Lough Neagh: Scars from dredging will take ‘decades if not centuries’ to recover

For years sand has been extracted from the lake bed and research shows the damage

New research has exposed severe scarring caused by the dredging of sand from the bed of Lough Neagh, with a leading fishermen’s body warning it could take “decades if not centuries” for the bed to recover.

The lough, the largest freshwater lake in Ireland and Britain, is an internationally significant habitat, supporting rare plants, thousands of birds and freshwater pollan – one of the most important fish species in Ireland.

For many decades, sand has been dredged from the bed of the lough.

However, environmentalists and fishermen have claimed that not enough research has been carried out into the impacts of dredging.

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New research by sand-mining expert Dr Chris Hackney has now revealed that dredging over many decades has caused deep scarring on the bed of the lough.

Dr Hackney, an academic at Newcastle University, carried out a survey of the depth of the bed in August to measure the impact of industrial sand extraction.

The survey looked at an area of half a square kilometre where bout two million tonnes of sand have been dredged over recent years.

His work found that sand dredging alone has created scars of up to 56 feet deep (17m) in places.

Dredging has also caused several deep “pockmarks” of up to 19.6ft (6m) deep.

Sediments removed

“The lough bed used to be around 4-5m deep in that part of the lough,” Dr Hackney told investigative website The Detail. “However, years of extraction has removed sediments from the bed such that depths are now, in places, 21m deep.

“That’s a 16-17m lowering of the lough bed as a result of extraction.”

Dr Hackney compared the current status of the lough with data from charts created more than 170 years ago, before any sand was dredged. “From admiralty charts and depths – collected back in 1851 – the lough bed showed a smooth, slowly sloping bed,” he said.

“However, our new survey demonstrates the lough bed is now highly uneven, with clear pockmarks and scars evident resulting from the suction-dredging. At the time of the survey, dredging vessels were not active in this area, so this uneven topography is a result of long-term dredging, suggesting that the uneven topography persists through time and does not even out back to a smooth surface. These individual pockmarks can be anywhere from 10-18m in diameter and up to 6m deep in places.

“By comparing the original lake surface to this survey it appears that this 0.5sq km area has lost around 1.29 million cubic metres (around two million tonnes of sand).”

Sand extraction at Lough Neagh was unregulated until 2021 when a handful of firms were licensed by the Northern Ireland Department for Infrastructure to dredge up to a total of 1.5 million tonnes annually.

Pat Close, chief executive of the Lough Neagh Fishermen’s Co-operative Society, said he believed the lough bed could take “decades if not centuries” to recover.

Mr Close said the areas of the lough where there had been the highest concentration of dredging over recent years were effectively “dead zones” for fish.

“To be cynical about it you could say that extracting sand from Lough Neagh is less controversial than opening an open-cast quarry in the Sperrins or somewhere else,” he said.

Mr Close said fishermen need a “worthwhile database” to look at the overall impact of sand dredging on the lough.

Fish populations

“We’ve suffered in the past from a lack of investment in research to have a good understanding of fish populations and how they are changing and so on,” he said.

Mr Close said the fishermen were working with the Department of Agriculture, the Environment and Rural Affairs and the Northern Ireland Agri-Food and Biosciences Institute to try to gather data.

The department did not respond to a request for comment.

Although the lough’s water is publicly owned, the bed and banks are owned by the Earl of Shaftesbury, an English aristocrat based in Dorset.

Sand traders pay the Shaftesbury Estate a levy for every tonne of sand they extract.

The estate was contacted about the new research but did not respond.

A spokesman for the Department for Infrastructure said the decision by then minister for infrastructure Nichola Mallon to allow continued sand extraction was taken following an extensive public process, including an independent planning appeal inquiry in 2018/2019.

“The decision that was made by the minister followed the recommendation by the Independent Planning Appeals Commission,” he said.

He said the department continued to monitor and regulate how much sand was extracted from the lough.

Companies that form part of the Lough Neagh Sand Traders’ Collective were contacted for comment.

Two of the five firms - Northstone Ltd and P&J Walls - declined to comment.

The other firms did not respond.