Yet coral is so sensitive that even a one- or two-degree shift in temperature can cause stress over time. When corals become stressed, they expel the symbiotic algae that live inside their exoskeletons and feed them—the very algae that keeps them alive. This expulsion causes the reef to turn a ghostly white in a process scientists call coral bleaching.
 

Mass coral bleaching events are occurring more often and the increased frequency is having a prolonged and devastating impact on our coral reefs. 

Climate change is the largest contributor to coral bleaching. The average global temperature has increased by at least 1.9°F (1.1°C) since 1880. Around 90% of that excess heat is being absorbed by the ocean, and higher temperatures can cause prolonged heat stress that leads to mass coral bleaching events.
 

The ocean also helps control the climate by absorbing carbon dioxide from the atmosphere. And as the ocean absorbs excess amounts of CO2, it becomes more acidic. Coral skeletons are made of calcium carbonate, a mineral that can dissolve in acidic environments, so lower pH levels make it more difficult for coral to grow and maintain their shells.
 

This is also true for any animal that relies on calcium carbonate structures including shelled animals like clams, oysters, and mussels, which are essential throughout the marine food chain. 

Humans also have an impact. Coral reefs need clean, clear water to survive. Plastic pollution can block sunlight, smother corals, and cause abrasions that often lead to deadly infections.
 

Chemical pollution from sunscreen is another contributor to coral bleaching. In fact, up to 28 million pounds (12,700 metric tons) of sunscreen reaches our coral reefs each year.
 

Most sunscreens are formulated with highly toxic ingredients like oxybenzone, which can disrupt coral’s reproduction and growth cycles, cause deformities in both coral larvae and baby corals, damage coral DNA, and contribute to abnormal skeletal growth—all of which can lead to bleaching.
 

And that’s not just from people swimming in the ocean, either! Modern wastewater treatments don’t remove harmful chemical ingredients like oxybenzone from wastewater before it’s discharged. All water systems are connected, so the sunscreen we choose matters whether we live 10 minutes or 10,000 miles from the beach. 

We’ve already lost half of our coral reefs. If the current rate of degradation and die-off continues, researchers say that without urgent and immediate action, coral reefs could disappear from our oceans in just a few decades.
 

But there is hope! 

Coral restoration is a hands-on approach to conservation that focuses on regrowing and rebuilding damaged, degraded, and dying coral reef ecosystems.
 

While corals are technically animals, the process is similar to gardening because it involves propagating resilient coral species from healthy parent colonies, cultivating the cuttings in coral nurseries, and outplanting mature coral fragments back onto the reef. In some cases, artificial coral reefs are created to replace coral reefs that have already died.
 

Regular monitoring of coral nurseries and restored reefs helps scientists assess the success of restoration efforts and provides valuable data for ongoing research. Understanding the factors influencing coral health and growth is crucial for refining restoration techniques and saving our coral reefs. 

Team up with 4ocean and our friends at Coral Gardeners to clean the ocean and help plant one million climate-resilient corals by 2025!
 

By purchasing a bracelet from the 4ocean x Coral Gardeners Restoration Collection, you will remove 5 pounds of trash from the ocean and plant one unique species of coral onto the reef.
 

Each bracelet is handcrafted in Bali by a local artisan with cord made from 100% recycled ocean plastic and a recycled glass bead that represents the one coral you planted.
 

Collect all five to maximize your impact and wear them often to jumpstart conversations that raise awareness about the important of protecting and restoring our coral reefs.