State of Nature report - RSPB

COASTAL
lthough some species are
faring well in our coastal
habitats, overall the news
is mixed: 60% of the 682 species
for which we have quantitative
trends have decreased, and 29%
have decreased strongly (see
Figure 16). However, we lack trends
for many species, so care should
be taken in generalising from
these findings.
61% of coastal invertebrates
have declined.
Twenty-five coastal flowering plant
species appear on the national
Red List, 13% of the total number
of species assessed.
All (682)
Invertebrates (405)
Plants (250)
Vertebrates (27)
Strong decrease
Slight increase
0 25 50 75 100
Percentage of species
Slight decrease
Strong increase
We know that the decline of
many species is due to the loss
and deterioration of their habitat.
Sand dunes and shingle areas have little
value for agriculture, but are prime sites
for tourist developments, such as caravan
parks. Such developments often result
in the loss of rare invertebrates, lichens
and the rich orchid populations of wet
dune slacks. What wildlife does survive
is often left marooned on dune “islands”
in a sea of development. Building work
also interferes with the dynamics of
dune systems. In recent years, damaging
developments have been given the green
light at Sovereign Harbour in East Sussex,
Foveran Links SSSI in Aberdeenshire
and Carlyon Bay in Cornwall.
For example, the stabilisation of soft
rock cliffs and sand dunes is likely
to have led to the declines in some
species of solitary bees and wasps 1 .
63% of the 680 rare invertebrate
species associated with sand dunes
rely on early successional habitats,
such as bare or sparsely vegetated
sand. These habitats are reduced
when dunes become stable and fixed.
Many species, including the large
mason bee (Osmia xanthomelana) and
the nomad bee (Nomada sexfasciata)
are now restricted to very few sites
in the UK.
Drainage, agricultural intensification
and sea level rise have all resulted
in the decline of birds that rely
on coastal grazing marshes and
saltmarshes. For instance, the number
of redshanks breeding on British
saltmarshes fell by 53% between
1985 and 2011 2,3 . However, the
general trend is that coastal birds are
increasing: in particular, several species
of overwintering geese have benefited
from changes to agricultural practices,
as well as reduced persecution.
Various species of fly that live
in coastal habitats have declined 4 .
In many cases, rare species rely on
specific coastal plants and are found
in small-scale and transitional habitats
such as coastal freshwater seepages,
dune slacks, upper saltmarsh, saline
lagoons and ditches.
One in six coastal plant species are
declining strongly, including sea barley
and slender hare’s-ear. Many plant
communities have also deteriorated
or been lost completely, particularly
those found on coastal dunes and
shingle, upper saltmarsh and soft
rock cliffs.
Some coastal plants and animals are
adaptable, and can cope with habitat
loss and change, but other species
have more specific needs and are more
vulnerable to change. The challenge is
to identify which species are at risk,
and ensure that their needs are met.
42 STATE OF NATURE 2013