Raising 500,000 babies for others and then having to return them, what is this doing?

Biologist Celia Leto dives to the bottom of the ocean with a plate of food.

Leto: Look at my dishes, do you want to pick one? | Aidan Harradence

Don't get me wrong, these coin-sized things are not little desserts for sharks, but immature coral babies .

These coral babies were born in the laboratory, and what Leto and her colleagues have to do now is to plant them one by one in the sea !

Leto scrapes hardened algae from the reef, clearing a small patch for the baby corals to take root, while her colleague Zachary Craig affixes tiny metal tags to the reef to identify the coral's genotype and record the planting date, so that the reef's growth can be monitored in the future.

After preparing all these, finally fix each coral baby on the coral reef.

Plant these coral babies in clusters of four and they will quickly merge together. | Ousama Farag/CBC

Their ultimate goal is to plant 500,000 baby corals in the world's most important coral areas within 20 years .

How do humans raise babies for corals?

Leto and her team raise coral babies and plant them artificially, all for a battle that has been repeatedly defeated - saving coral reefs. If they don't raise babies for others, the coral reefs will really die...

Since the 1980s, Florida, where Leto is located, has lost nearly 97% of its coral cover. Global warming, rising sea temperatures, is one of the main causes of coral bleaching and death. In April this year, the global average sea surface temperature soared to 21.1 degrees Celsius, setting a record so far, and the weather is still getting hotter...

Sick elkhorn coral. In addition to global warming, overfishing and coastal development are also important reasons for the disappearance of coral reefs | Zachary Craig

If corals are allowed to degenerate, the entire planet will be harmed.

Coral reefs are one of the most diverse ecosystems on Earth, providing habitat for thousands of species. They are at the heart of complex food webs, providing food and shelter for many marine organisms, including small fish, crustaceans and other plankton, which in turn provide food for other larger fish and marine organisms. If coral reefs continue to disappear, it will undermine the foundation of this ecosystem.

Because some coral reefs have degraded to the point where they can no longer reproduce naturally , Leto's team came up with a way to revive the corals - breeding new small pieces of coral on shore, and then grafting the small corals onto the reefs one by one .

Leto and Craig plant small corals in the Florida Keys, USA, and they can be considered as underwater farmers｜CBC

Leto's project has received millions in funding to try to revive seven dying coral reefs - an area equivalent to 59 football fields.

Baby corals grown in the laboratory

To breed baby corals, scientists must first determine which genetic type of coral is more heat-resistant and disease-resistant . After all, their ultimate living environment is increasingly hot sea water.

Now, the coral babies' parents, a 30-centimeter-long brown elkhorn coral, are suspended in a special tank that simulates the coral's spawning conditions - this coral only spawns once a year , usually around the full moon in August, with peak spawning times in the middle of the night and during hurricane season.

Coral parents in the tank｜Ousama Farag/CBC

Once the coral babies mature a bit, most are moved to outside tanks. To promote rapid tissue growth, the experimenters break them up into tiny pieces. Don't blame them for being cruel, this allows the corals to grow 50 to 60 times faster than they would naturally grow in the wild.

Left: Scientists tested corals to see how they cope with warming waters and disease; Right: Cutting small corals to encourage faster growth | Aidan Harradence

When the coral babies are finally ready, they will be transported to the coral reef to start a new life journey - just like they were planted one by one in the sea at the beginning.

Baby Coral Nursery｜Mote Marine Laboratory

King crab warriors defend coral reefs

As the ocean absorbs more and more carbon dioxide, ocean acidification causes certain algae to reproduce in large numbers, but it causes a decrease in the number of symbiotic algae (also known as coralline algae) in the corals. Once the coralline algae escape, these overgrown algae take over the nests and cover the coral reefs, hindering the photosynthesis and growth of the corals, and "suffocating" the corals .

How to deal with these algae explosions?

Oceanographers turned their labs into seafood markets and raised Caribbean king crabs . These king crabs are not the ones sold in the market - most of the crabs sold in the market are larger Alaskan king crabs, while Caribbean king crabs are smaller.

Caribbean king crabs used to protect coral reefs look like a vegetable market at first glance | cbc

King crabs love to eat algae, even if they are not tasty, they will eat them all. With the protection of king crabs, the coral babies that have just entered the water can adapt to the environment better and will not be killed by algae when they first arrive.

Scientists' goal is to breed 250,000 young crabs each year so that they can become loyal warriors of the coral reefs.

The coral reefs are growing slowly

The battle to save the coral reef has already begun to bear fruit. The left picture below shows the baby coral just after it was planted; the right picture shows the grown coral two years later, now firmly established in its new environment .

Baby corals adapt to new environment | Zachary Craig

Although time waits for no one, this year's El Nino will further increase sea temperatures and make coral bleaching more likely , the growing coral reefs still give Leto's team great encouragement.

“We’re slowly but surely doing a great job moving in the right direction, and that’s reassuring,” Leto said.

The hope of coral reefs may lie in the efforts that never give up.

References

[1]Rebuilding the reefs https://www.cbc.ca/newsinteractives/features/coral-reef-reconstruction

[2]Florida's coral reef is basically extinct, but scientists are trying to bring it back https://www.peoplesworld.org/article/floridas-coral-reef-is-basically-extinct-but-scientists-are-trying-to-bring-it-back/

Author: Xiu Beng Beng

Editor: You Shiyou

This article comes from GuokrNature (ID: GuokrNature)

If you need to reprint, please contact [email protected]

Welcome to forward to your circle of friends