The Cost of Coral Reef Bleaching

By Zoe Jee

In late April of 2018, the Australian government revealed their pledge to spend $379 million on the rehabilitation of the Great Barrier Reef. The project will focus on combating the damage caused by the effects of coral bleaching. But what exactly is coral bleaching and what is Australia’s solution to help save the reefs?

Coral bleaching is coral’s response to changes in its environment, such as elevated ocean temperature, overexposure to sunlight and nutrients, increased runoff and pollution, extreme low tides, and changes in the salinity of seawater. When this occurs, the coral expel the symbiotic algae living in their tissues. This is detrimental to the coral since the algae produces carbohydrates through photosynthesis which helps provide food for the the coral. Without algae, the coral loses its coloration causing the coral to turn white. This leaves the coral vulnerable as it is without food and more susceptible to disease. Coral bleaching is not always fatal as the coral can reabsorb algae once it is no longer stressed. However, if the coral continues to be stressed, then the coral will not reabsorb the algae, ultimately causing death. The dead coral soon becomes covered in a blanket of seaweed, which prevents fish from being able to use the coral beds as sanctuary or food. This causes fish to die which leads to a domino effect throughout the ecosystem. Additionally, the seaweed will eventually cause the coral to collapse.

Coral bleaching has become more prevalent as the Earth continues to warm and more pollutants are entering the reefs. This is a growing problem particularly in Australia. Not only are coral reefs home to 25% of marine species, they also protect shorelines and promote tourism for the local area. It is in Australia’s best interest, environmentally as well as economically, to protect the Great Barrier Reef as it supports approximately 64,000 jobs. Australia’s plan to rehabilitate the reef includes improving monitoring systems to measure the reef’s health, controlling major predators, and investing in coral restoration. $151 million of the budget will be focused on improving the water quality by working with farmers to reduce their use of fertilizers to reduce runoff into the ocean. A large portion of the Northern coast of Australia is used to farm sugar crops, producing about 35 million tons of sugarcane annually.

Approximately $76 million of the budget is dedicated to reef restoration and adaptation. This includes projects such as growing more resilient coral in laboratories. They also plan to combat the crown of thorns starfish, which has become an overwhelming coral predator. With this plan, the Australian government hopes to recover the hundreds of miles of reef that has died in the past two years.

While this plan is a step forward to improving the health of the Great Barrier Reef, it is still insufficient to solving the problem entirely. Many scientists have already declared that the damage to the reef is irreversible and it is too late to try to repair it. Furthermore, Australia’s economy is heavily reliant on the export of coal, which has an immense detrimental impact on the environment. While they have pledged to cut 2005’s greenhouse gas levels by up to 28% by 2030, Australia will still have a higher emissions rate per person than the U.S. or the UK. In order to effectively reduce their carbon footprint they will need to reduce their emissions by 60%.

Overall, it is important that Australia is shifting their focus toward rehabilitating their reefs and have created a plan to help lower the amount of coral bleaching. While their actions will be beneficial to the environment, it will still require a lot of continued hard work and research to bring these reefs back to their previous state.


Richard Hyman