Deep-Water Corals Glow for Their Lives

New research sheds light on the secrets of fluorescent coral reefs

Coral reefs are economic mainstays and critical habitats. But something else makes them amazing: their otherworldly glow. Both shallow and deep-water corals emit fluorescent light, but until now, scientists only understood why shallow-water corals light up. Now, reports Laura Castells for Nature, the other half of the puzzle has been revealed and it turns out that the different kinds of corals glow for very different reasons.

These glowing corals live deep in the Red Sea

Shallow corals emit green light as a kind of sunblock to protect them from the harsh radiation of the sun. But in a new study in the journal Proceedings of the Royal Society B, scientists reveal that their deep-water counterparts glow in an attempt to absorb the scant light at the bottom of the ocean.

In an inverse of what happens in shallower waters, the deep-water corals must absorb as much light as possible to allow their zooxanthellae the tiny symbiotic algae that give corals their brilliant color and energy to make food through photosynthesis. Read more

Earth’s Water May Be as Old as the Earth Itself

Ancient volcanic rocks may have preserved tiny samples of the planet’s original moisture.

Liquid water covers some 70 percent of Earth’s surface, making the planet unique in the solar system. But where that water came from has been a bit of a puzzle.

Early in its history, Earth’s surface was so hot that any water would have evaporated into space. Anything that is here today, scientists have thought, must have come from asteroids or comets that later struck the cooling world.

But maybe not. A new analysis in Science suggests that at least some of Earth’s current moisture derives from water-soaked dust particles trapped deep inside during the planet’s formation.

To figure out where Earth’s water came from, scientists look at the ratio of deuterium to hydrogen found in the H2O molecules. Deuterium is an isotope of hydrogen that contains a proton and a neutron in its core, while an atom of hydrogen has only the proton. Read more

Salt of the Earth: Dead Sea and Other Amazing Lakes

Salty lakes on our planet are not uncommon, although many of us think that there are much more freshwater ones. These lakes may look like small seas or as very modest ponds, but the size here is not the main thing. Each one has a unique ecosystem, and each one has its own mystery. They can be admired, they can get the right substances, they will help to improve health and tell about the past of the Earth. So, we represent TOP-9 amazing salt lakes.

Where do they come from? As a rule, the salt concentration in the inland reservoirs grows gradually, as the water evaporates. In this case, the source of salts can be both rocks and groundwater, but the main factor is a decrease in volume. This process can take thousands of years, but human intervention accelerates it at times. An example is the Aral Sea. If water is actively used by people for various needs, and its inflow decreases, the ordinary lake can dry up and become salty for several decades. The water in it is no longer suitable for drinking or fields irrigation. Lakes salinity is one of the pressing problems associated with the global water shortage. Read more

Global water woes: Australia’s looming water crisis

With the world facing a 40% water shortfall by 2030 threatening Australia’s food and water security, Kellie Tranter calls on the Abbott Government to urgently address the need for investment in water research and development.

NO-ONE cares about water until the taps run dry. It’s a reality now facing the residents of Broken Hill. In time we all will, including our Asian neighbours, unless we confront and plan for our water-insecure future.

In October 2010, the Prime Minister’s Science, Engineering and Innovation Council report, ‘Challenges at Energy-Water-Carbon Intersections’, highlighted that

‘Australia faces major challenges at energy-water-carbon intersections to mitigate climate change while continuing to supply energy and to cope with limited water availability while maintaining and increasing population. These challenges will demand transformational responses.’

Last year researchers from Aarhus University in Denmark, Vermont Law School and CNA Corporation in the United States warned that

‘by the year 2040 there will be not be enough water in the world to quench the thirst of the world population and keep the current energy and power solutions going if we continue doing what we are doing today.’

Calls for transformational responses are still lacking. Baker & MacKenzie’s April 2014 submission to the Government’s issues paper on Agricultural Competitiveness said that over 50 per cent of those surveyed believed the greatest challenge to Australia’s food supply was the availability of water. Read more

A World of Water Woes

From the Middle East to the Caribbean to Australia, people around the world are dealing with water scarcity.

It’s easy to look at a portrait of Earth and think of our home as a water planet. After all, 75 percent of the surface is covered with water. But the thin skin of liquid that surrounds our rocky home is misleading—if you took all the water on the planet and bunched it into a ball, that ball would be less than half the diameter of the Moon. That’s not a huge amount of water.

Plus, the proportion of water that humans can use for daily use is actually pretty small. Most of the world’s water is saltwater in the oceans. Only about three percent of the water is fresh. Half of that is locked in glaciers, the polar ice caps and snow. Read more