The Great Barrier Reef
…and the environmental threats it faces
Overview
The Great Barrier Reef is the most extensive coral reef ecosystem in the world. It is situated near the coast of Queensland, Australia. It spans over an area of 344,400 square kilometers and is home to a remarkable diversity of life. It is the largest unified structure made by living organisms to date and is so huge that it can be seen from outer space. It holds great significance in the local and global ecology. This natural wonder is under threat because of the climate crisis and increasing ocean acidification.
The Significance of GBR
In 1981, the GBR was named a World Heritage Site, and in 1997, it was declared to be one of the seven natural wonders of the world. It comprises 900 islands and over 2900 individual reefs. This rich and diverse ecosystem contains 4000 types of mollusk, 1500 species of fish, 240 species of birds and 400 types of corals. Additionally, it is home to a variety of sponges, sea snakes, coral trout, marine worms and an array of other organisms. Many of these species are endemic to the GBR. This shows the great scientific and biological significance of the Reef.
It occupies an area that is equal to that of Japan or Italy. It began its existence half a million years ago. The current Reef structure is thought to be 8000 years old. In all that time, it has faced very little threat to its survival, until the arrival of the agriculture and the industrial sector.
Tourism has grown to be a great contributor to the Australian economy, amassing over 3 billion AUD annually. The Reef has always been an important part of the cultures of the native Australians’ — the Aboriginals and the Torres Strait Islanders.
As global temperatures continue to rise, there will be even more serious consequences for the coral reefs worldwide. The communities whose livelihood greatly depend on the Reef will continue to face severe problems.
Environmental Threats Faced by the Great Barrier Reef
The climate crisis has become a serious threat to the coral reefs around the world. The Great Barrier Reef is already suffering the ramifications of climate change. This can be proven by the increased intensity of tropical cyclones and coral bleaching events in recent decades. Cyclones of high-intensity damage the corals, both individual and collective. Big floods drive pollution to the marine environment. Also, an increased influx of floodwater reduces the salinity of the reefs.
A fall in the species and number inhabiting the Reef has been observed. Another threat faced by the GBR is the increased population of Crown of Thorns Starfish. This coral-eating fish has disastrous consequences for the Reef. This is why the Reef 2050 plan is working on eliminating the population of this particular species.
Coral Bleaching
In normal climatic conditions, the Reef is capable of keeping itself healthy and fending off minor climatic disturbances. But the present-day climatic threats are far too powerful for the Reef to stay unaffected. Because of the increased frequency of bleaching events, the Reef is getting less and less time to recover and adapt. A study conducted in 2020 found that the GBR has lost above 50 per cent of its total corals since the mid-1990s. The increased intensity of thermal waves has acted as a catalyst in the destruction of corals. This also reduces the Reef’s ability to stay immune against other threats such as diseases. This not only harms the structure of the Reef, but also causes severe damage to the diverse variety of species residing inside it or dependent on it, directly or indirectly.
According to global analysis, these coral bleaching events have increased over five times in the span of just 40 years. One such event was the coral bleaching of 2016, because of which almost 30 per cent of corals situated between two to ten meters were lost. The most drastic effects of this were felt in the northern part of the Reef because it experienced the greatest amount of heat.
However, bleaching events are not as well documented as they should be. This is because the knowledge of these bleaching events that we have is limited to shallower parts of the Reef, and the bleaching events in the deeper parts often go unnoticed.
Conclusion
Apart from ocean acidification, The GBR faces a number of other serious threats, including degrading water quality and destruction unleashed by coral-eating starfish.
A big number of organizations are invested in the goal of preserving the Great Barrier Reef and in reversing the damage already caused. The UN Ocean Decade and the Reef 2050 plan has emerged to be a big part of the restoration plan. The Great Barrier Reef Marine Park Authority is continuing on making substantial improvements in the condition of the Reef.
But the current rate of damage control and prevention is far too slow for stabilizing the health of the GBR and its ecosystem in time. The rate at which the damage is occurring is far greater than the rate at which it can recover.
By the mid-21st century, the ocean will be a very different place from what it is today. The modern-day Great Barrier Reef will not be able to adapt to such a different environment.
Two main problems must be addressed with full force. The first is stabilizing the problem of climate change and rising greenhouse gas levels in the environment. The second is reducing the non-climate stress (like the coral-eating starfish). These two are responsible for reducing the Reef’s resilience against multifarious threats. There is a strong need to bridge the gap between knowledge and action if the Reef, and the rest of the natural environment in the world is to be saved.
Also read — Saving the Ocean and Increasing Ocean Acidification
