Ecosystems

Posidonia oceanica, commonly known as Neptune grass or Mediterranean tapeweed, is a seagrass species that is endemic to the Mediterranean Sea. It forms large underwater meadows that are an important part of the ecosystem.
Posidonia oceanica, commonly known as Neptune grass or Mediterranean tapeweed, is a seagrass species that is endemic to the Mediterranean Sea. It forms large underwater meadows that are an important part of the ecosystem.

Seagrasses are natural carbon dioxide sink, thanks to symbiotic bacteria

Seagrasses need nutrients to thrive, particularly nitrogen (N). Up to now, it has been assumed that the nitrogen is taken up by the seagrasses through leaves and roots from the surrounding seawater and sediment.

However, in many of the regions where seagrasses are most abundant, there is little nitrogen to be found. Furthermore, while nitrogen is abundant in the sea in its elemental form (N2), seagrasses cannot use it in this form. 

The reef was found in November, during a diving expedition to a depth known as the ocean's "twilight zone" - part of a global seabed-mapping mission.
The reef was found in November, during a diving expedition to a depth known as the ocean's "twilight zone" - part of a global seabed-mapping mission.

Pristine coral reef discovered off Tahiti

A research mission, led by UNESCO, found the reef, which stretches for nearly three kilometres and exists at depths down to 70m (230ft). This is around the ocean's "twilight zone," where there is just enough light to sustain life, and below which the ocean transitions into a dark abyss.

The reef probably took around 25 years to grow. Some of the rose-shaped corals measure more than two metres in diameter. This is highly unusual because, up to now, the vast majority of the world’s known coral reefs sit at depths of up to 25m.

Shadowfin soldierfish (Myripristis adusta)
Shadowfin soldierfish (Myripristis adusta). Growl and grunt sounds have been associated with soldierfish

The sound of coral reef recovery

Croaks, moans, purrs, growls, foghorns, whoops, grunts... these are just some of the many sounds that are heard coming from a healthy and diverse coral reef.

Researchers, who wanted to find out just how healthy restored reefs can be, focused on parts of reefs in Indonesia previously destroyed by blast fishing. The areas were restored through the Mars Coral Reef Restoration Project for years preceding the study.

Schools of planktivorous reef fishes strip the water of plankton, underpinning "sweet spots" of fish biomass production in tropical oceans.
Schools of planktivorous reef fishes strip the water of plankton, underpinning "sweet spots" of fish biomass production in tropical oceans.

Offshore plankton responsible for "sweet spots" at reefs

Plankton and plankton-eating fish play an important part in the productivity of tropical reefs by igniting "sweet spots" of abundance, according to a new study by ARC Centre of Excellence for Coral Reef Studies (Coral CoE) and Research Hub for Coral Reef Ecosystem Functions at James Cook University (JCU).

Environmental Project restores Belize Reefs

When Lisa Carne first visited Laughing Bird Caye National Park in 1994, the reef was vibrant and bursting with life, abundant with fish, corals, lobsters, crabs, sponges and sea turtles. After the hurricane, it was a scene of desolation, the seabed a swathe of rubble dotted with a few surviving corals. Hurricane Iris not only killed corals but uprooted their structure, making recovery more difficult.

Help protect the Coral Reefs

Our coral reefs are now under threat not only from the global warming, pollution and exploitation but also by the conduct of divers in these sensitive areas. The reefs are now calling for our protection both when we dive and as contributors to the ongoing struggle to preserve these unique ecosystems for future generations.

Previous studies of shipwrecks in the United Kingdom and the Red Sea have shown that such artificial reefs often create new and different types of habitat than natural reefs.

Fish thrive on WWII shipwrecks

In 2016, the National Oceanic and Atmospheric Administration (NOAA) undertook a closer examination of the wrecks of the German U-boat U-576 and the Nicaraguan freighter SS Bluefields, using glass-domed submersibles. The two historically significant and deep (200m) shipwrecks sank near one another on the continental shelf of North Carolina, USA, during World War II.

Giant kelp (Macrocystis pyrifera) is a species of kelp (large brown algae)

Kelp forests help the climate

Kelp is an ecologically and economically important foundation species in California, where forests line nutrient-rich, rocky bottom coasts. It also might alleviate acidification caused by too much atmospheric carbon being absorbed by the seas.

A new interdisciplinary analysis of giant kelp in Monterey Bay off the coast of California shows that near the ocean’s surface, the water was less acidic, suggesting the kelp canopy does reduce acidity.