Australia’s Great Barrier Reef is the world’s largest reef system. It’s so large, in fact, that it can be seen from outer space. Home to more than 1500 species of fish, this reef is also a haven for six sea turtle species, 30 species of whales, dolphins, and porpoises. And it’s a crucial nesting and feeding habitat for 215 species of birds, GreatBarrierReef.org reports.
But climate change has taken a devastating toll on this ancient reef that is potentially 20 million years old. Built by living corals by row upon row of dead ones, the reef suffered severe bleaching events in 1998 and 2002 as well as in 2016 and 2017. And other factors, including sediment buildup, nutrient and agricultural pesticide pollution from river runoff is compounding the problem.
Considered one of the seven natural wonders in the world, half of the Great Barrier Reef has now been killed by coral bleaching caused by climate change since 2016, National Geographic reports. In 2016, bleaching killed 30 percent of the reef, while an additional 20 percent was killed in 2017.
Fortunately, there’s a bright light in the darkness. Scientists previously thought the deeper reefs in this magnificent system only contained 32 species of corals, UPI reports. But new research, published earlier this week in the journal Proceedings of The Royal Society B, show that roughly half of the coral species living in the Great Barrier Reefs can also be found on deeper reefs.
Deeper reefs provide protection from bleaching and heat waves on the surface. The researchers’ findings suggest that these habitats could provide sanctuary for species threatened by global warming. Nearly all coral lineages were found living among the deep reefs, and that means these deepwater habitats could preserve their diversity as well.
Researchers with the Queensland Museum plunged to depths between 100 and 150 feet and focused primarily on corals living at these depths during dozens of expeditions. A November report warned that Earth’s corals face numerous environmental threats, and current efforts utilized to protect them are insufficient.
But amazingly, coral diversity continues to astound scientists, especially after a huge reef was discovered off the coast of South Carolina in August. Located two thousand feet below the water, the 85-mile-long reef is festooned with corals. And that’s also a bit of good news, but quite obviously efforts to protect this newly-discovered reef need to be stepped up.
In their report on the Great Barrier Reef, researchers noted:
“Deeper reef areas are clearly more diverse than previously acknowledged and therefore deserve full consideration in our efforts to protect the world’s coral reef biodiversity.”
Although corals resemble plants, they are actually tiny animals that attach themselves to the ocean floor, the National Oceanic and Atmospheric Administration (NOAA) reports. They have tiny tentacles that they use to sweep particles of food into their mouths.
Bleaching occurs when unnaturally hot water kills tiny algae that corals depend on for their survival. Algae feed the corals and in turn, are provided with nutrients and shelter. But when the situation heats up, corals become too stressed and expel the algae, starving as a result. This is the reason we see all these starkly white coral skeletons.
Worldwide, coral reefs support more than 4,000 species of fish and 800 species of hard corals along with hundreds of other species, the NOAA reports. and scientists estimate they may harbor another one to eight million species yet to be discovered.
And coral reefs are economically important as well. Each year they provide an estimated $375 million in goods and services. When you consider that they cover less than one percent of the Earth’s surface, that’s pretty amazing.
If anthropogenic (human-caused) climate change continues, the IUCN estimates that all of the 29 beautiful coral reefs that are considered to be world heritage sites will die by the end of this century. Many countries have aligned themselves with the Paris Agreement, which holds that limiting global average temperatures to well below 2 degrees C above pre-industrial levels can be one way to protect corals. If countries can limit the temperature increase to 1.5 C or less, reefs can be saved.
While President Donald Trump has rejected the famous agreement, the U.S. is still very much involved, but it’s sadly pushing an agenda that favors Big Coal, Climate Change News reports.
So while it’s good news that corals can survive in deeper waters, if we truly are to protect them, there’s obviously still much work to be done.
Watch the beautiful video below to find out about corals living in the deeper stretches of the Great Barrier Reef.