After a century of absence, oysters return to Belfast port

Long gone from the port of Belfast, where the Titanic was built, oysters are making a comeback with the installation of oyster reefs in this cove of Northern Ireland, in the hope of improving marine life and quality some water.

Until the early 20th century, the area was home to vast oyster reefs, but their populations were gradually decimated by overfishing, disease and pollution, says conservation organization Ulster Wildlife.

“We are bringing back a vanished habitat,” says its marine conservation manager, David Smyth, interviewed by AFP on a quay at the port, located near a noisy highway and imposing commercial buildings in downtown Belfast.

Humans have been harvesting these molluscs since the Stone Age in European seas, where vast beds of oysters are naturally present. But according to Ulster Wildlife, their populations have been reduced by 95% since the 19th century, making these reefs one of the most threatened habitats in Europe.

– “Coral reef” –

Last month, some 700 molluscs – brought from Scotland by truck, measured and then tested to prevent the introduction of diseases – were immersed in Belfast Inlet, in a dozen cages equipped with shelves.

Their introduction should help create a sort of “coral story,” says David Smyth, who monitors the health of these oysters with a team of researchers affiliated with this breeding park project.

David Smyth, head of marine conservation at Ulster Wildlife, measures the size of an oyster in Belfast Harbour, November 28, 2023 (AFP/Archives/PAUL FAITH)

After removing the cages from the water, the scientists work to carefully remove each shell, and place them on the pier to measure and weigh them.

The first step in forming a reef is the joining of two oysters into pairs, Mr Smyth explains.

“Imagine 100,000 of them stuck together, that’s what we want to achieve. Thanks to them, millions of larvae will settle around the shore and on the seabed,” he rejoices.

The reintroduction of these molluscs and the restoration of their habitat should help promote marine biodiversity and improve water quality, believes Ulster Wildlife.

“Once these animals begin to form their beds, small fish and crustaceans such as mussels, barnacles, worms, snails and algae will come to live and feed there,” explains David Smyth.

Each oyster also has the power to filter some 200 liters of seawater every day, allowing more light to pass through and more aquatic plants to grow.

– Encouraging signs –

The passage of cargo ships and ferries, which generate pollution in the waterways of the cove, can however pose difficulties in recreating this habitat.

Rachel Millar, from Ulster Wildlife, holds an oyster cage on November 28, 2023, in Belfast Harbour, where these molluscs are being reintroduced (AFP/Archives/PAUL FAITH)

For much of the 19th and 20th centuries, shipbuilding was one of Belfast’s flagship industries, and the yellow gantries of the shipyard that built the Titanic remain an emblem of this Northern Ireland landscape.

Coal storage and the activity of tanners have also degraded the port environment for many decades.

“It is very difficult for oyster larvae to establish and grow if they are exposed to pollutants in industrial shipping lanes,” acknowledges David Smyth.

But the project’s molluscs have performed “impressively” so far, with only two perishing out of 700 installed in Belfast.

Other reintroduction projects are to be launched in the coming years, he adds.

Several European countries are leading similar efforts, encouraged by the success of a program launched in New York around ten years ago.

“New York is the perfect example to show that these animals can thrive in an industrial zone,” explains Mr. Smyth, who hopes that in Belfast, as in the United States, improving marine biodiversity could bring back dolphins. “We never know!”

© 2023 AFP

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