'Explosive' plastic casings found on Hawke's Bay beach

Colin Lindsay of Beach Gannet Adventures has been left scratching his head after finding mysterious bits of orange plastic washed up along Haumoana and Cape Kidnappers. Photo / Warren Buckland

Running daily tours along the coast, Colin Lindsay of Beach Gannet Adventures is no stranger to finding washed-up plastic - but the words "danger" and "explosive" certainly stand out.

In the past week he's found several pieces of shredded, cylindrical pieces of orange plastic along the shore between Haumoana and Cape Kidnappers.

Lindsay said he often picked up plastic from the beach while operating the iconic red tractors which take tourists along the Cape Kidnappers coastline.

From plastic fish bins, rope, floating polystyrene, shoes, plastic bottles and cans, most of the rubbish seems to have a logical explanation.

"Everything else is sort of accountable," he said.

Plastic bottles, polystyrene, fishing items and other waste regularly wash up along the beach, particularly after periods of high river flow. Photo / Warren Buckland

About a week ago he started finding bits of orange plastic along the beach.

It wasn't until Wednesday that he found the next "piece of the puzzle" - a long piece with the words 'DANGER' and 'EXPLOSIVE' printed on the side.

"I thought, that's interesting."

It also contained what appeared to be the word 'anzite', a type of nitro-base explosive compound.

Lindsay wondered if it related to some kind of undersea explosions being carried out or if it was shredded plastic meant for recycling that had somehow made its way into the sea.

"It's a mystery to me," he said.

It's one of the more interesting pieces he's found, including an electric Kontiki fishing line.

He said a lot of the rubbish seemed to be related to river dumpings.

"If we see a flood, we get a lot more rubbish.

"It blows away on a windy day, down the drain into the water system and into the sea."

The words 'DANGER' and 'EXPLOSIVE' printed on the side of the plastic piece were certainly interesting Colin Lindsay said. Photo / Warren Buckland

"This year I picked up a plastic rubbish bag that was tied up and filled with household rubbish."

He said the country had only taken "small steps" to reduce plastic waste, citing the Government's ban on single use plastic bags in July 2019.

"I just ask who invented plastic," he said, with a shake of his head.

Lindsay said he'd like to have an artist turn the trailer-load of plastic he collects into a sculpture of some kind.

There was always something to pick up, he said.

"We are on the beach daily so we try to maintain it.

"If we see something, we pick it up."

The Hawke's Bay Regional Council's pollution response team has been notified of the plastic and was investigating.