Effects of sand dredging on Lough Neagh 'clearly visible from space' says new study which claims it's having an ecological impact

The new study, published in the Journal of Environmental Management, was led by Queen’s University Belfast in collaboration with Newcastle University.

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It is branded the ‘first-of-its-kind’ and implies that sand dredging may have broader and more persistent impacts on the lake than previously understood.

Lough Neagh supplies more than 40% of NI’s drinking water, supports fisheries with its habitats and wildlife that is internationally, nationally and locally designated.

However toxic algal blooms have blighted the lough in recent years. That, plus the loss of biodiversity, has become a symbol of environmental decline and a cause of immense public concern.

Dr Neil Reid, Reader in Conservation Biology at the Co-Centre for Climate + Biodiversity + Water in the School of Biological Sciences at Queen’s, and lead author of the study, said the work represents a step change in understanding.

“This is the first attempt to quantify the range of potential impacts from sand extraction throughout Lough Neagh and to infer potential ecological consequences. Our findings suggest disturbance is not localised, but widespread across much of the lake ecosystem.”

Sand is a vital resource that underpins modern infrastructure, used in concrete, construction, and land reclamation.

Using high-resolution sonar mapping, the researchers examined the lakebed in part of the dredging zone with results revealing extensive physical alteration. Dredging had carved deep depressions into the sediment, lowering the lakebed by up to 17 metres.

"Satellite imagery analysis revealed widespread sedimentation clearly visible from space, with plumes of silt spilling from dredging vessels, kicked up by vessel propulsion during transit, as well as runoff from landing sites. Sedimentation is a well-established cause of damage to aquatic ecosystems and a key factor in the decline of freshwater wildlife.”

Dr Reid added: “The situation at Lough Neagh reflects a wider global challenge. Demand for sand is increasing rapidly with extraction pressures growing in many aquatic environments, so understanding the full extent of the impacts is essential. This study suggests that the effects of sand dredging extend far beyond the point of extraction, influencing the entire ecosystem likely negatively effecting water quality, habitats, and biodiversity.

“For Lough Neagh, the message is clear. If the lake is to recover, management cannot focus on nutrients alone while ignoring physical disturbance. That places a responsibility on government to ensure that regulation, monitoring, and enforcement reflect the true scale of sand extraction impacts.

"There are practical ways to reduce the environmental footprint of dredging. Adjusting suction settings could reduce sediment disturbance while limiting hopper overflow could reduce sediment discharge. Slower vessel speeds and fixed shipping lanes could confine disturbance. In shallow water, avoiding high-thrust manoeuvres or protecting the lakebed could reduce resuspension."

In a statement to the BBC Lough Neagh Sand Traders (LNST) described the latest research as ‘incorrect’ saying it wasn’t the first assessment of the effects of sand extraction in Lough Neagh.

A spokesperson said the effects were the subject of an environmental impact assessment as part of the planning application, which "concluded there would be no adverse effect on the integrity of the Lough".

They said they would continue to operate under its current planning permission and engage with the regulator.