Dive into the unexplored universe beneath the waves: the beautiful, fragile (and sometimes terrifying) world of the ocean.

In this eye-opening talk, conservationist Ocean Ramsey explains why sharks -- highly intelligent marvels of evolution -- are actually an essential part of the ocean's ecosystem.

While the Earth's oceans are known as five separate entities, there is really only one ocean. So, how big is it? As of 2013, it takes up 71% of the Earth, houses 99% of the biosphere, and contains some of Earth's grandest geological features. Scott Gass reminds us of the influence humans have on the ocean and the influence it has on us. [Directe...

Are we turning the oceans into warm, noisy, uninhabitable bodies of acid? The short answer is, yes -- but there's still hope.

Inspiration from the ocean and on dry land.

When most people think of fishing, we imagine relaxing in a boat and patiently reeling in the day's catch. But modern industrial fishing -- the kind that stocks our grocery shelves -- looks more like warfare. Ayana Elizabeth Johnson and Jennifer Jacquet explain overfishing and its effects on ecosystems, food security, jobs, economies, and coasta...

Oceanographer John Delaney is leading the team that is building an underwater network of high-def cameras and sensors that will turn our ocean into a global interactive lab -- sparking an explosion of rich data about the world below.

Tuna are ocean athletes -- fast, far-ranging predators whose habits we're just beginning to understand. Marine biologist Barbara Block fits tuna with tracking tags (complete with transponders) that record unprecedented amounts of data about these gorgeous, threatened fish and the ocean habitats they move through.

Jackson Browne plays a song about being on the ocean ... or really, being anywhere among passionate friends. (He started writing this song aboard Mission Blue Voyage, a Sylvia Earle-inspired conference about saving the ocean.) "If I could be anywhere," he sings, "anywhere right now, I would be here."

Ocean explorer Robert Ballard takes us on a mindbending trip to hidden worlds underwater, where he and other researchers are finding unexpected life, resources, even new mountains. He makes a case for serious exploration and mapping. Google Ocean, anyone?

Oceanographer Paul Snelgrove shares the results of a ten-year project with one goal: to take a census of all the life in the oceans. He shares amazing photos of some of the surprising finds of the Census of Marine Life.

Legendary ocean researcher Sylvia Earle shares astonishing images of the ocean -- and shocking stats about its rapid decline -- as she makes her TED Prize wish: that we will join her in protecting the vital blue heart of the planet.

Enric Sala shares glorious images -- and surprising insights and data -- from some of the most pristine areas of the ocean. He shows how we can restore more of our oceans to this healthy, balanced state, and the powerful ecological and economic benefits of doing so.

Graham Hawkes takes us aboard his graceful, winged submarines to the depths of planet Ocean (a.k.a. "Earth"). It's a deep blue world we landlubbers rarely see in 3D.

When the ocean changes, the planet changes -- and it all starts with microbes, says biological oceanographer Angelicque White. Backed by decades of data, White shares how scientists use these ancient microorganisms as a crucial barometer of ocean health -- and how we might rejuvenate them as marine temperatures steadily rise.

In 1992, a cargo ship carrying bath toys got caught in a storm. Shipping containers washed overboard, and the waves swept 28,000 rubber ducks and other toys into the North Pacific. But they didn't stick together -- the ducks have since washed up all over the world. How did this happen? Jennifer Verduin dives into the science of ocean currents. [...

In this bracing talk, coral reef ecologist Jeremy Jackson lays out the shocking state of the ocean today: overfished, overheated, polluted, with indicators that things will get much worse. Astonishing photos and stats make the case.

In the deepest, darkest parts of the oceans are ecosystems with more diversity than a tropical rainforest. Taking us on a voyage into the ocean -- from the deepest trenches to the remains of Titanic -- marine biologist David Gallo explores the wonder and beauty of marine life.

Somersaulting manta rays, dashing dolphins, swarming schools of fish and munching sharks inhabit a world beneath the ocean's surface that few get a chance to see. Conservation photographer Thomas Peschak visits incredible seascapes around the world, and his photos reveal these hidden ecosystems. "You can't love something and become a champion fo...

Hundreds of meters below the surface of the ocean, Laura Robinson probes the steep slopes of massive undersea mountains. She's on the hunt for thousand-year-old corals that she can test in a nuclear reactor to discover how the ocean changes over time. By studying the history of the earth, Robinson hopes to find clues of what might happen in the ...

Can we solve the problem of ocean plastic pollution and end extreme poverty at the same time? That's the ambitious goal of The Plastic Bank: a worldwide chain of stores where everything from school tuition to cooking fuel and more is available for purchase in exchange for plastic garbage -- which is then sorted, shredded and sold to brands who r...

Noise pollution is normally seen as a problem for big cities. In this talk, marine biologist Steve Simpson sets the story straight, describing how human-made sounds are the culprits behind catastrophic marine disruptions. Simpson lays out several concrete methods for a relatively quick and easy fix to decrease our noise levels.

Explore endless waters with these captivating talks that shine some (literal) light on what’s going in the deepest, darkest parts of our oceans.

Oceanographer Kate Stafford lowers us into the sonically rich depths of the Arctic Ocean, where ice groans, whales sing to communicate over vast distances -- and climate change and human noise threaten to alter the environment in ways we don't understand. Learn more about why this underwater soundscape matters and what we might do to protect it.

For most of the year, the Gulf of Mexico is teeming with marine life, from tiny crustaceans to massive whales. But every summer, disaster strikes. Around May, animals begin to flee the area. And soon, creatures that can't swim or can't swim fast enough begin to suffocate and die off in massive numbers. What's going on? Kate Slabosky dives into t...

Deep in our solar system, a new era of exploration is unfolding. Beneath the thick ice of Europa; in the vapor plumes on Enceladus; and within the methane lakes of Titan, scientists are hunting for extraterrestrial life. These moons are 'ocean worlds'— they contain liquid oceans, which can support the formation of life. Does life exist on ocean ...

For billions of people, seafood provides a significant source of protein and nutrition, but over half the seafood we eat isn't caught in the wild, it's grown through aquaculture. Farmed seafood is one of the fastest-growing food industries, but the farming methods echo the problems we've seen in industrial agriculture. Is there a way to sustaina...

Is it a fuzzy sock? An overripe banana? A moldy tube of toothpaste? In fact, it's a humble sea cucumber: a brainless, fleshy form surrounding a digestive tract, and bookended by a mouth and an anus. And while it might look odd, its daily toil paves the way for entire ecosystems to thrive. Cella Wright journeys to the bottom of the ocean to explo...

The ocean is a naturally noisy place full of singing whales, grunting fish, snapping shrimp, cracking ice, wind and rain. But human-made sounds -- from ship engines to oil drilling -- have become an acute threat to marine life, says science journalist Nicola Jones. Watch (and listen) as she discusses the strange things that happen to underwater ...

Rob Dunbar hunts for data on our climate from 12,000 years ago, finding clues inside ancient seabeds and corals and inside ice sheets. His work is vital in setting baselines for fixing our current climate -- and in tracking the rise of deadly ocean acidification.