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.

Dr. Helen Czerski investigates the physics of ocean bubbles and spends a lot of time sharing the big scientific ideas hidden in the small objects around us.

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.

Dianna Cohen co-founded the Plastic Pollution Coalition, which is working to help end our cycle of plastics use.

Dustin Schroeder develops and uses geophysical radar to study Antarctica, Greenland and the icy moons of Jupiter.

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.

Kristina Gjerde is an expert on the law of the high seas -- the vast areas of the sea and seabed that exist beyond any national jurisdiction. These places belong to the world; Gjerde's work helps the world work together to protect them.

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...

A United Nations Young Champion of the Earth, Miao Wang prefers to be underwater or in the sky.

David Gruber and his team take a delicate approach to understanding whales and other life forms.

"Thousands have lived without love; none without water," said Sylvia Earle as she stood on the TED stage five years ago, accepting the 2009 TED Prize. Wearing a blue blazer and an aura of resolve, Earle quoted this verse from poet W.H. Auden as she laid out a bold wish for the world: that we all wise up to the gravity of human impact on our ...

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.

TED Fellow Mei Lin Neo is helping giant clams step out of their shells and show the world that they can be the heroes of the oceans, too.

  Closing out the weeklong Our Ocean conference at the State Department, on Tuesday US president Barack Obama pledged support for a proposal to create almost 700,000 square miles of newly protected ocean — no-fishing, no-drilling zones around US island territories. The protections would allow the ocean to rejuvenate, and perhaps replenish...

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...

TED Fellow Lauren Sallan is a "next generation" paleobiologist applying cutting-edge developments in big data analytics to reveal how evolution happens at the largest scales (macroevolution), particularly in the oceans.

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...

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.

Not only does Jonathan Trent grow algae for biofuel, he wants to do so by cleansing wastewater and trapping carbon dioxide in the process. And it’s all solar-powered.

Hamish Jolly brings his entrepreneurial eye to the rare but viscerally terrifying issue of shark attacks.

The Plankton Chronicles Project uses state-of-the-art optics to reveal the beauty and diversity of planktonic organisms. It was initiated by Christian Sardet, Noé Sardet and Sharif Mirshak.

As a Senior Scientist at the Marine Biological Laboratory in Woods Hole, Massachusetts, Roger Hanlon delves into the undersea world of chameleon-like, color-changing marine animals -- and the practical applications that will emerge when we crack their secrets.

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.

Jason deCaires Taylor's underwater installations offer views of another world, where the artistic efforts of man meet the vivifying power of nature.

Melissa Garren is a molecular and marine biologist with a passion for unlocking the mysteries of our ocean's ecosystems and finding new avenues for conservation.

Kristin Poinar uses remote sensing and numerical models to study the interaction of meltwater with ice flow, especially on the Greenland Ice Sheet.

For the past 13 years, Jim Toomey has been writing and drawing the daily comic strip Sherman’s Lagoon, about a daffy family of ocean dwellers.

Dawn Landes, with her bright, supple voice and her restless imagination, is drawn to create and collaborate. A master of singer-songwriter pop, she is now writing a musical called "Row."

Jonathan Wilker explores the science and engineering happening within our oceans. He works to understand the ways that sea creatures survive and how we can adapt their technologies to create new materials.

David Epstein obsesses over mistranslations of scientific research, and tries to temper the misconceptions that follow them.