SUSTAINABILITY

FEATURES
Enhancing biodiversity to the
Shoeburyness sea walls
team will involve a mixture of early
and late cutting; the latter likely to be
favourable for the late-nesting brownbanded
carder-bee which requires
wildflowers for nectar and pollen
throughout August and September.
On the seaward face of the flood
defences where the scarce shrubby
sea-blite may be affected by repairs to
the concrete revetment, biodiversity
terraces will be built to conserve this
upper salt marsh species. The terraces
will be planted with sea-blite to offset
losses due to works.
Flower-rich grassland on Foulness Island, excellent forage for bumblebees © Tim Gardiner
Sea walls (vegetated earth
embankments) are engineered
structures for the defence of coastal
land from tidal flooding. They have
strong linear characteristics and
there are over 2000km of sea wall
in England. They include a range of
habitats: landward and seaward slopes;
a landward berm/folding; borrowdyke
(from where clay was dug for sea wall
construction); and often abut salt
marsh (seaward side). Sea walls are
excellent habitats for a range of scarce
species such as the brown-banded
carder-bee Bombus humilis, sea barley
Hordeum marinum and shrubby seablite
Suaeda vera, all species found
along the 30km of sea wall which
protect the MOD’s Shoeburyness
Range (Foulness Island) in Essex.
On the Shoeburyness Range there
has been a recent focus on increasing
the biodiversity value of grassy
sea wall embankments, as part
of a large scheme to improve the
engineered condition of the flood
defences. During the planning of the
improvements to the condition of the
sea walls (such as replacing cracked
concrete revetment protecting the
seaward face), it became apparent that
enhancements could also be made
to their biodiversity value in liaison
with Natural England (the sea walls
are within the Foulness Site of Special
Scientific Interest) and ecological
consultants (notably Christian Whiting
of CH2M Hill).
To ascertain the focus of the
management regimes, botanical
and invertebrate surveys have been
undertaken in recent years, revealing
a diversity of wildflowers e.g. large
numbers of pyramidal orchids
Anacamptis pyramidalis, along with
previously mentioned scarce species.
Based on the results of these surveys
mowing regimes are to be targeted at
specific sections of sea wall to ensure
that these species and many others
flourish. The grassland cutting regimes
by QinetiQ’s ground maintenance
More information on sea walls and
their biodiversity interest can be
found in the recently published Sea
Wall Biodiversity Handbook (by Tim
Gardiner, Rob Pilcher and Max Wade).
The Handbook is available from
ANGEASTFRB @environment-agency.
gov.uk.
Tim Gardiner
Biodiversity Offcer
Environment Agency
Emma England
QinetiQ Ecology Assistant
MOD Shoeburyness Range
Pyramidal orchids © Tim Gardiner
Sanctuary 44 • 2015
45