For centuries, a patch of red coral lived on top of an underwater cave in the Scandora Marine Reserve in Corsica. And that's just the tip of the iceberg, with plenty of red coral hidden deep in the Mediterranean.
Photographed by ENRIC SALA
Written by Rachel Brown
In a shallow cave on the southern coast of France, a team of scientists and conservationists discovered an astonishing number of primitive populations of Mediterranean red corals!
Joaquim Garrabou, a marine ecologist at the Spanish Research Council, is the team leader. His colleague Jean-Georges Harmelin discovered the cave while surveying grouper populations at the Scandora Marine Reserve off the coast of Corsica. Garrabou recalls: "The first thought that crossed my mind was, 'Oh, I don't think there's anything good here.' ”
However, Garrabou's attitude soon changed 180 degrees, because the scene of the underwater rock cliffs was so shocking: the cave was only 279 square meters in size and the water was extremely shallow, but it was home to the densest number of red corals to date. The team members teased each other as they observed, and the dome-like cliff walls reminded ecologist Silvija Kipson of the Sistine Chapel he had been to: "I kept looking up and staring at the magic of nature, and my heart was full of awe." ”
Garrabou tells us: "I've been a marine biologist for 25 years, but I've never seen a scene like this. ”
Individual red corals (i.e., red coral groups) protrude bright crimson branches from cliff faces and cliff tops, and ghostly hydras wave through the currents to filter out a meal of algae and zooplankton for themselves. Sponges gather around the corals, and a variety of fish appear from time to time in the glimmer.
Nuria Teixidó, another member of the research team, the National Geographic Society's Original Ocean Project, said: "For the first 15 minutes, we were completely focused on our work, constantly taking pictures and measuring. But after the work, we began to enjoy, let go of the camera, just look at these red corals, immerse ourselves in it... Time seemed to freeze. ”
Divers are exploring a patch of red coral in the Scandora Marine Reserve, close to Cave B, where the research team is located.
Although the research team discovered the red coral in 2010, their paper was only published in Scientific Reports on February 15 this year, showing the living conditions of the red coral in this extraordinary place and throughout the Mediterranean for the first time.
According to study co-author Emma Cebrian, cave B is "a window into the past," a time when humans were not yet able to pick corals.
Environmentalists who want to sustainably manage MPAs must have a thorough understanding of healthy, pristine ecosystems so that they can develop sound strategies for ecosystem restoration. Cave B is a great example: it's home to mature corals, sponges, fish, zooplankton, and other marine life.
Most of the corals in the Mediterranean are small, loose coral formations. Centuries of over-harvesting have prevented coral populations from returning to full maturity. Before the discovery of Cave B, researchers generally believed that large coral populations existed only in the deep ocean. Yet Cave B, located in the shallow sea, has forcefully countered this claim with its size and health.
There, some corals were more than 30 centimeters long, the largest living sample the team had ever seen. Subsequent analyses revealed that Cave B had 100 times more populations than the second largest known coral population.
Enric Sala is a resident explorer at National Geographic, the founder of the Original Ocean Project, and one of the co-authors of the study. "It's like a museum without doors and locks, filled with countless treasures," he said. ”
As for protective measures, although motion detectors and laser gratings are not used there, they are also necessary for protection. The Scandora Marine Reserve, where Cave B is located, is one of UNESCO's World Heritage Sites and is often seen as a global model for environmental stewardship. It is also a no-go area, where diving, fishing and other activities are strictly prohibited.
Other places, however, have not been so lucky.
Red corals are picked hot
Since the Neolithic Age, humans have been picking red corals. Unlike other corals, however, the bones of red corals are bright red overall, not only the seaweed covering the surface is red. After polishing, the red coral will be transformed into expensive jewelry. The ancient Romans believed that red coral had powerful magic, and they would wear coral branches around the necks of children to keep them safe from danger. In addition, the kings of many countries will also compete for control of the coral harvesting land, eager to monopolize and profit from rare ornaments.
In the 20th century, motorboats replaced the "St. Andrew's Cross" (a net was added to the heavy wooden cross) used to pick corals, but the entire population was destroyed by the mere metal trawling net across the coral bed. This was illegal in 1994, and now it is illegal to scuba dive to pick corals.
The anemones live in caves in the shallow mediterranean seas. Under the wave of industrial development, this cave is the last habitat of the Mediterranean red coral. With the advent of scuba diving, even underwater caves have been looted.
As the world's most precious coral, the demand for red coral in the market has increased, and today its value has reached $1,000 per gram, which is particularly hot in China's consumer market. Some are driven by commercial interests to over-harvest red corals in defiance of international law.
The study notes that "red coral populations are lost as much as large-scale deforestation on land due to over-harvesting," the Amazon rainforest is a prime example.
Red corals are the foundation of many ecosystems in the Mediterranean, creating a physical environment that provides habitat for fish and other marine life. But researchers believe that the population of red coral has fallen sharply and can no longer function, and this population will eventually even go extinct.
It is commonly found in shallow Mediterranean seas. Before over-harvesting, red corals usually grow on shallow cliffs and overhanging rocks in the Mediterranean.
Red corals have a long lifespan, but grow extremely slowly. In just one year, continental plate drifts more than 100 times the diameter of individual coral populations. Sala said: "Corals the size of palms are 300 to 400 years old. "While coral populations destroyed by fisheries have a strong ability to survive and regenerate, they are still difficult to resist human harvesting, pollution, ocean acidification and warming of water temperatures. Time and resilience alone will not allow vulnerable coral populations to survive.
The water depths of the Mediterranean Sea are relatively shallow and highly vulnerable to climate change, so this is true even in cold-water areas where red corals are abundant. "You only have to look at the Coralligenous outcrop district, which is a biodiversity hotspot and a natural heritage site that was in good condition a few months ago, but after a heat wave, all the creatures died," Cebrian said. In the face of over-harvesting, the impact of climate change is already small.
The Mediterranean region, which has suffered crises such as overfishing, severe pollution and hundreds of invasive species, is "a microcosm of the world's oceans," Sala said: "We face serious cognitive problems due to the degradation of the globalized environment. The 'nature' we know is the kind of thing we see as a child, so we know what it goes through. But think about nature in the eyes of children today! It's important to change our bottom line if people care about environmental protection. ”
Turning the tide?
The brilliant coral formations found in Cave B are that bottom line, and scientists say there is evidence that the red corals of the Mediterranean Sea may still be in pristine condition. Although the path to ecological restoration is not so easy, and the positive impacts will take decades to truly manifest themselves, the research team firmly believes that ecosystems can be restored with public support and proper management.
Due to overfishing, the Mediterranean's blackfin grouper, like red corals, has become an endangered species. But in some marine protected areas, their numbers have rebounded, such as the Scandora Marine Reserve in Corsica.
The first step is to protect and maintain healthy populations, following the example of coral populations in Cave B, and to promote conservation measures to less than ideal places according to that standard. Studies have even found that coral genotypes are more tolerant of temperature changes and can therefore be tried to transplant to relatively more dangerous places. However, the paper also points out that this approach is only a stopgap measure, and that the long-term conservation of this population and the sexual maturity of coral populations require limiting the number of harvests and establishing a network of protected areas throughout the Mediterranean.
Despite the obstacles on the road to population conservation, some progress has been made, with more protection measures to be introduced in the near future. On the IUCN Red List of Threatened Species, red corals are endangered species and have been protected by legislation at home and abroad. The Catalan government recently issued a ten-year ban on fishing, which will come into effect in 2018. In addition, some jewelry companies have begun to refuse to purchase coral products after recognizing the difficulty of sustainably sourcing corals.
To marine ecologist and co-author Cristina Linares, the spectacular red coral population found in Cave B is like a beacon. "At that moment, for the first time, I really became optimistic."
(Translator: Sky4)