Goldie's Blog

OUR BARRIER REEF

11 May, 2016 | By Goldie Alexander

From:  Dr David Lloyd. Associate Professor,  Protected Area & Coastal Management. Academic Integrity Officer for the School of Environment Science and Engineering. Southern Cross University

Dr. Lloyd was my student way back when I was a secondary teacher. Please read what he says because it is VERY important.

Twenty years ago a report on the State of the Great Barrier Reef said that the great majority of the Marine Park is still relatively pristine when compared to coral reef systems elsewhere in the world. These findings were also supported by two major workshops to which over 100 scientists and management experts contributed  (Both these workshops were summarised in the report titled State of the Great Barrier Reef World Heritage Area 1998, released in November 1998). At the time there were those who warned that taking a reductionist approach was wrong. We did not understand the parameters of the system we were dealing with, let alone the interactions within it. The 35 million hectares of coral, seagrass, mangrove, soft bottom communities and island communities were too big to fail.

The first big bleaching events of the 1990s was a novelty, we could not dream that it would become an almost annual event affecting over 90% of reefs in the far north and many in the south, and, as I write this, we are sending students out to quantify the bleaching damage off Coffs Harbour and even down to Sydney. Bleaching is the last ditch attempt by coral to survive high temperatures by expelling the algae that contributes sugars through photosynthesis while safely cocooned by the coral. The algae, zooxenthallae, also gives the coral its wonderful colour which is why the corals look so bleak when they are gone.

At the time we were looking for the enemy within, crown of thorns, over fishing or pollution. Never thinking that a mature ecosystem, which has evolved over hundreds of thousands of years, would fall victim to a simple carbon atom, hooking up with a couple of oxygen atoms – but on a grand scale. The Great Barrier Reef is falling victim to our consumer society through global warming. We think of a few degree temperature rise as the difference between a warm 25 and slightly hotter 27  degree day. Perhaps the summers will be a little longer, the winters more pleasant. But what happens when your body temperature rises 2 degrees, you are sick. And, so are the more than 300 species of hard, reef-building corals corals.

The Great Barrier Reef is more than just corals. It also provides habitats for many diverse forms of marine life. There are an estimated 1 500 species of fish and more than 4 000 mollusc species and over 400 species of sponge. All living within a tightly controlled temperature range that affects breeding cycles, metabolism and food supply. The delicate balance is lost. At the same time carbon dioxide acidifies the oceans causing the calcium carbonate, the skeleton of the reef, to dissolve.

Warm oceans also fuel cyclones and storms. Without the reefs to slow them down the effect on the extensive seagrass beds, which are an important feeding ground for the dugong and turtle, is lost. As are the islands and cays that support several hundred bird species, many of which have breeding colonies there. Reef herons, osprey, pelicans, frigate birds, sea eagles and shearwaters are among the numerous sea birds that have been recorded- most at risk and all potential victims of the catastrophe that is unfolding.

So what have we learned? Nothing and no-one is too big to fail. Unfortunately the environment does not appear on the balance sheet. Loose one small part and who knows what is next.

 

 

 

 

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