Great Barrier Reef, AUS — Daddy bear’s porridge was far too hot. Mummy bear’s porridge was far too cold. Baby bear’s porridge, however, as just right. This familiar tale of Goldilocks and the Three Bears is a parallel to the current problem of Great Barrier reef coral bleaching. Coral bleaching is a significant problem for the great barrier reef; however, researchers have recently discovered cold patches of water that keep some coral reefs not as badly bleached, due to upwelling.
Just like daddy bear’s porridge, the water in the great barrier reefs is too hot. According to the National Oceanic and Atmospheric Administration, when water is too warm, corals will expel the algae living in their tissues, causing the coral to turn completely white. This is also known as coral bleaching. In the Great Barrier Reef Marine Park, 73% of reefs currently surveyed have prevalent bleaching, and the great barrier reef is known to have the worst bleaching in the world. Once these reefs die, they rarely come back, and with few corals surviving they struggle to reproduce, resulting in entire reef ecosystems to deteriorate (WWF).
Alongside the environmental impacts, WWF Australia states that the richness and uniqueness of the reefs are crucial for tourism and the Australian economy, sustaining more than 60,000 jobs and contributing $6.4 billion dollars annually to the national economy. Just to put that into perspective, this is roughly about twice the amount of people who live in Monaco.
This is where mummy bear’s cold temperature come into play. Recent surveys from the air and on water show reef groups, such as the Ribbon Reefs in the north, and Pompey reefs in the south are consistently escaping severe bleaching, whilst the neighbouring reefs are suffering. After detecting unusually cool water in satellite temperature maps and ocean models, researchers in the Commonwealth Scientific and industrial research organisation (CSIRO), an Australian Government authority, have recently concluded the reef’s survival is due to cold water. The majority of the reefs are in cooler waters, even as other parts of the reefs are suffering from heat waves.
After researching to see if the cold flows persist in 2050 and 2080,CSIRO’s modelling suggests that these cold currents could protect the reefs until 2080 even if surface temperatures were to rise another 3 degrees. This way they are able to safeguard the reefs and its variety of species.
https://www.csiro.au/en/news/All/Articles/2024/December/Great-Barrier-Reef-cool-water