath the blanket of water is a landscape more dramatic than any on land. A touchable model of part of the Atlantic seafloor reveals a varied terrain of mountains, islands, and chasms.

The center aisle introduces you to the ocean’s biodiversity through three large glass cases. Arranged in a sinuous line, the first and third cases are curved while the center one is rectangular, but each is free-standing so that you can walk around it to examine the specimens and photographs within.

Life-size models of organisms rise out of the tops of each case. In the first case, a white-and-orange Japanese spider crab (Macrocheira kaempferi) emerges from one side. Its long spindly legs are folded up so it’s about four feet wide, or 1.2 meters. A silver sailfish (Istiophorus platypterus) with a spear-like nose and dark blue dorsal fin appears to swim above the opposite side of the case. It’s about five feet, or 1.5 meters, long.

In the central case, a strand of giant kelp (Macrocystis pyrifera) seems to grow from the floor. From holdfast to tip it’s about 18 feet long, or 5.5 meters. A lion’s mane jellyfish (Cyanea capillata) with a three-foot-wide or 1 meter bell appears to float above the case. Its white tentacles dangle into the case and are nearly 20 feet, or 6 meters, long. A thresher shark (Alopias superciliosus) spans one side of the case. Its tail fin is about four feet, or 1.2 meters, long. On the other side of the case, a black-footed albatross (Phoebastria nigripes) appears to fly with its belly towards you and one of its outstretched wings peeking above the glass. Its wingspan is about six feet or two meters long.

Above the final case, a leatherback sea turtle (Dermochelys coriacea) appears to swim sideways to show off its black-and-white mottled skin. It’s about six feet, or two meters, long. On the other side of the case an Atlantic white-sided dolphin (Lagenorhynchus acutus) with a yellow stripe near its tail hovers just above the glass, as if mid-breach. It’s also about six feet or two meters long.

Both sides of each of these three cases explore questions about habitat, relatedness, and size. These are three of the ways that scientists try to organize marine organisms to make sense of the variety of life in the ocean. A large, dark blue text panel introduces the concept of biodiversity at the rotunda side of the first case and the back end of the last case. It emphasizes that diversity occurs at every level of life — genes, species, ecosystems. It’s a complex web of interactions. And it is essential for a healthy ocean. Altering the balance can have dramatic — and unforeseen — effects.

You’ve reached the end of the section overview. Up next are detailed descriptions of the touchable fossils, touchable seafloor, and key specimens and models.

You can touch four real fossils of different types of marine animals that lived in the ocean millions of years ago.

In the staggered series of walls on the left side of the Ocean Hall, head to the fifth wall. The text rail on the right corner of that wall is about two-and-a-half feet, or 0.7 meters, off the ground.

The first touchable fossil on the left side of the rail is a Heteraphyllus ammonite shell from Whitby, England. It’s been cut in half and polished to a smooth finish, showing the coiling pattern and chambers of the ammonite’s internal structure. Crystals formed in the shell after its burial, preserving these patterns and making the fossil hard as stone. This particular species lived during the Late Jurassic period, 161 to 145 million years ago.

The second fossil from the left is a Pleurotomaria armata gastropod shell from Bayeux, France. This apricot-sized snail shell is shaped in a low spiral, like a frosting swirl on a cupcake. Raised pea-sized bumps run along the spiral. This sea snail lived during the Jurassic Period, 200 to 145 million years ago.

The third fossil from the left is a sponge called Hydnoceras tuberosum. During the Late Devonian period about 370 million years ago, it lived in a seaway covering New York. In life its skeleton was made of glass, but the fossil is dark brown and has a smooth, almost metallic texture. Many pieces have broken off, so you’ll feel rough bumps along the front surface and hard edges along the top.

The fourth fossil is an Actinostreon bivalve from Gloucestershire, England. This palm-sized oyster has distinct accordion-like ridges running the length of its shell, and it closes in a zig-zag seam along the top. Each point of the zig-zag is the end of a ridge. This species lived during the Jurassic Period, about 200 to 145 million years ago.

Text on the wall to the right of the fossils explains that the family tree of every plant and animal alive today is rooted in the ancient ocean. The ancient ocean is where life probably began and evolved into a rich and endlessly fascinating variety. While ammonites are extinct, sponges, sea snails, and oysters still live in our ocean today.

You can touch a bronze model of the ocean bottom between Central America and the Mid-Atlantic Ridge.

In the staggered series of walls on the right side of the Ocean Hall, go to the fifth and longest wall. A long ledge is raised about two-and-a-half feet, or 0.7 meters, off the ground. Spanning this ledge is a topographic map that’s 12 feet long, or 3.6 meters. The texture of this map tells you about the ocean’s relative depth.

Starting on the right side, feel for lots of bumps — they’re worn smooth so they’re not sharp, but the overall texture is still rough. These peaks are part of the mid-Atlantic ridge. Feel a trench running diagonally from the bottom right corner up and to the left about two feet — this is the Kane Fracture Zone. As you move to the left, you’re moving west across the Atlantic. Further to the left, rough bumps smooth out to form a rippled texture — this is the near abyssal plain. To the left (or west) of the plain is another diagonal trench called the Puerto Rico Trench, which leads up immediately into the island of Hispaniola. The island drops off into the Caribbean Sea on its west side. You’ll feel a few raised sea mounts in the Caribbean before finishing with a flat, smooth raised area on the far left — this is the continental shelf of central America.

This varied terrain is typical of the ocean bottom. Underneath the ocean’s blanket of water, you’ll find Earth’s deepest valley, longest mountain range, and biggest volcano, not to mention towering cliffs, vast plains, and vents spewing heat and chemicals from deep underground.

One of the questions printed in big blue vinyl text on the first glass case reads, “Who is it related to?” Find the navy-blue panel titled “Relatedness” below the spider crab model. This display highlights how even fairly close relatives can look quite different.

Twenty-nine cone snails with varied shell patterns are arranged in two curving lines. Yet, each shell represents a species within a single genus of mollusk, Conus. Cones are predators. Each species injects its own particular blend of quick-acting venom to kill its prey. The largest of these shells, the Leopard cone (Conus leopardus, number 17) is eight inches, or 20 centimeters, long while the smallest, the Miterlike cone (Conus mitratus, number 29) is only an inch, or 2.5 centimeters, long. The marble cone (Conus marmoreus, number 24) has a black-and-white chain mail pattern, while the Zoned cone (Conus zonatus, number 23) has stripes, and the Geography cone (Conus geographus, number 16) is mottled cream and ochre. The Glory-of-India cone (Conus milneedwardsi, number 12) is sharply pointed at both ends while the Beech cone (Conus betulinus, number 18) has a wide, flat end.

To the left of the panel with all the cone shells is a canister containing a northern shortfin squid (Ilex illecebrosus), a model of a California two-spot octopus (Octopus bimaculatus), and the shell of a chambered nautilus (Nautilus pomilius).  Squid, octopuses, nautiluses, and snails — along with oysters, clams, mussels, and scallops — are all mollusks. It just goes to show the wide range of body types and lifestyles in the phylum Mollusca.

One of the large vinyl questions on the second glass case asks “How BIG is it?” Find the purple panel titled “Size” underneath the tail of the thresher shark model. The specimens, photos, and models in this case reveal that sharks come in all sizes.

We humans tend to focus on sharks like the thresher shark (Alopias supercilious), which is nearly 10 feet, or 3 meters, long. This shark uses the upper lobe of its tail fin — measuring half its body length! — to stun and herd its prey, which luckily for us are mainly small schooling fish. The lifelike model overhead has a sleek, gray body with a pale belly. Under its large, round, orange eyes, its small mouth is slightly open to reveal small teeth. Its face ends in a short, pointed nose. This shark’s dorsal fin is short compared to its much longer sickle-shaped pectoral fins.  

Most shark species are under three feet or one meter long, such as the scalloped hammerhead (Sphyrna lewini) specimen inside a glass cylinder in the lower right corner of the case. The hammerhead is positioned vertically in its jar, so that its head is at the top and its tail loops into a circle before touching the bottom. As you might have guessed from its name, this shark’s head resembles a double-sided hammer with eyes at each end. When the shark is swimming forward, the front edge of its head is wavy, like a scalloped pie crust. The hammerhead’s belly is facing you, and you can see its mouth, which is slightly open in a downward crescent. Its skin is wrinkled from the ethanol fluid in which it’s preserved, and its pectoral fins have faint rays.      

One of the smallest sharks, the dwarf lanternshark (Etmopterus perryi), is only about six or seven inches long, or 15 to 17 centimeters, long. A photo shows a preserved specimen in the palm of a person’s hand, where the shark’s nose doesn’t quite reach the tip of the middle finger. Like the hammerhead specimen, the lanternshark has turned tan and looks a little deflated and wrinkled from being preserved in alcohol. And like the thresher shark, its mouth is directly below its eye, though this specimen’s mouth is slightly open and curves upward as if it’s smiling.

In contrast, the whale shark (Rhincodon typus) can get up to 46 feet or 14 meters long — that’s 74 times bigger than the dwarf lanternshark. In fact, it’s the largest known fish species, and can weigh up to 15 tons or 13 metric tons. A photograph in the case shows a whale shark ascending to the ocean surface. Its body is dark gray with bands of bright white dots in between pale stripes, and its head and pectoral fins are entirely speckled with white dots. From this side angle you can’t see its five-foot-wide mouth, which spans the entire front edge of its broad, flat snout. Whale sharks eat by gulping mouthfuls of water and swallowing the tiny plankton that get caught in their gills. 

One the large vinyl questions on the third glass case reads, “Where does it live?” Find the blue-gray panel labeled “Habitat” underneath the dolphin model. The assemblage of specimens and photographs explains how different habitat conditions on the ocean floor affect who lives there.

Soft and sandy seabeds are home to burrowing animals and plants with roots. On hard bottoms, you’ll find animals and plants that attach themselves to the rocky surface and hold on tight.

A photograph shows a horseshoe crab crawling over fuzzy reddish sand dollars littering the yellow sandy seafloor of Cape Anne, Massachusetts. Below the photo is a dried Clypeaster subdepressus sand dollar that’s about eight inches, or 20 centimeters, long. Sand dollars are a type of flattened, burrowing sea urchin that nestle into the soft sediments of shallow ocean floors. This specimen looks like a large sugar cookie with a raised shape in the center that looks like a flower with five petals. In life, it would have been covered in soft tube feet (the red fuzz in the photograph), but this dried specimen has a rough texture all over, like a prickly stucco wall.

Hard-bottom areas of the ocean floor often support a colorful array of sponges, sea fans, sea stars, and reef-building corals. A photograph shows a vibrant red sea fan and other corals off Gangga Island, Indonesia. In life, the common sea fan Gorgonia ventalina is a vivid purple color, but the dried specimen in this case is off-white with orange veins. The flat, lacy fan grows from a thick base that would be anchored to a rock. It’s 14 inches, or 35 centimeters, tall. Similarly, the dried cushion star Culcita schmideliana has also lost its color, but in life these mottled orange stars would stand out against their rocky substrate. This specimen is six inches, or 15 centimeters, wide and has a sandpaper texture dotted all over with pea-sized bumps. It looks a bit like a plump wad of bread dough that’s been pinched into five points.

This is just a taste of all the biodiversity in the ocean. As we move to the next section of the tour, we’ll be focusing on just one group of marine animals — whales. 

To orient yourself, stand in the center of the hall with your back to the third biodiversity case, the one with the dolphin and sea turtle models. Directly in front of you, an enormous model of a whale hangs from the ceiling. To the left is a platform with whale skulls and fossil whale skeletons. To the right is a platform with text rails, object cases, and a model of an Inuit kayaker.

You can continue with this overview for more information on each of these areas, starting with the display on the left about the evolution of whales.

Or for detailed descriptions of the fossil whale skeletons, the whale model and its tactile callosity, and an Indigenous whaling object, jump to the next header.

A curved platform tapers on its left side to join one of the support columns separating the atrium area from the left side gallery. The side gallery deals with fossil marine life, and it will be the eighth stop on our tour. The whale evolution platform acts as a link between the ancient ocean and the ocean today, using fossils and modern specimens to show how early whales took advantage of the ocean as a rich food source and evolved new ways of feeding.

The front side of the platform, facing the rotunda, explores how whales’ transition from land to sea transformed their bodies. Three fossil skeletons suspended from the ceiling show the changes in their limbs, skulls, and tails. A monitor on the platform shows what these ancient whales might have looked like. Whales are mammals whose ancestors lived on land, and a small case on the platform highlights the similarities in the ankle bones of early whales and their distant cousins, deer.

The back side of the platform explores how some whales lost their teeth and evolved baleen. The early whales on the rotunda side of the platform evolved in a period of global warmth, but as polar climates cooled, marine resources became more concentrated in specific places, making filter feeding very effective. A cast of a fossil Llanocetus skull marks a transition to filter-feeding with both teeth and precursor baleen. Real skulls of an Antarctic minke whale (Balaenoptera bonaerensis) and a North Pacific right whale (Eubalaena japonica) highlight different feeding styles among modern baleen whales. A single baleen plate from a North Atlantic right whale (Eubalaena glacialis) is five and a half feet long, or 1.6 meters. Nearby is a jar full of copepods, which are the size of rice grains. These small crustaceans get trapped in the baleen’s fringe.

The rest of this section focuses on one type of baleen whale, the North Atlantic right whale (Eubalaena glacialis). The life-size model in the center of the hall depicts a real individual named Phoenix. The platform to the right follows her life history, as well as the history of her species, from polar to temperate waters, from surface to bottom, from high-traffic waterways to small, Indigenous whaling communities.

The side of the platform closest to the rotunda includes photographs of Phoenix throughout her life and explains that her distinctive face markings are called callosities. There’s a tactile model of a callosity at the right end of the text rail. Above the rail, a small specimen case contains one of the electronic tags used to track whales like Phoenix. A graphic panel nearby shows how North Atlantic right whales size up to other whale species.

The other side of the platform explains that the right whale got its name because for whalers, this was the right species to hunt: they were easy, lucrative prey. A model of an Inuit kayaker from Greenland appears to glide above a display case full of Inupiat objects from Alaska that illustrate the importance of whale hunting in Arctic communities. A text rail below outlines the history of the whaling industry in Europe and the United States for oil and baleen — a practice that nearly drove North Atlantic right whales to extinction. Another display case on the platform shows a tangle of gill nets and fishing lines, which along with ship strikes pose the biggest threats to these whales today.

You’ve reached the end of the section overview. Up next are detailed descriptions of the fossil whale skeletons, of Phoenix and her touchable callosity, and one of the Indigenous whaling objects. 

Above the vertical text panel titled “The Evolution of the Whale,” three fossil skeletons are suspended from the ceiling. The smallest, named Maiacetus, is about the length of a car; the next largest, Dorudon, is the length of a pickup truck, and Basilocetus is by far the longest, about the size of an articulated city bus.

Most of Basilocetus’ skeleton is real fossil material that’s a dark gray-brown color, but some bones are lighter beige to indicate that they’re casts. Both Maiacetus and Dorudon are entirely casts of fossil specimens, so their skeletons are a uniform grayish beige.

Maiacetus lived between 49 and 40 million years ago and is an example of an early whale that could both swim and walk on land. It has a long, strong tail, and a massive head with a long wolf-like snout. Its nostrils are on top of its snout, up towards the tip, which helped it breathe when it came up to the water’s surface. Its open mouth reveals conical, sharp front teeth and serrated, triangular back teeth, well-suited for eating fish. Its hind limbs are long and flipper-like and posed in a paddling motion, but the most special thing about its feet are its ankles, which aren’t obvious from this angle. A display case on the platform shows that Maiacetus’ ankle has a unique double pulley shape that looks strikingly similar to that of modern white-tailed deer. Whales, hippos, deer, and other even-toed hoofed animals all share a common ancestor that had these ankle bones. Maiacetus probably spent much of its life in the water, returning to land only to mate and give birth.

Dorudon lived about 38 to 36 million years ago, and its body suggests it couldn’t haul out on land like Maiacetus, instead living its whole life in the water. Like Maiacetus, it has a long snout filled with sharp conical teeth at the front and more triangular teeth at the back, so it probably ate fish and small marine mammals. Its nostrils are even higher up on its snout, for easier breathing at the surface. But the biggest difference is its hind limbs and tail. Dorudon’s hips, leg bones, feet, and toes are very small and dangle from its spine. Instead of paddling , it would have propelled itself through water thanks to a fluke at the end of its long, strong tail.

Basilosaurus lived between 40 and 35 million years ago and was also fully aquatic. You could think of it as a more extreme version of Dorudon. Perhaps that’s why the scientists who first discovered it thought it was a reptile and named it “regal lizard” (even though it’s a mammal). Like Dorudon and Maiacetus, it has a long narrow skull with nostrils on top. Sharp conical teeth in the front half of its snout and larger, triangular, saw-edged teeth at the back indicate that it ate fish and smaller marine mammals (including Dorudon). Basilosaurus has an extremely long, streamlined body and would have had a small tail fluke at the end. It has paddle-like front limbs with an elbow joint like a seal, and its back limbs are so tiny they wouldn’t have helped it swim, but they do provide a clue to its terrestrial ancestry. Even today, modern whales have remnant pelvic bones! 

Suspended overhead by four aircraft cables is a life-size model of a North Atlantic right whale (Eubalaena gracialis). The model is based on a real individual named Phoenix, and all her markings are true to life.

At 43 feet, or 13 meters, long, she’s about the size of a standard city bus. She’s posed in a gradual dive, with her tail higher than her head, with her mouth partway open as if she’s about to feed. Her head faces the rotunda and is about a third of her body length.

Her eyes, which are medium brown with a little white at the edge, look like they’re about the size of a baseball. Each eye is right next to the downturned corners of her mouth, which gives her a perpetual frown. At her chin, eyebrow, lower lip, and top of her snout and head are grayish-white bumps called callosities. Callosities look like hard, porous rocks but are actually patches of rough skin. The placement, size, and shape of the callosities act like fingerprints, helping scientists identify individual North Atlantic right whales.

Phoenix’s open mouth reveals rows of baleen plates that hang down from the roof of her mouth. The combined effect of all these vertical baleen plates looks like a sheet of corrugated metal or pages in a book. Her lower jaw has big flaps that curve up to cover the baleen when her mouth is closed. These baleen plates are made of keratin, the same material as your fingernails and hair, making them strong yet flexible. Each plate’s inner edge has a hair-like fringe that strains food from water. This fringe varies in thickness among species depending on the whale’s prey. Phoenix and other right whales eat copepods, tiny crustaceans about the size of a grain of rice. Right whales swim with their mouths open wide, then close their mouths and force water out through the baleen strainers, trapping the copepods inside. All the whale has to do then is swallow. Phoenix and her kin can eat more than 2,200 pounds (which is about 1,000 kilograms) of copepods daily.

Moving past her face and mouth, the rest of Phoenix’s body is a smooth, uniform texture with a mottled blue-gray color. Her front fins are spread out a little from her body, and she has a small white splotch in the middle of her belly. More white marks include lines on her right lip and two long parallel lines on her left tail fluke. These are all scars from being entangled in fishing gear. Phoenix got her name after surviving an entanglement in 1997. Right whales frequently get entangled in fishing gear — in fact, ship strikes and entanglements pose the biggest threats to North Atlantic right whales today. With only about 370  individuals left, they’re one of the most endangered whales in the world. One way to keep them safe is to use buoy lines with weak links like the one in the display case on the right whale platform, which release when whales pull on them.

You can touch a life-size model of one of Phoenix’s callosities. Go to the right end of the text rail about Phoenix’s life history.

A callosity is a hardened skin eruption, similar to a callus, that North Atlantic right whales develop on their faces. No two whales have the same pattern of callosities, so scientists use these bumpy growths to identify individuals.

This model callosity is about the size of a cantaloupe melon, and rough but not sharp. Try to feel around the underside where fewer people have touched the model, it’s less worn and feels more like what’s on Phoenix’s face.

This model is a grayish ivory color, but in real life, callosities look white from a distance thanks to the tiny pale crustaceans called cyamid amphipods or “whale lice” that live in the crevices of the callosity .

A display case on the back side of the North Atlantic right whale platform includes multiple Indigenous Alaskan objects. In the lower right corner is a harpoon box shaped like a whale.

The box is made of smooth, black wood and is about 10 inches, or 25.4 centimeters, long. The whale has a small round blue eye, downward curving mouth, stout body, and stumpy tail. A leather strap is wrapped just above the tail fluke. The main body is divided into hinged compartments with doors held together with leather cords. Two cream-colored pointed tools are attached on top.

For thousands of years, native peoples of the Alaskan coast and the Arctic have depended on whales. They treasure whales’ bounty and spirit. These hunters created one of the world’s first whaling societies. They still rely on whales for meat, oil, and bone. No part of the animal is wasted, from blubber to sinew, to gut.

Honoring the spirit of the whale, carved and decorated boxes like this one stored harpoon blades during whale hunts. “Living” inside the box was meant to give the blade spiritual powers to carry a harpoon back to the blade’s “home” in the whale. When these traditional whalers set out, they carry objects to appease the spirits  of the whales they kill. They believe that showing respect and giving proper thanks ensures a plentiful supply of whales in coming seasons.

Right whales spend most of their time near coastlines and at the surface, but they do go farther out to sea. Let’s continue on the tour to meet more organisms from different parts of the open ocean.

This section introduces the open ocean, from sunlit surface to twilight zone to inky depths, as well as the diverse and abundant life forms that make their homes throughout the entire volume.  

To orient yourself in this section, stand at the long, low tank under the model whale, with your back to the rotunda. In front of you to your right is a content area about the surface zone. Moving counterclockwise towards the back of the hall, two standalone walls deal with the deep ocean. Continuing counterclockwise, a content area about the twilight zone mirrors the surface zone. And in the center of this space is a tall tower showing the relative depths of the zones. Each zone is filled with models, specimens, text panels, and photographs. 

You can continue with this overview for more information on each of these areas, starting with the tank under the whale.

Or for detailed descriptions of the giant squid tank, the ocean sunfish model, the flashlightfish specimen, and the bubblegum coral specimen, jump to the next header.

The long, low tank that kicks off the open ocean section contains a real specimen of a giant squid (Architeuthis dux). This elusive animal traverses the open ocean from top to bottom, making it the perfect ambassador for a part of the world that’s far from shore and far from sight.

There are benches on the back side of the squid tank that face into the middle of the open ocean section. A text panel between the benches introduces the giant squid on the tank side, and the open ocean on the other.

In the center of this section is a towering column that’s 30 feet, or 9 meters, tall, depicting the three zones of the open ocean: the sunlit surface, the twilight zone, and the deep ocean. Each zone has a different mix of species adapted to its light levels, pressures, and temperatures. The zones are not equal in size. Graphics on the column depict the average ocean depth as 20 Washington Monuments stacked on top of each other. In reality, each monument is 555 feet, or 169 meters, tall, and the average ocean depth is a little deeper, at 13,210 feet, or 4026 meters. The surface zone makes up just 5 percent of the average depth, or just one Washington Monument. The twilight zone is the next 20 percent (or four stacked Washington Monuments). The remaining three-quarters of the ocean is deep, permanently dark, and cold.

Four curving rails around the base of the tower explain that with changing depth come changes in abundance, diversity, and form. Light disappears quickly with depth. Temperature drops and pressure rises. There is endless movement among these ocean layers. For organisms that have evolved (and are still evolving!) in the ocean, life in water offers rich possibilities for survival: ways of feeding, moving, and reproducing that would be impossible on land.

With your back to the rotunda entry, the ocean surface zone is to your right. If you turn to face into this zone, there’s a tall, freestanding display case with an introductory text panel on one side and models of organisms inside and above. Behind the display tower are two short, curved walls enclosing one of the gallery’s support columns. Behind them, a large curving wall anchors the back of this space. All these components have the same color scheme of light and medium blues with lime green accents.

The specimens and models in this zone represent a small fraction of the organisms that float and swim at the surface, which is home to the overwhelming majority of known species. Text and infographics explain how photosynthesis makes this zone so productive. The rest of the stories in this area explore the varied strategies for survival in the competitive surface ecosystem. A large photomural shows how schooling fish attain safety in numbers. A model of sargassum sea grass filled with organisms shows one way to camouflage and hide, while photographs show how other surface dwellers blend in with the water through countershading or with see-through bodies. A life-size bluefin tuna (Thunnus thynnus) model, which is about eight feet or two and a half meters long, explains how some animals evolved to be fast swimmers. Other organisms called plankton, which range from microscopic animals and plants to enormous sunfish and jellies, swim weakly or simply float.

On the left side of the ocean hall gallery is the twilight zone. It has the same layout as the surface zone — with a tall display tower in front, short curving walls wrapped around a column, and a large, curved wall behind — but the color scheme here consists of dark blues with red accents.

The specimens and models in this zone represent a wide array of life in the murky midwater. Some live here full time, and the vast majority have evolved ways to produce their own light, either to attract mates, lure prey, blend into the brighter water above, or distract predators. Other organisms commute to and from this zone every day, traveling to the surface at night to find food and avoid predators. The specimens along the back wall highlight midwater animals’ adaptations for snagging prey, and for keeping an eye on threats and opportunities coming from all directions. More specimens on this wall show how bioluminescence evolved over and over in many different groups. A small video monitor shows a compilation of different glowing organisms. A push-button display shows how counterillumination works, where animals produce light on their bellies so when viewed from below, they blend into the lighter water above.

The back end of the open ocean section is all about the deep ocean. A tall display tower features an introductory panel on one side and models within. It stands in front of and between two free-standing walls with specimens and models on either side. If you walk around to the back sides of the two walls, there are low railings that curve in a semicircle around the specimens and models on display. One of these back walls includes a video monitor with audio narration. The color scheme of this section is deep indigo with bright magenta accents.

Standing with your back to the rotunda, the free-standing wall on the left side deals with pelagic deep ocean animals, meaning those that cruise or drift just above the endless acres of the thick, soft ooze of the ocean floor. The wall on the right side deals with benthic deep ocean organisms, meaning ones that burrow, creep, or attach themselves to the bottom. Food is scarce for both kinds of animals, and they’ve evolved ways to snag food falling from above or catch each other while conserving energy. Each wall includes specimens near eye-level, and life-size models of organisms near the top. The model on the pelagic wall is a fin octopus (Cirrothauma magna), which is about three and a half feet tall by five feet wide, or roughly one meter by one and a half meters. The model on the benthic wall is a knifenose chimaera (Rhinochimaera atlantica), which is about three and a half feet, or one meter, long.

Looking at the walls from the back side of the ocean hall, the display on the left deals with hydrothermal vent communities, while the display on the right focuses on organisms that live on seamounts. These are two kinds of places where life thrives in the deep. Hydrothermal vents are found near places with volcanic activity and spew superheated water containing lots of dissolved minerals and gases. Microbes feed on these chemicals, and in turn support crabs, worms, lobsters, mussels, and clams such as the ones on display in jars. Undersea mountains swarm with life because they not only offer solid surfaces for animals to attach to, but currents welling up and swirling around them also bring a constant food supply of nutrients and plankton. A glass vitrine shows a coral specimen and a coral model in front of a mural of a seamount community, along with a crab specimen and a model fish.

You’ve reached the end of the section overview. Up next are detailed descriptions of the giant squid, the ocean sunfish model, the flashlightfish specimen, and the bubblegum coral specimen.

Inside the long, low tank at the front of the open ocean section is a real specimen of a giant squid, whose scientific name is Architeuthis dux. Fishermen caught this female squid off the coast of Spain in 2005, just a year after the first ever photos of a live giant squid and 130 years after the first photo of a dead squid. She’s roughly twice the size of the male specimen on display in the collections section of the hall, which will be Section 6 on our tour.

When this squid was caught, she was 36 feet, or 11 meters, long, but since soaking in a preservative fluid the specimen has shrunk to 24 feet, or 7.3 meters. It takes about a dozen steps to walk the length of the specimen in the tank. Four of those steps take you along the head, the next three or four steps take you down the arms, and the remaining steps span the squid’s two long tentacles.

The squid’s mantle, or head, is a large, pinkish gray cylinder topped with two triangular stabilizing fins. Its eye and beak area have become detached from the rest of the mantle and are held on by strings. The squid’s eight arms are each lined with suction cups and the color deepens to a reddish purple. The squid’s two long, thin tentacles are tipped with suction cups for the last foot-and-a-half of their length.

The giant squid’s realm extends deep below the surface to a world unseen by the sun — and until recently, unseen by us. This individual lived in deep water off Spain’s continental shelf, probably in or near an underwater canyon. She was caught in a fisherman’s net in water ranging from 1,312 to 2,133 feet deep (that’s 400 to 650 meters deep). We know that giant squid dine on fish and other squid in part thanks to the first footage of a live giant squid. In September 2004, a robotic camera about 600 miles south of Tokyo, Japan, recorded a giant squid attacking a bait line 3,000 feet, or 914 meters, deep.

Seeming to float above the surface zone’s display tower is a life-size model of an adult ocean sunfish, whose scientific name is Mola mola.

From the side, the ocean sunfish looks like a light gray fish head that is missing the rest of its body. But it’s not missing anything—it just has a short, lumpy pseudotail! With its top and bottom fins extended, the sunfish is about five feet tall by five feet long (that’s 1.5 by 1.5 meters), but only one-and-a-half-feet thick at its widest, or half a meter. Its body is relatively thin and flat with eyes that protrude from the sides of its head and a rounded mouth that cannot be completely closed.

To survive in the surface zone, organisms have to be able to stay in the surface zone. Ocean sunfish often bask at the surface, despite being among the heaviest known bony fish. One like this model could weigh 300-600 pounds, or 136-272 kilograms, and the heaviest Mola molas can weigh up to 5,000 pounds, or 2,270 kilograms. Unlike most other bony fishes, they don’t have a gas-filled swim bladder to help them float. Instead, they have large deposits of low-density gelatinous tissue beneath their skin that helps them stay buoyant at all depths. Their huge surface area also helps them hang out at the surface.

The larvae of many marine animals tend to live in the surface zone, and sunfish larvae are no exception. Here, they can find abundant food, spread to new areas, and grow up to breed with other populations, ensuring genetic mixing. Though the adult sunfishes are enormous, the larvae are only 0.1 inches, or 0.25 centimeters long. 

One of the specimens on display in the main curving wall of the twilight zone is an Atlantic flashlightfish, whose scientific name is Kryptophanaron alfredi. A recessed vitrine in the wall section titled “how do they light up” features two specimens in glass canisters. The specimen on the right is the flashlightfish. It’s about three inches, or 7.6 centimeters, long and displayed with its left side facing you. Its short, blunt snout points up and its forked tail points down, as if it’s swimming to the surface. In life the fish would be darkly colored but because it’s preserved in alcohol this specimen is golden yellow everywhere except for its large black eyeballs.

Like most other twilight zone predators, the flashlightfish hunts by eyesight, so it needs large, sensitive eyes to detect even faint silhouettes of nearby prey. The tissue underneath its eyes is also black except for a large golden-yellow patch just beneath the eye, or because this specimen is posed vertically, to the left of the eye. This bean-shaped organ looks like the under-eye gel patches that people wear to reduce puffiness. In life, it harbors light-producing bacteria that lets the fish see transparent organisms at night in order to eat them. An eyelid-like membrane allows the fish to reveal or hide its light.

Bioluminescent organisms produce light with chemicals. Energy released in a chemical reaction causes the glow, and different reactions produce different colors. On land, very few organisms produce their own light. But in the midwater, bioluminescence is the norm. More than 90 percent of twilight zone organisms glow, though they do it in different ways. Scientists divide bioluminescent animals into two broad categories. One group makes its own light using special organs called photophores. The second group, which includes this flashlightfish, doesn’t make its own light but instead hosts light-producing bacteria cultured in special sacs or separate light organs.

Go to the back side of the deep ocean zone and stand facing the seamount display on the righthand wall. Inside a large vitrine is a bubblegum coral specimen, whose scientific name is Paragorgea arborea. It’s three feet tall by three and a half feet wide, or 0.9 meters by 1 meter. This species is the largest known deep-sea coral, and it can reach several meters tall (around 10 feet). It’s named “arborea” (Latin for “tree”) because of its branching structure. But instead of each twig ending in a leaf, the branches are tipped with bulbous nodules. Though the specimen looks like it’s been shellacked, its pinkish tan color isn’t paint, it’s the real deal. In life, it would have been an even more vivid bubblegum pink.

Seamounts, which are usually extinct volcanoes hidden beneath the ocean’s surface, offer solid surfaces for corals like this one to attach themselves to in dense colonies. In turn, these corals provide habitat for other species. Upwelling currents bring nutrients and plankton for the corals and other animals to eat. There may be 30,000 seamounts in the Pacific Ocean alone. Less than one percent have been explored.

Now that we’ve met a number of ocean organisms, let’s move to the next section to see how humans interact with the ocean.

Who should care for the ocean? Everyone! The health of the ocean is in crisis, and the ocean needs protecting now. The back section of the ocean hall outlines how we depend on a healthy ocean and a healthy ocean depends on us, giving examples of ways we can care for the ocean.

To orient yourself, stand with your back to the rotunda, facing the back end of the Ocean Hall. Anchoring this back gallery is a long wall that features a collage of photographs, graphic panels, video monitors, specimens, and objects pulled from the ocean, all explaining the factors that drive ocean change today. At the right end of the wall, under a panel titled “Ocean Portal,” is an interactive station that lets you take a personality quiz to identify your ocean animal. Two doorways in this wall lead into a small exhibit gallery whose content is periodically updated, so on the day you visit you might find a photo show or a fossil display or something else entirely. To the right of the back wall is the Constitution Avenue staircase and the African Voices Hall. To the left of the back wall are the elevators and the Hall of Human Origins.

In front of the back wall are two long, low display cases sandwiched between pillars. Above and between them, suspended from the ceiling, is a black and red hand-carved canoe. If you’re still standing with your back to the rotunda, the case on the right talks about people’s relationship with salmon in the Pacific Northwest. The case on the left is periodically updated, and past stories have featured a reef made of plastic debris and models of the highly endangered vaquita porpoise. Both cases have touchscreen monitors on their back sides closest to the collage wall; the salmon case monitor includes three stories about Pacific Northwest cultures, and the monitor for the case with periodically updated content features ocean explorers in different parts of the globe.  

Suspended from the ceiling in between the elevators and the Ocean Explorer Theater is a submersible vehicle. In between the Ocean Explorer Theater and the Hall of Human Origins, a large display case featuring anthropological objects shows how different cultures have relied on the ocean through time.

You can continue with this overview for more information on the factors driving ocean change.

Or for detailed descriptions of the plastic pollution display, a model of an Ainu boat, and a salmon-boy statue, jump to the next header.

Spread across different areas of this exhibit section are yellow, pink, red, and purple text panels that identify six big drivers of change in the ocean: pollution, climate change, ocean acidification, overfishing, habitat destruction, and invasive species. The issues facing the ocean may feel overwhelming, but solutions are possible, and each story includes examples of actions you can take to help protect the ocean.

The center part of the back wall tackles three of these issues: pollution, climate change, and ocean acidification. Photos, specimens, a slider activity, and charts and graphs help explain how these human-caused issues harm marine ecosystems. You can skip ahead to the detailed description of the tangled porpoise to learn more about pollution.

The left side of the back wall between the elevators and the smaller exhibit gallery deals with overfishing. Photos, charts, and specimens show how Chesapeake Bay oysters (Crassostrea virginica) have gotten smaller due to overharvesting. A soundless video monitor embedded in the wall explains that as our impact on the ocean has surged over the last few centuries, we’ve gradually accepted a degraded ocean as normal. Turning your back to this wall, there’s a photo op in front to your left where you can step up onto a low platform and stand next to a fish that’s six and a half feet or two meters tall. It was caught in Key West Florida in 1958, and a nearby caption says, “It’s hard to find a grouper this big anymore!”

Just past the photo op, on the wall to the right of the entrance to the Ocean Explorer Theater, three overlapping panels deal with invasive species. Photos, maps, and an infographic explain how people move animals across the globe in ways that disrupt ecosystems. The display case to the right of these panels is titled “Being Human on an Ocean Planet,” and includes objects and stories that show how different cultural groups have lived along coasts and moved around the world since the early days of our species’ history.

Turning to the long low case nearest the stairs, a text panel above the touchscreen monitor deals with habitat destruction, and how the construction of roads, buildings, dams, and shipyards near the ocean threatens marine species such as salmon.

You’ve reached the end of the section overview. Up next are detailed descriptions of the plastic pollution display, the model of an Ainu boat, and the salmon statue.

In the center of the main wall, a display of debris runs almost all the way up to the ceiling, photographs show marine animals killed by mistaking plastic trash for food, and a small display case features specimens that got entangled in abandoned fishing gear. Text labels explain that 80 percent of all pollution in the ocean comes from the land — often hundreds of miles inland. Trash, toxic waste, sewage, oil spills, and fertilizers (even from your backyard) harm marine species and habitats. Society has choices to make. Doing nothing is a choice.

The marine debris display includes fishing nets and buoys, a kayak paddle and swim fin, detergent bottles and a laundry basket, a rubber boot and Nike sneaker, a soccer ball and baseball bat, a coat hanger, a toilet seat, and a hardhat. All of these items were collected from beaches at Midway Atoll National Wildlife Refuge in the Pacific Ocean.

Below the marine trash is a case containing an abandoned fishing net that snared lots of animals before floating to shore. The whole clump is about two and a half feet or three quarters of a meter long. Entangled in the fine white plastic strands are the spine and rib cage of a harbor porpoise (Phocoena phocoena), and a clump of brown-and-white feathers that belonged to a horned grebe (Podiceps auritus). A closer look reveals bits of coral, a rock crab’s claw and leg, and long strands of whelk egg cases, which look like puffy beige disks strung together like a pool lane divider. A paper tag on top of the net indicates this was collected through the marine mammal stranding program. Ghostfishing refers to abandoned fishing line, nets, and traps like this one that continue to catch and kill marine life. Don’t leave these behind in the water! Recycle or repurpose them.

How can you take action against pollution? Never litter on land or at sea; reduce your use of plastics and switch to non-disposable alternatives; and support a recycling program in your community.

Inside the case titled “Being Human on an Ocean Planet” is a one-sixth scale model of an Ainu Itaomachip boat. The Ainu people of northern Japan are descendants of seafaring people who inhabited Japan, coastal China, and Russia over 15,000 years ago.

The model is eight feet, or 2.4 meters, long by two feet, or 0.6 meters, wide, and spans the entire length of the case. The wooden boat is light tan and has an open top, much like a canoe. The front and back of the model curve upward. The front of the boat, also known as the prow or bow, is carved and painted black in a design that resembles the head of a stylized dragon or serpent, with beige circles and lines resembling waves. Four black-and-beige pendants are tied to the front of the carving with bright red ribbons. The inside of the boat is roughly carved. Five dark wooden bars wrapped in natural fiber rope cross the hull of the boat at even intervals, like seats in a canoe. A carved symbol of three comma-shaped swirls inside a circle rises up from the back of the boat.

The Ainu used boats similar to this model for fishing, trading, and migrating along the northern Pacific Coast. While we don’t know what kind of boats might have been used in ancient migrations, many archaeologists believe this was one way people spread into the Americas.

If you stand at the rotunda side of the salmon case, the glass vitrine to your lower left contains a pair of salmon-skin mittens, a Tlingit wooden carving of a salmon with a human figure inside it, and another Tlingit carving called “salmon-boy.”

The salmon-boy carving is about 20 inches, or 50 centimeters, tall. The left side of the carving shows a stylized human figure with a bright red body and a mask-like face with a red nose and mouth, black eyes and eyebrows, and greenish-blue skin with a tan forehead. His right arm is tucked up against his chest and his hand is holding a long black object that tapers at each end. The right side of the carving is a stylized salmon with its head at the top and tail pointing downward. The salmon’s face has the same colors as the boy, and its body is mostly black with a red belly. The bright orange-red hues in the carving match the red in the realistic, life-sized models of sockeye salmon (Oncorhynchus nerka) hanging above this case.

This carving is inspired by Tlingit stories throughout southeast Alaska that tell of a disrespectful boy who was captured by the salmon people. The boy lived with the salmon people in their underwater village and learned the proper way to show respect for the gift of salmon, before returning to his people as a great shaman.

For thousands of years, people along the Pacific Coast have relied on abundant salmon and their dependable migratory life cycles. Ancient hunter-and-forager societies settled in permanent villages along the coastline and rivers to harvest the salmon. These communities developed cultures with elaborate festivals and beautiful ceremonial objects honoring salmon. But human activities have drastically harmed wild salmon populations. Today, many groups are helping in the salmon recovery effort.

A text panel and touchscreen on the back side of the case explain more.  

Let’s move from Alaska to the next section, all about ocean life at the poles.

This zone explores two polar opposites, the Arctic Ocean and the Southern Ocean. One’s an ocean surrounded by land; the other is land surrounded by ocean. They don’t mix!

To orient yourself, stand at the doorway to the polar nook, which is a nearly enclosed room with specimen cases embedded in three of the walls. The opaque glass wall dividing this nook from the main gallery focuses on how climate change is affecting the poles. Two of the walls in this nook are divided into a top band labeled “Arctic Ocean” and a bottom band labeled “Southern Ocean.” The cases, photos, and ecosystem illustrations in each band introduce different organisms’ adaptations for coping with year-round cold, seasonal changes in ice, and six months of darkness. While some adaptations are similar, there are also profound differences between the poles.

You can continue with this overview for more information on these content areas, starting with the glass dividing wall.

Or for detailed descriptions of the polar bear and the Adelie penguin, jump to the next header.

The exterior side of the opaque glass wall explores how Indigenous Arctic cultures are adapting to changing conditions that make their environment unstable and unreliable. The interior side explains how scientists in Antarctica uncover information about climate change both past and present.  

Though the poles are experiencing the most dramatic increases in temperature, changes there will lead to changes everywhere. Photo murals to the left of the opaque glass wall explain the difference between sea ice, glaciers, and icebergs. All this polar ice helps regulate Earth’s climate by reflecting the Sun’s energy back into space. Without sea ice, Earth would absorb more solar radiation, and our climate would be much warmer.

Now let’s step inside the nook and explore the walls going clockwise from left to right, starting with the Arctic content on the top half of the walls. A map inside the entryway shows that the Arctic Ocean is nearly landlocked and seasonally covered by ice, so it’s relatively calm.

Moving past the opaque wall about science in Antarctica, the next wall deals with ways organisms cope with the cold and dark polar conditions, from insulation to migration. The cases and images in the top band include an Arctic cod (Boreogadus saida) in a jar, photos of a polar bear (Ursus maritimus) and a walrus (Odobenus rosmarus) mother and calf, a taxidermy Arctic tern (Sterna paradisaea), and a photo of an Inuit hunter.

Continuing along the top band to the next wall  of specimens, two cases with snail shells and sea stars reveal how invertebrates live on the bottom of the Arctic Ocean. At the right end of this wall is a mural portraying the Arctic food web, showing gray whales and walruses disturbing the muddy seabed below the ice and seals and polar bears on the ice above. The entire food web is supported by primary producers called ice algae that use sunlight to make food; they’re eaten by primary consumers, which are eaten by others, uniting organisms from smallest to biggest. In the Arctic, dangerous chemicals have entered the food web, brought by wind, water, rain, and snow.

Let’s go over this nook again, this time focusing on the Southern Ocean content on the bottom half of the walls. A map on the text panel inside the entryway shows that the Southern Ocean is broadly connected to the Atlantic, Pacific, and Indian Oceans, and because there’s no surrounding landmass, it’s more turbulent than the Arctic Ocean.

Moving past the opaque wall about science in Antarctica, the next wall deals with ways Antarctic organisms cope with the cold and dark, from slowed growth to sharing heat. The cases and images in the lower band include two fishes in jars, a photo of mackerel icefish gills, a model of an isopod crustacean, photos of an elephant seal and a colony of emperor penguins, and a taxidermy Adelie penguin (Pygoscelis adeliae).

On the next wall, limpets, worms, and urchins show how invertebrates live in intertidal zones and along the Antarctic seafloor. At the right end of this wall is a mural portraying the Antarctic food web. Sponges and corals live on the bottom, baleen whales hunt for krill, and penguins and seals hang out on the ice. The entire food web is supported by primary producers called phytoplankton and ice algae that use sunlight to make food; they’re eaten by primary consumers, which are eaten by others, uniting organisms from the ice above to the mud below. The Southern Ocean supports more abundant and varied life than the Arctic because it has been isolated for more than 30 million years, enough time for life to diversify. But today, some species of fishes, whales, and seals have been overharvested.

You’ve reached the end of the section overview. Up next are detailed descriptions of the polar bear and the Adelie penguin. 

Above a text panel titled “Are the Polar Oceans Pure and Untouched?” a taxidermy mount of a polar bear (Ursus maritimus) stands on what looks like a jagged ice floe, turning its head over its left shoulder to face into the exhibit nook. This bear is about eight feet, or 2.4 meters, long, and stands four feet, or 1.2 meters, tall at the shoulder. Polar bears like this one are Earth’s largest species of bear.

The polar bear’s fur appears white, but each of its two types of hair has no pigments at all. Its short underfur acts like a sweater, keeping the bear warm, while the long guard hairs act like a rain jacket, keeping out the elements. The long guard hairs also trap and scatter light, giving the bear its white appearance.

Polar bears are at home on land and in the water. Their large paws act as snowshoes, preventing them from falling through ice and thick snowdrifts. The black footpads on the underside of this bear’s paws are covered in bumps that help against slipping. When swimming, polar bears use their large, slightly-webbed front paws to paddle, and hold their hind legs together to steer.

Contrasting with its creamy white fur, the bear’s claws, eyes, nose, and lips are black. This bear’s mouth is open in a silent roar, showing its sharp canine teeth, and it’s standing with its left foot on top of a seal, which has bloody puncture marks on its neck  . While some Arctic animals hibernate or migrate during the cold dark winter months, polar bears hunt for seals from the sea ice, gaining most of their weight in winter. With sea ice breaking up earlier each year, bears have less time to hunt. And with less sea ice coverage each year, polar bears also spend more time scavenging for food along the coast.

Underneath the polar bear’s ice shelf, a display case near the floor contains an Adelie penguin (Pygoscelis adeliae) taxidermy mount. This bird stands about one and a half feet tall, or just under half a meter. Its head is turned slightly to the left so it’s looking at you with its right eye, which is totally black but surrounded by a ring of small white feathers. In fact, the only parts of this penguin that aren’t black and white are part of its beak and its fleshy feet, which would have been pink in life but have since yellowed. The black feathers on its head and back help absorb warming sunlight, while the white feathers on its belly and legs help the penguin blend in with lighter waters when seen from below. The penguin’s densely packed feathers have a downy section near the body that retains heat, and stiff tips that repel water when preened. Like other penguin species, young Adelie penguins huddle together for warmth and protection.

Each foot has three thick forward-facing toes and a tiny backward facing toe, each with a sharp black toenail. Penguins walk long distances over the icy Antarctic continent and can also slide on their bellies. But they move best in the water thanks to their torpedo-shaped bodies and their flippers, which are modified wings. This penguin is holding its right flipper away from its body to reveal the small white feathers covering the underside. Adelie penguins are agile swimmers that hunt for krill in the Southern Ocean. A glass jar holding thousands of these small shrimp-like crustaceans is in the wall to the right. 

Ready for warmer waters? Exit the polar zone and encounter organisms from around the globe, introducing the breadth and depth of our collections.

This section shows how museum collections help scientists organize and make sense of ocean life.

The section is made up of one long, convex curving wall that features large specimen cases embedded in the upper portion of the wall and smaller specimen cases below, all against a collage of x-ray images of fishes and black-and-yellow photos of specimens in jars. A small video monitor in the middle of the wall plays a narrated video taking you on a tour into our collections. Running along the entire wall is an angled rail with text, images, and specimen cases. The rail is about three feet, or just under a meter, off the ground. Underneath this rail are drawers that open to reveal additional specimens. Text panels at either end of the wall are titled “A Vast Library of Life.”

You can continue with this overview for more information on these content areas, starting at the left end of the wall.

Or for detailed descriptions of a triplewart seadevil and some whelks, skip ahead to the next header.

Near the left side of the curved wall is a large text panel titled “Why Do We Need So Many Specimens?” Objects on the left half of this wall highlight how our broad collection gives scientists a more accurate picture of the variations within a species. Recognizing these variations allows us to identify new species and to understand the process of evolution.

A wall vitrine of virgin nerite (Neritina virginea) shells and a drawer of tiger cowrie (Cypraea tigris) shells show color and pattern variations between individuals. Some ocean organisms have huge differences between males and females. One example is a jar between two text rails that includes a male and female triplewart sea devil (Cryptopsaras couesii). Another is the male giant squid in the vertical tank on the left edge of the wall, which is much smaller than the female in the central tank in Section Three. Some ocean organisms change dramatically as they grow up: three circular viewers on the left text rail show how young flounders transition into the adult form in the wall case above. Some variation within a species is geographical. Photos and specimens of the sea urchin Lutechinus variegatus illustrate how it can be light red, whitish, or greenish, but in Bermuda it's always purple. The last case on this half of the wall uses three specimens to explain how scientific names work and how they often include information about a species’ location or physical traits.

Near the center of the wall is another large text panel, this one titled “How do we use collections?” Specimens on the right half of the wall highlight how our collections help inform conservation, research, and policy decisions to manage and protect ocean life.

Scientists use collections to distinguish known species from new ones. Coral, sea star, snail, and goby specimens are just some of the many new species described by curators at this museum. Our museum specimens also showed that one species of commercially important mackerel was actually two species. Scientists also use collections to figure out who’s related to whom. Similar features shared by groups of organisms reveal evolutionary relationships, like the tubular nostrils on the bills of seabirds called petrels in one of the drawers. A model of a louvar (Luvarus imperialis) fish in a wall case and clues in the drawer below reveal how scientists discovered these fish were not closely related to tuna. Collections also document change, whether that’s from shifting tectonic plates or the introduction of invasive species. A rail case includes red-speckled blennies mapped onto the Pacific tectonic plate. A drawer shows the difference between knobbed whelks (Busycon carica) native to the Chesapeake Bay and introduced rapa whelks (Rapana venosa).

A video monitor embedded in the wall takes you on a narrated tour of the marine collections of our anthropology, botany, invertebrate zoology and vertebrate zoology collections. A large photomural on the right end of the wall shows drawers upon drawers of clams, scallops, snails, and other invertebrates.

You’ve reached the end of the section overview. Up next are detailed descriptions of the triplewart seadevil and the whelks.

For many ocean animals, males and females of the same species can look very different. Some female anglerfish, like the triplewart seadevil, are much bigger than the males.

Inside a square vitrine between the two text rails on the left half of the curved wall is a large fluid jar mounted sideways. Most of the jar is taken up by a female triplewart seadevil, but there are two males in here as well. The female is six inches (or 15 centimeters) long and four inches (or 10 centimeters) tall. She faces toward the left. Her large mouth is filled with thin needle-like teeth, and her tiny eye resembles a dark pin prick slightly above and to the right of the mouth. The fluid these specimens have been preserved in has wrinkled their skin and bleached them to a uniform yellowish white.

Two appendages protrude from about halfway along the female’s body near her underside. These may look like fins or weird little arms, but they are in fact two male seadevils! The tiny males attach to females as parasites and get all their nutrients from them.

Collections help us identify species, both invasives and others important for conservation. Open the drawer under the large image of specimens preserved in jars. It's just below and to the right of the case containing specimen labels from the collection.

Knobbed whelks, like the one on the left inside the drawer, are indigenous to the Chesapeake Bay. Rapa whelks, like the specimen on the right, are not.  

The invasive rapa whelks in the wild were identified by comparison with museum specimens. The rapa whelk has horizontal striations, a rough surface, and horizontal rows of bumps throughout the shell. The knobbed whelk on the left has a more uniform color and smoother surface overall. The larger invasive rapa whelk is five inches long by four inches wide (that’s 12.7 centimeters by 10.2 centimeters). The smaller knobbed whelk is four and a half inches long by two and a quarter inches wide, which is 11.4 by 5.7 centimeters. Both are shades of beige and tan.

Rapa whelks probably arrived as larvae in a cargo ship’s bilge water and now compete for food with the indigenous knobbed whelks.

To learn more about the Chesapeake Bay and other coastal ecosystems where many of these specimens are from, let's continue to the section on the opposite wall titled “Shores and Shallows.”

This section focuses on the shallow water ecosystems near continents and islands that are our gateway to the ocean. These ecosystems support abundant and diverse life, and humans depend on them, too.

To orient yourself, stand with your back to the curving wall of the Vast Library of Life section, close to the corner that leads you back to the whale model. The main long wall of this section features five massive photomurals of different coastal ecosystems, with a specimen case embedded in each one and a text rail below. The wall continues to the right along a bump-out that includes a live coral reef tank. A freestanding diorama case on the left depicting an estuary and another on the right depicting a sandy beach are positioned in the middle of the walkway, introducing you to a grand total of eight different coastal ecosystems.

You can continue with this overview for more information on these content areas, starting at the photomural wall.

Or for detailed descriptions of the estuary diorama, the beach diorama, and the coral reef tank, skip ahead to the next header.

Spanning the long wall are five photomurals, each about 12 feet tall by six feet wide, or 3.6 meters by 1.8 meters. Text on each mural poses the same question, “Are all coasts alike?” But the answer varies on each panel. Each of these ecosystems are important for humans and wildlife, but our actions can harm them in various ways.

From left to right, you’ll encounter volcanic islands, kelp forests, salt marshes, mangrove forests, and rocky tide pools. Each photomural is accompanied by a specimen case including one or more organisms from that ecosystem, such as snails that live at different depths in a kelp forest.

At a right angle from the tide pool wall is a composite satellite image of the Earth at night. It shows the concentration of urban areas along coastlines as brightly lit areas against the dark background of continents and ocean.

Continuing around the corner, a series of photo murals show aerial photos of a barrier reef, a fringe reef, and an atoll. Specimen cases underneath these photos include multiple types of coral and various species that live in reefs, while the text nearby explains why tropical reefs are so abundant and diverse, supporting more species per square meter than any other ecosystem in the ocean. To the right of these specimens is a live coral reef tank.

Two tall, narrow, freestanding, rectangular dioramas highlight additional coastal ecosystems. The diorama closest to the coral reef tank showcases a sandy beach based on a site near the Smithsonian’s Marine Station on a barrier island off Fort Pierce, Florida. A double-sided panel on one end of the diorama introduces beaches in general and this one in particular. At the other end of the diorama, a pillar inside the case contains three small video screens showing microscopic life amid magnified grains of sand. Text rails run along the long sides of the diorama, featuring more organisms that live in the sand, different sizes of sand grains and pebbles from different beaches, and examples of the ways humans can change or save beaches.

The diorama display closest to the polar zone showcases the Chesapeake Bay estuary, where the Smithsonian’s Environmental Research Center is based. A double-sided text panel on one side introduces estuaries in general and the Chesapeake Bay in particular. Text rails run along both long ends of the diorama, featuring stories about blue crabs, adaptations to changing salt levels, invasive species, and red tides. There’s a simple push lever interactive accompanying the invasive species story showing how ship ballast water transports organisms.

You’ve reached the end of the section overview. Up next are detailed descriptions of the estuary diorama, the beach diorama, and the coral reef tank.

Gently swaying with the water currents, this living coral reef display is modeled after those in the Indo-Pacific tropics. The tank has a thick, curving glass wall that bulges out toward you. The glass is about three-and-a-half feet tall by seven-and-a-half feet wide, or about a meter tall by 2.3 meters wide. It holds approximately 1,600 gallons, or 6,056 liters, of water.

Every day is a bright, warm day for the fish and corals living here. Colonial corals in vibrant green, purple, orange, and magenta form the multi-colored reef. The corals come in many different shapes: some resemble brains with wrinkled domes, others like a head of leafy lettuce, and most branch outward like elaborate candelabras. Solitary corals, like the green, disc-shaped mushroom corals, grow on top of other corals.  

Corals might look like rocks or plants, but they’re animals. Many coral species both filter feed and get food from the photosynthetic algae living in their tissue. Living corals and algae flourish on the calcium carbonate structures secreted by generations of corals over the centuries.

Layer builds on layer, and the reef expands. Coral reefs support more species per square meter than any other ecosystem in the ocean. They provide food and shelter for the thousands of species that live in them, including the bignose unicornfish  (Naso vlamingii)—it’s the largest fish in the tank at about a foot, or 0.3 meters, long. It usually drifts slowly around the bottom of the tank. While its blue coloring blends with the water, the brighter yellow vertical striations along its side stand out.

Small orange clownfish with black and white stripes (Amphiprion ocellaris) dart in and out from under the coral reef. Clownfish usually hide among an anemone’s stinging tentacles, to which they are immune. You’ll often find our clownfish in the lower right part of the tank, especially near the bright red coral. Perhaps a vibrant blue tang (Paracanthurus hepatus) with its black horizontal stripe and yellow tail fin is peeking out from the shadows of the reef. Tiny carnivorous white sea stars less than an inch across sometimes cling to the glass wall of the tank.

Healthy coral reefs benefit humans, too!  They provide food, jobs, recreation, income, new medicines, and protection to millions of people worldwide. 

As natural barriers, reefs shield coastlines from hurricanes and tsunamis. They are early warning systems of environmental problems. But due to soil erosion, pollution runoff, ocean acidification and rising temperatures due to human caused climate change, tropic reefs worldwide are under stress and in danger.

A narrow, rectangular diorama depicts a spring afternoon near the Smithsonian’s Environmental Research Center (or SERC) on the Chesapeake Bay. The tide is coming in and the estuary throbs with life. On one side of the case, large text along the top reads: “In an estuary, change is the only constant.” On the other side, text reads: “Estuaries: Our Playground. Our Resource. Our Responsibility.”

This diorama shows a flat, muddy floor covered in about a foot, or 0.3 meters, of clear water, represented by a sheet of clear acrylic with tiny ripples. Green eelgrass grows from the estuary’s bottom in clumps, with the blades nearly reaching the water’s surface. The cross section of the muddy bottom reveals clams in their burrows, where they can hide from predators and where salt levels remain more stable. In estuaries, the mixture of salty and fresh water varies from place to place and at different depths. Salt levels also fluctuate from season to season, even hour to hour, as tides and runoff alter the balance. So, plants and animals evolved a variety of mechanisms for coping with the water’s constantly changing salinity.

If you’re standing with your back to the collections wall, a great blue heron (Ardea herodias) stands on the right side of the diorama with its long, pointed bill hovering above the water, as if it’s searching for prey. The water comes about halfway up its legs. Under the heron’s bill, about a third of the way from the right side of the diorama, is a cluster of roughly 20 oysters (Crassostrea virginica). In the center of the diorama, a pipefish (Syngnathus fuscus) is wrapped around one of the grass blades with its head facing the top of the water. The pipefish is very well camouflaged and looks almost exactly like a blade of grass.

In the left third of the diorama, a young blue crab (Callinectes sapidus) crouches in the grass. The crab is mostly white with a blue tinge, and holds its left claw open in front of its body. Blue crabs are one of the species that can regulate their internal chemistry so that even as salinity in the water fluctuates, salt levels inside these animals remain constant. Blue crabs’ complex lifestyle takes them to nearly every corner of Chesapeake Bay. They hatch where the Bay meets the ocean, then travel out to sea. Young crabs ride the currents back into the bay, hiding among the eelgrasses. Adult females return to the Bay’s mouth to lay eggs. This crab is wearing a tracking tag on the top of its shell. SERC charts migration patterns by catching females, fitting them with ID tags, and releasing them. People who find tagged crabs report their catch to SERC. Understanding crab migration is essential to managing this important resource.

Blue crabs are among the most commercially and culturally valuable fisheries in the Chesapeake Bay, which is the U.S.’s largest estuary. In fact, most of what we catch for food and fun lived part of its life in an estuary. Estuarine wetlands and seagrass beds provide important habitats, filter pollutants, and are buffers against destructive storms. Estuaries are priceless. But they are threatened worldwide by invasive species, habitat changes, and degraded water quality. 

The diorama closest to the coral reef tank showcases a sandy beach based on a site near the Smithsonian’s Marine Station on a barrier island off Fort Pierce, Florida. It’s a late summer morning near the Smithsonian’s Marine Station on a barrier island off Florida. On one side of the diorama, large text along the top reads: “Sandy beaches are home to some of the most diverse creatures you’ve never seen.” From the other side, text reads: “Are we tipping the balance on beaches?”

Move around the diorama until you are facing toward the coral reef tank. Shells, rotting seagrass, and seaweed mark the high-tide line near the left end of the case. The yellowish sand slopes down to the right end of the case, with a thin acrylic sheet representing the water coming about halfway up the slope.

At the left end of the case, a baby loggerhead turtle (Caretta caretta) heads out to sea. A little further down the slope, one bone-colored ghost crab  scuttles on the sand while another burrows up from beneath the surface. Two shorebirds called a sanderling (Calidris alba) and a ruddy turnstone (Arenaria interpres) feed at the water’s edge. The sanderling’s slender, pointed bill hovers just above the retreating wave. At the right end of the case, beneath the surface of the water, a silvery gray fish with a forked yellow tail called a pompano (or Trachinotis carolinus) swims in the surf.

In addition to animals and plants like the ones in the diorama, even on a beach that looks empty, the sand is filled with life. When you step on a wet beach, there may be a million organisms underfoot. Most are too tiny to see, but they represent more than half of Earth’s major animal groups (called phyla). Not even tropical rainforests match this diversity. Three small video monitors to the left of the diorama magnify this hidden world.

Living in beach sand can be tough. Space is tight. Sometimes you’re underwater, sometimes not. Waves continually rearrange your home or threaten to wash you out to sea. What are some adaptations that help beach organisms to survive? Elongated, wormlike shapes make it easier for small and microscopic animals to slither and squeeze through narrow spaces between the sand grains. Most sand-dwellers, like the ghost crabs, can’t swim, so they hang on to the sand grains with claws, grippers, and glue-like secretions when waves threaten to wash them away. Shells, spines, and scales protect animals from being continually tossed by the waves. 
 
Let’s leave the beach and cross in front of Phoenix the whale to the gallery at the other side of the ocean hall — where we’ll step back in time.

Life on Earth probably began in the ocean at least 3.5 billion years ago in the form of single-celled microbes. The fossil record reveals bursts of evolution and expansion interrupted by massive extinctions.

This long gallery along the west side of the ocean hall explores the fossil history of the ocean. To orient yourself to the space, stand at the entrance closest to the fossil whales hanging from the ceiling. Cases full of fossils line each of the gallery’s long walls. In the center of the space are two separate freestanding displays with specimen cases on each side, and another freestanding glass case containing a set of shark jaws. Fossils also line the short wall at the end of the gallery closest to the rotunda.

You can continue with this overview for more information on these content areas, starting with the long wall closest to the fossil whale entrance.

Or for detailed descriptions of a touchable fossil predators, Cambrian specimens, fossils from before and after a mass extinction, and a tactile echinoderm, skip ahead to the next header.

Turn to face the wall dividing this gallery from the main ocean hall. A large text panel on the left end titled “What Is Geologic Time?” explains how scientists divide the vast stretches of Earth’s 4.6-billion-year history. Above a long metal bench is a text panel titled “The Anthropocene: The Age of Humans,” which asks if we should name the current geologic epoch after ourselves. To the right of the bench is another text panel titled “The Explosion of Early Life” that explains that life began in the ocean at least 3.5 billion years ago but animal diversity didn’t really take off until about 600 million years ago.

Directly to the right of that panel, another panel and four glass cases highlight fossils from the Cambrian explosion about 542 million years ago, which is when the basic body plans of all modern animals were set. Continuing down the long wall, a text panel titled “Life Gets Complicated” accompanies a display of four glass cases containing rocks and fossils that preserve traces of life’s earliest single-celled and, later, multicellular life forms.

At the right end of the wall, the panels titled “The Explosion of Early Life” and “What Is Geologic Time?” are repeated before you exit into the main ocean gallery at the rotunda.

If you’re still standing at the entrance under the whale fossils, stand with your back to the main ocean hall to face the other long wall in this fossil gallery. In front of you is a corner titled “Messages in Mud” with displays explaining how the ocean floor is like a time machine that scientists can dig into.

To the left is a tall text panel titled “Global Vanishing Acts” all about major mass extinction events. The displays to the left of this panel show fossils from the end-Cretaceous extinction event that killed the dinosaurs (as well as many marine species). Even further to the left is a tall wall case full of fossils from before and after the Permian-Triassic extinction, the largest extinction event in Earth’s history. To the left of that display is a repeat of the Global Vanishing Acts panel, then a walkway leading to the Ocean Terrace Café.

In between the walkway to the café and the entrance to the Rotunda is a short wall full of fossils of marine predators, ranging from modern killer whales to ancient scorpion-like eurypterids. Tall glass panels in front of these fossils are etched with illustrations of what the animals looked like in life. A small video monitor at the right end of the rails plays a soundless video about killer whales, also called orcas. In the space between the predator display and the walkway to the café is an enormous glass case housing a set of mega-toothed shark jaws.

Two double-sided freestanding displays sit in the middle of the fossil gallery. Each side has a tall glass case containing fossils. Let’s start with the display closest to the entrance with the fossil whales. The side facing the main ocean gallery is titled “Tall, Small, and In Between,” and deals with the diversity of crinoids in the seas in the Mississippian Period about 350 million years ago. A touchable sea urchin is attached to the right side of the case. The side facing the back wall is titled “Echinoderms: Changing with the Times” and explores how echinoderms such as crinoids and sea stars evolved over time.

The freestanding display closest to the shark jaws at the other entrance is also double-sided. The side facing the main ocean gallery is titled “A Reef Built by Clams?” and introduces rudist bivalves that dominated reefs during the Cretaceous Period 100 million years ago. You can touch a polished slab of colonial rudists on the right side of the case. The side facing the Permian-Triassic extinction display is titled “Trilobites: Everywhere… Then Nowhere” and deals with how trilobites evolved and flourished for 280 million years before finally disappearing.

You’ve reached the end of the section overview. Up next are detailed descriptions of touchable fossil predators, Cambrian specimens, fossils from before and after a mass extinction, and a touchable echinoderm.

In the Ancient Predators display nearest the rotunda entrance, find the touchable ammonite shell.

Not all deadly predators in the ocean were sleek swimmers with toothy grins. Ammonites were cephalopod mollusks related to modern octopuses and squid, but they had shells like nautiluses do. They hunted from inside the safe refuge of their coiled, protective shells. This Perisphinctes biplex ammonite shell from the Late Jurassic period (164 – 145 million years ago) spirals out from the center in a counterclockwise direction, becoming a little wider with each turn. The shell is a little taller than it is wide, but it’s roughly a foot and a half, or 43 centimeters, in diameter, or about the size of a beach ball. But it’s only three inches, or seven and a half centimeters, deep. Feel for the shell’s ribbed texture.

The opening of the shell is at the upper left end, or about 10:30 if it were a clock face. From this opening, the ammonite’s many tentacles would have reached out to pull prey toward its powerful beak. Etched in the glass just above and to the right of the touchable fossil is an artist’s illustration of what the ammonite might have looked like in life, with at least eight tentacles and one large eye peeking out of its shell. 

Next to the Ancient Predators display you can find the giant toothy jaws of the mega-toothed shark, named Carcharocles megalodon. The jaws of this now-extinct shark are about six feet tall and five feet wide, or 1.8 meters by 1.5 meters. In other words, it’s large enough for a full-grown adult human to step through. The mega-toothed shark was the biggest predatory fish that ever lived. Though this particular species evolved 23 million years ago, sharks as a group have been around for over 440 million years.

There are several rows of sharp teeth pointing inward toward the back of the mouth. Just in front of the case are two touchable teeth — the larger tooth on the right is from the extinct mega-toothed shark, the smaller tooth on the left is from a modern great white shark. Feel along the edges of both teeth. Can you feel the tiny serrations?

Competition from other sharks and toothed whales, along with the extinction of their preferred prey, which was small baleen whales, drove this gigantic predator to extinction 2.6 million years ago.

The case along the west wall contains almost 100 gray, white, and brown fossils in a wide variety of shapes and sizes displayed on a lime green wall. Just to the right of center, a bright red illuminated barrier with the word “P/T Extinction” separates the entire case into two groups: those fossils on the left from before the largest mass extinction in Earth’s history and those on the right from afterward. This is the Permian-Triassic extinction, which happened 251 million years ago and wiped out nearly 95 percent of all marine species.

To the left of the red extinction barrier, slabs of delicate and detailed fossil trilobites, stalked crinoids that look like plants, shelled brachiopods, corals, and other organisms demonstrate the diversity of marine life that lived during the Permian, between 487 million years ago to 251 million years ago.

To the right of the extinction barrier, only four small fossils represent the drastic decline of diversity found in the Triassic seas after the extinction event. One is a sea urchin, one is an apple-sized coiled ammonoid shell, and two are coin-sized clam-like bivalves. It took 20 to 30 million years for ocean diversity to rebound after the Permian extinction — much longer than other recoveries. When a few species vanish, others can take over their roles. But when nearly 95 percent disappear, entire ecosystems are destroyed. New species must evolve from the few survivors.

What caused this mass extinction? Scientists have identified several possible explanations from massive volcanic eruptions in Siberia (the most likely cause), to an asteroid collision, to temperature increases in the ocean halting circulation of oxygen-rich water from the deep ocean.

In the center of the east wall in this long gallery of fossils, find four glass cases just to the right of a dark gray panel with the headline “From Simple Beginnings: The Explosion of Early Life.” Most of the fossils in this display are a medium gray color with what appear to be faint, dark gray, irregular, flat shapes on them. There are small spotlights at the sides of each case to highlight the subtle differences in color and texture on each fossil.

These are fossils found in the Burgess Shale formation in British Columbia, Canada, and they date back to the Cambrian Period 542 to 488 million years ago when multicellular life in the oceans was rapidly diversifying. Mudslides in an ancient sea buried and preserved fossils of soft and hard bodies. This exceptional preservation revealed a world of previously unknown animals. These fossils may not resemble any life currently on Earth today, but the basic body plans of all modern animals were set during this period.

Near the bottom of the third case from the left is a set of three fossils surrounding a dark brown specimen label that starts with “Anomalocaris sp. (mouth).” The specimen to the left of the label is about three inches wide by two and a half inches tall, or 7.6 by 6.3 centimeters. The dark shape of the fossil consists of overlapping narrow lobes that radiate from a roundish center, like petals on a daisy. The specimen slab to the lower right of the label is about 5.5 inches wide by 4 inches tall, or 14 by 10 centimeters. The slab contains two long, curved shapes lined with smaller pointed projections on the concave side. They look a bit like the pincers of a crab’s claw. Scientists once believed the round fossil and the pincer fossils came from two different animals, until new discoveries revealed them to be the mouth and claws of one animal, called Anomalocaris. The third specimen, to the upper right of the label, is the closely related Laggania cambria. The slab is a six-inch square, or 15 centimeters. In the center, a blobby body made of overlapping plates shows the underside of the animal as faintly darker than the medium gray shale around it. In the upper center of this specimen is the round mouth part, which looks very similar to the first of these three fossils.

Not every Cambrian body plan was successful. But those that did succeed set the pattern for every animal that followed — in the water and on land. Your friends, family, and pet turtle may not look much like the creatures here. But we and our fellow animals are heirs of these ancient ocean dwellers.

Find the touchable fossil of a real sea urchin at the end of the free-standing cases nearest the gallery entrance next to the whale evolution display. The mottled brown, greenish-gray, and ivory colored fossil is mounted to a platform about three feet from the floor. The rocky slab has been cut into a rectangle that’s roughly 10 and a half inches by seven and a half inches, or 26.7 by 19 centimeters. In the center of the slab is the fossil of a sea urchin, Melonites multipora. The overall shape of the fossil is a slightly elongated circle, roughly the size of a large grapefruit. Five or six horizontal lobes radiate from a semi-circular region on the right side of the urchin’s body  , like stripes on a beach ball meeting at a circle at the pole. This region on the right is actually the mouth and feet of the sea urchin that would be moving along the ground. The stripes have different widths and textures — some are covered with hexagonal scales, some have a bumpy texture, and some are relatively smooth. Some places along the fossil’s body, especially in the center, are worn smooth by visitors’ touch over the years, and are a lighter white color than the rest of the fossil.

Sea urchins, like this one, are echinoderms and related to crinoids, the most prevalent life form in the ancient ocean of the Mississippian Period, 359 to 318 million years ago. Crinoids, which are echinoderms related to sea stars and sea urchins, varied in size and shape. They evolved a wide range of adaptations for feeding and sharing space, allowing a great number to flourish side by side. Other organisms adapted to life amid crinoid “forests.” Vast accumulations of dead crinoids produced most of the period’s limestone. 
You can find modern echinoderms and sea urchins in the main central “Earth is an Ocean Planet” gallery in the Ocean Hall.

At the back end of the fossil gallery, past the “Messages in Mud” section, is the entrance to a theater space where you can take a deep dive in the ocean.

Take a dive far from shore and down through the open ocean in the manned submersible Alvin.  

Along one wall of this darkened theater is a large screen that’s 15 feet long by 12 feet tall, or 4.6 meters by 3.7 meters. The program shows a 13-minute video that takes you from the ocean’s sunlit surface to its cold, dark depths. Discover an alien world that’s full of life from top to bottom as you travel with ocean researchers in a small underwater vehicle plunging miles down into the open ocean. Fewer humans have been in the deep sea than in outer space! The first half of the video covers deep sea exploration, and the second half of the program deals with whale falls, which is when a whale carcass sinks to the bottom of the ocean.

The back end of the theater bulges towards the screen in a convex curve. Seating is available along each of the side walls and in three rows of benches in the center of the room. Captions are provided on screen.

Cases near the Ocean Terrace Café entrance contain two totem poles, a surfboard, and other items from coastal communities. A display case just outside the other entrance to the theater also contains human-made objects and is called “Being Human on an Ocean Planet.” You can explore that content in section four of this tour. Just above the entrance is a real robot submersible suspended from the ceiling.

For a detailed description of the robot submersible, skip ahead to the next heading.

Step outside the Ocean Explorer Theater near the entrance to the Hall of Human Origins. Hanging overhead is a tethered robot submersible, known as an ROV (Remotely Operated Vehicle). 

The ROV is about six feet long by five feet wide, or 1.8 meters by 1.5 meters. Its boxy body has a mesh bottom, open sides, and a hard-shelled yellow top that says “Canada” in a red band. Peeking out of the middle of the box are lots of cables and two round lenses that look a bit like a pair of eyes. Two robotic arms extend out from the body, sort of like a hermit crab’s claws.

The ROV is made of materials that can withstand the enormous pressures of the deep ocean. Video cameras, lights, sonar systems, and sensors are mounted in and on the ROV. Because it is not completely enclosed, the instruments and wires on the ROV must be completely waterproof. Two robotic manipulator arms at front of the ROV allow scientists to collect biological and geological samples. The ROV’s movements are guided by a pilot on a ship at the surface. Because this is a deep-water ROV, it would normally have a cable several kilometers long that connects it to the ship.

No place on Earth is as distant or alien as the deep ocean. But technology, like the ROV, is gradually taking scientists to more places in this remote realm and lets us see and study where humans cannot go.

Speaking of scientific technology that helps us explore the ocean, let’s make our way to the final section, the Science on a Sphere Theater.

How do we study something as huge and complex as the ocean? We gather data using lots of scientific instruments.

In the center of this darkened room, a six-foot or 1.8-meter-wide glowing sphere hangs from the ceiling. This is our planet Earth with her continents and global ocean. Planetary data and animated images of atmospheric storms, ocean temperatures, and currents are shown on the sphere to explain global, and sometimes complex, environmental processes. Audio narration accompanies the media, and four screens surrounding the sphere provide captioning of the narration.

The media program covers four topics: plate tectonics and the ocean, ocean currents, how the ocean affects global weather patterns, and atmospheric carbon and climate change. Each program is about five minutes long for a total of 20 minutes, with a 5-minute break at the end.

There are benches along the four walls of the gallery facing the sphere, and four large artifact cases in the corners of the room. Each case holds a scientific instrument used to study different aspects of the ocean. A conductivity, temperature, and depth sensor (or CTD) is used to study the ocean’s chemical composition. A Klein 3000 side-scan sonar records the topography of the ocean floor. A drifting buoy records the ocean’s currents and movements. And an undulating plankton recorder tracks concentrations of phytoplankton.

To explore one of these instruments in detail, skip ahead to the Drifting Buoy Detailed Description.

Standing near the entrance closest to the coral reef tank and facing the large media sphere in the center of this gallery, turn toward your right to find a large, enclosed case titled “How Much Motion is in the Ocean?” that contains a large gray-and-red sphere the size of a beach ball.

The top half of this model of a drifting buoy is light gray and the bottom half is red. Blue lettering on the top half reads “Global Drifter 1250.” The buoy can measure temperature, air pressure, wind, salinity, ocean color, and other properties. The floating sphere holds sensors, a battery, and a transmitter. A wire tether connects the sphere to a navy-blue drogue — a funnel-shaped device made of heavy cloth that hangs down to catch the current and pull the buoy along. In this display, the drogue has been gathered into a hoop of fabric held together with thin white ropes.

Drifting buoys, along with other tools, gather data that are used to identify, chart, and measure ocean currents. Sound emitted by the buoy and bounced off particles in the water reveals the speed and direction of the currents.

You’ve reached the end of our descriptive tour of the Ocean Hall. If you’d like to continue your ocean explorations, check out our Ocean Portal website at ocean.si.edu.