“Well it’s not Cozumel.” Cole shrugged as he pulled himself back onto the dive boat, water pouring off his gear as I held on through the small waves below. We had just finished our first of the eight dives we would complete on the Great Barrier Reef (GBR) over the next three days on a live aboard boat, and so far he wasn’t impressed.
My brother, Cole, had last dived at Cozumel, an island just off of Mexico’s Yucatan Peninsula. Cozumel is home to the largest reef in the Western Hemisphere. With stunning colours and fish, he didn’t think the Great Barrier Reef was any comparison. That’s not to say that Cozumel hasn’t had it’s share of human impact and as such coral bleaching.
I pulled myself up, and as I deflated my BCD I replied, “Was it that much better?”
“100%”
My last dive had been off Sydney’s shores in the middle of winter. All I remembered was the inability to move my hands, and the panic that set in when I lost my buddy and couldn’t see a meter in front of me (worst dive ever, but that’s another story). In comparison, this was paradise.
Throughout the next few dives, I took the time to look at the pieces of reef that were slowly dying. The greyish white that was setting into the coral as it slowly bleached away and died.
It was only a month later; the headlines read that the Great Barrier Reef was officially DEAD. Not in danger, but absolutely dead.
We, humans, had killed a 20 000-year-old ecosystem, that was crucial for the marine environment around it.
The Great Barrier Reef is one of the most beautiful places to dive in the world. Sadly climate change is causing stress leading to death.
Coral Bleaching:
Coral bleaching is the result of reefs and corals being stressed. This can occur from temperature change (excess cold can cause this too), pollution or overexposure to sunlight (which occurs when temperatures are high). When these things occur the coral expels the algae from it’s tissue. Algae and coral work together to survive, forming what is know as a symbiotic relationship. Without the algae the coral turns white and can become diseased and eventually die.
Reefs can and have survived bleaching events. This is true, the GBR for example has had mass bleaching events in 1998, 2002, and 2006. This is where Climate Change skeptics might try to say, “see, this ISN’T human caused. Climate Change isn’t real. Look at the other bleaching events, you can’t say this is our fault.” However, I’d politely reply that they’d be wrong.
A turtle sits on the reef!
The Climate of Our Reefs:
In 1995, the first climate change summit (COP) occurred in Geneva. This was before the first mass bleaching event on the GBR. Scientists began to look in depth at climate change and human impacts on the climate in the 1970s. Even then there was outstanding evidence to prove humans were driving the increased temperatures.
The Great Barrier Reef Marine Park Authority (GBRMPA) predicts the oldest reef structures that were complete to have been 600 000 years old. However, the current reef we see today is 20 000 years old.
Corals are marine invertebrates that consists of many small individuals (polyps that are only a few millimeters in diameter). Corals have hard carbonate exoskeletons, which makes them quite unique compared to other invertebrates. The corals cluster together in order to create coral reefs. These reefs need relatively shallow water and sub-tropical to tropical temperatures to flourish and survive.
Coral is important for marine life. Coral reefs are full of complex invertebrates which have carbonate exoskeletons.
Most current coral reef systems were built as sea levels rose over continental shelves at the end of the last ice age around 10 000 years ago. As the water came over the shelf causing shallow water the corals were able to build into the reef systems we see today.
The GBR formed as Eastern Australia experienced tectonic activity and water flow changed during the last 66 Million years (the Cenozoic). Reefs grew as Queensland entered tropical waters and once sea level stopped changing allowing for sedimentation required for reef building.
Reefs need to stay within 60 m of the oceans surface. If sea level rises too much it will cut off their sunlight and they will die. Alternatively, if sea level lowers the reefs will be exposed to the air and also die.
Current sea level rise predictions from CSIRO estimate a rise of 2-3mm per year with Climate Change. However, if all the ice on the planet were to melt there would be a global sea level rise of 70m, which would cover every coastal city. This would also drown the reefs and they would disappear completely.
The beautiful coral that is slowly disappearing as sea level and temperatures change.
Latest Reef Health:
On November 29th, the ARC Centre of Excellence in Coral Reef Studies reported “the largest die-off of corals ever recorded on Australia’s Great Barrier Reef”. The 700km portion in the northern part of the reef is the worst effected.
Professor Terry Hughes of the ARC Centre of Excellence for Coral Reef Studies based at James Cook University says, “Most of the losses in 2016 have occurred in the northern, most-pristine part of the Great Barrier Reef. This region escaped with minor damage in two earlier bleaching events in 1998 and 2002, but this time around it has been badly affected.”
This 700km portion lost 67% of its shallow water reefs over the last 8 to 9 months. This will take 10-15 years to regain its lost reefs. Though if another bleaching event happens then the recovery process will be stopped and have to restart. Deteriorating cyclically until there is no hope.
The map, detailing coral loss on Great Barrier Reef, shows how mortality varies enormously from north to south Credit: ARC Centre of Excellence for Coral Reef Studies
Visiting the Reef:
Many people think that the GBR can only be accessed from Tropical Northern Queensland, Cairns and Townsville. However, you can access the Southern Great Barrier Reef from the town of 1770 with shuttles to Lady Musgrave and Lady Elliot islands.
From Cairns you can take a single day trip to the reef or multi day live aboard boat trips. It is good to book in advance. These trips are a must, while the reef is still there.
The evening sun over the GBR! A must see.
After my second last dive on the reef I was hanging up my gear. A gentleman beside me said, “I was here 10 years ago, and it doesn’t even compare. Pity.”
I looked out over the turquoise water and the green reefs scattered around the anchored boat and thought how beautiful it all looked from the surface. Peaceful, serene and delicate. The clouds billowed in the horizon and I thought it couldn’t get any more stunning.
There was still a little voice in the back of my head reminding me how glad I was that I had seen this wonder before it all went away.
According to the GBRMPA there were 2.25 million visitors to the Great Barrier reef during the 2015-2016 fiscal year. This is a huge source of employment and income. This could all be gone if the reef disappears.
The GBR from the dive boat! You can see the blue water and the green of the reef.
Looking to the Future:
The Australian government says they have a plan for protecting the reef all the way up to 2050. The comprehensive plan was implemented in 2015 and outlines the next 35 years. All the info can be found here. The Queensland Government is putting plans in place to help reef management, which includes restricting port access to those cities already with a marine port.
I often think about my visit to the reef as I hear about the destruction that is taking place. The fact is human impacts on the environment and climate change are causing destruction to something that has taken tens of thousands of years to build. In this day and age; the untimely death of the great barrier reef is just another box to check.
A giant clam which relies on the GBR for survival!
