One of the most significant developments over the last two decades for the management of marine aggregate extraction operations has been The Crown Estate requirement that all vessels dredging on production licences be fitted with an electronic monitoring system (EMS). The EMS automatically records the date, time and position of all dredging activity, and this data is automatically sent to both The Crown Estate and the industry regulator on a monthly basis. The data is carefully analysed to ensure that all operations are taking place in accordance with the Marine Licences they are operating under. Analysis undertaken by The Crown Estate showed that a total of 18,344 hours of dredging activity were recorded by EMS systems during 2011, equivalent to approximately 55,000km of dredge track.
BMAPA and The Crown Estate are committed to transparency in reporting the area licensed for dredging at any time. In March 1999 both parties issued a joint statement of intent which committed to reviewing all production licence areas over a rolling five year period, surrendering areas no longer containing useful resources of sand and gravel. This included a commitment to publish an annual report detailing the extent of dredging within regional licensed areas using analysis of EMS data.
Every year since 1998, BMAPA and The Crown Estate have jointly produced an annual report known as the Area Involved, which detailed changes in the area of seabed licensed and dredged at both national and regional scales. In 2005, we published a five-year review report which summarised the period 1998-2002 and this has been followed by two further reviews in 2009 and 2014, the most recent of which summarised the period 1998-2012.
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to be worked
Area involved fifteen-year review (1998-2012)
In September 2014, BMAPA and The Crown Estate published a fifteen-year review of the area involved initiative.
The review reports on trends across three key areas:
- Between 1998 and 2012 the area of seabed licensed decreased by 748km2.
- 1,237km2 of licensed area was surrendered.
- 489km2 of new area was licensed.
- The area licensed within 12 nautical miles of the coast decreased, while the area of seabed licensed beyond 12 nautical miles increased slightly.
- Between 1998 and 2012 the area of seabed dredged annually decreased by 126km2.
- The area of seabed dredged per year ranged from 222km2 in 1998 to 97km2 in 2012.
- The cumulative area of seabed dredged between 1998 and 2012 totalled 512km2.
- The area of new seabed dredged each year significantly decreased to only 6.1km2 in 2012. In 2004 this figure was 16.3km2 and in 2008 it was 14.5km2.
- A total of 314 million tonnes of marine sand and gravel was dredged from Crown Estate licence areas between 1998 and 2012. Averaged across the cumulative footprint, this represents 37cm of sediment being removed across the entire area dredged – equivalent to a single pass of a drag head.
- In reality, the extraction activity will not be spread evenly across the dredged area, and some areas will be dredged more intensively while others may not be dredged at all. Consequently, the actual thickness of sediment removed per unit area will vary according to the intensity of dredging operations and the depth limits of the sand and gravel deposits being targeted. Nevertheless the relationship between dredged area and extraction tonnage provides an indicator of the relative scale of dredging intensity.
Area involved 19th annual report (2016)
Summary information from the 19th annual report, published in November 2017, is as follows. This relates to the 2016 calendar year (2015 equivalents in brackets).
- A total of 17.94 million tonnes of sand and gravel were dredged from Crown Estate licences in England and Wales during 2016 (18.82 million tonnes in 2015)
- The total area of seabed licensed in 2016 was 934km2 (932km2 in 2015)
- Dredging took place within 87.53km2, 9.37 per cent of the licensed area, compared with 82.67km2 (8.87 per cent) in 2015
- The area of seabed dredged for more than 1 hour 15 minutes per year (high intensity – red on charts) was 7.52km2 (7.37km2 in 2015)
90 per cent of dredging from Crown Estate licences took place from an area of 33.92km2 (31.58km2 in 2015).