By Brisbane News Group, Australia
(Originally in English)
Australia’s Great Barrier Reef, listed as a World Heritage Area in 1981 for its exceptional natural beauty and qualities, extends for over 2,000 km along the northeast coast of the continent and covers 35 million hectares; about the size of Italy. It is also the largest protected marine ecosystem in the world. Internationally renowned for its size, beauty and biodiversity, the Great Barrier Reef is comprised of a network of almost 3,000 reefs formed from over 360 species of hard coral. Home to thousands of species, they provide complex habitats that support a great variety of reef-associated flora and fauna. The impact of climate change on coral reefs is a major concern from both the Australian and international perspectives. Two of the reef’s main research, protection and management bodies: the Australian Institute of Marine Science (AIMS) and the Great Barrier Reef Marine Park Authority are implementing strategies to deal with the global warming effects. However, they realize if key issues are not immediately addressed, the consequences for Australia’s coral reefs could be devastating despite their safeguarding efforts. Scientifically documented data from all around the world directly link the rise of sea water temperatures to the bleaching of coral reefs, known as “coral bleaching events.” Although the well-managed and protected networks of reefs can endure much of the localized human pressures, they are not protected against global warming or changes in the ocean’s chemistry. As global temperatures continue to escalate, the frequency of these bleaching events also increases. Dr. Janice Lough, Principal Research Scientist and leader of the Responding to Climate Change Team at AIMS, has been studying the impacts of climate change on coral reef systems for several years. In a recent interview, Dr. Lough explained how the corals form special symbiosis relationships with little algae, from which massive calcium carbonate skeletons are created, forming the backbone of the reef. “And it’s actually these algae, the photosynthetic pigments in those little plants, that give corals their colors.” However, the corals are very sensitive and when they become stressed, for instance, through rising water temperatures, they throw out the algae and the tissue layers become transparent so the corals lose their beautiful coloring. It’s referred to as bleaching because instead of the colorful corals, all that’s left are the white skeletons. Dr. Lough further explained that, “As a consequence of coral bleaching, there are various outcomes. The coral might recover once the stress has disappeared, it might partially die, or it can die completely.” In recent years, the Great Barrier Reef has experienced major bleaching events. In 1998 and in 2002, about 50% of the reef was affected, and again in the southern part of the reef in 2006. Fortunately, the reef is a well-protected system; so the chances of corals recovering from bleaching events are very high. The Great Barrier Reef Marine Authority Park monitors, controls and insures good usage of the reef. However, in order to protect it from further bleaching events, we need to drastically reduce our greenhouse gas emissions to prevent the sea water temperatures from increasing any further. The Great Barrier Reef is also at the mercy of changes in ocean chemistry, where the oceans are becoming more acidic due to their absorption of atmospheric carbon dioxide. These changes are also detrimental to our coral reefs because ocean acidification weakens their structures, creating more problems for the reef ecosystem. Many marine organisms use calcium and carbonate ions from seawater to produce calcium carbonate, which is how the corals form their skeletons. Increased carbon dioxide in the oceans decreases the availability of carbonate ions, thus reducing the ability of marine organisms to form skeletons and shells – the very backbone of a coral reef. This is a very serious threat because weaker reef structures means slower growth and reduced resilience to the natural forces of erosion, leading to a slower recovery of coral, if at all, after a bleaching event. Allowing the Great Barrier Reef to disintegrate due to human-induced climate change would be a terrible loss because the world would be losing something incredibly beautiful. Actually, the coral reef is not just a bunch of corals; it’s comprised of a whole stream of other organisms that depend on the coral, including fish and turtles and other marine life. Furthermore, coastal areas such as mangroves, wetlands, estuaries and sea grass beds are intimately linked to the reef, so we would be losing an entire ecosystem! Under the current global climatic changes,
coral reefs may not entirely disappear. However, their appearance,
structure and community make-up have been changing drastically; so
if we continue to allow our greenhouse gas emissions to rise without
conscience, we humans will be the source of destruction of such an
astounding ecological unit. This is why urgent greenhouse gas mitigation
strategies are necessary to prevent any further damage and alterations
to the coral reef environment. The Great Barrier Reef Marine Park
Authority is encouraging the general public to: plant more trees,
use sustainable energy, choose energy efficient products, drive less,
car pool, use public transport, walk or cycle, spread the word to
others, and offset or neutralize our greenhouse gas emissions any
way we can. Further to these, by adopting a vegetarian or vegan diet
we will considerably reduce our emissions, helping to save one of
the most beautiful and unique marine ecosystems in the world –
the Great Barrier Reef. References:
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