A Journey Along The Great Barrier Reef

In the central region of the Great Barrier Reef lies Myrmidon Reef, surrounded by colorful reef fish. In Greek mythology, the Myrmidons were Achilles' fierce and loyal warriors. Perhaps the enduring and ancient nature of this reef led to its name.

The Great Barrier Reef has a hugely diverse range of fish. Roughly 1,625 species have been discovered so far, reflecting all sorts of shapes, sizes, and colors of the rainbow.

Fish group together like this in what’s known as either a "shoal" or a "school." Shoaling is when fish swim close together, but individuals do their own thing. Schooling is when fish swim synchronised in a tight formation. 

One reason fish swim in schools is to gain protection from predators. In a group, there are more eyes looking out for threats. Schooling can also confuse and disorient predators into thinking a school is a larger fish.

On our journey up the Great Barrier Reef, we have to stop at one of the most famous shipwrecks in the world, the SS Yongala. Consistently rated as one of the "top 10" dive sites in the world, this over 100-year-old shipwreck is brimming with life.

In 1911, the luxury passenger vessel SS Yongala disappeared in a tropical cyclone south of Townsville, Australia. Over 100 people were on board, and none of them survived. The wreck site was not discovered until 1958.

Much of the ship's structure is still intact. The wreck is 109 meters long and lies at 30 meters depth, although the upper section is only 16 meters below the surface.

Since sinking, the ship has become encrusted in many different coral species, such as this brain coral here. It’s now a thriving artificial coral reef habitat, and attracts an abundance of marine life. See what animals you can spot!

There’s a strong ocean current running along the shipwreck, which contributes to why there is so much marine life here. Rays, like these bull rays can often be found cruising in the current.

For the next destination on our Great Barrier Reef journey, we’ll head north to meet one of the Reef’s friendliest residents, the potato cod. 

The Cod Hole was one of the first ever protected sites on the Great Barrier Reef thanks largely to the efforts of famous underwater photographers Ron and Valerie Taylor, who in the early 1980s witnessed the huge cod population decimated by overfishing.

This is one of the most famous dive sites on the reef because of the potato cod population here. They happily approach divers and their extremely friendly nature has earned them the nickname "the dog of the sea".

These cod are a bluish-grey color and have potato-shaped markings all over their body, which is why they’re named potato cod. However they are a bit bigger than potatoes, growing up to two metres (seven feet) in length.

Opal Reef, in the northern region, is one of the sights that have made the Great Barrier Reef so famous. It’s easily accessible by tourist boats and the colorful coral reef here is visited by many thousands of people each year. 

Corals are the backbone of coral reef ecosystems. Even though they can look like rocks, corals are all living animals, made up of tiny coral polyps. They essentially build the infrastructure that other species call home.

Corals come in all shapes and sizes. Some are as flat as plates, some have fingers that reach up into the water, and some are big and round and can look similar to rocks. 

Even though coral reefs cover less than 1% of the earth's surface, they support 25% of all marine species. They also provide food and livelihoods to over 500 million people worldwide.

North Broken Passage is in the far northern section of the Great Barrier Reef, more removed from human activity. This region’s reefs tend to be incredibly biodiverse and healthy, with plenty of big fish, sharks, and other marine creatures.

But it’s not just biodiversity that makes the Great Barrier Reef such a complex ecosystem. It’s also the interconnectedness of species and habitats. Any disturbance to this underwater world’s delicate balance could create a domino effect throughout the ecosystem. 

What makes the Great Barrier Reef such an exceptional wonder is its vast expanse of coral reef. Look how much of this wall in North Broken Passage is covered in different species of colorful coral, providing habitats to numerous reef creatures.

The Great Barrier Reef is home to 600 types of corals, 1,625 species of fish, over 100 species of jellyfish, 3,000 varieties of molluscs, 133 varieties of sharks and rays, and over 30 species of whales and dolphins.  

When you look at such a complex and productive coral reef ecosystem, and consider the huge scale of this living structure, it’s easy to see why the Great Barrier Reef is one of the natural wonders of the world.