A Plan to Bring Back Dublin’s Once-Plentiful Oyster Beds

Sitting by the Clontarf seafront, Cordula Scherer looks out onto Dublin Bay.

There’s no sign of it now, but at one point this stretch of shoreline hosted large oyster beds, says Scherer, a marine ecologist at the Trinity Centre for Environmental Humanities at Trinity College.

“All along here, they had artificial oyster beds in the 1700s,” she says. They were harvested at low tide, and sold on the city streets.

Oysters were hugely popular in Dublin, says Scherer, and were enjoyed by people of all classes.

But harsh winters, disease, and the gradual creation of North Bull Island, meant the oyster beds at Clontarf had almost disappeared by the beginning of the 20th century.

This area started to silt up, the sand came in, and then all the pollution stayed in the bay, Scherer says. “It destroyed the oysters.”

It wasn’t just Dublin Bay that lost its oysters. Another artificial bed further north along the coast in Sutton, and a natural oyster reef in Malahide, also suffered.

Chef Niall Sabongi – who works with Scherer on challenges around sustainable seafood – wants to bring these oysters back.

“I think it’d be fascinating to see if we could re-introduce the oyster to the east coast”, said Sabongi, who is also the founder of Sustainable Seafood Ireland, a seafood wholesale business.

“And what effect that would have on the green eco-culture,” he said.

Old but New

They wouldn’t be planting oysters in Clontarf like in times gone by – there are more suitable sites within the bay.

The disturbance caused by nearby Dublin Port wouldn’t be conducive, says Scherer, and the silting would fill up oysters’ gills too.

“They couldn’t filter and they couldn’t feed,” she says, gesturing to the water behind her.

So it would have to be a different spot. The project is in its infancy and so they haven’t settled on where yet, says Sabongi. “This is a long-term, kind of lifelong project.”

In Portrane in north Co. Dublin, coastal erosion is rife and an oyster bed could prove more effective than existing anti-erosion tactics, says Scherer.

“If we had oysters there, in theory, it would be a physical barrier, but it would be a soft barrier, not the hard structure they put in place,” she says.

With the natural defence of sand dunes ravaged over time, an oyster structure could instead absorb the impact of crashing waves.

If the project were to get off the ground, the benefits would be manifold, says Sabongi.

In New York City, the Billion Oyster project has placed approximately 47 million oysters in different spots in New York Harbour since launching in 2014.

The aim is to have one billion oysters in the water by 2035.

Sabongi travelled to New York in October 2018 to see the project. He hopes to model his initiative on that.

“It’s a restoration project to help clean the waters of New York,” Sabongi says. “It’s not done for commercial gain – as in for eating – it’s only done for marine purposes, for educational purposes.”

Oysters filter water, removing pollutants and storing them in their skin.

Scherer says that’s why they’re known as bioengineers and can dramatically improve water quality.

Says Sabongi, of the harbour water in New York: “They’ve seen massive, massive, massive, improvement.”

Oyster beds could have a huge impact on water quality in Dublin Bay, says Sabongi. One oyster can filter up to 240 litres of water a day.

Improved water quality isn’t the only incentive to restore oyster beds in the city.

Sabongi says he plans to introduce the gigas oyster to Dublin Bay, a species native to the pacific coast of Asia.

Oyster beds would bolster the biodiversity of the bay, says Scherer. “They would offer a shelter for young fish, juvenile fish, they would offer shelter for crabs.”

That’s not all. “They would have enough protection against wave surge for seagrass to come back,” she says.

And more seabirds would be attracted by the presence of juvenile fish. “They would help immensely with bringing diversity back and build a much better, more flourishing environment,” Scherer says.

Eventually, Sabongi wants to re-introduce native Irish oysters – the European flat oyster – to the Dublin coastline, too.

Finding the Means

The greatest challenge facing Sabongi, Scherer and others is funding.

Given the amount of money and time involved in a project of this nature, looking to the European Union is the most realistic avenue, says Scherer.

Scherer estimates that a five-year project would require a budget of €12 million.

But grant applications, even in themselves, are a lot of work and time. “They are humongous,” says Scherer.

“You need a really good network of scientists, of people like Niall, who also need to put time aside to do this,” she says.

Sabongi says he wants people to learn about the ecosystems around them and this project might help achieve that.

In New York, he was impressed by the emphasis placed on marine topics in the educational curriculum.

“I kind of questioned why don’t we have something like ‘islands studies’, or ‘beach studies’,” he says.

Despite Ireland’s storied relationship with the oyster, and more broadly with the sea itself, Sabongi says, most generations have missed out on any education to do with the island and the waters around.

“It might be a good opportunity to start a pilot project that would maybe encourage more people to be more interested in the ecosystem around us,” he says.