Trip report: Heron Island, Australia
Within the vast entity that is the Great Barrier Reef, Marie Barbieri finds a coral cay that proudly parades Australia’s most diverse ecosystem, home to a galaxy of quirky winged and finned inhabitants, both above and below the shoreline.
It’s like a re-enactment of the 1942 aerial bombardment of Darwin. Caught in the latest flyby, we advance, fearful of looking up for more than a millisecond, risking a shot to the eye. We emerge, relatively unscathed, as frenzies of breeding black noddy terns swoop, soar, and crash-land on the canopy above us as we hopscotch around their mosaics of droppings that paint the pathway like dried snowflakes.
Well I shouldn’t run into any bad luck today, as I walk, freshly painted in Pollock-like excrement. Indeed, Malaysian and Chinese miners thought they struck lucky in 1890 when prospecting Heron Island for guano: centuries-old seabird droppings that sold as fertiliser. Fortunately, the island was saved from excavation, and is today a protected seabird rookery—with a tart smell to testify!
I’m treasuring how wildlife dominates on this coral cay, part of the Capricorn Group of islands that straddles the eponymous Tropic. Within 24 square kilometres of shimmering reef, Heron Island basks 72 kilometres northeast of the seaport of Gladstone, where I caught the launch to arrive at a peacock-green lagoon.
Ambling on island time with Hannah, our naturalist guide, on a steamy January morning, we needle through the world’s largest pisonia forest in the heart of the Capricornia Cays National Park. Pisonia trees, with their giant, bright green leaves, suck up the island’s abundant freshwater, and are sheltered from winds by salt-tolerant octopus bush, casuarina trees and pandanus palms. The latter’s aboveground wigwam-like prop roots are as tall as us. And they somewhat propped up humans, as these palms supported life on tropical islands. Their stilted roots provide water; their fruits are protein-rich; and their leaves contain a woven fabric-like mesh ideal for basket and hat weaving. What more could one want?
The black noddy nests that dribble from the trees like shambolic chandeliers today intone a choir of squeaking week-old chicks. “We’ve got around 70,000 black noddies here at the moment,” says Hannah, “though numbers can balloon to 100,000!”
As we walk through what feels like a feather-fuelled cyclone whooshing around us, we observe males frantically plucking leaves from the swirling ground, before flying up with precision to nest-building females. If the leaf passes the quality test for the treehouse cot, the female accepts the male as her monogamous partner.
Around 30,000 wedge-tailed shearwaters (aka mutton birds) also breed on Heron Island annually. They mate at night, which they do for life, and return to the same underground burrows that they build, shelter and nest in, sometimes up to three metres long, incubating one egg for seven weeks. Tagged shearwaters have been known to voyage over 2,000 kilometres per trip to forage.
“At around 8pm,” says Hannah, “they return from a day fishing at sea, and their eerie courting call sounds scarily like wailing babies… some say dying cats!” However you interpret their hypnotic yowls, the drone only reconfirms immersion into this raw island wilderness.
We also spot some scavenging buff-banded rails, greater crested terns and ruddy terns that visit from as far as Siberia and Alaska. Some long-beaked bar-tailed godwits have also been tagged, and one was tracked from Alaska to New Zealand, covering 11,600 kilometres in just 12 days!
Shark Bay’s reef flats glisten beyond sands pocked with frenetic ghost crab activity, where eastern reef egrets (or herons, after which the island was named) dine on molluscs and crustaceans on the low-tide menu. It’s not paradise for all….
I join marine biologist, Nick, where the beach is connected to the reef by just footprints in the sand. He immediately articulates the reef-walking safety rules, and spits it right out:
“If they feel threatened, cone-shells defend themselves by extending a paralysing neurotoxin-filled harpoon into fish…” he says, nonchalantly, “and humans if they are not careful!” The full moon means we’re knee-deep in water today, so armed with my SeaScope, I take aim, and prudently inspect my course.
I begin ticking off my ‘been there, SeaScoped that’ list through a rainbow of critters, of which Nick carefully selects a variety. First I shake limbs with a constellation of tuberculate sea stars, then inspect a pickle of sea cucumbers; from the burnt sausage to the spiky greenfish and the large variegated type. Tantrum-throwing sea cucumbers can spit out their internal organs as ensnaring sticky white webs when threatened. Remarkably, they can regenerate these organs post attack. Handy that!
A headshield slug captivates me, resembling a slice of wavy black jelly, set within a luminous violet rim. This otherworldly creature is an opistobranch; a type of mollusc with gills located behind its heart.
RAINFORESTS OF THE OCEAN
The biodiversity of Heron Island’s bountiful ecosystem depicts a living and breathing art gallery. The world’s most revered oceanographer and diving legend, Jacques Cousteau, referred to Heron Bommie as one of his ten favourite dive sites in the world. And with the reef being shallow, sheltered and boasting unrivalled visibility, the snorkelling is just exceptional.
Finning above abundant staghorn coral, I check out if any manta rays have checked in. They use the bommie as a cleaning station, courtesy of the local goby fish. A pair of white-spotted eagle rays, with stealth-jet fins, makes up for the no-show. They gradually slip from radar, cognisant of a territorial blacktip reef shark, which sinuously swaggers by in a slow-motion salsa swing. Thankfully, reef sharks are harmless to humans unless provoked.
Near some menacing-looking moray eels, it’s marine-traffic congestion central, and I squeal through my snorkel upon spotting a paddle-tailed sea snake. Like their mainland-based brothers, sea snakes are highly venomous, but their mouths are not large enough to bite a limb. I tuck my fingers in nonetheless.
Drift snorkelling to Pam’s Point, our marine guide points out emperor angelfish and a beautifully pinstriped sweetlips fish. Schools of barracuda loiter nearby, but I find solace alongside a graceful green turtle dining on algae, and watch a luminous blue and green parrotfish chiselling coral with its powerful jaws containing a gob-full of fused teeth.
Back on silica firma, I clock three eagle rays somersaulting above the horizon. Hungry for what lies beneath, I glide into the jetty area’s bathwater where, for two minutes, the world darkens into a flickering kaleidoscope. I needle through a battalion of baitfish, by the thousand, attempting to avoid predation. Tracking a fin, I play catch-up with a lemon shark, until the sun filters through, with a school of bigeye trevally being the next act. On the main stage, three giant shovelnose rays tile the sandy floor, as if self-consciously aligned for a photojournalist. They stir only when a two-metre long Queensland Grouper (affectionately named Gus by the islanders) arrives to show that this is his yard!
NAVIGATORS OF THE SEA
Between sunset and midnight, from November to March, endangered loggerhead and green turtles nest on Heron Island. That they nest in the near-exact spot where they were born decades before remains an unexplained, wondrous phenomenon. Their hatchlings begin life by sprouting from the sand after seven weeks. Sitting beneath the spotlight stars that beam down onto North Beach, I hope hard that I might witness either spectacle.
It’s a harsh world, as even without human interference, only one in a thousand hatchlings survive to adulthood, to then live up to 100 years. Green turtles breed only from the age of 30 and only every three to eight years. Heron Island’s nesting turtles have feeding grounds as far off as Fiji, approximately 3,000 kilometres away.
After a few hours of inactivity, I head back, lugging my heavy heart. Then, not long before sunrise, up from the shoreline pops a large turtle’s head. It’s too dark to identify what type, but I’m struck by the life-force of nature. She scans the beach. I crouch down. Her coast is clear. She arduously crawls up past the high-tide mark to protective casuarina trees. Back flippers begin a feverish, powerful excavation, as she painstakingly digs the pit for the egg chamber. I pain observing her exhaustion. It’s a long night, and you could hear a grain of sand move. I don’t dare approach as she deposits what could be up to 130 eggs, before covering her offspring with sand.
As daylight tiptoes in, I see that she is a rare loggerhead turtle. For every 50 green turtles that might nest on this island per night, there’ll be one loggerhead. It’s a huffing and puffing return to the water. And as she vanishes into the ocean, I’m a changed person.