Great Barrier Reef myths, busted by marine biologist Russell Hore

Ever wondered why the coral you see on the Great Barrier Reef might look a little different than the tourist brochure? Or what exactly is coral bleaching? Perhaps you’re unsure if you need scuba diving certification to see the best parts of the Reef?

With the help of marine biologist Russell Hore, Reef Biosearch Manager at Quicksilver Cruises, we’re answering all your questions about our most famous and fascinating Australian. With 34 years of experience in reef interpretation, monitoring and researching Queensland’s biggest natural wonder, there’s nobody better to separate fact from fiction, help us understand the state of the reef, and explain the ongoing efforts to keep it thriving.

Let’s dive in.

Myth #1 – All healthy coral is colourful

Healthy coral comes in a kaleidoscope of colours, shapes and sizes. There are around 600 different coral species on our Great Barrier Reef, each with its own unique characteristics.

“The colours we see are all based on the plant cells within the coral, most of which belong to the brown algal family. About 80% of all corals are actually yellow or brown in colour. Yes, there are red, pink, and blue corals out there – which are often the ones you see in the brochures or Attenborough documentaries – but these are in the minority,” Russell explains.

“Unhealthy coral is pretty easy to spot. It will usually be covered in algae, and if it has bleached, it will be white.”

Myth #2 – The Reef is dying, so there’s no point in visiting

The Reef isn’t dying, nor is it dead. The truth is, the Great Barrier Reef faces many threats and parts of our vast reef have experienced coral bleaching events which caused significant damage. However, through extensive monitoring, research and conservation efforts, marine scientists are now witnessing remarkable renewal and growth on the Reef.

The Great Barrier Reef is home to thousands of species of marine life, and there’s so many unique and incredible things to see and do if you get the chance to visit.

“We love our Reef, and we want to keep it how it is. Reef education on the reef is one of the best tools we have. The more you know, the more you want to protect it – which is what we try to instil in every visitor.”

Myth #3 - Coral bleaching occurs only due to rising sea temperatures

There are actually many environmental threats that can lead to coral bleaching.

“Coral bleaching is a stress reaction. Coral can be stressed by a number of different factors: rapidly warming water, rapidly cooling water, large amounts of freshwater from tropical low weather patterns that sits on top of the reef and doesn’t move, and when sediment flows into coastal waters – such as after a cyclone – which reduces the ability of the sunlight to get through to the coral,” Russell explains.

“When we talk about mass coral bleaching, that specifically relates to extreme warm water conditions. This is a global problem affecting coral reefs worldwide as a result of changes to the Earth’s climate.”

So, what exactly happens when coral bleaches?

“When coral bleaching occurs, corals will expel the plant cells in their tissues – called zooxanthellae – which predominantly belong to the brown algal group. It is the algae which give the corals their colour, so as they lose their algae, they start to lose their colour. During this process, the coral can turn from brown to lighter brown, then become very pale, then white. Without these plant cells, the coral has no way to absorb sunlight – its food – and can starve to death if the causation of the bleaching is a prolonged event, such as if the ocean temperatures stay extremely warm for a long period. That’s when you can be left with sections of bleached, colourless reef.”

Myth #4 - Bleached coral is dead coral

We talk about coral bleaching a lot. But as Russell explains, it’s important to understand that bleached coral isn’t dead coral.

“The distinction between bleaching and mortality is so important when discussing reef health.”  

“Bleached coral doesn’t mean that it is dead, nor that it is going to die. It is obviously not very well – but in the vast majority of situations, the coral is still alive and will recover.”

“Unfortunately, with the oceans getting warmer, we are starting to see more situations where the period of bleaching is prolonged – because the oceans are staying in that dangerous warming zone for longer – and the coral has effectively starved. That’s what is very concerning.”

Myth #5 - Coral only dies due to environmental or human impact

As a thriving, complex ecosystem, the Great Barrier Reef is a constant circle of life – and death is an important part of the process. This can be due to marine creatures, such as parrotfish, who live and scour among the coral, or damage from waves and tides, among other factors.

“You actually need to have a certain amount of coral mortality all the time, especially coming in to spring – ahead of coral spawning, which is the annual reproduction cycle. Coral polyps expelled during spawning need a ‘clean canvas’ – or somewhere to land – in order to grow. They can’t land on sand, algae or living coral, as that would reduce the living coral’s ability to absorb sunshine, which is its food source,” Russell explains.

“Coral mortality is absolutely essential for a dynamic, healthy reef system. What we don’t want are these mass bleaching events.”

Myth #6 - Damaged coral can't be restored

“On mildly or moderately bleached coral reefs, there’s a good chance it will survive and recover. We have even started to witness coral start to regrow on parts of the Great Barrier Reef that were impacted by mass bleaching events in 2016 and 2017, which is remarkable.”

“It shows that if there is enough time between ocean warming events, the coral can be replenished.”

Not only can damaged coral be restored, but the Great Barrier Reef is producing new life, too. Each year the Great Barrier Reef puts on the world’s largest, most impressive coral spawning event. Essentially, a synchronised reproduction of billions of coral polyps – and it can take just a single polyp to start a new reef.

“It’s probably one of the most incredible natural phenomenon on our Reef. Coral spawning usually occurs around 3-5 nights after the full moon around November – but the actual time of year depends on the ocean temperatures and currents. It’s absolutely awe-inspiring,” Russell said, who has witness coral spawning several times throughout his career.

Myth #7 – There’s nothing we can do to help protect the Reef

The largest coral reef in the world is also the best-managed reef in the world. While global climate change is a big threat to tackle, marine researchers and scientists are working hard to protect our Great Barrier Reef.

“From an environmental management perspective, we look at things we can work to control or influence within our area. Around Port Douglas, where Quicksilver Cruises is based, this includes education on better farming practices to reduce the impact of agriculture on our waterways, such as top soil, fertilisers and run-off; urban development restrictions; and well-managed commercial fishing. Over the past few decades huge improvements have been made in these areas and the flow-on effect is a healthier, more protected reef system. We’re lucky that the Great Barrier Reef is so vast, and many reefs are set aside just for science so we can continue to monitor, research and learn.”

However, the reality is that changing climate conditions pose the biggest threat to coral reefs globally, including rising sea temperatures, ocean acidification, and increasingly erratic weather such as cyclones.

“Truly making an impact on climate change requires a global response, and changing the way we as a society use and waste energy sources. We’re making improvements – but this needs to speed up. And it impacts more than our reef, but our rainforests and alpine areas too.”

“From an individual perspective, my best advice is if you live in coastal areas, do the right thing by your waterways.”

Myth #8 – Visiting the Great Barrier Reef is actually damaging it

Tourism plays a vital role in ensuring the Great Barrier Reef thrives. In fact, visiting is one of the best ways to help conservation efforts.

“I’ve been working up here for 34 years, and marine tourism is absolutely vital for the Great Barrier Reef. It’s not only an important tool for education, but with more eyes on the reef we are able to conduct important reef monitoring and research that couldn’t be done otherwise.”

“Reef tourism is extremely highly regulated in order to protect the environment as much as possible.”

Each time you take a trip to the Reef with a tour operator, part of your ticket includes an Environmental Management Charge which helps contribute to the day-to-day management of the marine park, and also helps to fund the ongoing important research which helps make the Great Barrier Reef the world’s best managed coral reef system.

Your visit to the Great Barrier Reef can have a greater impact, too, thanks to a range of citizen science programs where you can get hands-on with reef research and conservation efforts, learning from Master Reef Guides and marine biologists.

When visiting the Reef, remember to treat it kindly:

• Don’t touch the coral
• Don’t pollute
• Wear reef-safe sunscreen to avoid contaminating the water, and opt to wear a wetsuit as sun protection to reduce your use of sunscreen
• Adopt a coral with the Reef Restoration Foundation: for as little as $50 you can contribute to the planting of new coral colonies in underwater nurseries along the reef.

Read more on how to help the Great Barrier Reef here.

“Everything we do, whether it’s skydiving, mountain biking in the rainforest, jumping in the car to grab a coffee – it all has an impact. It’s impossible to have no impact. But what we can do is make that impact very minimal. We want to look after our Reef, and are always improving the way we operate – from establishing permanent reef pontoons to limit impact on the surrounding coral, supplying visitors with lycra suits to reduce the use of sunscreen, and recycling and composting any waste produced on tour. We’re also investigating future fuel sources for boat tours, such as hydrogen and alternative energies.”  

Myth #9 – The only way to see the Great Barrier Reef is to visit North Queensland  

When it comes to the Reef, the numbers are staggering. It’s comprised of around 3,000 individual reefs, 900 islands, and stretches for some 2,300km from the Torres Strait Islands and tip of Cape York to Bundaberg down south.

Imagine the United Kingdom, Holland and Switzerland combined. The Great Barrier Reef is still bigger.

With such vastness, it makes sense that there would be more places to experience the Reef than in Cairns. While Cairns is an incredible tourist destination and the most well-known gateway to the Great Barrier Reef, the Reef is actually made up of five precincts.

• Cairns and Port Douglas
• The Wild North, encompassing Cape Tribulation, Cape York and Torres Strait Islands
• Townsville
• The Whitsundays
• Southern Great Barrier Reef, including islands off Gladstone, Bundaberg and Yeppoon.

Read more about the precincts of the Great Barrier Reef – and what to do in each – here.

Myth #10 – It’s really expensive to visit the reef

You can have the experience of a lifetime on the Great Barrier Reef without having to splash some serious cash. There are endless ways to explore the Reef, from backpacker tours to five-star experiences and everything in between.

If you’re looking for tours that stretch your holiday savings a little further, get the latest information – from low cost boat tours to camping guides here.

Myth #11 – You can only see the reef properly if you scuba dive

Home to some of the world’s best dive sites, it’s little wonder why experienced divers from across the globe make their way to the Great Barrier Reef. At the same time, beginners are learning the skills and love for scuba right here thanks to dive schools from Heron Island to Cairns and Port Douglas. But there are incredible ways to see and experience the Reef without pulling on a BCD, dive computer and flippers.

With a lot of vibrant life on the Reef existing within the shallow waters of fringing reef and outer reef, you’re just a snorkel and fins away from exploring famous bommies and coral cays, swimming with marine life, or even meeting elusive dwarf minke whales in the remote northern reaches.

Don’t think you have the sea legs for a full day on a boat? Head to one of these Great Barrier Reef islands instead.

There’s even ways to see the Reef without getting wet, whether you’re a non-swimmer or have very young kids in tow that might not yet be old enough for an ocean swim. Quicksilver Cruises and Quicksilver Dive also offer reef pontoon experiences and PADI dive courses for people living with disability.

Myth #12 – You can only visit the Great Barrier Reef during Australia’s winter

Australia’s winter – June through August – might be peak tourist season on the Great Barrier Reef, but this UNESCO World Heritage site is yours to explore year-round. Every season holds something wondrous to experience.

Summer might be more humid, but it’s often when prices are a little lower. Waterfalls are at their peak, and northerly winds can bring calmer seas and incredible water clarity for Reef tours. Just be sure to wear a wetsuit to protect your skin from the sun and marine stingers that may be present during this time of year.

Wildlife lovers should time their visit when it’s possible to witness new life on the reef, such as turtle nesting and hatching season on the Southern Great Barrier Reef from November – March.

Still fascinated? Here’s more interesting facts about the Great Barrier Reef.