Jncc coastal Directories Project Region 11 The Western Approaches

dulcamara, and in the most south-westerly sites tree mallow
Lavatera arborea becomes a major component of the
community.  Where there is a high silt content in the shingle
matrix, common scurvygrass Cochlearia officinalis and grass-
leaved orache Atriplex littoralis are sometimes associated
with the sea beet.  Unique to the Isle of Scilly is a sea beet
community with a large number of associate species, the
commonest of which are sea carrot Daucus carota subsp.
gummifer and rock samphire Crithmum maritimum.  On sites
where sand is the major component of the matrix, sea
sandwort Honkenya peploides is typical, often with sea
campion Silene maritima, sea-holly Eryngium maritimum, sea
spurge Euphorbia paralias and occasionally marram
Ammophila arenaria.  Secondary pioneer communities
frequently contain curled dock, yellow horned-poppy
Glaucium flavum, common ragwort Senecio jacobaea, sticky
groundsel S. viscosus and biting stonecrop Sedum acre or
English stonecrop S. anglicum.
Further inland on more stable shingle structures, fescue
grasslands develop.  Where there is a silt matrix, for
example in Bridgwater Bay, red fescue dominates, with
buck’s-horn plantain Plantago coronopus, spear-leaved orache
Atriplex prostrata and greater sea-spurrey Spergularia media.
In the Isles of Scilly and at other south coast sites, thrift
Armeria maritima, sea beet and sea mayweed are the main
associates.  More widespread and away from saltmarsh, red
fescue has common bird’s-foot-trefoil Lotus corniculatus,
ribwort plantain Plantago lanceolata and mosses Dicranum
scoparium and Hypnum cupressiforme as major associates.  On
sandy matrix sites marram and sand sedge Carex arenaria are
the main associate species.
Heath communities are not present on shingle structures
in this region, but the most inland parts of Porlock beach are
stable enough to allow a gorse Ulex europaeus - bramble
Rubus fruticosus scrub, or bramble - false oat-grass
Arrhenatherum elatius scrub to develop.  The most sheltered
sites on Scilly contain an open bracken Pteridium aquilinum -
bramble community rich in grass species, and at the base of
the lee slope of the Bridgwater Bay ridges there is a western
blackthorn Prunus spinosa - bramble scrub, with ivy Hedera
helix, burnet rose Rosa pimpinellifolia and bittersweet.
There are good populations of sea kale on the south
Cornwall sites and the Isles of Scilly.  Sea knotgrass
Polygonum maritimum and purple spurge Euphorbia peplis
had their last strongholds on fine shingle in this region but
have not been recorded in recent years.  Ray’s knotgrass 
P. oxyspermum is, however, still present though declining
(Margetts & David 1981).  The tree mallow, though present
elsewhere in the south-west, reaches its greatest vigour in
this region, as does the sea radish Raphanus maritimus.
Region 11  Chapter 3  Terrestrial coastal habitats
50
Table 3.3.2  
Surveyed shingle structures
Site name
Grid ref.
Area surveyed
Site type
Conservation
Activities/management/disturbances
(approx. ha)
status
Isles of Scilly
SV900100
10
Shingle bars and
SSSI
Some trampling, light rabbit grazing,
raised beaches
seabird enrichment
Porlock Beach
SS890484
28
Storm beach and shingle
NT
Localized trampling, tidal damage,
stabilisation measures
Bridgwater Bay
ST239457
25
Multiple ridge with thin
SSSI, NNR
Grazing, vehicular damage, past
alluvial cover
gravel extraction, natural reworking
Porthkerry
ST091670
2
Limestone shingle bar
None
Light trampling
East Aberthaw
SS033657
10
Sandy and silty shingle spit
SSSI
Groyne stabilisation
Source: after Sneddon & Randall (1994).  Key: NT = National Trust, NNR = National Nature Reserve; SSSI = Site of Special Scientific Interest.
Table 3.3.3  
Fringing shingle beaches
Site name
Grid ref.
Length of
Site type
structure
(km*)
Fal Estuary
SW8031
0.5
Sandy shingle
(Swanpool)
Loe Bar
SW6425
1.0
Flint shingle with
coarse sand
Penzance
SW4629
1.0
Sandy shingle
Westward Ho!
SS4329
1.0
Mobile sandy shingle
Appledore
SS4532
0.5
Pebble bank
Minehead
SS9847
2.0
Semi-mobile shingle
with sand matrix
Watchet
ST0744
0.5
Mud and sand matrix
in shingle
Barry
ST1267
1.0
Sandy coarse shingle
Nash Point
SS9169
0.5
Coarse shingle and
boulders
Source: Randall (unpublished survey, early 1980s).  Key: *to nearest
0.5 km.
Shore dock is a rare Celtic fringe species that has its best
development in the Isles of Scilly (see also 
section 5.2
).
The invertebrate fauna of shingle sites in this region has
not been well studied, but Loe Bar is the only known site for
the Cornish sandhill rustic moth Luperina nickerlii leechi (see
also 
section 5.3
).  The shingle sites of the Western Rocks and
the Eastern Isles, Scilly, are important roosting and nesting
locations for shag, guillemot, storm petrel and manx
shearwaters (see 
sections 5.10
, 
5.11
and 
5.12
) as well as being
haul-out sites for seals (see 
section 5.14
).
3.3.3  Human activities
Many of this region’s shingle sites are subject to recreational
pressure.  Bridgwater Bay has vehicular access, and gravel
has been extracted in the past.  Portlock Beach and East
Aberthaw have both been groyned and graded.  The more
distant islands of the Isles of Scilly are subject to landing
restrictions during the bird breeding season.  None of the
fringing shingle beaches of this region is grazed.
3.3.4  Information sources used
Not all shingle sites are vegetated, especially not those on
exposed high-energy coasts or where disturbance is great.
Unvegetated sites have not been surveyed.  The major

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