3 Aggregates and Dredging
3.1 Spatial Extent and Intensity of Activity and Interests
3.1.1 Marine aggregates are sand, gravel or crushed rock used in construction, principally as a component of concrete or for land reclamation projects. Most aggregates come from land-based sources, although developers have been increasingly reliant on marine sources to supplement demand and meet national construction needs. Aggregate extraction has taken place at two sites in Scottish waters to date: the Firth of Forth and the Firth of Tay. However, there is currently no marine aggregates extraction taking place or planned in the PFOW area. Figure A1 in the Appendix shows the location of marine aggregates in the PFOW area which could potentially be extracted in the future.
3.1.2 Dredging is an activity that involves the extraction of sediments from the seabed and disposing of them at a different location to maintain safe port operations and keep waterways navigable. The activity of dredging may require a licence from Marine Scotland, which normally defines the geographical extent of the area permitted to be dredged, along with the term, the maximum tonnage to be dredged during that term and the maximum tonnage to be dredged in a single year. Consents are typically accompanied by conditions which define the management, mitigation and monitoring controls. Extracted materials are usually deposited at recognised disposal sites, an activity for which a marine licence from Marine Scotland is needed and would be combined with any licence to dredge. Dredging takes place in the PFOW area waters to maintain safe port operations and keep waterways navigable.
3.2 Economic value and employment
3.2.1 As there is no marine aggregates extraction taking place in Scottish waters at the moment there is no economic value associated with it.
3.2.2 Table 7 shows the historic records of material from dredging activity disposed at each disposal site within the PFOW area, provided by Marine Scotland Licensing Operations Team. National Marine Plan interactive data are available but given the size of each site and the spatial resolution this has not been included in this plan. The status of Open refers to sites in use; disused to sites not in use for at least five years; and closed to sites not in use for at least ten years or specifically closed e.g. a sewage sludge site which is no longer permitted for sea disposal.
Table 7 Dredging level within the PFOW area (2001-2013) 
|Disposal Site Name||Area KM²||Status||Quantity Tonnes Disposed|
|SCRABSTER EXTENSION||0.068||OPEN (used in error)||422408|
|Total KM²||3.858||Total Tonnes||41925||422408||8246||48276||55679||66|
3.2.3 It is not possible to calculate the GVA associated with dredge spoil disposal. However, it is clear that without dredging, including disposal at sea, access to ports and harbours would either be limited or face costly alternative means of disposal, which could affect the maritime transport sector's contribution to the economy. Beneficial use of dredged material in construction or beach replenishment can save costs associated with such projects, supporting coastal protection and recreation. There are no available data of employment directly linked to this activity.
3.3 Historic and future trends
3.3.1 There will be requirements for appropriate dredging activities at ports and harbours in the plan area on an on-going basis. The expansion of ports within the PFOW area is covered in more detail in the Ports and Harbours section.
3.4 Data Gaps and Limitations
3.4.1 Marine Scotland has accurate data covering location, area covered and volumes of disposed material. However, from these available data it is not possible to place a value on the contribution the sector makes to the wider economy. It is also not clear how significant this sector is in facilitating the operational feasibility of other sectors ( e.g. ports and harbours).
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