Physical loss pressure layer combines all human activities that cause physical loss of seabed. The pressure is given as area lost in each cell (km2).

For the polygon datasets the area was assumed to be the lost area. For line and point datasets spatial extents were calculated with buffers (below in brackets). If no buffer extent is indicated, the data was reported as polygon.

The human activities used for the physical loss pressure:

Land claim - Area of polygon or 50 m buffer for points, 30m buffer for lines.

Area of polygon - buffered line or point data, equals lost area.

Watercourse modification - 50 m buffer. Area of polygon, buffered line or point data, equals lost area.

Coastal defence and flood protection - 50 m buffer for lines, area of polygon. Area of polygon, buffered line or point data, equals lost area.

Extraction of sand and gravel - Area of polygon. Area of polygon equals lost area.

Dredging (capital) - Area of polygon or a 25/50 m buffer for <5000 m3 / >5000m3 sites. Area of polygon, buffered line or point data, equals lost area.

Oil platforms - 25 m buffer. Buffered point data, equals lost area.

Pipelines - 15 m buffer around cables with operational status. Area of polygon, buffered line or point data, equals lost area.

Wind farms - 30 m buffer around each turbine with operational status. Buffered point data, equals lost area.

Cables - 1.5 m buffer around cables with operational status. Buffered line data, equals lost area.

Harbours - Polygon with 200 m buffer. Area of polygon, buffered line or point data, equals lost area.

Marinas and leisure harbour - Point with 200 m buffer. Buffered point data, equals lost area.

Bridges - 2 m buffer. Buffered line data, equals lost area.

Finfish mariculture - 150 m buffer. Buffered point data, equals lost area.

Shellfish mariculture - Area of polygon, 150 m buffer for points. Buffered point data, equals lost area.

Activities are combined and potentially overlapping areas are removed. Dataset is clipped with coastline. Combined layer is intersected with 1 km grid to calculate % of area lost within a cell.