Marine aggregates play an important part in the provision of high quality raw materials for both the UK construction industry and for coastal protection. Sand and gravel are generally taken from the seabed by trailer suction hopper dredgers that are capable of transporting cargoes of up to 9,000 tonnes from offshore dredge sites direct to the wharves located close to the point of end use. The dredge areas are licensed from The Crown Estate following an extensive Environmental Impact Assessment (EIA) and stakeholder consultation process formerly regulated through Communities & Local Government (CLG) and Defra and now through the Marine and Fisheries Agency (MFA), an executive agency of Defra.
Delivery of sands and gravels into coastal towns and cities direct from the dredge site by ship reduces the need for road transport and thus confers some environmental advantages as far as transport is concerned, compared with aggregates derived from land quarries. Nevertheless there has been an increasing awareness that removal of dredged material from the relatively small areas of the seabed around the coasts of England that are under licence for aggregate extraction may have potential impacts on the biodiversity of marine communities of conservation significance, and on fisheries resources of economic importance. With the development of increasingly sophisticated methods of mapping and evaluating the seabed, it is also becoming clear that the shallow waters surrounding our coastline contain archaeological and historic resources of considerable importance that warrant protection.
Our understanding of the nature and distribution of these resources, and on improved methods of minimising impacts from aggregate dredging has in the past been limited mainly by both the level of funding available to support appropriate research, and by technical difficulties of research in the marine environment. Studies on the impacts of aggregate dredging has in the past mainly been supported through Defra Research & Development funds and on a voluntary basis by the aggregates industry both through the British Marine Aggregate Producers Association (BMAPA), by The Crown Estate and by individual operating companies. In 2002 the Government provided an additional source of funding by the imposition of a levy on primary aggregates from both land-won and marine sources. This Aggregate Levy Sustainability Fund (ALSF) has four main objectives:
- Minimising demand for primary aggregates
- Promoting environmentally friendly extraction & transport
- Addressing the environmental impacts of past aggregates extraction
- Compensating local communities for the impacts of aggregates extraction
In all, approximately £30m per year is potentially available through the ALSF in England, of which about 10% of the net amount released from the Treasury to Defra has been allocated to projects relating to the marine environment – reflecting the proportion of the English aggregate requirements derived from marine sources. The remaining 90% of the fund is allocated to terrestrial-based projects.