Aggregate resources and marine environment
Tarmac Marine supplies around 3.5 million tonnes per year of sand and gravel from some 18 licensed dredging areas.
Dredging areas are held under commercial and legal Production Agreements issued by the Crown Estate, the mineral owner. Consent to dredge (a Marine Licence) must be obtained from either the Marine Management Organisation (MMO) in English waters or Natural Resources Wales (part of Welsh Government) in Welsh waters. These consents are issued only after a rigorous environmental assessment and consultation process has been followed to demonstrate that the dredging activity will not result in unacceptable environmental impacts.
Environmental assessments consider all the potential effects on the environment of offshore dredging, including effects on the coastline, marine life, fisheries and archaeology. A successful protocol between the Industry and Historic England for reporting and investigating archaeological finds on the ships and at the wharves is in place. Finds include prehistoric remains such as mammoth bones, teeth and tusks from the ice ages, cannon balls and aircraft wreckage from WWII.
Dredging is undertaken to a high degree of accuracy with reference to high resolution shallow seismic profile data and seabed core samples. This data also allows the Company’s marine mineral reserves to be accurately assessed. When loading a cargo, the dredger’s position and tracks are displayed on the bridge in real time together with geological and licence boundaries to ensure that only the best quality resources are extracted. The vessel’s activity is also constantly recorded by a Crown Estate electronic monitoring system linked to the navigation receiver and the dredge gear sensors. This records when and where the ship is dredging to ensure compliance with licence conditions.
The accompanying leaflets provide further details of the dredging licence areas and some of the interesting marine issues faced in each of the regions where Tarmac Marine operates.