Covered with velvet-like glimmering algae of gold, deep purples and turquoises, the giant clams were at least three feet across. They were scattered among the coral, planted on the ocean floor. The encrusted grooves and ridges of the shell define the giant clam, which can live to be 100 years. The mollusk breathes in and out through the siphon, a hole in the flesh, luring plankton and divers.
I was mesmerized by the slow movement and the iridescence of this ancient living being. It was my first dive of many along the Great Barrier Reef and I was captivated. It was our first visit to the Land of Oz in 1991 and the next four days we spent our time on the live aboard dive boat, exploring the Great Barrier Reef. While my partner was getting his PADI scuba certification, I spent time diving with others who were already certified.
As I got closer to the giant clam, I noticed iridophores, the bright colors of circles on the clam’s flesh which direct sunlight onto its mantle. If the giant clam senses there’s not enough light filtering through to the algae, it extends the fleshy mantle out of its shell and reduces the color pigmentation to offer it more. Unfortunately, the flesh of this ancient creature is considered a delicacy by the Chinese. Unable to defend itself, this magnificent creature is listed as endangered.
As I lay prone swaying in the ocean’s water, there was a slight movement just below me, darting along the sand among the coral. It was tiny, yellowish with contrasting dark blue rings and fast. Lucky for me, he had no interest in me as I was no threat to him. The blue-ringed octopus is one of the most venomous of the octopus, despite the fact it could easily fit in my palm.
When diving in Australia, you learn to touch nothing. You keep your hands clasped across your chest or by your side. This prevents divers from killing coral and the ecosystem they provide, but also protects the diver.
A Potato cod, six feet in length, swam lazily next to me, like an old, faithful golden retriever. They have massive jaws but are the friendliest fish in the sea. They are bluish, with large, dark brown blotches that give the grouper their name. Because they are so friendly, they are easy to spear and now, they are rarely seen outside of protected Australian waters.
There was so much life; I was dizzy, twirling in the water, trying to see everything. The orange-striped clownfish were darting through brain corals, and lemon-yellow trumpet fish were hanging, motionless, upside down. Several species of psychedelic-colored wrasse and vibrant-blue parrot fish darted through the swaying branches of blue, orange, and yellow soft coral.
Hypnotized by the colors dancing in the back ground of the deep blue sea, I did not notice the large shark coming toward us. There must have been an invisible wall, because it suddenly veered away. The three of us, spellbound were expelling air bubbles rapidly while levitating in the water as still as we could.
As of April 2020, the GBR had suffered three major bleaching events on all portions of the great reef in the last five years. The water temperatures, recorded by the documentary crew of the film Chasing Coral, had risen as high as 80 degrees Fahrenheit. This event alone sent a clear warning to everyone that our Earth is in crisis.
Have we listened to her cry?
The Great Barrier Reef is unique as it extends over 14 degrees of latitude, from shallow estuarine areas to deep oceanic waters. It makes up about 10 per cent of the world's coral reef ecosystems, and is one of the best known and most complex natural systems on Earth. It is the 'sea country home' for the first Australians — more than 70 Traditional Owner groups — whose connections to the marine environment date back more than 60,000 years.
Today the Reef is a Marine Park and World Heritage Area, supporting a range of commercial activities and attracting millions of visitors each year who come to enjoy its beauty above and below the water. The Great Barrier Reef is an economic powerhouse, contributing more than $6.4 billion each year to the Australian economy and around 64,000 full-time jobs.
Within this vast expanse are a unique range of ecological communities, habitats and species – all of which make the Reef one of the most complex natural ecosystems in the world. Sea surface temperatures in March of 2022 were some of the hottest on record since 1900, in the Northern and parts of the central Great Barrier Reef. The southern Reef was also above average but not by as much.
The degree of coral bleaching within the water vary across multiple regions of the Marine Park. An increasing number of surveys are reporting completely white colonies and coral mortality where heat stress accumulation has been highest through a broad area of the central Reef.
The decline of the coral reef ecosystems is worldwide, but there is hope! Stay tuned.