Climate change has put Australia’s Great Barrier Reef under threat, with ocean temperature rising, resulting in the bleaching of coral reefs in the past couple of years.
According to the The Australian Institute of Marine Science, “although the reef’s condition had stabilised during a “relatively mild” summer in 2023, it remained in a precarious position.”
As per Australia’s weather bureau, an El Nino weather pattern is likely to develop over the country in the coming weeks, bringing warmer ocean temperatures to the Pacific -and the renewed risk of coral bleaching.
The Great Barrier Reef is situated in the north-east coast of Australia. It inhabits the world’s largest collection of coral reefs, with 400 types of coral, 1,500 species of fish and 4,000 types of mollusc.
In 1981, The Great Barrier Reef was declared as a World Heritage site. The Great Barrier Reef covers an area of 348,000 square kilometres. It also includes extensive cross-shelf diversity, stretching from the low water mark along the mainland coast up to 250 kilometres offshore. This wide depth range includes vast shallow inshore areas, mid-shelf and outer reefs, and beyond the continental shelf to oceanic waters over 2,000 metres deep, states UNESCO.
The two phenomena, El Nina and El Nino, have both been impacting the coral reefs present in the Great Barrier Reef. These two phenomena are decreasing and increasing the world ocean temperature, respectively, over the years, at a much higher frequency.
These changes result in the bleaching of the coral reefs present in the vast oceans. In 2010, UNESCO for the first time raised the alarm about the reef’s deterioration. But as per official data, there have been six mass bleaching events on the Barrier Reef, the world’s largest coral reef, since 1998. Marine heatwaves have caused mass coral bleaching on the Great Barrier Reef in 2016, 2017, 2020 and 2022.
The El Nina phenomenon in 2022 alarmed scientists, when coral reefs bleached even during the phase when oceans were cooler compared to the El Nino Phenomenon.
According to the World Meteorological Organization latest forecast, there is a 90 percent probability that the El Niño event will continue during the second half of 2023, with at least a moderate strength.
WMO has also officially declared July as Earth’s hottest month on record, globally. With a slew of heatwaves across the globe. However, scientists and experts are yet to find out if the current El Nino phenomenon had any impact on the global temperature.