National Character Area 158

Isles of Scilly - Key Facts & Data

Landscape and nature conservation designations section contains a map

Note that numbers and figures in the body of the text are based on the 2014 profiles, unless otherwise stated. The maps contain live frequently updated datasets.

The Isles of Scilly form an archipelago of more than 200 low-lying islands and rocks. All the islands and outcrops are both an Area of Outstanding Natural Beauty (AONB) and a Heritage Coast with both designations covering an area of 1,638 ha (Natural England, 2011).

Relationship with the coast

The adjacent coastline is covered by the following Shoreline Management Plans:

  • Rame Head to Hartland Point

The adjacent coastline includes the following Marine Plan – Marine Character Areas (MCAs):

  • Isles of Scilly



Designated nature conservation sites

The NCA includes the following statutory nature conservation designations (Natural England, Special Protection Areas; Special Area of Conservation; Ramsars; National Nature Reserves; Sites of Special Scientific Interest and Local Nature Reserves, 2021):

Please note: (i) Designated areas may overlap (ii) all figures are cut to Mean High Water Line, designations that span coastal/marine areas below this line will not be included.

Condition of designated sites
All designated sites within England are covered by Sites of Scientific Interest (SSSI) units. The condition to these SSSI units within the NCA are as follows (Natural England, Sites of Special Scientific Interest Units, 2021):



Landscape and nature conservation designations map for NCA158

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Landform, geology and soils section contains a map

Note that numbers and figures in the body of the text are based on the 2014 profiles, unless otherwise stated. The maps contain live frequently updated datasets.

Elevation

The NCA is on average 17m above sea level with a maximum elevation of 51m and a minimum of -0.2m below sea level (Natural England, 2010).

Landform and process

There are more than 200 low-lying granite islands and rocks scattered across 200sq km, set out in the Atlantic 40km south-west of Land’s End. The granite has weathered to form coastal tors and other landforms (Isles of Scilly Natural Area Profile, Isles of Scilly Countryside Character Area description)

Bedrock geology

The islands are formed of fine- to coarse-grained granite and are part of the Cornubian Batholith, a large body of igneous rock which Now intruded during the Carboniferous-Permian at the end of the Variscan Orogeny (mountainbuilding episode). There is a small area of Tertiary gravels on St Martin’s (Isles of Scilly Natural Area Profile, Isles of Scilly Countryside Character Area description, British Geological Survey maps).

Superficial deposits

During the Quaternary, deposits (alluvium), head (periglacial soil and scree deposits) and blown sand were laid down. Glacial till from the Irish Sea ice sheet is found on St Martin’s and Tresco. There are also raised beach deposits which illustrate previous sea level changes. Peninnis Head SSSI forms a prominent cliff headland on the south side of St Mary’s and is significant for Quaternary geomorphology including granite tors and other weathering features (Isles of Scilly Natural Area Profile, Isles of Scilly Countryside Character Area description, British Geological Survey maps).

Designated geological sites

The NCA includes the following geological sites (Natural England, Geological and Mixed Sites of Special Scientific Interest, 2021):

wdt_IDNCA_IDNAMENCAAreaHaInterest typeArea (ha) 2021Percent of NCA (2021)Count
2361NORTH NORTHUMBERLAND COASTAL PLAIN37,669.6Geological6.80.01
2371NORTH NORTHUMBERLAND COASTAL PLAIN37,669.6Mixed1,029.52.75
2382NORTHUMBERLAND SANDSTONE HILLS72,694.6Geological45.40.14
2393CHEVIOT FRINGE51,591.3Geological17.10.02
2404CHEVIOTS36,487.9Geological165.00.52
2414CHEVIOTS36,487.9Mixed3,488.99.61
2425BORDER MOORS AND FORESTS127,155.9Geological85.70.18
2435BORDER MOORS AND FORESTS127,155.9Mixed35.80.01
2446SOLWAY BASIN98,350.4Geological7.20.02
2456SOLWAY BASIN98,350.4Mixed5,569.25.74

Soils and Agriculture Classification

The soils of the Isles of Scilly are poorly formed and acidic; the arable/bulb fields are situated on sandy soils (Isles of Scilly Natural Area Profile).

The main grades of agricultural land in the NCA are broken down as follows (as a proportion of total land area) (Natural England, Provisional Agricultural Land Classification, 2019):


Landform, geology and soils map for NCA158

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Key waterbodies and catchments section contains a map

Note that numbers and figures in the body of the text are based on the 2014 profiles, unless otherwise stated. The maps contain live frequently updated datasets.

Major rivers/canals

The following major rivers/canals (by length) have been identified in this NCA (Natural England, data informing the 2014 National Character Area Profiles, 2010):

wdt_IDREF_CODENAME_1NameLength (km)SumOfShape_Length
11NORTH NORTHUMBERLAND COASTAL PLAINRiver Aln7.67,587.2
21NORTH NORTHUMBERLAND COASTAL PLAINRiver Coquet5.55,516.0
31NORTH NORTHUMBERLAND COASTAL PLAINWhiteadder Water2.92,904.9
410NORTH PENNINESBlack Burn11.911,853.4
510NORTH PENNINESCroglin Water10.010,042.3
610NORTH PENNINESCrowdundle Beck4.34,337.4
710NORTH PENNINESDevil's Water20.520,464.6
810NORTH PENNINESHarwood Beck9.79,740.2
910NORTH PENNINESRiver Allen4.94,889.0
1010NORTH PENNINESRiver Derwent15.315,268.4

Please note: other significant rivers (by volume) may also occur. Tidal stretches of rivers are not included, which may include some major rivers.

Water quality

Nitrate Vulnerable Zones (NVZs) are areas designated as being at risk from agricultural nitrate pollution. These can impact surface water (waterbodies and waterways located above ground) and groundwater (water bodies and waterways located below ground).

Waterbodies such as lakes can also be designated as “eutrophic waters” if the enrichment of the waterbody by nitrate pollution causes accelerated growth of algae, impacting the quality of the water and the balance of organisms within it.

The following NVZs are located within the NCA (Environment Agency, Nitrate Vulnerable Zones Designations, 2021):

Water framework directive

River basin management plans cover river basin districts and describe the challenges that threaten the water environment and how these challenges can be managed and funded. The plans include the classification of water quality of surface waters and ground waters.



Click on the Water Framework Directive layers on the below map to view the corresponding river names.

Key waterbodies and catchments map for NCA158

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Trees and woodlands section contains a map

Note that numbers and figures in the body of the text are based on the 2014 profiles, unless otherwise stated. The maps contain live frequently updated datasets.

Total woodland cover

Ancient woodland is any area that has been wooded continuously since at least 1600 AD. National Forest Inventory (NFI) woodland includes all forests and woodlands (0.5 hectares and over). The total woodland cover within the NCA is as follows (Natural England, Ancient Woodland, 2021; Forestry Commission, National Forest Inventory, 2020):

Distribution and size of woodland and trees in the landscape

The Isles of Scilly are largely treeless and windswept. There are conifer belts on Tresco around the Garrison and on St Mary’s on the hillsides below Maypole. Remnant elm woods occur in the sheltered valleys on St Mary’s (Isles of Scilly Countryside Character Area Description).

Woodland types

A statistical breakdown of the area and type of woodland found across the NCA is detailed below (Forestry Commission, National Forest Inventory, 2020):

Area and proportion of ancient woodland and planted ancient woodland sites (PAWS) within the NCA (Natural England, Ancient Woodland, 2021):


Trees and woodlands map for NCA158

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Boundary features and patterns

Note that numbers and figures in the body of the text are based on the 2014 profiles, unless otherwise stated.

Boundary features

Boundary features in the Isles of Scilly NCA are typically evergreen hedges (locally referred to as fences) and stone walls (Isles of Scilly Countryside Character Area description; Countryside Quality Counts (2003).

Field patterns

Fields form a unique pattern of small bulb fields enclosed by evergreen hedges (Escallonia, Euonymus, Pittosporum and Hebe) intermixed with areas of pasture enclosed by stone walls. These areas are complemented by a fringe of unenclosed heathland (Isles of Scilly Countryside Character Area description; Countryside Quality Counts, 2003).

Agriculture section contains a map

Note that numbers and figures in the body of the text are based on the 2014 profiles, unless otherwise stated. The maps contain live frequently updated datasets.

The following tables provide the most recently available statistics from Defra on agriculture within the NCA.

Farm type

The following farm types are located within this NCA (Defra, Structure of the agricultural industry in England and the UK at June, 2016):

Farm size

The following table outlines the sizes of farms within the NCA (Defra, Structure of the agricultural industry in England and the UK at June, 2021):

Farm ownership

The following table outlines the ownership of farms within the NCA (Defra, Structure of the agricultural industry in England and the UK at June, 2016):

Land use

The following table outlines the types of agricultural land use within the NCA (Defra, Structure of the agricultural industry in England and the UK at June, 2016):

Livestock numbers

The following livestock are farmed within the NCA (Defra, Structure of the agricultural industry in England and the UK at June, 2021):

Farm labour

The following table outlines the types of farm labour within the NCA (Defra, Structure of the agricultural industry in England and the UK at June, 2021):

Please note: (i) Some of the Census data are estimated by Defra so may not present a precise assessment of agriculture within this area (ii) Data refers to commercial holdings only (iii) Data includes land outside of the NCA where it belongs to holdings whose centre point is recorded as being within the NCA.



Note that the below map only shows agri-environment scheme coverage, and not other schemes.

Agriculture map for NCA158

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Key habitats and species section contains a map

Note that numbers and figures in the body of the text are based on the 2014 profiles, unless otherwise stated. The maps contain live frequently updated datasets.

Habitat distribution/coverage

A valuable facet of the Isles of Scilly’s vegetation is that, in many places, there is a complete natural succession from the foreshore up to the tops of the hills. In low lying areas, one can move from sand dunes through species-rich maritime grassland and beyond to higher ground covered with waved heathland. On many of the islands the transition is from rocky shores and boulder beaches to steep sea cliffs topped by maritime heath and grassland. In some locations the coastal habitats are backed by predominantly freshwater systems, supporting wet grassland, pools, marshland and swamp vegetation. Elm hedgebanks and copses represent a significant habitat for birds and epiphytic lichens and are also of interest since the mainland has lost a great deal of its elms due to Dutch elm disease. The many shelter belts also provide cover for the many migrant bird that use the islands as a landfall, especially in the autumn. The Isles of Scilly contains many excellent examples of important habitats such as lowland heathland and maritime cliff and slope. The islands exhibit a diversity of marine, shallow water and intertidal habitats with an associated richness of algal and invertebrate communities and species. The sediment shores and eel grass beds are particularly rich, including many animal species usually having a more southern distribution (Isle of Scilly Natural Area Profile).

Key Habitats

The NCA contains the following areas of key main habitats, as mapped by the national Priority Habitat Inventory (Natural England, Priority Habitats Inventory, 2021):






Key habitats and species map for NCA158

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Settlement and development patterns section contains a map

Note that numbers and figures in the body of the text are based on the 2014 profiles, unless otherwise stated. The maps contain live frequently updated datasets.

Settlement patterns

Only the islands of St Mary’s, St Agnes, St Martin’s, Tresco and Bryher, covering 14 km2, are inhabited 9Isles of Scilly Countryside Character Area description; Countryside Quality Counts, 2003)

Main settlements

Hughtown on St. Mary’s forms the principal settlement with small hamlets and solitary farmhouses. There are tiny settlements on St Agnes (Middle Town), Higher Town on St Martin’s island. New Grimsby harbour has granite cottages which link the main settlements on Tresco (Isles of Scilly Countryside Character Area description, Countryside Quality Counts, 2003)

Local vernacular and building materials

Small hamlets of austere older granite buildings and rendered colour-Nowhed modern ones are characteristic of the five populated islands (Isles of Scilly Countryside Character Area description; Countryside Quality Counts, 2003)

Settlement and development patterns map for NCA158

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Key historic sites and features section contains a map

Note that numbers and figures in the body of the text are based on the 2014 profiles, unless otherwise stated. The maps contain live frequently updated datasets.

Origin of historic features

There are distinctive Tudor and Napoleonic war fortifications on prominent sites, chambered barrows and standing stones of the late Neolithic/early Bronze Age period. The islands were fortified in the 16th century and Star Castle is the most obvious surviving feature of that period. Monastic holdings were acquired by lay lords during the same time. A ship building industry Now developed in the early 19th century. The islands were fortified during the world wars. Tourism has also developed especially after the Duchy of Cornwall sold the freeholds of Hugh Town in 1949 (Draft Historic Profile, Countryside Quality Counts, Isles of Scilly Countryside Character Area description).

Designated historic assets

The NCA includes the following designated historic assets (Historic England, National Heritage List for England, 2021):

Listed buildings

The NCA includes the following listed buildings (Historic England, National Heritage List for England, 2021):

Heritage at Risk Register

The NCA includes the following designated historic assets listed within the Heritage at Risk Register (Historic England, Heritage at Risk Register, 2023):



Key historic sites and features map for NCA158

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Recreation and access section contains a map

Note that numbers and figures in the body of the text are based on the 2014 profiles, unless otherwise stated. The maps contain live frequently updated datasets.

Public access

The following areas of public access for recreation are located within this NCA (Natural England, 2021; National Trust, 2021):


Please note: Public access areas may overlap.
The following linear routes or public access for recreation are located within this NCA (Natural England, 2021; Sustrans; 2021):

Recreation and access map for NCA158

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Experiential qualities

Note that numbers and figures in the body of the text are based on the 2014 profiles, unless otherwise stated.

Tranquillity

Based on the CPRE map of tranquillity (2006) the islands are of medium to high tranquillity, with St Martin’s and Tresco being the most tranquil.

A breakdown of tranquillity values for this NCA are detailed in the table below (CPRE, Tranquillity Map, 2006):

Dark skies

Light pollution is a generic term referring to artificial light that shines where it is neither wanted nor needed, and can impact on people’s experience of the countryside within the NCAs. CPRE host an interactive map, depicting the light pollution and dark skies within the NCA.

Intrusion

The 2007 Intrusion Map (CPRE) shows the extent to which rural landscapes are ‘intruded on’ from urban development, noise (primarily traffic noise), and other sources of visual and auditory intrusion. This shows that the southern parts of Tresco and St Mary’s are intruded by visual and auditory intrusion but that the rest of the islands are not intruded upon.

A breakdown of intrusion values for this NCA is detailed in the table below (CPRE, Intrusion Map, 2007):

Notable trends from the 1960s to 2007 are not applicable to this NCA (due to the lack of baseline data).