OR/14/063 Site assessment - ELC 30: Aberlady Bay

Whitbread, K, Ellen, R, Callaghan, E, Gordon, J E, and Arkley, S. 2014. East Lothian geodiversity audit. British Geological Survey Internal Report, OR/14/063.

ELC_30: Aberlady Bay
Site Information
Location and Summary Description: Aberlady Bay comprises a varied assemblage of coastal landforms located north of the village of Aberlady. It includes sand dunes, salt marsh, extensive intertidal flats, an active sand spit and raised shorelines.
National Grid Reference: Mid-point: 346004, 681262	Site type: Natural landform Natural view
Site ownership: Mostly Local Nature Reserve (East Lothian Council); part owned by local golf courses	Current use: Open country, recreation
Field surveyors: John Gordon	Current geological designations: Part of Firth of Forth SSSI
Date visited: 5 November 2014	Other designations: Firth of Forth SPA and Ramsar site, Aberlady Bay Local Nature Reserve

Site Map

Figure 35     Aberlady Bay Map. The site boundary has been drawn to include the dominant intertidal portion of Aberlady Bay including sand flats, and the dune system. The site boundary is largely coincident with that of the Aberlady Bay Local Nature Reserve. The neighbouring bedrock/Quaternary ELC Geodiversity sites (ELC_13, Gullane and ELC_14, Kilspindie Shore) are included for reference, along with the geomorphological Gullane Bents (ELC_29) site, shown as transparent greyed out areas.

Site Description

Background The site comprises an area of sand dunes, salt marsh, intertidal sand and mud flats, an actively forming sand spit and raised shorelines (ELC_30 P1). Different aspects of the geomorphology and coastal evolution are described by Smith (1972), Rose (1980), Firth et al (1997), Kirby (1997) and Babtie Group ABP Research & Consultancy Ltd. (2002). Quaternary Deposits and Landforms Several relict erosional coastal features occur within the site. Kirby (1997) identified fragments of two raised shore platforms at Gullane Point, while Smith (1972) described a buried planated till surface at 1.8 m OD between the village of Aberlady and the footbridge at the entrance to the Local Nature Reserve. Intertidal shore platforms are present at Gullane Point and Aberlady Point, planed across a variety of dipping Carboniferous strata. Glacial erratic blocks are present on their surface (ELC_30 P2). Smith (1972) identified two raised Holocene shorelines at 8–9 m OD and 6–7 m OD on the southern flank of Gullane Hill within Luffness Links Golf Course (ELC_30 P3). From radiocarbon dates on peat, Smith concluded that all the deposits below 6 m OD formed in the last c.2500 years. Running south from Gullane Point, a succession of dune ridges and intervening dune slacks form part of a prograding coastal foreland that has built westwards during the late Holocene from the lower slopes of Gullane Hill (Rose, 1980; ELC_30 P4). According to Kirby (1997), a series of five sand spits formed south of Gullane Point, with dunes subsequently accumulating on their surfaces under conditions of abundant sediment supply. The present sand spit is the latest in the sequence reflecting a net southward movement of sand that has also diverted the Peffer Burn southwards. Analysis of coastal changes on Ordnance Survey maps indicates that much of the shoreline of Aberlady Bay underwent accretion between 1907 and 1999 (Babtie Group ABP Research & Consultancy Ltd, 2002). The present coastal dune edge along the beach south of Gullane Point is vegetated but relatively steep-fronted, suggesting wave erosion at the base (ELC_30 P5). Aberlady Bay itself is a large sediment sink with extensive intertidal sand and mudflats fringed by salt marshes (ELC_30 P6, P7). As noted by Firth et al. (1997), those on the southern margins of the bay are fronted by a small cliff and undergoing erosion (ELC_30 P6). There are close associations between the different landforms, vegetation and the diversity of physical features which provide the basis for a range of habitats and vegetation communities (Kirby, 1997). The salt marsh and intertidal flats also form important wintering grounds for geese.

Assessment of Site: Access and Safety
Aspect	Description
Road access and parking	Access is from the A198 coastal road east from Edinburgh at Aberlady. There is a public car park and toilets 500 m east of the village and a footbridge across the Peffer Burn at the entrance to the Local Nature Reserve. Access to the southern shore of the bay can be gained by walking along the road from Aberlady to Kilspindie Golf Course. The site can also be accessed by walking along the coast from Gullane.
Safety of access	No additional precautions beyond those normally associated with visiting a beach and dunes. Visitors should be aware of incoming tides if accessing the sand spit and intertidal flats.
Safety of exposure	The tide rapidly rises in the intertidal flats and visitors should be aware of tide times.
Access	There is good access on footpaths from the public car park 500m east of Aberlady. Part of the site lies within a golf course adjacent to the Local Nature Reserve.
Current condition	The condition is good.
Current conflicting activities	None known.
Restricting conditions	The active sand spit and intertidal areas are covered at high tide. Seasonal access restrictions may apply over parts of the Local Nature Reserve during the bird breeding season.
Nature of exposure	Coastal.

Assessment of Site: Culture, Heritage & Economic Value
Aspect	Description
Historic, archaeological & literary associations	Not known.
Aesthetic landscape	Coastal landscape.
History of Earth Sciences	The John Muir Way passes through part of the site.
Economic geology	Not known.

Assessment of Site: GeoScientific Merit
	Rarity	Quality	Literature/Collections	Primary Interest
Lithostratigraphy
Sedimentology
Igneous/Mineral/Metamorphic Geology
Structural Geology
Palaeontology
Geomorphology	Regional	Good	Smith (1972), Rose (1980), Firth et al (1997), Kirby (1997), Babtie Group ABP Research & Consultancy Ltd (2002)	X

Site Geoscientific Value

Aberlady Bay displays a good range of coastal landforms and sedimentary environments that demonstrate coastal evolution, particularly during the latter part of the Holocene. There is significant potential for research on coastal processes and coastal evolution, as well as education and public interpretation on coastal dynamics and the links between geodiversity and biodiversity. Aberlady Bay is an excellent example of an assemblage of depositional coastal landforms and sedimentary environments with regional significance.

Assessment of Site: Current site usage
Community	The beach and dunes within the Local Nature Reserve are heavily used for recreation, including walking and bird watching. The area includes parts of the Luffness Links and Gullane Links golf courses.
Education	There is significant potential for education and public interpretation on coastal dynamics and evolution.

Assessment of Site: Fragility and potential use of the site
Fragility	Trampling, off-road vehicle use, tree planting, tipping and hard engineering responses to coastal erosion; likelihood of development. However the site is carefully managed as a Local Nature Reserve by East Lothian Council. Note that coastal erosion is part of the natural process of coastal evolution.
Potential use	School education and public interpretation addressing coastal dynamics and living with a dynamic landscape in the context of climate change and sea-level rise.

Geodiversity Summary

The site is a good example of a range of coastal landforms and there is potential for developing its value for research, education and public interpretation through greater promotion of existing information.

Site Photos
Photo ELC_30 P1:    View north across Aberlady Bay from Kilspindie on the south shore. © John Gordon.	Photo ELC_30 P2:    Glacial erratic block on an intertidal shore platform near Gullane Point. The platform is cut across dipping Carboniferous strata. © John Gordon.
Photo ELC_30 P3:    Raised shorelines at Luffness Links Golf Course. © John Gordon.	Photo ELC_30 P4:    Sand dune system south of Gullane Point. © John Gordon.
Photo ELC_30 P5:    Steep coastal edge south of Gullane Point. © John Gordon.	Photo ELC_30 P6:    Saltmarsh and intertidal flats near the entrance to the Local Nature Reserve. © John Gordon.
Photo ELC_30 P7:    Intertidal flats near the entrance to the Local Nature Reserve. © John Gordon.