Great Barrier Reef photo by Hok Wai Lum

By Nicolle Berroa, age 11 and Indykids Staff

In late 2018, an underwater robot named LarvalBot delivered 100,000 baby coral larvae into damaged reef systems in the Great Barrier Reef off the northeast coast of Australia. The Great Barrier Reef is the largest coral reef system in the world, but it’s currently endangered because of climate change, which is caused by pollution, the burning of fossil fuels and other greenhouse gases.  

In 2016, the Great Barrier Reef experienced a searing heat wave, which “bleached” 30 percent of the coral. Another 20 percent died in 2017. Now half of the Great Barrier Reef is dead.  When corals are exposed to heat, they expel the colorful algae from their tissue. This algae provides 90 percent of the coral’s energy source, which it derives from the sun as well as from nutrients and plankton in the water. So when that algae goes, so does the coral’s source of food. This loss of colorful algae means the coral looks white, or “bleached.” If temperatures do not quickly return to safe levels, the corals starve and die. In addition to climate change, greenhouse gas emissions, such as carbon dioxide, not only make the water warmer, the gases also make the water more acidic, which makes it difficult for coral to grow and survive.

For the next six to nine months, Peter Harrison, the leader of the coral restoration project, and his team will monitor the trial run to see if the baby coral grows.

While the robot is a small step to saving the reef, marine scientists say that if we don’t address the root of the problemclimate changethere will be no change. “It’s like coming up with a robot to replant trees after the devastating wildfires that just happened. It’s not addressing how to stop the wildfires in the first place,” Mark Eakin, a coordinator of the National Oceanic and Atmospheric Administration’s Coral Reef Watch program, told NBC News.

Marine scientists say that if drastic steps aren’t taken to reduce climate change by 2030, it’s expected that 60 percent of coral reefs around the world will be threatened. By 2050, it’s possible that coral reefs around the world will die off completely. Without coral reefs, there could be a rippling ecosystem collapse in the oceans, with devastating effects for the planet. A healthy ocean depends on coral reefs. A healthy Earth depends on a healthy ocean. It’s estimated between 70 and 80 percent of the world’s oxygen supply comes from the ocean.

Glossary:

Corals invertebrate marine animals that live in tropical oceans. Corals have polyps that use calcium carbonate (limestone) from seawater to build a hard, cup-shaped skeleton. They also have algae that live on the polyps, which give the corals nutrients and their color. As the algae are plants, they can get energy from the sun via photosynthesis and transfer this food to the coral.

Fossil fuels– Natural fuel such as petroleum, coal or gas formed over millions of years from decayed or fossilized remains of dead plants and animals, containing energy originating in ancient photosynthesis. Fossil fuels contain high percentages of carbon, so when they burn, they create high levels of carbon dioxide, a greenhouse gas.

Greenhouse Gases– Gaseous compounds such as carbon dioxide and methane that absorb infrared radiation from the sun and trap heat in the atmosphere, meaning the Earth receives more incoming energy from sunlight than it radiates to space. This net gain of energy will cause global warming, otherwise known as the greenhouse effect.