Nancy Knowlton

A bluefin trevally swims in Hawaii’s Maro Coral Reef, part of the Papahānaumokuākea Marine National Monument.

Two Views of Coral Reefs: Thriving and Threatened

Coral reefs are beautiful, vibrant ecosystems that house roughly one quarter of all marine species and provide billions of dollars in products and services to humans each year. But they are also vulnerable to...
Cover of the Book Citizens of the Sea

Citizens of the Sea

Order a copy of the book, Citizens of the Sea . Credit: National Geographic The incredible variety of marine life—in numbers, body form, behavior, and more—is at the heart of Citizens of the Sea...
Caribbean boulder star coral (Montastrea cavernosa)

Star of the Reef: One Species at a Time

Each month, the Naked Oceans podcast invites a leading marine researcher to pick the "critter of the month" by asking: if you were a marine organism, which one would you be? This month, Dr...

2011 Student Summit on the Ocean & Coasts Webcast, Part 1

Recorded Feb. 15, 2011, this video from the Third Student Summit on the Ocean and Coasts includes a tribal song written and sung by Suquamish Tribal member Bearon Old Coyote; a welcome to the...

Lecture: One Year After the Gulf Oil Spill

On April 20, 2010, the Deepwater Horizon oil rig exploded, opening up a well that pumped nearly 5 million barrels of oil into the ocean. It was the largest spill in U.S. history. In...

Where did Half of the Great Barrier Reef's Coral Go?

In the past 30 years, the Great Barrier Reef -- Australia's iconic natural wonder -- has lost half of its coral to a combination of forces. Dr. Nancy Knowlton, Sant Chair of Marine Science...

Where the Shark and the Snapper Roam

Grey reef sharks are among the most versatile and tough predators on a Pacific coral reef, but they are also among the most vulnerable species, as they are threatened by wasteful fishing practices like...
Nancy Knowlton speaking about the "Future of the Ocean"

The Future of the Ocean

Nancy Knowlton, the Sant Chair of Marine Science at the Smithsonian National Museum of Natural History, asks "What is the likely future of our ancestral home?" The answer depend on what humans do now...
Coral Spawning by Moonlight

A Tale of Sex and Stress in the Ocean

A coral has just spawned. Each of the hundreds of polyps releases a small pink bundle of sperm and eggs. Credit: Raphael Williams Welcome to Citizens of the Sea , a new blog series...
An adult and juvenile killer whale frolic in the water.

Menopausal Moms: A Mammal Mystery

Killer whales ( Orcinus orca ) have something in common with humans: early menopause. Credit: Robert L. Pitman, NOAA Fisheries, USA In honor of Mother's Day, the Citizens of the Sea blog salutes ocean-going...