3 euro Austria 2023 - Coral Reef

Stony Coral, the fifth 3 euro coin in the Luminous Marine Life series, transports you straight to the most species-rich marine habitat of all: the coral reef. Indeed, hard corals are used as material to build fantastic living worlds where other marine creatures also thrive, including the clownfish, with its bright orange body and three white stripes edged in black.

Hermatypic or reef-building corals can have the most diverse growth forms. Most hard coral species excrete calcium carbonate at their base, forming a calcareous skeleton through symbiosis with zooxanthellae, single-celled microalgae. They reproduce by forming new coral calyces on top of old ones, or when coral polyps become independent. If left undisturbed, they will continue to do so as long as the seawater remains clean and there is sufficient sunlight.

Some hard coral species can live for several hundred years, which may explain why, at certain points in the Earth's history, hard corals have formed entire islands and archipelagos for thousands of years, such as the Bahamas, Bermuda and the Maldives. What's more, around 600,000 years ago, corals began building the Great Barrier Reef off the coast of Australia. Today, with its 359 species of hard coral, the reef is the largest structure created by living beings on earth, and provides a habitat for a multitude of other species.

That said, global coral mortality has been linked to rising surface water temperatures caused by global warming. Severe "coral bleaching" occurred in 1998 after the onset of the El Niño phenomenon in the western Pacific and Indian Oceans, when temperatures were 1 to 3°C above the long-term average for months at a time. To ensure that the ocean habitat remains as diverse and colorful as it is on Luminous Marine Lifecoins , it is therefore imperative that we protect it, not least from ourselves.

Coin design

The 12 magical sea creatures from the Luminous Marine Lifeseries are silhouetted on the obverse of the coin. Air bubbles between them and a tail fin disappears beneath the waves on the right. On the reverse, a wide band reminiscent of an old-fashioned porthole frames an aquatic scene featuring a coral reef. Hard corals are depicted at top left, gorgonians at right, brain corals in the center and sea anemones at bottom left, while clownfish are scattered around the reef. When the piece is illuminated with UV light, the corals and sea anemones glow and change color.