Page 385 - Alderney Regional Environmental Assessment of Renewable Energy: Environmental Report

Alderney Regional Environmental Assessment of Renewable Energy:
Environmental Report
Site Area Habitat Community Types Features of Interest Main Biotopes
10a Braye Breakwater Boulder slope down
to 3m
depth at the inner
end and 17m depth
at the outer end.
Seaweed dominated by a
kelp forest of cuvie Laminaria
hyperborea, with significant
amounts of furbelows
Saccorhiza polyschides.
At the inner site other large
brown seaweeds included
thongweed Himanthalia
elongata, mermaid’s tresses
Chorda filum and japweed
Sargassum muticum. There
was also an understorey of
smaller red and brown
seaweeds.
At the outer end of the
breakwater the kelp and most
of the seaweeds did not
extend below 15m and the
last 2m of boulders had silted
surfaces, with many
cupcorals, both the common
Devonshire cup-coral,
Caryophyllia smithii and the
scarce scarlet and gold cup-
coral, Balanophyllia regia.
The outer site was unusual in
that it included
both plant and animal
dominated habitats. There
was a good range of species
which included the scarce
scarlet and gold cup-coral
and also the ormer, Haliotis
tuberculata.
IR.LIR.K.LhypLsac Mixed
Laminaria hyperborea and
Laminaria sacchaina on
sheltered infralittoral rock
11a Braye Rock Rock Surfaces dominated by a rich
animal turf of sponges (16
species recorded), ascidians
(especially Stolonica socialis)
and bryozoans (especially
Bugula spp.)
The variety of sponges was
notable and included
relatively unusual species
such as Adreus fasicularis,
Haliclona fistulosa,
Homaxinella subdola and a
white species of Tethya, as
well as significant numbers of
more common south-westerly
species such as Axinella
dissimilis, Polymastia
boletiformis and Axinella
damicornis. Other relatively
scare or more local species
included pink sea fan,
Eunicella verrucosa, yellow
cluster anemones,
Parazoanthis axinellae, here
found in abundance, red
mullet, Mullus surmuletus and
black face blenny
Tripterygion deleasi.
CR.HCR.XFa.ByErSp
Bryozoan turf and erect
sponges on tide-swept
circalittoral rock
SS.SSa.CMuSa circalittoral
muddy sand
12a Hannaine Bay Hard surfaces Dominated by predominantly
brown seaweeds. The main
species were serrated wrack
Fucus serratus, in the
intertidal zone and
thongweed Himanthalia
elongata and furbelows
Saccorhiza polyschides in the
shallow sublittoral. Pink
encrusting algae were
common on the rocks and
there were red coralline
seaweeds growing in the
areas of solidified sand.
There were no unusual
species recorded, except for
the ormer, Haliotis
tuberculata, and very few
sessile animals present.
LR.MLR.BF.Fserr Fucus
serratus on moderately
exposed lower eulittoral rock
IR.HIR.KSed.Sac Saccorhiza
polyschides and other
opportunistic kelps on
disturbed sublittoral fringe
rock
SS.SSa.IFiSa.IMoSa
infralittoral mobile clean sand
with sparse fauna
13a Les Étacs (north) Bedrock Dominated by a kelp forest of
cuvie Laminaria
hyperborea with an
understorey of red and
smaller brown seaweeds.
Species recorded included
the nationally scarce sponge
Adreus fasicularis, and the
black face blenny
Tripterygion deleasi.
IR.HIR.KFaR.LhypR.Ft
Laminaria hyperborea forest
with dense foliose red
seaweeds on exposed upper
infralittoral rock
R/4001/7 B.3 R.2129