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Column: New hope for the Great Barrier Reed

Sheffield scientists have found that there is still hope for the corals in the Great Barrier Reef
Sheffield scientists have found that there is still hope for the corals in the Great Barrier Reef

University of Sheffield researchers identify corals less vulnerable to damage

Sheffield scientists have found that there is still hope for the corals in the Great Barrier Reef.

New research has found that one hundred coral reefs may be resilient enough that they could aid in the recovery of the damaged natural wonder.

The Great Barrier Reef is made up of thousands of smaller reefs, creating a huge coral ecosystem that is the largest on Earth. However, rising sea temperatures and increased predation from starfish has meant that many of these reefs are damaged and reducing in size. One hundred coral reefs have been identified by scientists, which are less vulnerable to the disastrous effects of coral bleaching and damage from starfish. They are well connected to other coral reefs by ocean currents, meaning that smaller baby corals can travel across the sea to new areas, to replenish surrounding reefs.

Though they look like plants, corals are actually structures with tiny living creatures inside, known as polyps, which give them their bright colours. Due to climate change and increasing carbon dioxide, sea temperatures are increasing globally. While this might sound pleasant for us, when sea temperatures get too warm for corals, they expel the tiny living creatures inside them, causing them to lose their colour and a phenomenon known as coral bleaching. If water temperatures remain too high for long, the polyps will not return to the coral, and it will die. Coral bleaching has had dramatic effects all over the world, and especially on the Great Barrier Reef, with up to 70 percent of corals dead in some areas.

However, global warming is not the only threat to coral reefs, as those that can survive the rising sea temperatures are also being eaten by the crown-of-thorns starfish. On healthy coral reefs, the coral-eating starfish plays an important role and is even welcome! The starfish tend to feed on the fastest growing corals, which means slower growing coral species get enough food and space. However, an epidemic of the venomous starfish poses a significant threat to the Great Barrier Reef. According to surveys, corals have declined by 50 percent over a 27 year period in some areas. Crown-of-thorns starfish caused almost half of this decline. Therefore, to save our coral reefs, we need a solution – and fast. The new study from Australian and Sheffield scientists found several ideal qualities of a coral reef, which may help to promote coral recovery. Reefs in cool areas are less likely to become damaged from coral bleaching and hence will be relatively healthy. This means they are able to reproduce and create much needed healthy coral larvae. These larvae travel to new reefs by drifting on ocean currents and so ideal coral reefs should be should be as close to these currents as possible. Lastly, these reefs should not aid in the spread of the crown-of-thorns starfish which could cause further damage to surrounding corals.