SURVEY AND COMPARISON 167
from this creek near Site 4A shows a chloride content of 16.0
grams per litre (1.6 per cent), and water draining into the
outlet contains 16.5 grams per litre (1.65 per cent). This
value is nearly as high as that found in sea-water itself and
in the creeks of the salt marsh. Considerable seepage
through the base of the sea-wall must, therefore, occur,
because this high salinity is not shown by all of the ditches
of the drained marsh. The seepage seems to be greatest at
the eastern end, as water taken from near Site 4C showed
a slightly lower salinity, i.e., 13.7 grams chloride per litre
(1.37 per cent). This is probably because at the eastern
end a creek of the salt marsh follows the sea wall on the
outside, whereas further west the creeks of the main marsh
are further away from the wall. Seepage through the area
of mud between the creeks and the wall would presumably
be slower than direct seepage from a creek near the wall.
East of Site 4B the banks of Creek 4 are badly trampled
by cattle. This means that along the edge of the creek
there is a narrow area of soft wet saline mud, which is
colonised by some of the halophytic species. Scattered
plants of Salicornia sp., Suaeda and Spergularia marginata
(D.C.) Kittel occur here. Enteromorpha intestinalis (L.)
Link is found in large quantities in the water at. the eastern
end of Creek 4. Near Site 1, where there has been much
trampling and the creek is very broad, the water dries up
rapidly in the early summer, and colonisation of the creek
base takes place. At the margins of this area. Puccinellia
distans (L.) Pare., Suaeda maritima, Spergularia marginata,
Triglochin maritimum and Juncus Gerardi Lois. are the
most frequent species. The. latter is particularly abundant.
The salinity here is .014 grams chloride per gram soil (14
per cent). In the centre of the creek base, Puccinellia distans
and Juncus Gerardi persist, but Salicornia Smithiana Moss
is very abundant here. This plant has a very spreading
habit and here shows a much deeper red anthocyanin
colouration than other Salicornia species. Suaeda maritima,
occurring in scattered patches in the creek base, also shows
a more spreading habit than when it grows in a closer com-
munity on the salt marsh. Juncus maritimus is found at one
place in this area. At Site 4B, Creek 3 joins Creek 4 and
there is a patch of very wet, very saline ground. Salicornia