Dozens of animals, some on land but many in the ocean, can produce light within their bodies through chemical reactions. Scientists are still trying to understand when and why this trait developed.
Warm water expands, raising sea levels, which worsens storm surge during hurricanes. It’s only one risk from warming oceans.
AP Photo/Gerald Herbert
Just as the world’s zoos breed critically endangered animals in captivity to repopulate the wild, scientists are building a global effort to freeze corals for reef restoration.
The Great Barrier Reef is facing its worst summer of sustained heat stress since the mass bleaching event of 1998, but now with less time to recover amid repeated brutal conditions.
At a depth of more than 60 metres, the gorgonians are healthy, colourful and in good condition, protected from the rise in temperature.
Alexis Rosenfeld/Unesco
In the Mediterranean, heat waves are decimating underwater forests that are essential to ecosystems. The gorgonians seem to be better able to resist in the depths, but this refuge may only be temporary.
A school of grunts on a sunken World War II German submarine in the Atlantic Ocean off North Carolina.
Karen Doody/Stocktrek Images via Getty Images
Avery Paxton, National Oceanic and Atmospheric Administration
When ships sink, they add artificial structures to the seafloor that can quickly become diverse, ecologically important underwater communities.
Not only do corals inhabit the cold waters of the St. Lawrence, but the species that holds the title of largest marine invertebrate on the planet is present at the entrance to the Gulf.
(Fisheries and Oceans Canada)
In the vast St. Lawrence River, an impressive variety of animals live on the seabed. This group of organisms is called benthos or benthic invertebrates.
Coral impacted by excess nutrients in the Great Barrier Reef.
Ashly McMahon
After a chance discovery in the lab, this team used IVF to make hundreds of coral babies for restoration projects in New South Wales. So far the IVF babies are doing well in the wild.
A healthy reef on Kiritimati (Christmas Island, Republic of Kiribati).
(Danielle Claar)
Exploring the often unseen, and poorly understood, nuances of diversity within coral reefs may prove essential for ensuring the long-term health of Earth’s oceans.
A healthy coral reef in Palau in the western Pacific Ocean.
Liam Lachs
Ian Enochs, National Oceanic and Atmospheric Administration
Water temperatures in the 90s off Florida in July are alarming, a NOAA coral scientist writes. Scientists in several North American countries have already spotted coral bleaching off their coasts.
Natural records suggest a cooling trend was underway thousands of years ago.
DeAgostini/Getty Images
Rats are disrupting the flow of nutrients towards the sea on many tropical islands – this has consequences for fish behaviour and the wider ecosystem.
Researchers discovered five new species of black corals, including this Hexapathes bikofskii growing out of a nautilus shell more than 2,500 feet (760 meters) below the surface.
Jeremy Horowitz
Black corals provide critical habitat for many creatures that live in the dark, often barren, deep sea, and researchers are learning more about these rare corals with every dive.
Establishing the age of K'gari (Fraser Island) confirms it emerged before the reef, despite the climate being suitable for coral growth long before then.
An underwater forest formed by the purple gorgonian (Paramuricea clavata) off Marseille at a depth of 60 metres.
Romain Bricoult / CC BY-NC-ND
Corals in the Persian Gulf are tough - they can withstand temperatures that would kill corals elsewhere. And there’s good news: it’s easy to cross-breed their heat-tolerance genes into other corals.
Researchers found 16% of coral species have not been seen for many years. This finding is alarming, because local extinctions suggest global extinctions may be looming.