While the world continues to battle with the COVID-19 health crisis, an ecological crisis has continued to worsens as the Great Barrier Reef is now at risk of disappearing completely due to coral bleaching. This past month, Australia’s Great Barrier Reef has experienced its most widespread and severe bleaching on record with the south of the iconic reef bleaching extensively for the first time. This is the third mass bleaching event for the reef in the last five years and there is consensus amongst scientists that rapid warming of the planet due to human emissions of heat-trapping greenhouse gasses are to blame.
A primary cause of coral bleaching is rising temperature levels of the ocean as when water is too warm, the coral turns white as a stress response. This happens because they are expelling the algae that grow inside them which is their main energy source and gives them colour. While bleaching doesn’t kill coral immediately, it takes many years, even decades, for coral to recover. The issue is if temperatures remain high eventually coral will die destroying a natural habitat for many fish species.
Reefs are some of the most vibrant and diverse marine ecosystems on the planet and it is estimated that between a quarter and one-third of all marine species rely on reefs at some point in their life cycle. This is why the Great Barrier Reef is so significant as it is the world’s largest reef system. The Great Barrier Reef is estimated to be greater in size than the United Kingdom, Holland and Switzerland combined and it is where around 10 percent of the world’s total fish species can be found.
The first recorded mass bleaching event along the Great Barrier Reef occurred in 1998, which then was the (then) hottest year on record. Since then there have been four more mass bleaching events and more temperature records broken with the most recent being this year.
This year, February had the highest monthly sea surface temperatures ever recorded on the Great Barrier Reef since the Bureau of Meteorology’s records began in 1900. Analysis by Dr Terry Hughes, Director of the ARC Centre of Excellence for Coral Reef Studies at James Cook University and others from the Great Barrier Reef Marine Park Authority found that coastal reefs along the entire length of the iconic reef (2,300 kilometres) from the Torres Strait in the north, right down to the reef’s southern boundary had been bleached. This is especially significant as this is the first time major bleaching has taken place in the southern parts of the reef. Further concern should be had as around 70% of the world’s coral reefs now undergo these major bleaching events simultaneously thus making it a global issue, not just an Australian one.
Additionally, the economic impacts that coral bleaching has is often overlooked or ignored. It is estimated that the Great Barrier Reef brings in over $4 billion worth of tourism each year for Australia. However, the reef is currently at the brink of losing its world heritage status due to the ongoing effects of bleaching. In addition, according to the United Nations on the Economics of Ecosystems and Biodiversity, coral reefs benefit about 850 million people worldwide, with at least 275 million people depending directly on reefs for livelihoods and sustenance, particularly in the developing world. Although researchers are exploring ways to revive reefs through methods such as coral farming, these efforts will not be enough if the root causes of this crisis is not addressed: human-caused climate change.
“The Great Barrier Reef will continue to lose corals from heat stress, until global emissions of greenhouse gasses are reduced to net zero, and sea temperatures stabilise. Without urgent action to achieve this outcome, it’s clear our coral reefs will not survive business-as-usual emissions”
Dr. Terry Hughes (Professor at James Cook University)
This shows the importance of policymakers needing to intervene and keep climate change at the front of their minds when legislating. Unfortunately, this has not been the case in practice.
Most recently as this week, the Trump administration is rolling back environmental policies, most notably around car pollution standards. Instead of the Obama-era car pollution standard, which required an average 5% reduction in greenhouse emissions annually from cars and light truck fleets. The proposed Trump administration’s Safer Affordable Fuel-Efficient Vehicles Act will require just 1.5%. If manufacturers follow these new looser guidelines it would add 1.5 billion tonnes of carbon dioxide to the atmosphere, the equivalent of 17 additional coal-fired power plants. Decisions such as these put further pressure on reefs due to their environmental impact.
With coral bleaching occurring more frequently and with less time for reefs to recover, action is needed now. Legislators need to invest in policies which reduce carbon emissions and benefit reefs. Australia’s Great Barrier Reef is the largest and most extensive reef system in the world. Nearly half of the Reef was killed off in two consecutive years of coral bleaching in 2016 and 2017 and it is currently bleached again. It would be a shame if generations from now people could not see the beauty of reefs first hand nor have the benefits of reefs we have today. We need action and we need it now.
