The Essex Naturalist
145
The coast
More than four-fifths of the Essex coastline has heen given SSSI status, a
reflection of its immense importance on a national and international scale, as
one of the most important areas around the entire North Sea basin. This
comprehensive coverage has been criticised as exceeding the original brief of the
SSSI series to embrace a representative selection of sites; we consider it is
justified by the fact that each of the eight major estuarine areas of the Essex
coast is of international significance, according to accepted criteria, in its own
right.
Wintering waterfowl, Typically more than 300,000 birds, is the high-profile
feature of our coast; these birds depend for food upon high densities of
invertebrates in the inter-tidal mud, and stands of green algae and other
palatable plants. The fundamental conservation aim therefore is to maintain
sufficient expanses of unpolluted, undisturbed feeding habitat, especially during
the crucial stress periods of migration and during adverse weather conditions.
But the estuaries are not important solely for overwintering and migrating
waterfowl. They support winter flocks of small seed-eating birds, most notably
twite; breeding populations of little terns, redshank, shelduck and other water
birds; and numerous characteristic, scarce and rare plants and invertebrates.
Examples of the latter groups are listed below for each component habitat:
Salt marsh golden samphire, rock sea-lavender (of the north-east
Essex endemic subspecies saxonicum), ground lackey moth,
Essex emerald moth (although this was recently declared
extinct, there may be potential for later re-establishment)
Sand dunes, shingle sea pea, Ray's knotgrass, the spider Heliophanus auratus
and shell banks
Seawalls hog's fennel, least lettuce, Fisher's estuarine moth,
Roesel's bush cricket
Bottowdykes and annual sea-purslane, soft hornwort, soldier flies, scarce
brackish ditches emerald damselfly
Grazing marsh divided sedge, upright Chickweed, great green bush-
cricket.
Inland waters and wetlands
The largest body of fresh water in the county is Abberton Reservoir, which is
also of international importance for waterfowl. In addition, its renowned tree-
nesting colony of cormorants was until recently a unique feature in Britain. The
value of Abberton Reservoir as a wildlife resource is enhanced by its proximity