The importance of the oceans, their wildlife and ecosystems

This will be my sixth visit to Heron Island but only the second time I’ve been in the cooler ‘winter’ months. But this time I was with a friend equally obsessed with snorkelling. We had a week to look forward to nothing but staring at fish – and maybe a few turtles too! This is our trip report snorkelling Heron Island.

For more information, visit my Heron Island page.

Photos by Simon Mustoe and Carla Bond

DAY 1 – Unseasonal weather

We arrived on Heron Island and the weather was frankly appalling. ‘Unseasonal’ conditions were being reported on the news. Excited by the prospect of any snorkelling though, we skipped the orientation and headed straight into the ocean. It was cold. Snorkelling is best done in sunlight with heat on your back and head. For the next few days there would only be rain and inky skies.

Within moments, however, a hundred metres from the resort bar we were accompanied by two curious Blacktipped Reef Sharks. One was sporting two remora (suckerfish). Then a Hawksbill Turtle joined in. This was to be the first of many epic snorkels. Heron Island immediately proves its worth in any conditions.

DAY 2 – The only thing warm was the shower

The following morning it was lashing it down with rain. The kind of big rain that plops in puddles and creates those mini craters in time-lapse film, with crown-like edges, that dissipate faster than the eye can see. Our swimming gear was still wet from the day before. The only way to stay warm enough was to perform ‘wet entries’, as they became known. We’d suit-up in warm showers before we hit the waves, cameras-in-hand.

It was low tide. On Heron Island the lagoon can almost dry up at the lowest ebb. We swam with our chests so close to the sand, we had to crane our necks up to look among cracks and crevices below little coral bomies. To our delight we found a sea hare. This relative of the snail looks like a cross between a slug and a week-old lettuce. Despite being the size of a small football, it was perfectly camouflaged among the clump of algae on which it was feasting.

Unbroken torrential rain for the next 24 hours dropped the air temperature to 18 degrees (felt like 10!). The inky skies did little to spotlight the vibrancy of the reef and our clothes, within hours, were damp. Without artificial heating or drying (for who needs it normally) we resigned ourselves to climbing into clammy, cold wetsuits every time.

A shark among the dark

Darkness and fresh water have a way of changing things. Indeed, on that first morning snorkel we came across one such animal. A Banded Bamboo Shark (adults lack the bands), more usually feeding at dusk and dawn, was making the most of the overcast conditions.

By now the rain was heavy again. Underwater it sounded like rice-crispy breakfast cereal crackling. It didn’t bother the shark. It was hunting using an electromagnetic sense; detecting the faint signals from the muscles of animals buried beneath the sand. Suddenly it writhed its body, thrust its head down, opened its gills and sent up clouds of sediment. We’d been gifted an intimate moment to observe an ancient creature hunting. I doubt this would have happened if the weather had been nicer.

Confiding cowtails

By the afternoon, we were back in among it. You don’t need more evidence of a place’s importance than the predators and we’d already seen our fair share. This snorkel was to be no exception. This time we ventured out to the old abandoned wreck placed here in the 1940s in order to keep the sea defences intact. The sea here was warmer than the fresh, rain-soaked surface water closer to the island.

Staring at a white-tipped reef shark among hoards of snapper, rabbitfish, cowtail rays and countless colourful reef fish, we knew we were in a functioning ecosystemHow ecosystems function An ecosystem is a community of lifeforms that interact in such an optimal way that how ecosystems function best, is when all components (including humans and other animals) can persist and live alongside each other for the longest time possible. Ecosystems are fuelled by the energy created by plants (primary producers) that convert the Sun's heat energy More. You don’t need to know what everything is to realise this significance. Drifting overhead, or among the melee of sea life, signifies something far greater than science can ever teach us.

There aren’t many places left on planet Earth where you can still feel this. Heron Island is one such place.

One of the cowtail rays was a particularly curious individual. A tiny cleaner-wrasse was desperately trying to deliver its service but the ray was far more interested in hanging out with us. This is the second time this year that I’ve come face to face with a ray who’s as interested in me as I am in them. And this is why.

DAY 3 – A stinger-eating turtle

Heron Island is an oval sand island covered in trees contained inside a coral lagoon. The egg-shaped lagoon extends many kilometres to the east so the reef-edge is closest on the north, west and southern sides of the island.

We took a boat trip at 9AM for a drift snorkel over spectacular coral reef to the island’s north. The southern Great Barrier Reef is adorned with healthy coral reef. The subtle blues, greens and vibrant hues, layered among stacks of plate corals, swirling with brightly coloured fish.

In the afternoon we ventured out in the channel again but this time we pushed on further towards the reef break. Whereupon we encountered a very obliging young turtle that was feeding on ‘red siphonophores‘. These are related to Portuguese man-o-war and are not jellyfish. They let out a trail of stinging tentacles … as I discovered that afternoon. The turtle didn’t seem to mind as it moved around hoovering them up.

That evening we ventured out after dark for a night snorkel but we didn’t last very long due to the cold. Some very fancy abalone were out en masse. But the highlight was a huge sleeping loggerhead turtle. We also briefly used the UV light and looked at the stunning glowing corals – it turns out that corals absorb the Sun’s UV and reemit it at night. This glow is too faint for us to see until we stimulate it using a torch. The results are quite amazing.

DAY 4 – That’s a moray

It is the water depth that dictates where and when you can swim on Heron Island and that is determined by tides. At low tide, there can be barely enough water to swim anywhere and currents can rage. However, in front of Baillie’s Bar, it is quite protected. Snorkelling in shallow water can be great fun as you find things that aren’t normally apparent. There are a lot of creatures hiding among the coral that you would otherwise swim past – like the sheep-like sea-slugs common on the rocks right next to the beach, or banded pipefish.

By the afternoon we felt we could make it along the channel and out to the wreck. Swimming in the channel is banned from 8am – 5pm because of research and dive boat traffic. Hence, we kept out to the sides.

Being high tide when currents were negligible, we were able to explore the edges of the wreck, before heading east along the reef edge. Here we found abundant parrotfish in huge schools. They would flow over the reef edge, as though on a mission. The wind changed direction and started to blow strongly from the northeast so we stopped our swim short and headed back into shelter behind the island. Heron Island is open ocean so you need to be very cautious about conditions. Wind can cause currents to change.

On the way back in we crossed the lagoon flats south of Shark Bay and stumbled across a laced moray, a type of eel. These stunning animals can grow to 2m! We also found the first of two epaulette sharks. These diminutive and colourful sharks hide among the coral. At low tide they literally crawl in the open air, digging around for food that’s trapped by the falling water.

Day 5 – sunlight, sea slugs and shovel-noses

We woke up for the first time with bright sunlight and warmth. It was a welcome sight after the torrential rain from the days before. So, we decided to take the walk through the forest to Shark Bay to see the sunrise before breakfast.

It only takes about 45 minutes to walk around Heron Island. The black noddies were waking up beginning to flock out to sea. As we approached the beach, we disturbed a rose-crowned fruit-dove. And there were black-faced cuckooshrikes and a spangled drongo flitting among the she-oaks on the beach. The birds were enjoying the sun as much as we were.

After breakfast we decided to return to the spot south of Shark Bay where we had swum the day before. It was low tide and we figured we could find some critters among the bommies. We ran out of water after about an hour and the wind had risen from the south making it a bit chilly. But not before we found a wonderful sea slug that looked like a scary clown, some colourful shrimps and a pair of sea hares. Shark Bay was out of the wind and we made use of the sunlight to warm up and dry our gear.

After a light snack we were back in near channel but this time we swam from Baillie’s Bar and headed out to the reef edge. A Blue-spotted ray was a highlight, as well as a big eagle ray that swam past us over the reef. A green turtle had made itself at home chomping on algae-covered coral, as several colourful wrasse hid beneath its head, darting out to feed on particles.

Shark Bay

The best of the day was yet to come though. Shark Bay thrilled us with a gathering of shovel-nosed rays, whiptail rays, cowtail rays and green turtles at high tide. The pictures speak for themselves.

Day 6 – The dark and deep

Over the last few days we’d managed to rack up over 5.5 hours swimming each day. And it just kept getting better! Today would be no exception. As I mentioned earlier, tides are everything. High tide was about 4AM but sunrise wasn’t until 6:45AM. We ventured out with lights while it was still dark and crept into the channel finding many of the fish still asleep including the big Queensland groupers.

Out at the wreck the sharks were still active. Black-tipped and White-tipped Sharks were feeding together. A ray that was shedding skin ducked into a crevice and when I went down to look, a loggerhead turtle sped out. I’m not sure who was more surprised. A prickly ray was a welcome sight near the jetty and the sunlight made the whole experience look incredible.

At 9AM we joined another snorkelling group, this time to nearby Wistari Reef. The reef here isn’t in as good condition but there were lots of different types of fish, including paranoid-looking yellow boxfish.

It was like commuter hour. Twice I bumped into turtles (literally) blocking my way forward. They didn’t care. There were a black-tipped reef shark, couple of dozen greens, one loggerhead (the same one from the night before), shovel-nosed ray, dozens of whiptail and cowtail rays, half a dozen spotted eagle-rays, a couple of hundred golden trevally, a few-dozen blue-spotted trevally and hundreds and hundreds of big colourful reef fish. We also found a crown-of-thorns starfish, the only one for the trip.

This would be our last swim. But enough of a reminder of how epic this place is. This trip – my sixth – has certainly cemented Heron Island in my mind as among the top snorkelling destinations on Earth. The channel itself (pictured below) would have to be one of the only places in the world where you can see such a stunning array of reef megafaunaThe largest animals that represent the top of the trophic pyramid. These are the final building blocks in ecosystem structures for maximum entropy production. Megafauna can be measured at any spatial scale. The largest animal that ever lived on Earth is the Blue Whale. In a grassland, spiders could be considered megafauna The term is generally reserved for animals larger More so close to shore.

Batfish and sleeping turtles

In the afternoon we decided to swim out to the reef edge ourselves, to the south of the channel, to the bommies marked by the dive buoys. Imagine our surprise then, when no more than a few metres offshore and in 1.5m of water, a giant trevally swims right past us! Further out, we were surrounded by dense schools of chloris and then we were delighted to find dozens of turtles, schools of batfish and beautiful landscapes on the reef edge.

And there was still time for another high tide swim in the channel after 5PM that evening, when we were joined by spotted eagle-rays, white-tipped reef sharks and the ubiquitous turtles. The most impressive thing was watching the big loggerhead cruising in to find its spot to sleep safely on the reef.

Day 7 – Commuter hour on the reef

It was our final day but the ferry didn’t leave until 12:30. We were up at dawn again, this time even earlier. As we entered the water it was apparent things were going to be great. There were sharks present, briefly, but the tide was an hour later … and what a difference that made.

It was like commuter hour. Twice I bumped into turtles (literally) blocking my way forward. They didn’t care. There were a black-tipped reef shark, couple of dozen greens, one loggerhead (the same one from the night before), shovel-nosed ray, dozens of whiptail and cowtail rays, half a dozen spotted eagle-rays, a couple of hundred golden trevally, a few-dozen blue-spotted trevally and hundreds and hundreds of big colourful reef fish. We also found a crown-of-thorns starfish, the only one for the trip.

This would be our last swim. But enough of a reminder of how epic this place is. This trip – my sixth – has certainly cemented Heron Island in my mind as among the top snorkelling destinations on Earth. The channel itself (pictured below) would have to be one of the only places in the world where you can see such a stunning array of reef megafauna so close to shore.

Advice on Heron Island snorkelling

I hope you enjoyed this trip report about snorkelling Heron Island. It’s certainly good to have some advice before visiting. If you’d like to know more, please consider booking a trip via me, by putting your contact details here: https://deluxelife.com.au/experience/nov-2021-heron-island-turtle-spectacular-6d-5n.

For more information, visit my Heron Island page.