What is causing the most damage to the Great Barrier Reef?
Climate change is the greatest threat to the Great Barrier Reef and coral reefs worldwide. Climate change is caused by global emissions of greenhouse gases, such as carbon dioxide from the burning of fossil fuels (coal, oil and natural gas), agriculture and land clearing.
What pollutes the Great Barrier Reef?
Chemical pollution When too much fertiliser is applied to crops, like sugar cane, excess fertiliser washes into rivers and waterways, where it is carried out to the Great Barrier Reef. Nitrogen from these fertilisers are linked to harmful algal blooms, which is a food source for juvenile crown-of-thorns starfish.
Is Great Barrier Reef dead?
In 2020, a study found that the Great Barrier Reef has lost more than half of its corals since 1995 due to warmer seas driven by climate change. As global warming continues, corals will not be able to keep up with increasing ocean temperatures.
What killed the coral reefs?
And they are dying. Coral reefs are under relentless stress from myriad global and local issues, including climate change, declining water quality, overfishing, pollution and unsustainable coastal development.
How many animals live in the Great Barrier Reef?
Around 1300 species, including a number that are commercially important (for example, some species of crabs and prawns). More than 3000 species known from the Great Barrier Reef.
What causes bleached coral?
Coral bleaching occurs when corals are stressed by a change in environmental conditions. They react by expelling the symbiotic algae that live in their tissues and then turn completely white. The symbiotic algae, called zooxanthellae, are photosynthetic and provide their host coral with food in return for protection.
What percentage of the Great Barrier Reef is bleached?
60 per cent of the Great Barrier Reef bleached in 2019-20 Of the 1036 reefs surveyed by scientists in a plane, 60 per cent had either moderate or severe bleaching.
Why is coral bleaching happening in the Great Barrier Reef?
Bleaching occurs when corals are under stress. A primary cause of coral bleaching on the Great Barrier Reef during summer is heat stress from raised water temperatures and increased UV radiation. A temperature increase of just one degree Celsius for only four weeks can trigger bleaching.
Why is the Great Barrier Reef losing its color?
As ocean temperatures rise, warmer waters stress corals, causing them to release algae that lives inside them, which gives them up to 90 per cent of their energy. This event causes the vibrantly-coloured communities of coral to turn white – an effect called coral bleaching.
Do coral reefs produce oxygen?
Just like plants, providing oxygen for our earth, corals do the same. Typically, deep oceans do not have a lot of plants producing oxygen, so coral reefs produce much needed oxygen for the oceans to keep many species that live in the oceans alive.
What is the largest animal in the Great Barrier Reef?
Groupers are among the largest of all bony fish and boast equally big mouths. The Potato Cod’s cousin, the Queensland Grouper, or giant grouper, is the largest bony fish found on the Great Barrier Reef, known to grow to more than 2m long and weigh up to 400kg.