Plant distribution and topographical
survey of Sully Island, Nr. Penarth, South Glamorgan
This color plant distribution map of the
kilometer-long Sully Island was a teenage project, dating from
1957-58. It shows main features of relief and topography, and
records the location of several species of ecological
significance. These include the bee orchid Ophrys maculata
(L.), adder's-tongue Ophioglossum lusitanicum (L.) and
the sea spleenwort Asplenium marinum (L.).
Sully Island is a kilometer off the South
Wales coast between Penarth sand Barry. Curiously, it is
connected to the mainland for about half the time, and cut off by
the sea for the other half. The rate of tidal rise and fall is
the highest in the old world (only the tidal race in the Bay of
Fundy, Novia Scotia, is greater). Many people have been swept to
their deaths through trying to leave the island on a rising tide.
Other projects, not yet available on the web, included tidal
measurements, time-lapse photography, collection of marine
phyophytes, beach pollution and many photographs of habitats and
geological features. A note of the plant
species whose distribution is plotted is separately
For references see also habitat records by
Brian J Ford [in] Hyde, H. A. and Wade, A. E., 1969, Welsh
Ferns, fifth edition, pp 70, 138, 162.
Aerial Photograph of Sully Island in 1980
The aerial photograph shows the true outline.
It may be compared with the view from the
mainland. The aerial view reveals that the north-east
promontory projects further than the sketch-map suggests. There
are visible changes due to weathering over two decades. Erosion
has exaggerated the outline of the two small headlands to the
south-west, and the main footpath has extended across in a
south-easterly direction. The area of swampland (showing purple
in colour to the west of the center) has contracted. Fungal
'fairy rings' recorded in the original map are visible in this
view. The shipwreck visible to the north of the center of the
island (top map) has continued to move in a northly direction
under tidal forces. Coastal erosion of the soft red shale in this
area is up to five centimeters a year. Ingress of sandy shingle
along the central northern coast is apparent, as is the loss of
the distinct south-eastern headland, site of a Saxon fort.