SEAWEEDS OF THE BLACKWATER ESTUARY 315
vesiculosus and Fucus spiralis. Sheltered beneath these larger
forms were growths of Pleonosporium borreri, Ulothrix flacca,
Enteromorpha compressa, Pilayella littoralis, Porphyra umbili-
calis, Ulva lactuca and, on a wreck at Sales Point, Rhodymenia
palmata.
Wrecks such as these were examined at Bradwell Creek, East
Mersea Stone, Cocum Hills and Sales Point.
8 The Sublittoral Area
The large area of sea bed which was examined with dredge and
trawl seemed to be bare of algae. Dredging in shallow water at
Goldhanger and Thirslet Creeks and off the Mersea shore revealed
only a few specimens belonging to the same species as were
recorded from the lower shore. Similar results came from trawling
and dredging off St. Osyth, Colne Point and the Cocum Hills.
9. Epiphytes
A deliberate search for algae living as epiphytes was not made.
During the course of examination of larger, free-living species
however, some epiphytes were recorded.
All of the larger algae seem liable to bear epiphytes but
species of Cladophora and Ceramium were particularly well
colonized. Many algae which might normally be expected to
attach themselves to rocks or similar substrates grow anchored to
the other algae present.
The following epiphytes were found :
Characium marinum on Ceramium deslongchampsii
Ulothrix flacca on Fucus spiralis and F. vesiculosus
Enteromorpha torta on Fucus vesiculosus
Ectocarpus confervoides on Chorda filum
Pilayella littoralis on various Fucoids
Streblonema sp. on Ceramium sp.
Leptonematella fasiculata on Fucus vesiculosus
Acinetospora pusilla
Erythrotrichea carnea on various algae.
Goniotrichum elegens on various algae
Ceramium deslongchampsii on various algae
Ptilothamnion pluma on various algae
During the course of this survey examination of the literature
revealed that with few exceptions (Baker (1912), Baker and
Bohling (1916), Carter (1933)-) very little had been published on
the marine algae of Essex since 1894 (Batters (1894)); of these
exceptions, only the work of Carter (1933) gave any compre-
hensive list of algae. The herbaria of the British Museum (Natural
History) and the Passmore Edwards Museum were also searched
but failed to yield any additional records.
As several species previously unrecorded in Essex were found
in the Blackwater Estuary, and as there has been considerable
reorganization in algal nomenclature (Parke and Dixon (1964))