Repairing Reefs

Corals depend on plant-like organisms called algae to survive. Tiny algae live inside the corals. In exchange for the homes that corals provide, the algae turn the sun’s energy into food that the corals eat. 

The relationship between algae and corals is an important part of a diverse ocean ecosystem. When corals thrive, other organisms like fish and crabs do too. These creatures are food for larger animals. Coral reefs are home to one-fourth of all ocean life. 

Corals rely on algae to survive. Algae are tiny plant-like creatures. They live inside corals. Corals give algae a home. And in return, the algae turn the sun’s energy into food for the corals.

Algae and corals are an important part of their ocean ecosystem. When corals thrive, so do other animals like fish and crabs. These creatures are food for larger animals. Coral reefs are home to one-fourth of all ocean life. 

Coral reefs are important for other reasons too. They protect shorelines by slowing down waves. They also boost businesses by drawing tourists. 

But the world’s coral reefs are in danger. One threat is water pollution, which can make corals sick. Overfishing is also a problem. If fishers catch too many fish, the types of algae the fish eat can grow out of control on the corals, killing them.  

Coral reefs are important for other reasons too. They slow down waves. That protects coasts. Reefs also draw tourists to the area. That boosts business.

But the world’s coral reefs are in danger. One threat is water pollution. It can make corals sick. Too much fishing is also a problem. Fish eat algae that grow on corals. Without fish, algae can grow out of control on corals. That can kill them.

The biggest threat to coral reefs is rising ocean temperatures due to climate change. When water is unusually warm, it can cause corals to spit out the tiny algae inside them. The corals can then turn white and starve. This is called coral bleaching. 

Scientists say nearly all coral reefs could disappear in the next few decades if people don’t take action. “The loss of reefs has huge consequences for the environment and the people on our planet,” says marine scientist Madhavi Colton. She leads the Coral Reef Alliance, an organization working to save the world’s coral reefs.

But there’s an even bigger threat to coral reefs. It’s warming oceans. They’re getting hotter because of climate change. It’s causing corals to spit out the tiny algae inside them. The corals can then turn white and starve. This is called coral bleaching. 

Scientists say nearly all coral reefs could disappear. It could happen in the next few decades if people don’t take action. “The loss of reefs has huge consequences for the environment and the people on our planet,” says Madhavi Colton. She’s a marine scientist at the Coral Reef Alliance. It’s a group working to save the world’s coral reefs.

In Hong Kong, many of the corals broken by the typhoon weren’t dead. They just needed a hard structure where they could grow and reproduce. Baker worked with architect Christian Lange to design hexagon-shaped tiles full of nooks and crannies where corals could attach. The tiles were 3-D printed out of a type of clay.  

The team created 128 tiles in two weeks. In July 2020, divers placed the tiles on the seafloor. Then they collected broken pieces of corals. Baker and other scientists cleaned the coral pieces to remove harmful organisms. The team then glued the coral pieces to the tiles. 

At one site, Baker installed a device that crabs and other animals can crawl inside. “It’s like a little hotel,” says Baker. In a few months, he will bring the device to the lab to study the organisms inside it. That will tell him if the tiles are helping restore the reef’s living things. 

The typhoon broke corals near Hong Kong. But many weren’t dead. They just needed a new place to grow. Baker teamed up with an architect named Christian Lange. Together, they created tiles shaped like hexagons. The tiles are full of spaces where corals can attach. The tiles were 3-D printed out of a type of clay.  

The team created 128 tiles in two weeks. Divers placed the tiles on the seafloor in July 2020. Then Baker and other scientists collected broken pieces of still living corals. The group cleaned the pieces to remove dangerous organisms. Then they glued the corals to the tiles. 

Baker set up a device at one site. Crabs and other animals can crawl inside it. “It’s like a little hotel,” says Baker. He’ll return the device to his lab in a few months. He’ll study the animals it contains. That will tell him if the tiles are helping bring animals back to the reef.