Are Coral Reefs Disappearing Forever?
I wish I could tell you for sure that coral reefs are going to make a comeback.
But the fact is that the world’s coral reefs are critically endangered, and nothing will change this fact unless drastic actions are taken — and taken soon. Like, yesterday.
You might be wondering “Why should we care about coral reefs in the first place?” Fasten your seatbelts.
“Why should we care about coral reefs in the first place?”
1. Food
Half a billion people are estimated to live within 100 kilometers of a coral reef, which means that many people depend on them to provide marine life habitats for food production. Due to coral reef decline, many countries are suffering because their main source of food production has atrophied greatly.
A fishing village in Indonesia called Seraya Besar was forced to manually restore their coral reefs in order to provide themselves with food. While this particular village was able to restore the reef, there are other poorer regions that depend on reefs for food who may not have enough resources or external support to carry out this type of extensive reef-restoration process.
2. Drugs
Coral reefs are called the “medicine chests of the sea” because there are chemical compounds found in reef species used in pharmaceuticals.
Scientists have already used chemicals in reef plants and animals to develop treatments for ulcers, lymphoma, skin cancer, leukemia, cardiovascular diseases and other ailments. Isn’t that amazing!?
For example, scientists extracted the nucleoside vidarabine from the marine sponge tethya crypta found in Caribbean Sea reefs; this chemical is now used as an antiviral agent for the treatment of human immunodeficiency virus (HIV) and herpes simplex virus (HSV).
3. Ecosystem Services
Not only do coral reefs provide food and medicine, they provide environmental services like water purification, air purification, carbon and nitrogen fixing, and coastal protection. The 2018 World Wildlife Fund (WWF) Living Planet Report estimates that nearly 200 million people depend on coral reefs for protection from storm surges and waves.
After the 2004 Indian Ocean tsunami, the Sumatra coast was badly affected. However, the healthy reefs on this coast prevented even more damage and destruction. A scientific model estimates that healthy reefs offer coastlines at least twice as much protection as dead reefs. This is because healthy reefs have rougher surfaces that slow waves with friction before they reach the coast.
4. Economic/Commercial Benefits
At least 76% of the world’s coral species are concentrated in the Coral Triangle, which spans over Indonesia, Malaysia, Papua New Guinea, the Philippines, the Solomon Islands and Timor-Leste. This region has more coral fish diversity than anywhere else in the world, making the Coral Triangle a center for economic opportunities.
Overall, the National Oceanic and Atmospheric Administration estimates that coral reefs provide goods and services up to USD $375 billion a year through fisheries, coastal protection, tourism development and pharmaceuticals.
At this point, hopefully you’re thinking “Oh, I should definitely care. So what the heck is happening with coral reefs that’s making them disappear?”
“So what the heck is happening with coral reefs that’s making them disappear?”
Simply, it is climate change. Of course it is climate change. Climate change is ruining everything.
But to start off, let’s learn a little about coral reefs in the first place:
Reefs are built by coral polyps that secrete calcium carbonate, which allow them to cluster and form structures that can span for hundreds or even thousands of kilometers. The structures made by reef-building corals provide habitats and protection for thousands of species of fish, shrimp, invertebrates, sea turtles, anemones, and more.
However, coral reefs are in decline globally due to the effects of climate change. A lot of this decline is attributed to coral bleaching.
Corals have an endosymbiotic relationship with photosynthetic zooxanthellae in which the corals provide a habitat for the algae while the algae provide the coral with oxygen and nutrients. When corals are stressed by environmental triggers, they expel the pigmented algae from their tissues and become “bleached” (white). If the environmental conditions that stress the corals are sustained for long periods of time, the corals will die from starvation or disease.
One of the main causes of coral bleaching are water temperature variations, including rising water temperatures due to global warming and ENSO (El Niño Southern Oscillation) events. Carbon dioxide from the atmosphere is absorbed into the world’s oceans; because of increased air pollution, ocean acidification has worsened and is another significant coral bleaching trigger.
Additionally, overfishing in coral reefs causes certain species of zooplankton to thrive due to lack of predators and can lead to oxygen starvation of corals.
Case Study: The Great Barrier Reef
The Great Barrier Reef is the largest coral reef in the world, stretching over 2300 kilometers off the northeastern coast of Australia.
However, after mass bleaching events occurred in 2016 and 2017, it was estimated that 1500 kilometers of the Great Barrier Reef had been bleached. The significant decline of the reef has been attributed to climate change, predation by Crown-of-Thorns starfish (COTS), cyclones, and nutrient runoff.
Overall, it is just a really sad situation for one of the most beautiful places on Earth.
“What can be done?”
According to the 2018 World Wildlife Fund (WWF) Living Planet Report, up to 90% of the world’s coral reefs could disappear by 2050 if current trends continue. So while the future for the Great Barrier Reef and other reefs look grim given the circumstances, government intervention and scientific innovation may help them make a comeback.
Before the mass bleaching events took place in 2016 and 2017, the Australian government launched the Reef 2050 Long-Term Sustainability Plan in 2015 to begin recovery.
In addition to government intervention, scientists have been working to restore the Great Barrier Reef with creative innovations. Electrified metal frames have been shown to attract mineral deposits that help corals grow 3 to 4 times faster than normal in the Indian Ocean, Caribbean Sea, and South-East Asia. Some coral has started to grow in the Great Barrier Reef using this technology, but it will take at least 10 years for even the fastest-growing species to fully recover.
In 2019, a different experiment was held in the Great Barrier Reef that led to a doubling in overall fish abundance and 50% greater species richness. During this six-week trial, the sounds of healthy reefs were emitted to attract various fish species to the damaged reefs to encourage symbiotic relationships. ISN’T THAT INSANE!?
Essentially, a boom box made fish come swimming back to the coral reefs and helped restore them!
THE GOOD NEWS: Even though it takes many years for most corals to recover from bleaching events, there are several species that are highly resistant to the effects of climate change. These thriving species are most likely the future for coral reef restoration.
These results are promising for the future of the Great Barrier Reef and reefs all over the world. With the help of government intervention and regulation enforcement, reefs may have a fighting chance after all.