Whales have a surprising and important job, says marine biologist Asha de Vos: these massive creatures are ecosystem engineers, keeping the oceans healthy and stable by ... well, by pooping, for a start. Learn from de Vos, a TED Fellow, about the undervalued work that whales do to help maintain the stability and health of our seas -- and our pla...

Some 80 to 90 percent of undersea creatures make light -- and we know very little about how or why. Bioluminescence expert Edith Widder explores this glowing, sparkling, luminous world, sharing glorious images and insight into the unseen depths (and brights) of the ocean.

David Lang is a maker who taught himself to become an amateur oceanographer -- or, he taught a robot to be one for him. In a charming talk Lang, a TED Fellow, shows how he and a network of ocean lovers teamed up to build open-sourced, low-cost underwater explorers.

The way we fish for popular seafood such as salmon, tuna and shrimp is threatening to ruin our oceans. Paul Greenberg explores the sheer size and irrationality of the seafood economy, and suggests a few specific ways we can change it, to benefit both the natural world and the people who depend on fishing for their livelihoods.

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.

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.

You don't have to be a scientist to help protect the world's oceans, says underwater drone expert and TED Fellow David Lang -- in fact, ordinary citizens have pulled together to save the planet's natural treasures many times in history. Lang asks us to take a lesson from the story of the US National Parks Service, offering a three-point plan for...

The "aliens" of Earth live in the deepest parts of the ocean, and marine biologist Alan Jamieson has the photographs to prove it. Explore the depths with Jamieson as he challenges what you may believe (or have been told) really lies waiting in the world's darkest, most remote waters. A fascinating, bizarre and surprisingly peaceful dive into the...

The world needs clean water, and more and more, we're pulling it from the oceans, desalinating it, and drinking it. But what to do with the salty brine left behind? In this intriguing short talk, TED Fellow Damian Palin proposes an idea: Mine it for other minerals we need, with the help of some collaborative metal-munching bacteria.

For sculptor Jason deCaires Taylor, the ocean is more than a muse -- it's an exhibition space and museum. Taylor creates sculptures of human forms and mundane life on land and sinks them to the ocean floor, where they are subsumed by the sea and transformed from lifeless stone into vibrant habitats for corals, crustaceans and other creatures. Th...

We need a radically new approach to ocean conservation, says marine biologist and TED Fellow Alasdair Harris. In a visionary talk, he lays out a surprising solution to the problem of overfishing that could both revive marine life and rebuild local fisheries -- all by taking less from the ocean. "When we design it right, marine conservation reaps...

Planetary scientist Joel Levine shows some intriguing -- and puzzling -- new discoveries about Mars: craters full of ice, traces of ancient oceans, and compelling hints at the presence, sometime in the past, of life. He makes the case for going back to Mars to find out more.

While living and working as a marine biologist in Maldives, Charles Anderson noticed sudden explosions of dragonflies at certain times of year. He explains how he carefully tracked the path of a plain, little dragonfly called the globe skimmer, only to discover that it had the longest migratory journey of any insect in the world.

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.

At the Harbour School in Hong Kong, TED Senior Fellow Cesar Harada teaches citizen science and invention to the next generation of environmentalists. He's moved his classroom into an industrial mega-space where imaginative kids work with wood, metal, chemistry, biology, optics and, occasionally, power tools to create solutions to the threats fac...

Artist Dianna Cohen shares some tough truths about plastic pollution in the ocean and in our lives -- and some thoughts on how to free ourselves from the plastic gyre.

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.

Peter Tyack of Woods Hole talks about a hidden wonder of the sea: underwater sound. Onstage at Mission Blue, he explains the amazing ways whales use sound and song to communicate across hundreds of miles of ocean.

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.

Underwater filmmaker Mike deGruy has spent decades looking intimately at the ocean. A consummate storyteller, he takes the stage at Mission Blue to share his awe and excitement -- and his fears -- about the blue heart of our planet.

We all share one planet -- we breathe the same air, drink the same water and depend on the same oceans, forests and biodiversity. Economist Naoko Ishii is on a mission to protect these shared resources, known as the global commons, that are vital for our survival. In an eye-opening talk about the wellness of the planet, Ishii outlines four econo...

What will we find in the twilight zone: the vast, mysterious, virtually unexplored realm hundreds of meters below the ocean's surface? Heidi M. Sosik of Woods Hole Oceanographic Institution wants to find out. In this wonder-filled talk, she shares her plan to investigate these uncharted waters, which may hold a million new species and 90 percent...

Photographer Brian Skerry shoots life above and below the waves -- as he puts it, both the horror and the magic of the ocean. Sharing amazing, intimate shots of undersea creatures, he shows how powerful images can help make change.

Almost everything we own and use, at some point, travels to us by container ship, through a vast network of ocean routes and ports that most of us know almost nothing about. Journalist Rose George tours us through the world of shipping, the underpinning of consumer civilization.

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...

Cartoonist Jim Toomey created the comic strip Sherman's Lagoon, a wry look at underwater life starring Sherman the talking shark. As he sketches some of his favorite sea creatures live onstage, Toomey shares his love of the ocean and the stories it can tell.

Think of penguins as ocean sentinels, says Dee Boersma -- they're on the frontlines of sea change. Sharing stories of penguin life and culture, she suggests that we start listening to what penguins are telling us.

Five years ago, Roz Savage quit her high-powered London job to become an ocean rower. She's crossed the Atlantic solo, and just started the third leg of a Pacific solo row, the first for a woman. Why does she do it? Hear her reasons, both deeply personal and urgently activist.

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.

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...