Great Barrier Reef – Is it Doomed?
The answer to that question depends on who you are listening to, but the fact cannot be denied that the Great Barrier Reef is in serious trouble. The coral comprising the reef is experiencing bleaching for the second consecutive year. In the northern region of the reef, where the 2016 bleaching was the most intense, two thirds of the coral has died.
Coral bleaching (above) occurs when coral, which is thermally sensitive, becomes stressed by warmer water temperatures. The symbiotic algae which lives inside the corals, their main source of food and responsible for their vibrant colours, is expelled by the coral as a self defense mechanism. This causes the coral to become extremely vulnerable to other risk factors such as storm damage or attack by algae.
Coral bleaching in not necessarily a death sentence. In 1998, when ocean temperatures rose 1°C, there was a coral bleaching event. Of the 21 reefs in the Seychelles that were bleached, 12 have since recovered but the other 9 are now seaweed covered ruins. The Great Barrier Reef also suffered bleaching in 1998 but has recovered. This recovery can take up to 10 years. The main concern now is that two consecutive years of bleaching events is unheard of and the odds of recovery from such a traumatic event is unknown.
The Great Barrier Reef has been declared a World Heritage Area. The United Nations considered listing the Great Barrier Reef as “in danger” in 2015, but based on Australia’s conservation plan, ruled to leave the status unchanged. Australia has until 2020 to ensure the reef shows signs of improvement to its health when the matter will be re-examined.
Warmer ocean temperatures is not the only factor threatening the reef. Poor water quality, caused in part by the land based run-off, coastal development and illegal fishing are increasing the man-made pressures that the reef is trying to withstand.
Scientists are working on ways to mitigate some of these threats. Using seagrass to reduce ocean acidification, creating artificial surfaces to attract coral to more favourable environments and studying the effects of increased CO2 levels and how to counteract their effects, are examples of some of the research currently underway.
The Great Barrier Reef is one of the seven natural wonders of the world and the largest living structure on the planet, even visible from space! It is home to 1,625 species of fish, 10% of the total world species, 215 species of birds and six of the seven species of turtles.
Over 2 million people visit the reef every year generating tourism revenue of approximately AU$6 billion per year. That figure does not consider the revenue raised by the commercial fisheries or the recreational fishing trips which increases the economic impact to in excess of $20 billion (AUD) annually.
Coral reefs act as a natural barrier against storm damage and provide a food source for millions of people and a home to a diverse range of sea creatures. Coral reefs the world over are being threatened by human actions while scientists are predicting El Nino could return by the end of 2017, further raising ocean temperatures.
Time is running out for these natural wonders and the time to act is now!