5 Coral Species You Can Spot at Rottnest Island

Discover the island’s vibrant coral gardens and see it all for yourself.

3 minutes

Goniastrea Australensis (Brain Coral)

Just below the surface of Wadjemup / Rottnest Island’s turquoise waters lies a thriving tapestry of coral that’s as colourful and unique as the island itself.

Here, more than 20 species of coral form vibrant marine gardens – an impressive diversity found just a short distance from Western Australia’s coast.

Rottnest Island’s reefs owe their lushness to the warm Leeuwin Current, which flows southward from Indonesia carrying coral spawn that settles and grows into intricate reef systems. These reefs flourish among the island’s underwater limestone ridges, remnants of a time when Wadjemup was connected to the mainland, creating caverns, ledges, and pockets where corals take hold in spectacular shapes.

For snorkellers, this underwater world couldn’t be more accessible. Many reefs sit only a few flipper kicks from shore, providing an immediate glimpse of the corals and hundreds of tropical fish species among them. Not sure where to start? This guide will help you get to know five of the most eye-catching corals that bloom beneath Wadjemup’s waters.

Before You Dive In

It’s important to respect the marine environment when exploring the colourful underwater world. Avoid touching or taking anything from the reef to help preserve its delicate ecosystem for future generations.

Coral To Look Out For

Pocilliporidae Damicornis (Cauliflower Coral)

This cauliflower is not for consumption! One of the most widespread corals around Wadjemup, Pocillopora damicornis is known for its compact clusters of short, upright, knobbly branches that look remarkably like a head of cauliflower.

Found throughout tropical and subtropical oceans, this veggie-lookalike thrives in shallow waters between one and 15 metres deep. Its colours can range from pink and cream to vibrant greens and purples. In deeper or more sheltered locations, the coral forms thinner, broader branches as it adapts to lower light and gentler water movement.

As a reef-building species, cauliflower coral can grow into colonies anywhere from a few centimetres to several metres across, creating a vital habitat for countless marine creatures.

Pocillopora Damicornis (Cauliflower Coral)

Pocillopora Damicornis (Brain Coral) on Wadjemup.

Pocillopora Damicornis (Cauliflower Coral)

Pocillopora Damicornis (Cauliflower Coral)

Goniastrea Australensis (Brain Coral)

The Goniastrea australensis, commonly known as brain coral, is a frequent sight around Rottnest Island. Its rounded shape and maze-like pattern of deep, interconnected grooves give it the distinctive appearance of a brain. Colours vary from earthy browns to brighter, more vibrant shades.

Although it grows slowly, brain coral can become impressively large, forming dome-shaped structures up to two metres tall or sprawling colonies that carpet the reef. Thanks to their size and incredibly strong skeletons, brain corals play a vital role in reef ecosystems. They help build the reef framework, provide habitat and protection for marine life, and act as natural barriers that help shield coastlines from wave energy.

Goniastrea Australensis (Brain Coral)

Turbinaria (Plate Coral)

Think of Turbinaria as the “dinner plates of the sea”. Commonly known as plate corals, this species forms flat, round structures that can appear as solitary features or impressive stacks of overlapping discs. These corals can even shift position across the maambakoort (ocean) floor over time.

This stony, single-polyp coral has a slightly sunken mouth at its centre and can grow to more than 30 centimetres in diameter. Plate corals also come in a vibrant palette of colours, including pink, blue, cream, and orange, making them a striking sight on the reef.

Turbinaria (Plate Coral)

Porites Lutea (Mound Coral)

Mound coral is one of the slowest-growing corals on the reef. These colourful, lumpy structures take decades to mature because of their incredibly dense internal skeleton. As it expands, the coral polyps gradually build outward and upward, creating the rounded mounds they’re known for.

Despite their slow growth, mound corals can reach impressive sizes, growing several metres across and living for hundreds of years, forming long-lasting foundations of the reef ecosystem.

Porites Lutea (Mound Coral)

Acropora Selago (Bushy Acropora)

The rare Acropora selago is one of only two Acroporidae species found around Wadjemup. This cushion-shaped coral is made up of many short, tightly clustered corallites that grow vertically, giving the colony its dense, compact appearance.

Acropora Selago (Bushy Acropora)

BEFORE YOU GO

Wadjemup is home to five marine sanctuary zones, created to protect Rottnest Island’s spectacular reefs, coral systems, and marine life. You can help us to conserve this unique marine environment by remembering not to touch, stand on, or take anything, as even small disturbances can harm these fragile ecosystems within the five marine sanctuary zones.

Explore with a Guide or Go Your Own Way

To deepen your understanding of the island’s underwater wonders, join a guided snorkelling tour and let the experts lead the way. Spend the day with Rottnest Snorkel, who will take you to some of the island’s top snorkelling spots while sharing insights into the marine life that calls these waters home. For a unique experience above the water, step aboard Charter 1’s iconic yellow catamaran for their snorkel and sail tour. And if you’re after a full day of adventure both on land and in the water, join Laura the Explorer on a cycling tour, complete with snorkelling stops throughout the day.

Prefer to explore at your own pace? You can easily hire snorkelling gear from Pedal & Flipper Hire or Rottnest Rentals before setting off on your self-guided adventure.