Steve Braunias goes to sea in search of a treasure island

Pollen Island is as urban as the Sky Tower but all you can see of it from the motorway is a flat expanse of mangroves and sedge grass. Photo / Supplied

Pollen Island! The name immediately evokes adventure and mystery, something on the edge of civilisation or even way beyond it – all islands are the stuff of romance. They interrupt the sea. They rise out of the ocean, unto themselves, their own republic, measured by tides and shores. There are islands guarded by reefs and lapped by lagoons; there are islands so small and remote that they remain nameless.

Pollen Island is as urban as the Sky Tower. It's right beside the North-West motorway on State Highway 16 in West Auckland. More than 100,000 motorists drive past it day and night as they cross a six-lane causeway on a lapping edge of the Waitematā Harbour between Pt Chevalier and Te Atatū. The causeway is low-slung, a kind of 4.8km-long plank laid out on the mudflats; it was raised 1.5m a few years ago to prevent flooding. Its highest point is when it arches up as a bridge, over the river Whau.

Pollen Island is around the corner from my house and I've been dying to go there ever since I moved to Te Atatū but the problem was not knowing exactly where the hell it is. It's marked on maps but maps don't make a lot of sense in the actuality of broad daylight; all you can see from either side of the motorway is a flat expanse of mangroves and sedge grass but no obvious sign of its shores. My good friend Sir Bob Harvey is on intimate terms with every inch of West Auckland. He drove me over the causeway one day and I said, "Where exactly is the island?" he said, "There." He waved a hand. "Where's 'there'?'", I said. "There," he repeated, and once more waved his knightly paw. I said, "Do you mean that flat expanse of mangroves and sedge grass?" He drove in silence for a while, and then he said, "Well, sort of."

Pollen Island belongs to the Motu Manawa Pollen Island Marine Reserve and as such is officially managed by the Department of Conservation and voluntarily, enduringly, superbly managed by the Motu Manawa Pollen Island Marine Reserve Restoration Group. The volunteers make an annual pilgrimage to the island and pick it clean of trash. This is exactly the kind of activity I live for and practise constantly on the streets and creeks of Te Atatū. I got on to the group's mailing list four years ago and have begged to go with them but numbers were limited – the island is a delicate ecosystem, you don't want a

horde of do-gooders tromping over the glasswort - and I was refused entry. Persistence pays off though and I got the good word to go out on Saturday, March 13.

"Pollen Island," said Team Leader Michael, "is pretty brutal. It gets Darwinian out there." A fit and shining-eyed band of 18 volunteers met on a street in Te Atatū South. Team Leader Kent said this was the 12th year of the clean-up. "We don't do it for money," he said. "We don't do it for fame." It was a beautiful morning and we set off along the side of the motorway, then ducked beneath the Whau River bridge and went along a flat expanse of mangroves and sedge grass. I said, "Is this it?" No, said Team Leader Kent. Team Leader Michael gave a very interesting talk on the island's geological history. When we set foot on the island, he said, we would be walking over bedrock that was 10 million years old. We had to be careful and stay together. Team Leader Kent had a first-aid kit and the group included a man from the Department of Conversation who was armed with an air horn.

Pollen Island! There it was, glittering and treacherous, on the other side of a wide channel of water, passable only at one specific point at low tide – careful investigation had revealed underwater bedrock, allowing people to step on to it and then clamber up on to the thick, sucking mudbanks of that fabled island. "I have an announcement," said Team Leader Kent. We gathered around. "I got the tides wrong. It's actually coming in." There was a shocked silence and then Team Leader Michael said, "That's a fundamental mistake." Team Leader Kent said, "I don't know how I got it wrong! I'm sorry, but we can't go out." Team Leader Michael stared into the distance. "Fundamental," he repeated. We turned back. The island felt further away than ever.