Coral bleaching

Close-up photograph of translucent coral polyps, showing the symbiotic algae living inside.

Zooxanthellae and Coral Bleaching

Tiny plant-like organisms called zooxanthellae live in the tissues of many animals, including some corals , anemones, and jellyfish , sponges, flatworms, mollusks and foraminifera . These microscopic algae capture sunlight and convert it...
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...
Coral reefs are the most diverse of all marine ecosystems.

Coral Reefs: One Species at a Time

Coral reefs are bustling cities of marine life, until rising ocean temperatures turn them into ghost towns. Can reefs spring back from devastating bleaching events? In this episode of the Podcast of Life ,...

World Oceans Day 2012 - Live Webcast

On World Oceans Day - June 8th, 2012 - the Living Oceans Foundation hosted a live web-based conversation between Sylvia Earle at the Smithsonian's National Museum of Natural History and a team of scientists...
Swimmers brave the waters in the shadow of a coal-fired power plant.  Coal plants like this one emit CO2 into our atmosphere which is warming the planet and altering the chemistry of the ocean.

Climate Change

Today, carbon dioxide (CO2) levels in our atmosphere are the highest they've been in 15 million years. It's the cumulative impact of an ever-expanding population―7 billion people and rising―and an ever-increasing thirst for energy,...
Where the pH is the lowest, corals can no longer grow - sand, rubble and seagrasses replace the reef.

Sneak Peek: Future of Coral Reefs in an Acidifying Ocean

Scientists don’t often get the opportunity to travel through time. But nestled among the beautiful coral reefs of Papua New Guinea (PNG) is a place that provides a glimpse today of what could be...
Corals, sponges, and algae are the major components of most coral reef communities as shown in this picture.

Corals and Coral Reefs

Coral reefs are the most diverse of all marine ecosystems. They teem with life, with perhaps one quarter of all ocean species depending on reefs for food and shelter. This is a remarkable statistic...
Colorful corals are disappearing in the Great Barrier Reef.

The Great Barrier Reef – Going, Going, Gone???

Video of Storms, Starfish Wiped out Half of Great Barrier Reef Coral Dr. Nancy Knowlton, Sant Chair of Marine Science and Editor-in-Chief of the Ocean Portal, went on PBS NewsHour to talk about Great...

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...
A decomposing sea star loses its grip on a rock.

Sickly Starfish: A Q&A with Dr. Chris Mah

A morning sun star ( Solaster dawsoni ) loses its grip on a rock surface as its body slowly decomposes from starfish wasting syndrome off the coast of Vancouver in September 2013. Credit: Jonathan...

Coral Under Pressure: Monitoring Bleaching In Real Time

A coral head in the Mesoamerican Reef has both bleached and living coral. The white sections are bleached and the brown parts still contain zooxanthellae, the symbiotic algae that provide food to their coral...
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 underwater photo of coral recovering from a bleaching event.

A Pleasant Surprise: The Recovery of Bleached Panamanian Corals

These corals are still in recovery after a mass bleaching in Panama, in the summer of 2010. You can see some bleaching on the tops, but the sides are looking good. Credit: Amanda Feuerstein...