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Colonization of an artificial reef in
south-west England—ex-HMS ‘Scylla’
keith hiscock
1
, sally sharrock
2
, james highfield
3
and deborah snelling
4
1
Marine Biological Association, Citadel Hill, Plymouth PL1 2PB, UK,
2
Seasearch, 19 Hawthorn Drive, Wembury, Plymouth PL9
0BE, UK,
3
Plymouth Marine Laboratory, Prospect Place, West Hoe, Plymouth, Devon, PL1 3DH, UK,
4
National Marine Aquarium,
Rope Walk, Coxside, Plymouth, PL4 0LF, UK
An ex-Royal Navy frigate, HMS ‘Scylla’, was placed on the seabed in Whitsand Bay, south Cornwall on 27 March 2004. After
five years, the reef supported a mature steel wreck community. The colonization of the reef showed wide fluctuations in species
abundance in the first two years but, by 2006, most species that dominated or characterized the reef after five years had settled.
Significant colonization events included settlement of barnacles, tubeworms and hydroids within a month and remarkably
high settlements of the sea urchin Psammechinus miliaris and the queen scallop Aequipecten opercularis in the first year
together with starfish Asterias rubens, solitary sea squirts and ephemeral algae. The plumose anemone Metridium senile,
a characteristic species of wrecks, arrived in late summer 2004 but the widely distributed dead man’s fingers Alcyonium digi-
tatum was not observed until spring 2005. Wrasse were slow to colonize the reef but were established in small numbers by the
end of 2007. Sea fans, Eunicella verrucosa, were first observed in August 2007. The species count for the reef stood at 263 taxa
by the end of March 2009. The inside of the reef remained poorly colonized even after five years. Areas coated with tributyltin
(TBT) antifouling paint only had colonization where the paint had flaked-off or on non-toxic paint markings, but with some
indication that colonization may be occurring by a very few species especially near to non-TBT areas. Many species charac-
teristic of natural reefs had not settled and neither do they occur on older wrecks including branching axinellid sponges, some
cushion sponges and the yellow cluster anemone Parazoanthus axinellae. The artificial reef developed a community that was
distinctly different to nearby natural rock reefs and such artificial structures should not be considered as a replacement for
damaged or destroyed natural habitats.
Keywords: artificial reef, shipwreck, colonization, seasonal change, TBT, community development
Submitted 27 May 2009; accepted 11 October 2009; first published online 14 January 2010
INTRODUCTION
Studies of colonization of new artificial surfaces help us to
answer science questions concerned especially with dispersal
of organisms and likely colonization/recovery rates that are
important information for marine environmental protection
and management. They help us to understand which species
settle readily, which species do not populate new surfaces or
colonize very slowly, the time for a community to reach
maturity (at least visually), the similarity (or otherwise) of
communities on natural and artificial surfaces, and the
growth rates of species. Such studies can also help to under-
stand likely recovery rates where natural communities have
been damaged and, where antifouling paints have been used
on artificial surfaces, if and after how long colonization can
occur there. Artificial habitats have often been placed to
enhance fisheries or recreational SCUBA diving and have
been seen as enhancing biodiversity or as a way of restoring
degraded marine ecosystems (see, for instance, Seaman, 2007).
Studies of colonization have been undertaken worldwide
and often involve deployment of concrete structures with an
associated programme of monitoring settlement (see, for
instance: papers in Jensen et al., 2000; Moura et al., 2007;
Nicoletti et al., 2007; Relini et al., 2007). In the north-east
Atlantic, the biogeographical area in which the study
described here was undertaken, colonization on oil industry
structures and, more recently, offshore wind farm pilings
and other energy devices has been studied. Whomersley &
Picken (2003) provide a summary of long-term dynamics of
fouling communities on offshore installations. Shipwrecks
are another source of information on colonization of artificial
surfaces. Leewis et al. (2000) described five different commu-
nities occurring on wrecks in the southern North Sea off
Holland. Detailed descriptions of the communities living on
steel wrecks include those of Zintzen et al. (2008a) off the
Belgium coast and Hiscock (1981) of a wreck off Lundy,
south-west England. More detailed unpublished data are
also available from the Lundy wreck. Jensen & Collins
(1995) undertook a detailed and systematic study of coloniza-
tion on an artificial reef of concrete blocks in Poole Bay and
Leewis & Hallie (2000) of a reef of basalt boulders off the
coast of Holland. Most recently, Langhamer et al. (2009)
describe colonization of mainly concrete surfaces at a test
park for wave power devices on the Swedish west coast.
‘Scylla’ provided the opportunity to describe colonization on
a large steel structure in south-west England.
Comparisons of artificial with natural reefs are few and
many of the studies of colonization on artificial structures
are short term and often on small settlement panels so that
Corresponding author:
K. Hiscock
Email: khis@mba.ac.uk
69
Journal of the Marine Biological Association of the United Kingdom, 2010, 90(1), 69 –94. #Marine Biological Association of the United Kingdom, 2010
doi:10.1017/S0025315409991457
the species assemblages recorded have had insufficient time
and are not subject to the same processes to become similar
to natural rock communities. Perkol-Finkel & Benayahu
(2005) report distinct differences between coral reef commu-
nities and an artificial reef community after ten years. In
another study, Perkol-Finkel et al. (2006) compared natural
coral reef communities and those on a 119-year old shipwreck
and concluded that, even after a century, an artificial reef will
mimic its adjacent natural communities only if it possesses
structural features similar to those of the natural surroundings
and that, if the two differ structurally, their communities will
remain distinct. Connell (2001) found that different commu-
nities developed on artificial habitats compared to natural
rock habitats in studies using the same types of settlement
panels on pontoons, pilings and natural rock reef habitats in
Sydney, Australia. For seabed habitats in Britain, analysis of
survey data from the Marine Nature Conservation Review of
Great Britain (Connor et al., 2004) identified a distinctive
biotope for steel wrecks as ‘Alcyonium digitatum and
Metridium senile on moderately wave-exposed circalittoral
steel wrecks’. For the study of colonization ‘Scylla’ provided
the opportunity to see if a newly placed structure developed
into that biotope and also to compare communities on
‘Scylla’ with those on nearby bedrock.
Parts of the hull of ‘Scylla’ were coated with tributyltin
(TBT) antifouling paint. TBT has been found to have
chronic effects on a wide variety of aquatic organisms (see
Arai et al., 2009), including decreasing species diversity and
abundance in the marine environment (see, for instance,
Smith et al., 2008 for the Crouch estuary). A study of coloni-
zation of ‘Scylla’ would help to understand the extent to which
the anti-fouling coating remained effective and on which
species.
After ‘Scylla’ had been on the seabed for five years, it was
considered timely to record the sequence of colonization in
a way that will be useful to those concerned with understand-
ing the character and dynamics of marine communities and
the likely marine biological outcomes of any future place-
ments of a steel reef.
MATERIALS AND METHODS
On 27 March 2004, an ex-Royal Navy frigate, HMS ‘Scylla’,
was placed on the seabed in Whitsand Bay, south Cornwall
at position 50819.640N4815.200W and depth to the seabed
20 m below chart datum. The placement had been licensed
under UK Food and Environmental Protection Act regu-
lations. The vessel had been prepared for placement by,
amongst other removals, cleaning of potential contaminants,
removal of high parts of the superstructure, sealing-off poten-
tially dangerous areas and cutting many large holes in the
sides for diver access. After careful consideration, Defra (the
Department for Environment, Food and Rural Affairs)
decided that there was no requirement for the anti-fouling
paint to be removed from ‘Scylla’ before its placement.
Following the placement of ‘Scylla’, it became clear that the
monitoring that had been put in place to record colonization
was not reporting many of the most significant events. To
ensure that a record was kept of colonization, a simple meth-
odology was developed that involved recording occurrence of
conspicuous species, abundance of those species, seasonal
occurrences/changes and growth rates of organisms. The
first two authors together with colleagues and using the
Seasearch programme of volunteer divers maintained a
record of when and what species were seen, aided by acqui-
sition of images. Those observations had started a few days
after placement of the vessel. However, the limited personnel,
financial and diving resources available meant that the survey
was always going to be descriptive and opportunistic, but
accurate in terms of identification of species.
Records were made and images were collected on all of the
dives that the authors undertook on the reef. Samples were
taken when identification of a species required confirmation.
The dives were undertaken about once a month in the first
18 months following placement. Subsequently, dives were
about every 10 weeks (K.H. undertook 33 dives, S.S. 22
dives). This paper describes colonization and succession
over the five years since placement (first dive 30 March
2004 to last dive 18 March 2009).
In addition to recording abundance of conspicuous species,
samples of animal and algal turf to identify smaller associated
animal species were collected on 30 August 2006 from the
foredeck of ‘Scylla’ using a suction sampler similar to that
described by Hiscock & Hoare (1973). In the subsequent
week, the suction sampler was used occasionally to collect
turf samples but most were collected by scraping on vertical
and overhanging surfaces and allowing the scraped material
to drop into a bag which was then sealed. Each area
sampled was about 0.1 m
2
and nine samples were fully ana-
lysed for species present and numbers of individuals. The
samples were fixed in 4% formalin and then washed in
water before being picked and identified and finally stored
in 70% IMS.
To compare the community present on ‘Scylla’ by the end
of summer 2008 with species that occur on natural bedrock
reefs, records from sites surveyed off the open coast from
off Plymouth Sound to Stoke Point in South Devon were
inspected and a representative abundance, taking account of
knowledge of the first two authors of the area, noted for
lower infralittoral and circalittoral habitats. The records
were from Hiscock & Moore (1986) and from a download
of records held by the UK National Biodiversity Network
for surveys undertaken in 1996 by the Devon Wildlife Trust.
Where abundances of species are referred to, the notations
approximately follow the SACFOR (Superabundant, Abundant,
Common, Frequent, Occasional, Rare) scale (Connor & Hiscock,
1996) and are for areas on which those species occur and which
were not coated in antifouling paint.
The extent of TBT antifouling paint was noted when the
hull of the vessel was inspected (by the first author) immedi-
ately after being placed in dry dock at Devonport, Plymouth,
in November 2003. The vessel had been moored at
Portsmouth for many years prior to transfer to Plymouth.
Advice from paint specialists in the dockyard suggested that
the TBT paint coating was then more than 15 years old. The
impact of TBT antifouling paint on colonization of the reef
was addressed by observation of whether organisms settling
on the reef also colonized areas coated with TBT paint and
adjacent to those areas.
RESULTS
All of the taxa observed, collected and identified from photo-
graphs are listed in Appendix 1 together with the date first
70 keith hiscock et al.
recorded and notes on abundance, growth rates (where
observed) and any fluctuations in occurrence. Authorities
and recent synonyms of species are given in Appendix 1.
Appendix 2 is a comparison of species reported from
natural bedrock surfaces in similar subtidal habitats to
‘Scylla’ with abundances of conspicuous species on horizontal,
vertical and inner surfaces of ‘Scylla’. Appendices 1 and 2
are available in the electronic version of this paper on http://
journals.cambridge.org/action/displayJournal?jid=MBI.
Figure 1 illustrates the annual increase in number of taxa
observed or reported on the reef. Figure 2 illustrates the colo-
nization sequence for the most characteristic (of different
stages of settlement on ‘Scylla’ or of inshore reefs in the
area) conspicuous species.
Colonization by conspicuous species
After initial settlement of opportunistic species (filamentous
algae, hydroids, serpulid polychaetes and barnacles especially)
in the first one or two months (Stage 1), there was a steady
recruitment and growth of species during the first summer
including of species that were not necessarily there for the
long-term (Psammechinus miliaris,Mytilus edulis and
Aequipecten opercularis) (Stage 2). During the first winter
after placement, die-back of some seasonally abundant
species occurred but also grazing by starfish and sea urchins
removed much of the settlement of barnacles and tube
worms so that, by late winter, large areas of the reef were
again bare (Stage 3). Spring and summer of the second year
completed recruitment of most of the species that were to
become visually dominant although their abundance and
size was low. The sea urchins also declined in abundance
removing significant grazing pressure (Stage 4). After two
years, winter reductions in abundance of some species were
no longer part of succession but natural variability. The next
stage was a prolonged period (spring 2006 to summer 2008)
when species that were to become dominant grew or expanded
in abundance and a very few additional species that were to
become conspicuous settled (Urticina felina,Eunicella verru-
cosa and Cellepora pumicosa) (Stage 5). From the end of the
summer of 2008, the reef community was composed mainly
of long-lived species or there had been the same seasonal
abundances of ephemeral species as in previous years so
that the reef community was considered ‘mature’ (Stage 6).
The time of settlement, seasonal occurrence, location and
growth of the most visually abundant species are noted below.
algae (plantae, chromista and
rhodophycota)
Algae showed considerable seasonality in their presence with
very sparse occurrence in winter. The earliest algae to be
recorded were ectocarpoid (Hinksia) species which, on inspec-
tion in the laboratory, had many diatom species associated
with their filaments. The kelp Saccorhiza polyschides settled
early on and was noted as 15 cm high on 9 June 2004.
Another early colonizer was Cutleria multifida as its
‘Aglaozonia’ encrusting stage which was first noted in June
2004. In 2004 and 2005, there were very few foliose red
algae although filamentous reds were visually dominant in
spring through to autumn with Pterothamnion plumula and
Polysiphonia elongata abundant on decks. Heterosiphonia
plumosa and unidentified Ceramiales were present in
samples in July 2004 and H. plumosa was noted as ‘secondarily
dominant’ in May 2008. Brongniartella byssoides was recorded
in 2005 and 2006 and was the dominant red alga in 2007 and
2008. Other conspicuous species that were common on the
upward parts of the vessel from spring through to early
autumn were Dictyopteris polypodioides (¼D. membranacea),
Dilsea carnosa and Kallymenia reniformis. The fleshy red alga
Scinia turgida, usually characteristic of disturbed habitats, was
present in 2006 and common on decks in summer 2007.
Halopteris filicina, a frequent species on nearby reefs, was
not observed until 2008. In winter, Callophyllis lacinata
remained conspicuous and H. filicina persisted. The midribs
of Delleseria sanguinea were all that was visible of that
species in December but by February new fronds had
grown. In early December 2008, there were many very small
unidentified algal fronds on the foredeck when silt was
swept away, suggesting the beginning of new growth.
sponges (porifera)
Calcareous sponges (Leucosolenia botryoides and Sycon cilia-
tum) were the first sponge species to be seen and occurred
during late winter early in 2005. Both species appeared to be
present in greatest abundance or only in winter to early
summer. Demospongiae, Halichondria bowerbankii and
Oscarella lobularis, were much less abundant but were seen
sporadically from summer 2006 with many colonies of
O. lobularis present by 2009. Hemimycale columella and
Suberites carnosus were seen for the first time in 2008.
anthozoa (cnidaria: anthozoa)
One of the earliest colonizers was the anemone Sagartia tro-
glodytes var. decorata, occurring frequently by mid-summer
2004 and still present at the end of 2008. Plumose anemones,
Metridium senile, characteristic of wrecks in the area, were
first observed in late summer of the first year. Elegant ane-
mones, Sagartia elegans, also a characteristic species of steel
wrecks in the area, were first seen in mid-summer 2005 and
by the end of the summer in 2006 were well established
with large groups and all of the different colour varieties
present. The dahlia anemone, Urticina felina, which was
abundant on ‘Scylla’ on arrival from Portsmouth, was first
seen at the end of August 2006. It is not a common species
off Plymouth and numbers remained low on the reef for the
rest of the study period although, based on observation of
visible individuals, there may have been some increase in
abundance after summer 2008. Jewel anemones, Corynactis
viridis, were first observed in summer 2004 when they had
Fig. 1. Increase in the numbers of taxa (mostly identified to species) observed
in each year. The taxa are ones that have been recorded by in situ survey
including from photographs and exclude species identified as genus
only and where the same genus is identified elsewhere to species. One
hundred and forty-eight taxa are included out of a total of 263 taxa
identified by the end of March 2009.
colonization of an artificial reef in south-west england 71
Fig. 2. The arrival, growth and succession of major colonizing species during the first five years of the establishment of a reef community on ‘Scylla’. A single line
indicates present but very rarely recorded. The width of the histogram is illustrative of abundance (on the surfaces preferred by each species) on a three-point scale
approximating to: 1. Rare and Occasional; 2. Frequent and Common; and 3. Abundant and Superabundant (see Appendix 9 of Hiscock, 1996). P, present.
Tubularian hydroids were mainly Ectopleura larynx with some Tubularia indivisa. Filamentous red algae were not identified to species on all occasions but
were mainly Pterothamnion plumula,Polysiphonia elongata and unidentified Ceramiales. Heterosiphonia plumosa was noted as present in July 2004 and as
secondarily dominant in May 2008 but there are insufficient records to plot abundance through time.
72 keith hiscock et al.
already started to form patches of many individuals produced
by asexual division and therefore of the same colour. They
occurred mainly on the outer part of the vessel but also
inside. The Devonshire cup coral Caryophyllia smithii was
first observed in September 2005. The coral was still only
occasional on the reef after five years and only one has been
seen colonized by the barnacle Bostrychia anglicum, which
lives only on stony corals.
The common alcyonacean Alcyonium digitatum was first
observed in early summer 2005 and grew to nearly full size
in one year although it had only just started to branch in
summer 2006. By early 2009, A. digitatum had become a visu-
ally dominant part of the reef community. The more unusual
soft coral Alcyonium glomeratum, which occurs on other
wrecks in the area as well as on rock reefs, was first observed
in April 2007. It remained occasional on the reef at the end of
the study. Sea fans, Eunicella verrucosa, which are a major
feature of the marine life on most wrecks in the area, were
especially searched for and eventually found on 12 August
2007, in the fourth year of the reef. There also appeared to
be a settlement in summer 2008. Sea fans occur on the
bedrock reefs within 50 m of ‘Scylla’. Growth was initially
rapid and by the end of the first winter, individuals were up
to 6 cm high and some had started to branch. By winter
2008–2009, the largest individuals were about 17 cm high
and some had several branches.
hydroids (cnidaria: hydrozoa)
Obelia dichotoma was recorded within a month after place-
ment of the vessel. The most conspicuous hydroids to settle
early in colonization were Tubulariidae. Both Tubularia indi-
visa and Ectopleura (¼Tubularia)larynx were present but
were often difficult to tell apart and were most likely interwo-
ven in places. Ectopleura larynx was the most abundant. Both
species suffered the attentions of facellinid sea slugs which
devastated colonies over a few days. Once kelp plants had
settled, they were readily colonized by Obelia geniculata.
A few colonies of the widespread Sertularella gayi were
observed in early 2006. The widespread antenna hydroid
Nemertesia antennina was first observed in August 2005
and, in autumn 2006 was still only present in small
numbers but in 2007 was common and by 2008 was visually
dominant on the decks and some internal horizontal surfaces
together with occasional Nemertesia ramosa. Nemertesia spp.
died-back in early winter but showed new growth by about
December.
jellyfish (cnidaria: scyphozoa)
The schyphistomae of Aurelia aurita were frequently seen.
gastropod molluscs (mollusca: gastropoda)
Shelled gastropods have mainly been recorded from samples
although some small species (Nassarius incrassatus and
Rissoa parva) may be sufficiently abundant and conspicuous
to be seen in situ. An unusual find (for hard substratum)
was of six juvenile Aphorrhais pespelecani in a 0.1 m
2
suction sample from the foredeck (A. pespelecani are normally
characteristic of muddy sediments). A notable record was of
the non-native slipper limpet Crepidula fornicata collected
in samples in September 2006. Sea slugs were sometimes
numerous, feeding mainly on Tubulariidae. The most abun-
dant species appeared to be Flabellina (¼Coryphella)
brownii,Facelina auriculata and Facelina bostoniensis.
However, appearance in massive numbers has been ‘fleeting’
and may last as little as a week in mid-summer. The nudi-
branch Trapania maculata, which is rare in Britain, was also
recorded in one of the scrape samples. Trapania maculata is
a southern and Mediterranean species which is at its northern
most limits in Britain with records from Portland and the
Lleyn Peninsula (Picton & Morrow, 1994).
bivalve molluscs (mollusca: bivalvia)
Mussels, Mytilus edulis, occurred and grew to a length of
about 3 cm during the first summer but only in a few
locations. However, they were not seen subsequently except
as spat in samples. It is suspected that they were consumed
by starfish, Asterias rubens. There was a remarkable settlement
of large numbers of queen scallop Aequipecten opercularis
from July to August 2004. Individuals were 15 – 20 mm
across by November but there were much smaller numbers,
most likely because of migration away from hard substratum
onto sediment off the reef. Most other bivalve molluscs were
cryptic and may be more abundant than in situ records
suggest. For instance, the saddle oyster Heteranomia squa-
mula was rarely observed in photographs and samples but
was most likely common on hard substratum. Hiatella
arctica is a nestling species that was common in algal or
animal turf samples but was not recorded during in situ
surveys.
polychaete worms (polychaeta)
The most conspicuous early settlers on ‘Scylla’ were the serpu-
lid tubeworms Pomatoceros triqueter (P. lamarkii have also
been recorded). Individuals grew rapidly and soon dominated
parts of the reef during summer 2004 but were widely separ-
ated by mid-winter 2004 – 2005, most likely having been
grazed by sea urchins, Psammechinus miliaris.Pomatoceros
triqueter appeared to be largely displaced in 2005 by a
similar tube worm, Hydroides norvegicus. Both were signifi-
cant parts of the fauna and dominant in places by the end
of 2008. The peacock worm Sabella pavonina was first seen
in September 2004 and was occasional by the end of 2008.
A chaetopterid (parchment tube) worm (Chaetopterus vario-
pedatus was identified from one sample in September 2006)
was common on decks in December 2008 and could be seen
when silt was swept away. Significant numbers of small
cryptic polychaete species were present in the samples
collected in September 2006.
barnacles (crustacea: maxillopoda:
cirripedia)
Balanus crenatus was one of the earliest species to settle, seen
four weeks after placement and was conspicuous in the first
year but, as with P. triqueter, grazed by sea urchins and star-
fish in the first winter. Verruca stroemia settled in ‘massive’
numbers apparently in early June 2004. There were probably
steady but low numbers of both species and they have not
been a conspicuous member of the fauna since 2004.
decapods (crustacea: malacostraca:
decapoda)
Crabs, lobsters and shrimps were very slow to settle. There
were early records of spiny spider crabs, Maja squinado that
had no doubt encountered the reef whilst moving over the
surrounding seabed. Edible crabs, Cancer pagurus, were seen
colonization of an artificial reef in south-west england 73
in the first year but remained only occasional and present in
fissures and openings. Prawns, Palaemon serratus had colo-
nized the reef by 2005 and continued to be frequent on the
roofs of swim-throughs. The long-clawed porcelain crab,
Pisidia longicornis was present in samples and is most likely
a common member of the cryptic fauna. Small Inachus
species also seemed to be widely occurring.
amphipods (crustacea: malacostraca:
amphipoda)
The tubicolous amphipods Jassa falcata and Monocorophium
sextonae were abundant from late spring through to autumn;
the former especially on structures that are subject to strong
currents. Several Astacilla danmoniensis were observed emer-
ging from muddy tubes from samples collected on 10
December 2008 from algal stumps. Ericthonius punctatus
was also abundant in those samples. Caprellid amphipods
were abundant and were identified as several Caprella
species together with the similar Pseudoprotella phasma and
Phtisica marina. They were particularly conspicuous in photo-
graphs of hydroids. Several other amphipods were identified.
bryozoa
A sea-mat, most likely Electra pilosa but samples were not col-
lected, occurred in early June 2004, and formed conspicuous
star-shaped colonies on fabric lining the bridge and on
surfaces elsewhere. As soon as there were mature kelp
fronds to colonize, Membranipora membranacea occurred.
The orange pumice bryozoan Cellepora pumicosa was not
seen on the reef until January 2006 but became abundant by
August 2007 and was a visually dominant species on the
outer surfaces of the reef throughout 2008. Similarly, Ross
‘coral’, Pentapora fascialis foliacea, was first seen in January
2006 and, by the end of 2008, the fragile colonies were
about 20 cm across but mainly restricted to places protected
by protruding structures. However, colonies that had just
started to produce foliose structures were frequent on the fore-
deck in early March 2009. Patches of encrusting orange
Bryozoa, identified as Schizomavella linearis in samples,
occurred widely on open surfaces. Erect branching Bryozoa
are not a common part of the reef community to the west of
Plymouth and have not colonized to any great extent on
‘Scylla’, although several species have been recorded.
Although common on many wrecks and rock reefs in the
area, Alcyonidium diaphanum has been observed only once
from ‘Scylla’.
echinoderms (echinodermata)
The spiny starfish Marthasteris glacialis appeared on ‘Scylla’
shortly after placement, believed to be individuals wandering
over the seabed and encountering the reef. The common star-
fish, Asterias rubens, settled in large numbers in autumn 2004
and has persisted since then but as mostly small individuals.
The green sea urchin Psammechinus miliaris settled in large
numbers in the first year. Those numbers dwindled during
early 2005 until, by mid-summer, few could be seen but a
‘midden’ of urchin shells suggested they had been predated.
There was no apparent settlement in 2005 but, in 2006,
there were several 8– 10 mm individuals in a scraped
sample. The feather star Antedon bifida was slow to establish
and, although individuals were seen occasionally, it was not
until summer 2007 that large numbers of small individuals
were seen. By 2008, large numbers of large individuals colo-
nized spars inside the reef and, in late 2008, were a visually
dominant species on the grid afterdeck. The widespread sea
urchin Echinus esculentus was very slow to colonize (or at
least to be seen on open surfaces) and the maximum
number seen in one dive has been three. The cucumarians
Leptopentacta elongata and Thyone fusus were present in
samples collected in September 2006.
ascidians (chordata: tunicata: ascidiacea)
Large solitary ascidians (Ciona intestinalis and Ascidiella
aspersa) were the most conspicuous large species to settle
and were first seen in June 2004. Numbers declined later
that year probably as a result of depredations of starfish and
urchins but large solitary ascidians remained a dominant
part of the reef community, both on outer and inner surfaces
at the end of 2008. Abundance of C. intestinalis appears to
have reduced in 2008. Ascidia mentula,Botryllus schlosseri
and Diplosoma spongiforme are other conspicuous ascidian
species on the reef. Stolonica socialis, which is widely distrib-
uted on reefs in the area, was not observed until May 2008.
One of the most notable species recorded was the non-native
leathery sea squirt Styela clava which is not normally seen
outside of Plymouth Sound. There have been several settle-
ment events for S. clava based on appearance of small ‘fresh’
individuals.
fish (chordata: vertebrata: pisces)
Poor cod, Trisopterus minutus, were present on the reef within
days of placement but have remained in small numbers since.
Similarly, bib, Trisopterus luscus, which are a major feature of
nearby wrecks, were not noted until August of the first year
and remained present in only small numbers by the end of
2008. Pollack, Pollachius pollachius, had a similar ‘slow start’
but, by 2007, were abundant at the upper edges of the reef.
Wrasse have been very slow to colonize the reef and were
present in only small number during 2008. The abundance
of pollack and wrasse declined on the reef during winter.
Similarly, leopard spotted gobies, Thorogobius ephippiatus,
were not seen until summer 2006 although suitable habitats
(silty fissures and corners) had been present since 2004.
There are many vagrant or migratory species that have colo-
nized ‘Scylla’ for periods of time and then moved on.
Succession
Figure 2 illustrates occurrence, expansion of populations and,
in some cases, decline of the most visually abundant species on
‘Scylla’ over five years since placement. 2005 and 2006 were
years of large fluctuations and transition to a community
dominated by species that were there for the long-term.
Successional change in the first year after placement was
dominated by the grazing activities of sea urchins and starfish
which conspicuously removed barnacles and tube worms but
probably also species that would have become abundant early
on if grazing had not been so severe. The barnacle Verruca
stroemia settled later than Balanus crenatus in the first year
and took-over dominance by barnacles. The tube worm
Hydroides norvegicus also became more conspicuously abun-
dant after the first year than Pomatoceros sp. (p). Although
it was the autumn of 2004 and the spring of 2005 that saw
the arrival of two visually dominant species (Metridium
senile and Alcyonium digitatum respectively) they were not
74 keith hiscock et al.
to reach a density and size that made them dominant features
until 2007. However, they did not have to out-compete or
grow-over other species as far as we could tell as there were
bare surfaces for them to colonize. Also, the demise of the
Psammechinus miliaris sea urchins in 2005, most likely
because wrasse had colonized the reef and eaten them,
allowed significant settlement of a wide range of species. It
was not until 2006 that foliose algae established in large
amounts and a variety of species, albeit seasonally in spring
and summer. The round domed colonies of Cellepora pumi-
cosa were a late arrival and only became abundant in late
2007. One of the last major colonizers in the five years of
study was, arguably, the most significant: the sea fan
Eunicella verrucosa is a protected species in Britain. The
‘Scylla’ study shows that, if there are populations nearby,
E. verrucosa can recruit readily but most likely not every
year. The abundance of the solitary sea squirt Ascidiella
aspersa had not apparently diminished after five years
although that of another initial colonizer, Ciona intestinalis,
had declined significantly by 2007 and 2008.
Effect of TBT coatings on colonization
In dry dock, the areas of hull coated with TBT anti-fouling
paint were observed to be from about 1 m below the boot
line and extended all over the steel hull except where there
were divers lines (10 cm wide black lines along the length
of the hull) or fibreglass acoustic domes. The propeller shaft
was also apparently painted with non-toxic paint.
Observations in the dry dock were that the TBT coated
parts of the hull were free of fouling.
Observations over the first five years of the vessel being on
the seabed were that the TBT coated areas remained mainly
free of colonization. Close inspection of images showed that,
adjacent to areas where colonization was dense, some small
patches of tubicolous amphipods occurred on the TBT
coated areas which, in turn, appeared to become colonized
by Ectopleura larynx. Under the stern, some E. larynx colonies
appeared to be attached to TBT coated areas. Barnacle scars
have also been observed in the same sort of area. Mobile
species such as starfish and sea urchins have never been
seen on the coated areas, although topknot Zeugopterus punc-
tatus, have. Where paint has flaked-off, blistered to rusty
metal or on areas coated with non-TBT paint, colonization
by anemones, hydroids, alcyonaceans, barnacles, tube-
building amphipods and ascidians was very dense and
extended right up to the TBT coated areas.
Fate of the records
The records given in Appendix 1 have been entered into a
Marine Recorder database and, once processed, they will be
sent to the UK National Biodiversity Network (www.
searchnbn.net) where they can be viewed and downloaded.
Images, presentations and recording forms related to coloni-
zation of ex-HMS ‘Scylla’ are available from www.marlin.ac.
uk. Specimens from the sampling exercise in September
2006 are held by Unicomarine Ltd. A set of dated digital
images of species has been lodged with the Data Archive
for Seabed Species and Habitats (www.dassh.ac.uk) at the
Marine Biological Association.
DISCUSSION
Comparison with species present on nearby
bedrock reefs
Comparisons of the communities that have developed on
parts of ‘Scylla’ with natural hard substratum communities
help to better understand the extent to which artificial reefs
can replace or mimic natural reef communities. Such com-
parisons are, as pointed-out by Perkol-Finkel & Benayahu
(2005), scarce. Our comparison of the conspicuous species
present on natural bedrock reefs in the same area as ‘Scylla’
with those on different surfaces of the artificial reef is shown
in Appendix 2. One hundred and twenty-two conspicuous
species are listed in Appendix 2 of which 39 species recorded
on bedrock reefs had not been recorded from ‘Scylla’ by the
end of the study. Nine species were recorded on ‘Scylla’ but
not the natural bedrock reefs. The species are listed in Table 1.
Species that were most notably absent from ‘Scylla’
included many sponges, especially axinellid sponges and
some cushion sponges, and the yellow cluster anemone
Parazoanthus axinellae that also do not occur on shipwrecks
in the area that are more than 60 years old (personal obser-
vations). The abundance of some species on ‘Scylla’ was still
low by the end of the study compared to on rock or ship-
wrecks. Colonization by the sea urchin Echinus esculentus
had been slow and numbers remained low on ‘Scylla’ by the
end of the study. However, on wrecks that are surrounded
by sand (such as the Maine off Bolt Tail), sea urchin
numbers are also very low. The same situation occurs for
the sea cucumber Holothuria forskali which has not yet been
seen on ‘Scylla’ and is sparse on wrecks surrounded by sedi-
ment. The absence of encrusting coralline algae is notable
but some of the algae not recorded on ‘Scylla’ are ones that
typically occur in the upper circalittoral zone and might not
be expected to be present in the lower infralittoral conditions
on the decks of the reef: Myriogramme heterocarpum,
Polyneura gmelinii and Rhodymenia pseudopalmata. The con-
clusion by Perkol-Finkel et al. (2006) that even after a century
an artificial reef will mimic its adjacent natural communities
only if it possesses structural features similar to those of the
natural surroundings, seems likely to apply also to artificial
reefs in temperate waters but, furthermore, there may be
species that are long-lived and slow growing or that have
short larval dispersal times that should not be expected to
colonize.
The species recorded from ‘Scylla’ but not on the rock reefs
used in comparison are ones that, nevertheless, occur on rock
reefs in different conditions. For instance, Metridium senile
occurs on shipwrecks in the area and on offshore wave or
tide-exposed rock reefs. Antedon bifida occurs in small
numbers on some offshore reefs but, as with Ectopleura
larynx, is abundant on some reefs in Plymouth Sound.
Oscarella lobularis has been seen on reefs in Plymouth
Sound but nowhere in the abundance that it has been seen
on ‘Scylla’. The fleshy red seaweed Scinaia turgida occurs on
disturbed substrata such as cobbles. The occurrence on
‘Scylla’ of sometimes large amounts of the leathery sea
squirt Styela clava, not normally seen outside of Plymouth
Sound (‘Scylla’ is about 12 km from the Plymouth Sound
breakwater), is notable. However, one individual has been
seen (by K. Hiscock) on the wreck of the ‘Rosehill’ to the
colonization of an artificial reef in south-west england 75
west of ‘Scylla’. Ascidians generally have short dispersal
distances but there have been several settlement events
for Styela based on appearance of small ‘fresh’ individuals
on ‘Scylla’. The absence of Clavelina lepadiformis and the
‘late arrival’ of Stolonica socialis, both commonly seen on
rock reefs, may also be due to poor larval dispersal for those
species.
Species expected but not yet seen or in low
abundance on ‘Scylla’
Species that are commonly seen on wrecks in the area out of
Plymouth but not yet observed on ‘Scylla’ include the sandaled
anemone Actinothoe
¨sphyrodeta (although there is a possible
sighting), the yellow cushion sponge Cliona celata, the
painted topshell Calliostoma zizyphinum and the cotton
spinner Holothuria forskali. Numbers of lobster, Homarus
gammarus, on wrecks in the area are low but, as a species par-
ticularly looked for by divers, it is remarkable that none had
been reported from ‘Scylla’. Some species that occur abun-
dantly on steel wrecks in the area out of Plymouth were still
scarce on ‘Scylla’ by the end of 2008: Caryophyllia smithii,
Echinus esculentus and all of the wrasse species. More
unusual/scarce species that have colonized steel wrecks else-
where out of Plymouth include the Weymouth carpet coral
Hoplangia durotrix, the southern cup coral Caryophyllia inor-
nata, the pink sea fingers Alcyonium hibernicum and the foot-
ball seasquirt Diazona violacea, but none of those species have
yet been seen on ‘Scylla’.
Comparison with other studies of artificial
reefs
colonization and succession
Our account of the types of species colonizing ‘Scylla’ and the
length of time taken for the community to reach a compo-
sition that appeared stable is broadly similar to that of other
long-term studies of artificial reefs. Species with larvae or
spores in the water at the time of placement are likely to
settle almost immediately and be conspicuous after a few
days or weeks (tube worms, barnacles and hydroids on
‘Scylla’, on the basalt reef described by Leewis & Hallie,
2000 and from concrete structures off the west coast of
central Italy: Nicoletti et al., 2007). Some mobile species
such as fish, crustaceans and echinoderms may also encounter
and colonize the reef very soon after placement. However, a
study of colonization and succession of major groups of
organisms on four offshore installations in the North Sea
(Whomersley & Picken, 2003), suggested a much slower rate
of colonization on some structures than on ‘Scylla’ with
hydroids and tube worms generally abundant from the
first year but anemones (Metridium senile is specifically
mentioned) appearing or becoming abundant only after
three to five years and soft corals (Alcyonium digitatum)
appearing in the third to fifth year. On the ‘Gannet Alpha’
platform, M. senile and A. digitatum began to recruit in the
second year.
Method of colonization might not always be as expected.
We believe that Metridium senile reached ‘Scylla’ as larvae
but Leewis & Hallie (2000) observed that the anemone
Table 1. Species recorded in inspected records from open coast bedrock reefs near Plymouth but not on ‘Scylla’ and species recorded on ‘Scylla’ but not
on open coast bedrock reefs. ( ), one unconfirmed record on ‘Scylla’. Records from ‘Scylla’ are to 18 March 2009.
Species recorded from inspected records from bedrock reefs off the
open coast near Plymouth but not on ‘Scylla’
Species recorded on ‘Scylla’ but not from
inspected records from bedrock reefs
off the open coast near Plymouth
Algae Tethya citrina Algae
Calliblepharis ciliata Sea anemones Scinaia turgida
Carpomitra costata (Actinothoe
¨sphyrodeta)Sponges
Corallinacea indet. (pink encr.) Parazoanthus axinellae Oscarella lobularis
Cryptopleura ramosa (and as
Acrosorium uncinatum)
Hydroids Sea anemones
Drachiella spectabilis Abietinaria abietina Metridium senile
Halarachnion ligulatum Aglaophenia tubulifera Sagartiogeton lacerata
Myriogramme heterocarpum Halecium halecinium Hydroids
?Myriogramme bonnemaisonii Polychaetes Ectopleura larynx
Polyneura gmelinii Filograna implexa/
Salmacina dysteri
Polychaetes
Rhodophyllis sp. Crustaceans Sabella pavonina
Rhodymenia pseudopalmata Homarus gammarus Echinoderms
Schottera nicaeensis Molluscs Antedon bifida
Sponges Calliostoma zizyphinum Ascidians
Amphilectus fucorum Bryozoans Ciona intestinalis
Axinella damicormis Parasmittina trispinosa Styela clava
Axinella dissimilis Echinoderms
Axinella infundibuliformis Aslia lefevrei
Ciocalypta penicillus Asterina gibbosa
Cliona celata Henricea sp.
Pachymatisma johnstonia Holothuria forskali
Polymastia boletiformis Pawsonia saxicola
Raspailia hispida Ascidians
Raspailia ramosa Clavelina lepadiformis
Stelligera stuposa
76 keith hiscock et al.
(presumably as an anemone) had been transported to the reef
they were studying on currents.
Comparison of the rate of increase in number of taxa and
eventual total number of taxa recorded on ‘Scylla’ with other
artificial reefs needs to take account of depth to the reef and
turbidity (and therefore whether or not algae colonize), geo-
graphical location (some biogeographical areas are naturally
richer/poorer in species), structural complexity of the reef
and on method of study. Jensen & Collins (1995) illustrate
colonization on concrete blocks by about 90 species during
the first year (June 1989 to June 1990), rising to about 220
species during the second year and reaching about 240
species after 30 months: a much higher rate of colonization
than for ‘Scylla’. Furthermore, their species numbers were
for macro fauna and flora and did not include smaller
species associated with animal and algal turfs. Based on
detailed information (J. Mallinson, personal communication),
whilst tube worms, barnacles and solitary ascidians made a
rapid appearance (as on ‘Scylla’), so too did wrasse and
gobies which were very slow to colonize ‘Scylla’, whilst
foliose algae were also much quicker to colonize in Poole
Bay and the variety was higher than that recorded on ‘Scylla’.
As for total numbers of species recorded on artificial sur-
faces, after about five years on the seabed, the MV ‘Robert’
off Lundy had been colonized by 222 recorded plant and
animal taxa (Hiscock, 1981), after 30 months, the concrete
and fuel ash blocks in Poole Bay by about 240 plant and
animal taxa (not including small species associated with
turfs) and very thorough sampling from ten shipwrecks in
the Belgium part of the North Sea had recorded 224 animal
species (V. Zintzen, personal communication) (compared to
127 species or higher taxa identified by Leewis et al. (2000),
from 21 shipwrecks in the adjacent waters off Holland).
Taking account of the different methods used and such fea-
tures as higher turbidity in the North Sea, the total species
count seems similar for the different reefs although the
variety of species colonizing the Poole Bay reef was much
higher than for ‘Scylla’.
similarity of communities on ‘scylla’ with
other artificial reefs
How ‘predictable’ are the types of community likely to develop
on artificial reefs such as ‘Scylla’? Studies of shipwrecks in the
southern North Sea by Leewis et al. (2000) distinguished six
communities: Metridium senile; tube dwelling amphipods;
Halichondria panicea,Hydractinia species—Cuthona nana;
Campanularidae– Tubularia [¼Ectopleura]larynx;
Psammechinus miliaris;Mytilus edulis. Assemblages on differ-
ent parts of ‘Scylla’ could be identified with all of those commu-
nities except Hydractinia species—Cuthona nana but the
Mytilus edulis community never developed to any significant
density and was extremely short-lived, whilst the
Psammechinus miliaris community lasted only the first winter
and early summer of 2005 before, it is believed, wrasse predated
them: species not abundant in the North Sea. The records of
Zintzen et al. (2008a) from North Sea shipwrecks suggest a
very similar community to that which has developed on
‘Scylla’ characterized most conspicuously by Metridium senile
and by Tubularia [¼Ectopleura]larynx and Tubularia indivisa.
Asteria rubens,Sagartia sp. and Pomatoceros triqueter were also
important characterizing species as they were on ‘Scylla’ but the
southern North Sea wrecks also had Diadumene cincta,a
species mainly restricted to variable salinity conditions in the
Plymouth area. Mytilus edulis, which colonized ‘Scylla’ early
in 2004 but failed to establish, was common on the North
Sea wrecks as was Psammechinus miliaris and Aequipecten
opercularis, both of which were abundant in the first year on
‘Scylla’. The turf fauna of inconspicuous species on the North
Sea wrecks was, as on ‘Scylla’, dominated by a very high abun-
dance of amphipod species, especially tubicolous species and
passive suspension feeders. Conspicuous species abundant on
‘Scylla’ but not on the North Sea wrecks were Alcyonium digi-
tatum,Cellepora pumicosa and large solitary ascidians,
although A. digitatum was mentioned as on offshore wrecks
in the North Sea.
There are regional differences in steel wreck/reef commu-
nities even in south-west England waters. For instance, the
MV ‘Robert’ off Lundy (Hiscock, 1981) had a high abundance,
as did southern North Sea wrecks, of Ross worm Sabellaria
spinulosa which were scarcely present on ‘Scylla’. The
‘Robert’ was visually dominated by a turf of erect Bryozoa,
which have been notable as very scarce on ‘Scylla’, as they
are on rock reefs and wrecks in the area. However, wrecks
in Bigbury Bay to the east of Plymouth have a higher coloni-
zation by erect branching Bryozoa than ‘Scylla’ or other
wrecks and rocks near to ‘Scylla’. In the Plymouth area,
many steel wrecks are dominated by barnacles, especially
Verruca stroemia, which, although present widely on ‘Scylla’
were not conspicuously dominant. Brittle stars, Ophiothrix
fragilis, are a conspicuous feature of some wrecks in Mounts
Bay Cornwall (personal observations) as they were on the
North Sea wrecks but were in small numbers and highly
cryptic on ‘Scylla’.
The dominant and characteristic species present on ‘Scylla’
by the end of the study corresponded, with few exceptions, to
those listed as characterizing species of the ‘Circalittoral
fouling faunal communities’ biotope ‘Alcyonium digitatum
and Metridium senile on moderately wave-exposed circalit-
toral steel wrecks’ (Connor et al., 2004). However,
Actinothoe
¨sphyrodeta, one of the five most characteristic
species in the biotope, had not yet colonized ‘Scylla’ whilst
another anemone, Sagartia elegans, which was common on
‘Scylla’, is not listed as a characteristic species of the biotope.
Elements of another biotope in the same biotope grouping,
‘Ascidiella aspersa on circalittoral artificial substrata’, could
also be identified on ‘Scylla’.
seasonal variation and stochastic change
in species present
Whilst Figure 2 gives some record of variation in abundance
of species and Appendix 1 information on particular species
present on ‘Scylla’, observations are descriptive rather than
quantitative. Changes in the occurrence and abundance of
tubularian hydroids on ‘Scylla’ were similar to those recorded
by Zintzen et al. (2008b) for Tubularia indivisa on a North Sea
shipwreck where species richness in the associated community
ranged from 15 to 42 through the year. Changes were not only
seasonal but related to predation events, particularly of sea
slugs on tubularian hydroids.
Impact of TBT anti-fouling paint
Our study has revealed that, more than 20 years after TBT
paint was applied to ‘Scylla’, it is still effective in maintaining
colonization of an artificial reef in south-west england 77
the hull clear of fouling. This lack of colonization by both
sessile and mobile species on TBT coated areas suggests that
whole organism effects are related to avoidance of poisonous
areas or the death of early stages of settled organisms.
Nevertheless, the observation that tube-building amphipods
have settled (in a very minor way) on coated areas and, in
turn, seem to facilitate other organisms such as tubularian
hydroids settling may mean that eventual colonization is a
possibility. No literature has been found describing coloniza-
tion on TBT coated surfaces.
It is notable that species had settled right up to TBT coated
parts of the hull and that rust blisters were observed to provide
locations where species could settle and form ‘oases’ of life
surrounded by lethal or unpalatable paint. Hydroids appeared
to thrive on such areas and may benefit if their predators,
nudibranch sea slugs, cannot cross the paint.
The measurement of TBT levels in organisms (one each of
Asterias rubens,Metridium senile,Tubularia sp., Ciona intes-
tinalis and Alcyonium digitatum) collected from ‘Scylla’ as a
part of required monitoring (Snelling, 2006) recorded levels
that ranged from 18–218 g/kg 15 months after the vessel
had been placed. After two years, similar results were obtained
although one sample of Alcyonium digitatum taken from the
lower part of the hull (closest to TBT coated areas) contained
780 g/kg TBT. Further work is needed to identify the concen-
tration of TBT in organisms and how far away from the
painted areas there are or may be both lethal and sublethal
effects on both large conspicuous species and on smaller
turf-dwelling organisms.
Sampling methods
The authors realize that, ideally, there would have been a sys-
tematic and well-designed programme of recording and
sampling to catalogue the colonization of the reef. However,
the results described here inform scientific knowledge of
such matters as recovery potential, maturity times and con-
nectivity distances for species and were obtained by structured
opportunistic observation and sampling. Nevertheless, some
approaches were not successful and included that some
records made by recreational divers had to be discarded as
they could not be validated by images or by parallel records
by reliable recorders. A significant issue seemed to be that
non-scientist divers would identify to the nearest species illus-
trated in a photographic guide rather than indicating that
something was unidentifiable or turning to a more compre-
hensive source to aid identification.
Informing environmental protection and
management
The study of colonization of ‘Scylla’ described here contributes
to our understanding of ecosystem processes that are relevant
to assessing likely recovery rates of damaged marine ecosys-
tems. However, a much longer period of observation than
our five years will be needed to assess whether species that
are believed not to recruit to new surfaces or to be very slow
growing or that reproduce infrequently will eventually colo-
nize. One of the last major colonizers in the five years of
study was, arguably, the most significant: the sea fan
Eunicella verrucosa is a protected species in Britain and
easily damaged by mobile fishing gear. The ‘Scylla’ study
shows that, if there are populations nearby, it can recruit
readily but most likely not every year.
The observation that TBT anti-fouling paint continued to
be effective in preventing colonization is a significant matter
for consideration in any future placement of discarded
vessels and it would be informative, for environmental protec-
tion and management, to understand better how TBT is
affecting species on ‘Scylla’ and if TBT from the vessel is
affecting the surrounding area.
Our study has shown that, although a diverse community
has developed on ‘Scylla’, it is distinctly different to nearby
natural rock reefs and, in particular, it lacks species that are
considered rare, scarce or threatened, notably the branching
and cushion sponges. Whilst artificial reefs are often seen as
enhancing biodiversity in an area or as helping to restore
degraded ecosystems, artificial surfaces do not appear to
attract some of the rare, scarce and threatened species coloniz-
ing rock reefs, and should not be seen as a replacement for
natural surfaces.
ACKNOWLEDGEMENTS
The project to place ex-HMS ‘Scylla’ on the seabed was under-
taken by the National Marine Aquarium (NMA) in Plymouth
with funding from the South West of England Regional
Development Agency. Their initiative and that of their prede-
cessors, the Artificial Reef Consortium, has enabled this study.
We are grateful to the University of Plymouth Dive Centre for
collection of scraped samples in September 2006 and to Emma
Delduca of Unicomarine for assistance with sorting the
samples. The ‘Settling on Scylla’ project, which sought
records of colonization from divers, was initiated by the
Marine Biological Association in collaboration with the
NMA and the volunteer recording project ‘Seasearch’. Amy
Bugg and Judith Oakley collated early results. Jenny
Mallinson summarized the early settlement on the Poole
Bay reef for us. Dr Nick Pope provided valuable advice on
TBT contamination and effects. All of the contributors of
records, the charter boat skippers and dive clubs that have
(knowingly or unknowingly) helped us to collect information
used to compile this paper are thanked.
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Biology 153, 405– 420.
APPENDIX 1
Species recorded from ex-HMS ‘Scylla’. Dates when species
were first observed or sampled and notes on expansion,
growth and loss are given. Records from the sampling
exercises undertaken during the week 4 to 8 September in
2006 are given the date 08/09/2006. Samples were taken
from nine locations and identified species were recorded
only as ‘present’. Taxonomy including vernacular names
is from the World Register of Marine Species (www.marine-
species.org) in January 2009 with additional vernacular
names from Wood (2007). Species names are given
alphabetically within the taxonomic levels they are usually
separated to. Records of abundance are approximately
to the SACFOR (Superabundant, Abundant, Common,
Frequent, Occasional, Rare) scale (Connor & Hiscock,
1996) except that some species have been transitory and an
abundance is only given in ‘Notes’. Specimens from the
sampling in September 2006 are held by Unicomarine.
Images of species used for identification are deposited in the
Data Archive for Seabed Species and Habitats (www.dassh.
ac.uk) and further specimens and pressed algae are held by
K. Hiscock.
colonization of an artificial reef in south-west england 79
Name Date first
noted
Generalized
maximum abundance
during the year by
end of 2008
Notes
Kingdom: PLANTAE
Division: CHLOROPHYTA
Class: Ulvophyceae
?Chaetomorpha sp. 26/06/2004 In image
Ulva lactuca Linnaeus, 1753 (sea lettuce) 07/09/2005 Noted on one occasion as ‘scattered’.
Kingdom: CHROMISTA
Phylum: BACILLARIOPHYTA
Class: Bacillariophycea
Bacillariophycea indet. 12/05/2004 High abundance of diatoms in samples of ectocarpoid algae
Phylum: OCHROPHYTA
Class: Phaeophyceae
Cutleria multifida (J.E. Smith) Greville, 1830 25/06/2004 First seen as crusts (Aglaozonia stage) on the hull and
probably this species in its foliose form also seen in 2004
Desmarestia sp. 23/04/2005 Present on the bridge
Dictyopteris polypodioides (De Candolle) J.V.
Lamouroux, 1809 (¼D. membranacea)
(midrib fan weed)
18/08/2006 Occasional Identified from pressed specimen and conspicuous in
images. Also recorded in summer 2008
Dictyota dichotoma (Hudson) J.V.
Lamouroux, 1809 ( forkweed) (brown fan
weed)
18/08/2006 Occasional Identified from pressed specimen. Also recorded on 22/05/
2008
Ectocarpacea indet. (maiden’s hair) 12/05/2004 Patchy but extensive coverage (Common) on shallow upward
facing surfaces in late spring of first year but, by 30/07/
2004, noted that very few conspicuous ectocarpoids left.
Also recorded mid-March to mid-June 2005 and
doubtless present at other times but not again in the initial
abundance. Patchy cover on a scraped area of horizontal
deck on 22/05/2008. See Hinksia sp. and Hinksia
sandriana below
Hinksia sp. 12/05/2004 Several species of this ectocarpoid alga present (identified
from sample by Dr D. Schroeder)
Hinksia sandriana (Zanardini) P.C. Silva,
1987
30/07/2004 (Identified from sample by Dr D. Schroeder)
Laminaria ?hyperborea (Gunnerus) Foslie,
1884 (tangle or cuvie or forest kelp)
07/09/2004 In images of the bow on 07/09/2004. On 15/06/2006, a small
individual but with a frond and holdfast typical of
L. hyperborea
Saccharina latissima (Linnaeus) C.E. Lane,
C. Mayes, Druehl & G.W. Saunders
(¼Laminaria saccharina J.V. Lamouroux,
1813) (sugar kelp)
15/07/2005 A few in summer 2005 on the shallowest part
Saccorhiza polyschides (Lightfoot) Batters,
1902 ( furbelows)
09/06/2004 Frequent Settled in the first year and about 15 cm long when a few first
seen on 09/06/2004. By 30/07/2004, plants were up to
50 cm long. Visually dominant on upper surfaces in June
2005. Always present on the uppermost areas and on rails
but sparse. Recorded as ‘Frequent but widely separated’ on
10/12/08
Halopteris filicina (Grateloup) Ku¨tzing, 1843 10/12/0008 Frequent Frequent on decks
Phylum: RHODOPHYCOTA
Class: Rhodophyceae
Bonnemaisonia asparagoides (Woodward)
C. Agardh, 1822
15/07/2005 Identified from an image
Brongniartella byssoides (Goodenough &
Woodward) F. Schmitz, 1893
07/09/2005 Abundant Identified from specimens in 2005. The dominant red alga
during spring and summer on upward facing surfaces in
2007 and 2008 at least
Callophyllis lacineata (Hudson) Ku¨tzing,
1843
15/07/2005 Frequent Most likely present in 2005 and, by summer 2006, a
conspicuous part of the biota on upward facing surfaces.
Common amongst other foliose algae in 2008 at least and
persisting into the winter
Ceramiales indet. 30/07/2004 In collection
?Corallinales indet. (encrusting) 23/04/2005 Thin patches on the upper part of the starboard side near the
bow. On tubes of Pomatoceros on 17/08/2007. Very thin
red ‘stains’. No sign of pink encrusting algae
Continued
80 keith hiscock et al.
Name Date first
noted
Generalized
maximum abundance
during the year by
end of 2008
Notes
Delleseria sanguinea (Hudson) J.V.
Lamouroux, 1813 (sea beech)
06/11/2004 Common Very few in 2004. One recorded on 06/11/2004 as 4 cm high.
By 2008, the second most conspicuous foliose algae during
spring and summer
Dilsea carnosa (Schmidel) Kuntze, 1893
(red rags)
18/08/2006 Frequent Early records but not validated. First validated records are in
August 2006 and in May 2008 when it was frequent on the
decks
Grateloupia turuturu Yamada, 1941 07/09/2005 Pressed specimen identified by Professor C. Maggs
Hypoglossum hypoglossoides (Stackhouse)
Collins & Hervey, 1919
28/04/2007 (Frequent) Identified from photograph in 2007 and pressed specimen on
22/08/2008. Probably Frequent
Heterosiphonia plumosa (J. Ellis) Batters,
1902
30/07/2004 Abundant Sampled on 30/07/2004. Probably present in all years and
noted as ‘secondarily dominant’ on 22/05/2008
Kallymenia reniformis (Turner) J. Agardh 18/08/2006 Common Recorded as ‘Common on upfacing surfaces’ on 18/08/2006
and on 22/05/2008. Most likely present every spring and
summer
Lomentaria orcadensis (Harvey) F.S. Collins 25/03/2006 In image of Tubularia larynx
Nitophyllum punctatum (Stackhouse)
Greville, 1830
22/05/2008
Phyllophora crispa (Hudson)
P.S. Dixon, 1964
22/05/2008
?Platoma marginiferum
(J. Agardh) Batters
17/05/2007 In image
Plumaria plumosa (Hudson) Kuntze, 1891
(¼Plumaria elegans F. Schmitz, 1889)
18/05/2006 Identified from pressed specimen
?Polyneura hilliae (Greville) Kylin 22/05/2008 Identified from pressed specimen
Polysiphonia elongata (Hudson) Sprengel,
1827
30/07/2004 One of the dominant species on the decks in summer 2004.
Not recorded in subsequent years
Polysiphonia elongella Harvey, 1833 07/09/2005 Pressed specimen identified by Professor C. Maggs
Polysiphonia sp. 22/05/2008
Pterothamnion plumula (J. Ellis) Na
¨geli, 1855 30/07/2004 Generally abundant on upward facing surfaces in summer
2004
Rhodophyta indet. ( filamentous) 12/05/2004 Present in samples on 12/05/204
?Schizymenia dubyi (Chauvin ex Duby)
J. Agardh, 1851
19/09/2008 In images
Scinaia turgida Chemin 18/05/2006 Common Present in 2006 and common on decks in summer 2007.
Regularity of occurrence uncertain and a species typical of
seasonally disturbed habitats
Kingdom: PROTOCLISTA
Lagotia viridis Wright, 1858 08/09/2006 In one sample 08/09/2006
Kingdom: ANIMALIA
Phylum: PORIFERA
Class: Demospongiae
Halichondria bowerbanki Burton, 1930
(bread-crumb sponge)
20/08/2006 In image. Also recorded on 28/08/2006 and summer 2008
and image on 10/12/2008
Halisarca ?dujardini Johnston, 1842 28/08/2006 In image. Identified by B. Picton
Hemimycale columella (Bowerbank, 1874)
(crater sponge)
16/09/2008 Rare Small colonies in 2008. Two small colonies seen on the
foredeck on 18/03/2009
Oscarella lobularis (Schmidt, 1862) 15/06/2006 Occasional Also recorded on 28/07/2006 and Occasional in summer
2008
Porifera indet. (yellow crust) 30/07/2004 Reported once
Suberites carnosus (Johnston, 1842) 10/12/2008 One small individual on the aft deck
Class: Calcarea
Leucosolenia ?botryoides (Ellis & Solander,
1786) (spiky lace sponge)
18/02/2005 Occasional Seen particularly during the winter to early
summer. Frequent at times. May be
Leucosolenia complicata (Montagu, 1818) (advice
from B. Picton)
Leucosolenia ?variabilis (Haeckel, 1870) 06/04/2006 Spreading over extensive areas of the bow in images between
balls of Leucosolenia ?botryoides on 06/04/2006. In images
on 01/05/06
Leucosolenia sp. 08/09/2006 In three samples
Sycon ciliatum (Fabricius, 1780) (purse
sponge)
18/02/2005 Occasional Seen particularly during the winter and early spring.
Frequent at times
Continued
colonization of an artificial reef in south-west england 81
Name Date first
noted
Generalized
maximum abundance
during the year by
end of 2008
Notes
Phylum: CNIDARIA
Superclass: Anthozoa
Alcyonium digitatum (Linnaeus, 1758) (dead
men’s fingers)
10/06/2005 Common/Frequent Colonies were about 10 mm across/high when first observed.
Five weeks later, they were about 35 mm high, and 10
weeks later, 50 mm high. After one year, colonies
appeared near to full size and were beginning to branch.
Colonization was sparse in 2005 and did not occur in all
areas but was much denser in subsequent years. Small
individuals were again observed in August 2006. By 2008,
a visually dominant part of the community. All white
except one brown individual observed on 28/01/2006 and
a very few more subsequently. Very small (8 mm across)
but frequent individuals on 18/03/2009
Alcyonium glomeratum (Hassal, 1843) (red
fingers)
28/04/2007 Rare When first observed, a colony about 4 –5 cm long. By late
2008, a few small colonies recorded from the sides and
rudder. On 18/03/2009, one observed colony was large
with six branches
?Actinothoe
¨sphyrodeta (Gosse, 1858)
(sandaled or white striped anemone)
26/06/2004 In images from June 2004 and October 2007 but
identification uncertain
Corynactis viridis Allman, 1846 ( jewel
anemone)
09/08/2005 Occasional The 2005 records were of widely separated individuals in
small groups. Patches remained small during 2005 but
some dense stands were present from 2006
Caryophyllia smithii Stokes & Broderip, 1828
(Devonshire cup coral)
07/09/2005 Occasional Recorded by Seasearch divers on 6 November 2004 but not
found in searches during May and July 2005. One found
on the port side in September 2005. Recorded as Frequent
on decks on 12/10/2008. A common species on nearby
wrecks
Cerianthus lloydii Gosse, 1859 (burrowing
anemone)
07/09/2005 Small individuals in mud pockets inside
Eunicella verrucosa (Pallas, 1766) (pink sea
fan)
12/08/2007 Common Searched for but not found on15/06/07. The first one
recorded was 15 mm high and by mid-August, individuals
were 1 to 3 cm high and unbranched with density
estimated as 4– 5 per m
2
on horizontal surfaces at deck
level. Abundance was 1 per 0.1 m
2
along the walkways in
autumn 2007 but much reduced during winter 2007/2008
and density less than 1 per 10 m
2
on walkways and other
surfaces by spring 2008. Growth rate wasrapid at first with
colonies 4 to 5 cm high by mid-December 2007 and up to
6 cm high and branching by spring 2008. In December
2008, density was patchy but up to four per 0.1 m
2
and
individuals were generally 6 m high or less high in
December 2008
Metridium senile (Linnaeus, 1767) (plumose
anemone)
25/09/2004 Abundant Recorded on 30/08/2004 but record not validated. On 25/
09/04, one small one found. Becoming more abundant
during the winter of 2004/2005 with up to one per m
2
in
January and recorded as ‘Common and quite large’ on
18/02/2005. Rising in abundance during 2006 and, by
2007, dominating some structures. Present especially on
the sides but also inside the reef. By the end of 2008, a
visually dominant part of the reef community
Sagartia elegans (Dalyell, 1848) (elegant
anemones)
10/06/2005 Frequent/Common Several var. rosea in an image of the bow on 10/06/2005. One
var. mineata seen in September 2005. Becoming more
abundant during 2006 and, by October, varieties venusta,
rosea and mineata had been reported. The variety nivea
was also present. Most conspicuously on the sides and
stern and in corner habitats but, in December 2008 and
later, many var. venusta were observed scattered on the
foredeck
Sagartiogeton laceratus (Dalyell, 1848) 21/07/2004 Frequent Mainly identified from images. Often several seen together
on barish surfaces in early 2006. By late 2007, part of the
dense cover with other species
Continued
82 keith hiscock et al.
Name Date first
noted
Generalized
maximum abundance
during the year by
end of 2008
Notes
Sagartia troglodytes var. decorata (Price in
Johnston, 1847)
30/07/2004 Occasional Present in large numbers (Frequent to Common) in
summer 2004 but some may have been small
Sagartiogeton laceratus. Recorded on several occasions
in 2004 but as ‘now occasional only’ in November 2004
and ‘not found’ on 30 January 2005 but recorded on
several occasions later in 2005. Subsequent records
from 2008
Urticina felina (Linnaeus, 1767) (dahlia
anemone)
28/08/2006 Occasional First observed in image from 28/08/2006. Several together at
sides of walkways in 2007. Some on decks. Possibly less in
2008
Superclass: Hydrozoa
Campanularidae indet. 08/09/2006 In two samples
Clytia hemispherica (Linnaeus, 1767) 09/06/2004 Present on collected Verruca stroemia and various hydroids.
Widespread on wreck surfaces and other organisms but
only identified when specimens collected. Also on
18/03/2009
Corymorpha nutans Sars, 1835 (solitary
stalked hydroid)
25/05/2008 One on a metal spar at the stern
Ectopleura larynx (Ellis & Solander, 1786)
(¼Tubularia larynx Ellis & Solander,
1786) (branched oaten pipe hydroid)
12/05/2004 (Frequent) Two colonies were seen on 12/05/2004. By 09/06/2004
there were ‘occasional colonies anywhere’. On 23/07/2004,
the colonies had been completely consumed. Similarly,
on 15/07/2005, there were no live ones, only tubes.
Swarms of facellinid nudibranchs have been observed
on many occasions on Tubularia. Most abundant on
rails and wires but also on areas where antifouling
paint has flaked-off and where they might be
protected from predators. Declines greatly in
abundance during mid-winter (January – February and
into March). Apparently new growth on rails in images on
18/03/2009
Eudendrium ramosum (Linnaeus, 1758) 09/06/2004 New growth attached to long-dead Eudendriidae (from
Portsmouth tenure). Also, probably this species on
21/07/2006
Kirchenpaueria pinnata (Linnaeus, 1758) 18/02/2005 Identified from image. Growing in an ‘oasis’ of
organisms amongst TBT coated paint. Also on 01/05/
2006 in image
Nemertesia antennina (Linnaeus, 1758)
(antenna hydroid)
17/08/2005 Abundant In an image on 17/08/2005. The first recorded observation on
28/01/2006 was of ‘Nemertesia spp.’ and noted as at ‘one
location’ (image shows N. antennina). Recorded as
‘common inside’ on 18/08/2006. Overall, sparse in 2006
but was the most conspicuous hydroid and common in
places by 2007. Dying back in early winter and new growth
noted on 10/12/08
Nemertesia ramosa (Lamarck, 1816)
(branched antenna hydroid)
05/04/2007 Rare/Occasional Seen in images on 05/04/2007 and 22/05/2008. Sampled with
gonothecae on 18/03/2009
Obelia dichotoma (Linnaeus, 1758) (sea
thread hydroid)
23/04/2004 Sporadic patches with a stolon length of up to 20 mm and
height of branches 10 mm four weeks after placement. By
12/06/2004, present in many places and forming bushy
growths in some. Gonothecae on 12/06/2004. ‘Much less’
by 30/07/2004 and possibly consumed by predators.
Probably this species in images on 20/08/2006. Most likely
widely present but inconspicuous. In samples on
18/03/2009
Obelia geniculata (Linnaeus, 1758) (kelp fur) 15/07/2005 Abundant Present on kelp fronds and extensively by the end of the
summer
Plumularia setacea (Linnaeus, 1758) (little
seabristle)
18/03/2009 Most likely widely present but inconspicuous. Attached to
Nemertesia spp. In samples on 18/03/2009
Sertularella gayi (Lamouroux, 1821) 28/03/2006 Rare Observed and photographed on a few occasions
Sertularia cupressina (Linnaeus, 1758) (sea
cypress/white weed)
26/02/2009 One clump seen and sampled from aft deck. In samples on
18/03/2009
Sertulariidae indet. 08/09/2006 In three samples
Continued
colonization of an artificial reef in south-west england 83
Name Date first
noted
Generalized
maximum abundance
during the year by
end of 2008
Notes
Tubularia indivisa (Linnaeus, 1758) (tall
Tubularia) (oaten pipe hydroid)
09/06/2004 (Occasional) T. indivisa appeared to be mixed-in with the predominantly
E. larynx and the comments for that species apply to
T. indivisa. The date given is for when both species were
present
‘Tubularia’ spp. 12/05/2004 Several single tubes several cm high were recorded in
May 2004. The species is often difficult to identify in situ
and there may be mixed groups but most seem to be E.
larynx
Superclass: Scyphozoa
Aurelia aurita (Linnaeus, 1758) (moon
jellyfish)
28/01/2006 Attached scyphistomae observed on both inside and outside
surfaces in January, May, August and December
Phylum: PLATYHEMINTHES
Class: Turbellaria
Turbellaria indet. 08/09/2006 In four samples
Phylum: NEMERTINI
Nemertini indet. 08/09/2006 In six samples
Phylum: NEMATODA
Nematoda indet. 08/09/2006 In two samples
Phylum: MOLLUSCA
Class: Gastropoda
Acmaea virginea (Mu¨ ller O.F., 1776) (white
tortoiseshell limpet)
08/08/2006 In one sample
Aeolidia papillosa (Linnaeus, 1761) (grey
sea slug)
08/08/2006 In one sample
Aporrhais pespelecani (Linnaeus, 1758)
(pelicans foot shell )
30/08/2006 Six juveniles in samples collected on the foredeck. Also seen
on sediment adjacent to the reef. (Identification confirmed
by Dr J. Light.)
?Bittium reticulatum (da Costa, 1778) 10/12/2008 In sample
Buccinidae indet. 08/09/2006 In one sample
?Caloria elegans (Alder & Hancock,
1845)
07/10/2006 In photograph from the starboard side
Coryphella lineata (Love
´n, 1846) 25/05/2008
Crepidula fornicata (Linnaeus, 1758)
(slipper limpet)
08/09/2006 In three samples. Notable that this distinctive species, which
is a non-native, has not been seen in situ or in images
Chrysallida suturalis (Philippi, 1844) 08/09/2006 In one sample
Cuthona sp. 28/04/2007 Feeding on ‘Tubularia’ sp.
Dendronotus frondosus (Ascanius, 1774)
( frond aeolis) (Christmas tree sea slug)
09/06/2007
Doto pinnatifida (Montagu, 1804) 17/08/2007 In photograph
Eubranchus farrani (Alder & Hancock,
1844)
19/04/2004 Present with eggs. (Identification confirmed by B. Picton.)
Eubranchus exiguus (Alder & Hancock,
1848) (balloon aeolis)
26/06/2004 In image. (Identified by B. Picton.)
Eubranchus pallidus (Alder & Hancock,
1842)
19/04/2005 In collection. (Identified by B. Picton.)
Flabellina (¼Coryphella)browni (Picton,
1980)
26/07/2004 Abundant The species is seen sporadically through the year feeding on
‘Tubularia’ hydroids and laying eggs. In 2004, it appeared
to ‘arrive’ on 26 July, destroy the hydroids within a week
and was reported crawlingdown the sides of the vessel and
away over the sediment on 3 August (S. Syson, personal
communication)
Flabellina pedata (Montagu, 1815) (violet
sea slug)
06/05/2008
Facelina auriculata (Mu¨ller, 1776) 26/06/2004 Feeding on ‘Tubularia’ sp. Present in large numbers with
eggs in March and April 2005
Facelina bostoniensis (Couthouy, 1838)
(boston facelina)
26/06/2004 Common One of the most abundant sea slugs that occur in large
numbers for a short period feeding on Tubularia spp.
(Identified by B. Picton.)
Gibbula cineraria (Linnaeus, 1758) (grey top
shell)
28/01/2006 One on the foredeck
Goniodoris nodosa (Montagu, 1808) 08/09/2006 In one sample
Continued
84 keith hiscock et al.
Name Date first
noted
Generalized
maximum abundance
during the year by
end of 2008
Notes
Nassarius incrassatus (Stro
¨m, 1768)
(¼Nassarius (Hinia) incrassata (Stro
¨m))
15/07/2005 In images on 15/07/2005 and 07/10/2006. Many in suction
samples taken on 30/08/2006. Also, in seven samples on
08/09/2006. Most likely an abundant part of the
cryptofauna
Janolus cristatus (delle Chiaje, 1841) (crystal
sea slug)
09/06/07 Also recorded on 16/09/2008
Odostomia acuta Jeffreys, 1848 08/09/2006 In three samples
Onchidoris muricata Mu¨ller O.F., 1776) 08/09/2006 In one sample
Onoba semicostata (Montagu, 1803) 08/09/2006 In two samples
Euspira pulchella (Risso, 1826) (¼Polinices
pulchellus) (common necklace shell)
08/09/2006 In one sample
Polycera faeroensis Lemche, 1929 (yellow
edged polycera)
20/08/2006 In images in 2006 and recorded again on 09/06/2007 and in
May and August 2008
Retusa truncatula (Bruguie
`re, 1792) 08/09/2006 In one sample
Rissoa interrupta (J. Adams, 1800) 08/09/2006 In three samples
Rissoa parva (da Costa, 1778) 08/09/2006 In seven samples. On 10/12/2008, there was a very high
abundance on the afterdeck, visible after sweeping silt
away. Samples were of R. parva var. interrupta
(J. Adams, 1798)
Trapania maculata Haefelfinger, 1960 08/09/2006 In one sample. A species that was first reported from Britain
in 1976 and considered nationally rare
Class: Bivalvia
Aequipecten opercularis (Linnaeus, 1758)
(queen scallop)
26/07/04 Small individuals in late July 2004 when noted as ‘in ones and
twos, much less than one per m
2
on vertical hull’. Large
numbers were present by the end of August in 2004 on
rails, decks and sides. By 6 November 2004, individuals
were about 15– 20 mm across but there were many fewer.
There was no settlement observed in 2005 but ‘stragglers’
from 2004 continued to be present and reported up to
70mm across on 15/07/2005. There was another
settlement in 2006 with individuals about 12mm across
on 30/08/2006 and 16mm on 07/10/2006 but sparse. In
three of eight samples on 08/09/2006. None were seen in
2007. A small (10mm) individual was present in a sample
collected on 22/05/2008
Anomiidae indet. 08/09/2006 In four samples
Heteranomia squamula (Linnaeus, 1758) 25/06/2004 Small individuals in photograph on 26/06/2004 and
29/09/2004
Hiatella arctica (Linnaeus, 1767) (red nose) 08/09/2006 In six samples. One in sample on 10/12/2008. Probably a
common member of the cryptofauna
Modiolarca subpicta (Cantraine, 1835)
(¼Modiolarca tumida (Hanley, 1843))
08/09/2006 In four samples
Modiolus modiolus (Linnaeus, 1758) (horse
mussel)
08/09/2006 In one sample
Musculus discors (Linnaeus, 1767) (mat
mussel)
08/09/2006 In one sample
Mya truncata Linnaeus, 1758 08/09/2006 In one sample
Mytilus edulis Linnaeus, 1758 (edible mussel) 26/07/2004 One small individual in photograph on 26/07/2004. Present
in 2004 initially as spat in large numbers on netting and
railings especially. By 25/09/2004, there were clumps of
large individuals on the roof of walkways. Still present as
solitary individuals on sides and as clumps on roof of
walkway on 06/11/2004. Looked for but not found on
30/01/2005 and subsequently in 2005. Most likely eaten by
starfish (Asteria rubens) that settled in late summer 2004.
Present in five of seven samples on 08/09/2006. Possibly
one in ‘oasis’ paint flake under stern on 10/12/2008
Parvicardium ovale (Sowerby G.B. II, 1840) 08/09/2006 In one sample
Class: Cephalopoda
Loligo vulgaris Lamarck, 1798 (common
squid)
06/05/2008 Eggs recorded on 06/05/2008 and in hawse pipe on 22/05/
2008. Other reports of mating behaviour over the reef
Continued
colonization of an artificial reef in south-west england 85
Name Date first
noted
Generalized
maximum abundance
during the year by
end of 2008
Notes
Phylum: ANNELIDA
Class: Polychaeta
Alentia gelatinosa (M. Sars, 1835) 08/09/2006 In three samples
Anaitides longipes Kinberg, 1866 08/09/2006 In four samples
Anaitides mucosa (Oersted, 1843) 08/09/2006 In two samples
Chaetopterus variopedatus Cuvier, 1827 08/09/2006 In one sample. Possibly this species seen as parchment tubes
about 60mm long on decks cleared of silt on 10/12/2008
Eumida sp. 08/09/2006 In one sample
Eunereis longissima Johnston, 1840 08/09/2006 In one sample
Harmothoe impar (Johnston, 1839) 08/09/2006 In six samples
Harmothoe sp. 08/09/2006 In three samples
Hydroides norvegicus Gunnerus, 1768 25/09/2004 Common Subordinate to Pomatoceros sp. (p) in 2004 and 2005 but, by
15/06/2006, recorded as ‘most [relevant] surfaces now
dominated by Hydroides’. Continued high abundance on
vertical surfaces not coated with antifouling paint
subsequently. In six samples on 08/09/2006
Jasmineira elegans Saint-Joseph, 1894 08/09/2006 In two samples
Lepidonotus clava (Montagu, 1808) 08/09/2006 In one sample
Lepidonotus squamatus (Linnaeus, 1758) 08/09/2006 In two samples
Lumbrineris gracilis Ehlers, 1868 08/09/2006 In one sample
Marphysa sanguinea (Montagu, 1815) 08/09/2006 In one sample
Neanthes irrorata (Malmgren, 1867) 08/09/2006 In four samples
Nematonereis hebes Verrill, 1900
(¼N. unicornis)
08/09/2006 In two samples
Nereis pelagica Linnaeus, 1758 08/09/2006 In five samples
Nereis zonata Malmgren, 1867 08/09/2006 In seven samples
Ophryotrocha sp. 08/09/2006 In one sample
Polycirrus sp. 08/09/2006 In two samples
Polydora caeca (O
¨rsted, 1843) 08/09/2006 In one sample
?Polydora ciliata (Johnston, 1838) 17/08/2007 Most likely this species seen living in colonies of Cellepora
pumicosa
Pomatoceros lamarki (Quatrefages, 1866) 08/09/2006 In six samples
Pomatoceros triquetor (Linnaeus, 1758)
(keel worm)
23/04/2004 Abundant One of the first species to settle. Very small tubes on dead
oyster valve photographed four weeks after placement.
High density of separated individuals about 7 mm long
on rudders and other locations near the stern on 12/05/
2004. Approximately 20mm long tubes following black
lettering on signs on 04/06/2004. In eight samples. Several
per 0.01m
2
(Abundant) and some 20mm long on 09/06/
2004. Abundance greatly reduced during winter 2004/05
most likely due to predation by sea urchins and starfish
and low in 2005. Partially usurped by Hydroides
norvegicus after 2005 when sea urchin numbers had
declined but still occurring widely and Superabundant in
places
Protula tubularia (Montagu, 1803) 07/09/2005 Occasional In photograph in 2005 and occasionally seen subsequently
amongst other tube worms
Pterocirrus macroceros (Grube, 1860) 08/09/2006 In one sample
Sabella pavonina Savigny in Sars, 1835
(peacock worm)
25/09/2004 Occasional A few on the stabilizer edges on 25/09/2004. Mainly seen in
the swim-throughs, often attached to cables
Sabellaria spinulosa Leuckart, 1849 (Ross
worm)
08/09/2006 In one sample
Scoletoma sp. 08/09/2006 In two samples
Serpula vermicularis Linnaeus, 1767 (organ
pipe worm)
28/08/2006 In one sample. In images on 28/08/2006
Subadyte pellucida (Ehlers, 1864) 08/09/2006 In five samples
Syllidia armata Quatrefages, 1866 08/09/2006 In five samples
Syllis hyalina Grube, 1863 (¼Typosyllis
hyalina (Grube, 1863))
08/09/2006 In four samples
Syllis variegata Grube, 1860 (¼Typosyllis
variegata (Grube, 1860))
08/09/2006 In four samples
Continued
86 keith hiscock et al.
Name Date first
noted
Generalized
maximum abundance
during the year by
end of 2008
Notes
Phylum: ARTHROPODA
Subphylum Chelicerata
Class Pycnogonida
Achelia echinata Hodge, 1864 08/09/2006 In three samples
Callipallene brevirostris (Johnston, 1837) 08/09/2006 In one sample
Subphylum: Crustacea
Class: Maxillopoda
Infraclass: Cirripedia
Balanus crenatus Bruguie
`re, 1789 (crenulated
acorn barnacle)
23/04/2004 A group of small Balanus crenatus photographed on the hull
four weeks after placement. Very high settlement of
barnacles on 12/05/04 but extremely small on that date.
On 12/05/2004, the size of larger (earlier settled)
individuals was about 5mm across and density about 20
per 0.01m
2
where present. Barnacles were subordinate to
tube worms in coverage and density throughout and
scarcely visible after other species had taken dominance.
There were no specific records of B. crenatus after 2006
Elminius modestus Darwin, 1854
(Australasian barnacle)
20/08/2006 In a photograph on the side of the vessel below an anti-fouled
area
Megatrema anglicum (Sowerby, 1823) 18/03/2009 One found after inspection of about 20 Caryophyllia smithii
Verruca stroemia O.F. Mu¨ller, 1776 (verruca
barnacle)
09/06/2004 Tiny V. stroemia on collected paint blister on 09/06/2004.
Probably this species described as ‘massive settlement of
barnacles’ on 09/06/2004. In all nine samples 08/09/2006.
Also, a very high settlement of barnacles recorded on
20/08/2006. Probably present continuously but not
specifically recorded. In samples on 18/03/2009
Class: Malacostraca
Subclass Eumalacostraca
Superorder Eucarida
Order: Decapoda
Cancer pagurus Linnaeus, 1758 (edible crab) 30/08/2004 Rare Single records in 2004. Possibly Occasional by summer 2008.
Present in fissures and in openings. Present in two sample
08/09/2006
Eurynome sp. 08/09/2006 In one sample.
Galathea strigosa (Linnaeus, 1767) (spiny
squat lobster)
09/06/2007 One recorded
Galatheidae indet. 06/11/2004 Rarely seen and recorded mainly from inside
Hippolyte varians Leach, 1814 09/06/2004 Collected with ectocarpoid algae. In one sample 08/09/2006
Hippolytidae indet. 08/09/2006 In one sample
Inachus phalangium (Leach’s spider crab) 08/09/2006 In one sample
Inachus sp. 08/09/2006 In one sample. One dislodged from roof of walkway by
bubbles on 07/10/2006
Liocarcinus depurator (Linnaeus, 1758)
(harbour crab)
07/09/2005 One inside on silt
Maja squinado (Herbs, 1788) (spiny spider
crab)
06/11/2004 Rare Records of solitary individuals on several occasions
Necora puber (Linnaeus, 1767) (velvet
swimming crab)
06/11/2004 Occasional Small numbers recorded inside especially from 2005
Palaemon serratus (Pennant, 1777) (common
prawn)
15/07/2005 Frequent The earliest record of ‘shrimps’ (on the rudder) was 16/04/
2004. The first record of P. serratus was on 15/07/2005
when there were several full grown individuals seen on the
ceilings inside. The junction between walls and ceiling
inside the reef appears the favoured habitat
Pandalus montagui Leach, 1814 (humpback
prawn)
09/06/2007 Reported on 09/06/2007 and in images on 17/08/2007
Pilumnus hirtellus (Linnaeus, 1761) 08/09/2006 In two samples
Pisidia longicornis (Linnaeus, 1767)
(long-clawed porcelain crab)
08/09/2006 In five samples
Superorder Peracarida
Order: Amphipoda
Ampelisca diadema (Costa, 1853) 08/09/2006 In one sample
Continued
colonization of an artificial reef in south-west england 87
Name Date first
noted
Generalized
maximum abundance
during the year by
end of 2008
Notes
Aoridae indet. 08/09/2006 In two samples
Apherusa bispinosa (Bate, 1857) 08/09/2006 In one sample
Astacilla (¼Arcturella) danmoniensis
(Stebbing, 1874)
10/12/2008 Several emerging from muddy tubes collected on algae
stumps
Astacilla sp. 08/09/2006 In one sample
Caprella acanthifera Leach, 1814 08/09/2006 In two samples
Caprella linearis Linnaeus, 1767 08/09/2006 In four samples
Caprella penantis (Leach, 1814) 08/09/2006 In one sample
Caprella septentrionalis Krøyer, 1838 08/09/2006 In two samples
Caprella tuberculata Bate & Westwood, 1868 08/09/2006 In one sample
Caprellidae indet. 17/08/2007 Caprellid amphipods were frequently seen in images of
Hydrozoa, especially Nemertesia sp. Also using Eunicella
verrucosa as an elevation structure
Dexamine spinosa (Montagu, 1813) 08/09/2006 In one sample
Ericthonius punctatus (Bate, 1857) 08/09/2006 In one sample. Also, large numbers on collected Tubularia
sp. (p) on 10/12/2008
Iphimeda nexa Myers & McGrath, 1987 08/09/2006 In one sample
Jassa falcata (Montagu, 1808) 08/09/2006 (Frequent) In seven samples on 08/09/2006 but most likely present
from soon after placement. Tubicolous amphipods that
appear to be this species in images are abundant in
places of accelerated tidal flow but also widely distributed
on vertical surfaces and amongst worm tubes etc.
Numbers appeared to decline in late winter and increase
in summer
Leptocheirus hirsutimanus (Bate, 1862) 08/09/2006 In one sample
Monocorophium sextonae (Crawford, 1937) 08/09/2006 Present in nine samples. Also, large numbers in muddy tubes
on collected Tubularia sp. (p) on 10/12/2008
Phtisica marina Slabber, 1769 08/09/2006 In seven samples
Pseudoprotella phasma (Montagu, 1804) 08/09/2006 In four samples
Stenothoe monoculoides (Montagu, 1815) 08/09/2006 In four samples
Order: Isopoda
Cymodoce truncata Leach, 1814 08/09/2006 In one sample
Phylum: BRYOZOA (ECTOPROCTA)
Class: Gymnolaemata
Order: Cheilostomatida
Bicellariella ciliata (Linnaeus, 1758) 26/06/2004 In images on two occasions
Bryozoa indet. (orange, encrusting) Occasional No date is given for first observation but orange encrusting
Bryozoa were present in 2006 at least and continue to be
seen as small patches mainly on vertical surfaces. See
Schizomavella linearis
Bugula turbinata Alder, 1857 28/08/2006 Also on 22/05/2008. Rarely seen
Bugula angustiloba (Lamarck, 1816) (¼B.
flabellata (J. V. Thompson, in Gray, 1848))
15/06/2006 Occasional Occasionally in images. In one sample on 08/09/2006
Bugula plumosa (Pallas, 1766) 09/06/2007 In images on 09/06/2007 and 06/05/2008. Rarely seen
Cellaria sp. 28/08/2006 In images. Also on 16/09/2008
Chartella papyracea (Ellis & Solander, 1786) 28/07/2006 In image
Cellepora pumicosa (Pallas, 1766) (orange
pumice bryozoan)
28/07/2006 Abundant Possibly present in images from the stern on 28/01/2006 but
certain record from image on 28/07/2006. Present in two
samples on 08/09/2006 and on 06/10/2006 when ‘several
large colonies’ recorded. Becoming abundant by August
2007. Normally deep orange in colour but tended to be
‘washed-out’ in colour during the winter. A visually
dominant species on the outer part of the reef in 2008 and
early 2009
Electra pilosa (Linnaeus, 1767) (hairy sea
mat)
09/06/2004 Probably this species present on vertical surfaces but
especially notable as star-shaped colonies on fabric lining
of the bridge on 09/06/2004. Continued to be obvious
during summer 2004 but not afterwards although most
likely present. In image on 15/07/2005 and recorded on
16/09/2008. In three samples on 08/09/2006
Continued
88 keith hiscock et al.
Name Date first
noted
Generalized
maximum abundance
during the year by
end of 2008
Notes
Membranipora membranacea (Linnaeus,
1767) (sea mat)
08/09/2006 Abundant Extensively present on kelp (Saccorhiza polyschides) fronds
and on foliose red algae. In four samples on 08/09/2006
Omalosecosa ramulosa (Linnaeus, 1767)
(monkey puzzle bryozoan)
20/08/2006 Present in a photograph. Also recorded on 28/08/2006 and
16/09/2008
Pentapora fascialis foliacea (Pallas, 1766)
(¼P. foliacea (Ellis & Solander, 1786)
(potato crisp bryozoan)
25/03/2006 Occasional Searched for but not found on 28/01/2006. The colony on
25/03/06 had plates and was about 8cm across but
colonies located in summer 2006 were described as
crusts with plates just starting. By 15/06/2007, colonies
were about 15cm across and up to 25cm across on 10/12/
2008. Crustose colonies with erect portions at early
stage of growth were present on several parts of the
foredeck on 18/03/2009. Colonies most likely persisted
where they were protected by structures such as racks
and steps or on vertical surfaces not on main routes for
divers
Schizomavella linearis (Hassall, 1841) 18/03/2009 ?Frequent Identified from a sample from the portside hause pipe but
likely to be the most common orange flat encrusting
bryozoan
Schizoporella sp. 08/08/2006 In one sample
Scruparia chelata (Linnaeus, 1758) 08/09/2006 In two samples
Scrupocellaria reptans (Linnaeus, 1767) 08/09/2006 In two samples
Scrupocellaria sp. 28/01/2006 In images on several occasions
Smittina affinis (Hincks, 1862) 08/09/2006 In one sample
Order: Ctenostomatidae
Alcyonidium diaphanum (Hudson, 1778) (sea
chervil/finger bryozoan)
12/08/2007 One colony in image on 12/08/2007
Class: Stenolaemata
Order: Cyclostomatida
Crisia sp. (white claw sea moss) 25/05/2008 In image. In sample on 18/03/09
Disporella hispida (Fleming, 1828) 08/09/2006 In one sample
Plagioecia patina (Lamarck, 1816)
(¼Diastopora patina (Lamarck, 1816))
28/04/2007 In images on three occasions
Phylum: ENTOPROCTA
Order: Colonialies
Barentsia sp. 08/09/2006 In one sample
Phylum: ECHINODERMATA
Subphylum: Asterozoa
Class: Asteroidea
Asterias rubens Linnaeus, 1758 (common
starfish)
25/09/2004 Common Although observed on the seabed near the reef in
summer 2004, the first records on the reef are of common
50mm individuals on 25/09/2004. There was another
settlement in 2005 when, on 07/09/2005, 10mm
individuals were recorded. Abundance was Common or
Abundant during winter 2004/05 and, with
Psammechinus miliaris, they extensively denuded the
reef. However, size remained small. In four samples on 09/
08/2006
Luidia ciliaris (Philippi, 1837) (seven armed
starfish)
10/12/2008 Many small individuals on the aft deck. On 26/02/2009,
several about 7cm across seen on the aft deck.
Marthasterias glacialis (Linnaeus, 1758)
(spiny starfish)
12/05/2004 Occasional First seen as a large individual on the propeller shaft and
subsequently occasional large individuals on the reef, most
likely having found it from the surrounding sediment
Ophiothrix fragilis (Abildgaard, 1789)
(common brittlestar)
20/08/2006 In five samples on 08/09/2006. A large individual in an image
on 20/08/2006 and small ones in image on 10/12/2008.
Probably widespread but sparse and very cryptic
Ophiura albida Forbes, 1839 (white flecked
sand brittlestar)
08/09/2006 In one sample. In samples on 10/12/2008
Ophiura sp. 20/08/2006 Recorded on two occasions
Subphylum: Crinozoa
Class: Crinoidea
Continued
colonization of an artificial reef in south-west england 89
Name Date first
noted
Generalized
maximum abundance
during the year by
end of 2008
Notes
Antedon bifida (Pennant, 1777) (rosy
featherstar/common featherstar)
25/09/2004 Frequent/Common A large individual was seen on 25/09/2004 and solitary
individuals in November 2004 but not reported again until
September 2006. Juveniles were present on 17/08/2007. By
2008, abundant in places and dominating some spars and
ribs inside. Scattered individuals along the sides. Large
numbers attached to the grid on the helicopter deck in
winter 2008/09 at least
Subphylum: Echinozoa
Class: Echinoidea
Echinus esculentus Linnaeus, 1758 (edible/
common sea urchin)
30/09/2007 Rare Maximum of three seen in one dive. Individuals seen were
large and it might be that small individuals were present
earlier but hidden
Psammechinus miliaris (P.L.S. Mu¨ller, 1771)
(green sea urchin/shore urchin)
25/09/2004 When first observed, there were densities of more than one
per 0.1m
2
in places and on 30/01/2005 approximately five
per 0.1m
2
in places. During winter 2004/2005 and, with
Asterias rubens, they extensively denuded the reef. There
were less observed in June of 2005, many less in July when
a midden of broken shells was found on the foredeck
suggesting that they had fallen prey, probably to fish.
There were still many present in October 2005 but, on
28/01/2006 only one was found by each of two divers. In
seven samples on 08/09/2006. On 07/10/2006, several
were seen amongst the faunal turf and described as
‘heavily disguised’. None were seen in 2007 or 2008
Class: Holothuroidea
Leptopentacta elongata (Du¨ben & Koren,
1846)
09/08/2006 In one sample
?Ocnus lacteus (Forbes & Goodsir, 1839) 15/08/08 Probably this species in image
Thyone fusus (O.F. Mu¨ller, 1776) 08/09/2006 In one sample
Phylum: CHORDATA
Subphylum: Tunicata
Class: Ascidiacea
Ascidia mentula Mu¨ller, 1776 (red sea squirt) 23/04/2005 Occasional
Ascidiella aspersa (Mu¨ ller, 1776) ( fluted sea
squirt)
25/06/2004 Abundant The first individual recorded was seen when it was 30mm
long. Although ‘held-back’ by the urchins and starfish in
the first year, it rapidly became visually dominant with
Ciona intestinalis on the sides of the vessel and patchily
inside so that, by summer 2006, it was Abundant to
Superabundant in places. [Although a certain
identification, some characteristics on this species are at
variance with some descriptions.]
Botrylloides leachii (Savigny, 1816) 15/06/2006 Sometimes difficult to differentiate with Botryllus schlosseri.
Several colonies reported in summer 2008
Botryllus schlosseri (Pallas, 1766) (star sea
squirt)
30/07/2004 Occasional The first record is a ‘probable’. Definitely present on 25/09/
2004. Continued as Occasional on the sides of the reef. In
one sample on 08/09/2006
Ciona intestinalis (Linnaeus, 1758) (yellow
[ringed] sea squirt)
09/06/2004 Frequent The first record is of one individual found on a roof inside
and a patch of scattered individuals over 1m
2
on the
side. By 25/06/2004, there were large numbers but
scattered. By 30/01/2005, they were dominant on black
paint and scattered on grey paint on the hull. There was a
further settlement with many small individuals on 15/07/
2005. Numbers declined in 2006 but there was a
settlement in 2007 with small individuals seen on 15/06/
2007. They were very sparse by summer 2008 and
recorded as ‘odd ones embedded in epifauna’ on 10/12/
2008. In one sample on 08/09/2006
?Corella parallelogramma (Mu¨ller, 1876) (gas
mantle sea squirt)
25/09/2004 Also recorded on 23/03/2006. Most likely this species in
images on 28/08/206 although might be Corella eumyota
?Diplosoma listerianum (Milne-Edwards,
1841) (grey slime sea squirt)
25/05/2008 Identified from image by B. Picton
Continued
90 keith hiscock et al.
Name Date first
noted
Generalized
maximum abundance
during the year by
end of 2008
Notes
Diplosoma spongiforme (Giard, 1872) 18/02/2005 Occasional First sighting was of a large patch on the bow. Probably
Occasional but noted as ‘lots of patches’ in December
2008. Identified from image on 16/09/2008 by B. Picton
Stolonica socialis Hartmeyer, 1903 (orange
sea squirt)
22/05/2008 Rare Observation was of a small patch on the port side below the
bridge
Styela clava Herdman, 1881 (leathery sea
squirt)
23/04/2005 Occasional A few present in 2005 but more abundant in early 2006 with
a ‘grove’ of about 20 individuals described on 15/06/2006
on the port side. There were very few in 2007 and by
summer 2008, none could be found. However, on
19/09/2008 occasional small individuals were present and,
on 18/03/2009, two large individuals were seen. In two
samples on 08/09/2006
Subphylum: Vertebrata
Superclass: Pisces
Balistes capriscus Gmelin, 1789 (¼Balistes
carolinensis Gmelin, 1789) (grey trigger
fish)
07/2008 Reported by D. Peake
Callionymus lyra Linnaeus, 1758 (dragonet) 21/06/2004 Also on 17/08/2007. Observed from photographs
Centrolabrus exoletus (Linnaeus, 1758) (rock
cook)
06/05/2008 Occasional First recorded in summer 2008 when groups were present
amongst seaweeds especially on shallowest parts
Chelon labrosus (Risso, 1827) (thick-lipped
grey mullet)
07/10/2006 Often present in late summer as shoals
Chirolophis ascanii (Walbaum, 1792)
(Yarrell’s blenny)
25/05/2008 One. Yarrell’s blenny (a northern species) was observed at
several locations near Plymouth in spring 2008
Conger conger (Linnaeus, 1758) (conger eel) 12/06/2004 Rare Rarely seen and possibly not resident during first five years
Ctenolabrus rupestris (Linnaeus, 1758)
(goldsinny wrasse)
18/08/2006 Occasional Although reported on 06/11/2004, this wrasse was not
reliably seen until summer 2006. Possibly becoming
frequent during the summer by 2008
Dicentrarchus labrax (Linnaeus, 1758) (bass) 06/05/2008
Labrus bergylta Ascanius, 1767 (ballan
wrasse)
29/03/2004 Occasional The first was seen only 45 hours after sinking. Subsequently,
mainly sporadic records but consistently small numbers in
2008. Three or four large individuals foraging on the
foredeck on 18/03/2009
Labrus mixtus Linnaeus, 1758 (cuckoo
wrasse)
06/05/2008 Rare One female seen on 19/09/2008. A late arrival and very few
compared with nearby wrecks
Molva molva (Linnaeus, 1758) (ling) 15/09/2007
Parablennius gattorugine (Linnaeus, 1758) 06/11/2004 Another reported on 09/06/2007. In image on 25/05/2008
Pollachius pollachius (Linnaeus, 1758)
(pollack)
30/03/2004 Common Solitary individuals in first year, sparse and generally small in
2005, sparse in 2006 but abundant at the edges of the reef
by 2007 and subsequently. Less in mid-winter
Pomataschistus sp. 17/08/2007 One inside the reef
Solea solea (Linnaeus, 1758) (sole) 30/08/2004 One on the aft deck
Symphodus (¼Crenilabrus)melops
(Linnaeus, 1758) (corkwing wrasse)
30/01/2005 Occasional One seen on the walkways in early 2005 but observed
numbers remained very low. A few seen on 18/03/2009
?Syngnathus acus Linnaeus, 1758 (greater
pipefish)
24/04/2004 Reported by G. Rhodes on aft deck
Taurulus bubalis (Euphrasen, 1786)
(long-spined sea scorpion)
06/11/2004 Rare Often photographed
Thorogobius ephippiatus (Lowe, 1839)
(leopard spotted goby)
17/06/2007 Rare Present in silty corners inside the reef
Trachurus trachurus (Linnaeus, 1758) (scad) 30/08/2004 Shoals in late summer
Trisopterus luscus (Linnaeus, 1758) (bib or
pouting)
30/08/2004 Occasional Small numbers under the hull and inside the reef
Trisopterus minutus (Linnaeus, 1758) (poor
cod)
12/04/2004 Frequent Probably this species seen as a shoal of 20– 30 (D. Pelley) on
12/04/2006 and on 23/04/2004, a shoal of very small
individuals under the stern. Numbers had subsequently
consolidated but, by the end of 2008, it was still not as
abundant as on nearby wrecks
Zeugopterus punctatus (Bloch, 1787)
(topknot)
06/11/2004 In photographs on 06/11/2004 (J. Hagger) and 03/03/2005.
Two together on TBT anti-fouling paint coated areas on
26/02/2009 and two together inside on 18/03/2009
Zeus faber Linnaeus, 1758 (John Dory) 07/09/2005 A wandering predator found especially on wrecks
colonization of an artificial reef in south-west england 91
There is a record of Ostrea edulis from samples collected in
September 2006 but shells of that species persisted from the
vessel’s tenure in Portsmouth and the species has not been
seen alive in situ. The record has not been included.
APPENDIX 2
Comparison of conspicuous species present on natural
bedrock reefs from locations off the coast east of Plymouth
and on surfaces of ‘Scylla’ by the end of 2008 (see Appendix
1). (Data from tables 12 & 13 of Hiscock & Moore (1986),
from surveys undertaken by Devon Wildlife Trust in 1996
and from personal observation in the same period as the
‘Scylla study.) P, present, no record of abundance, usually a
single record; ( ), seasonal abundance. Species recorded as
Rare in one habitat only have been excluded. Species names
were those current in www.marinespecies.org on 30 July
2009. Abundances are approximately those given in
Appendix 9 of Hiscock (1996).
Natural rock
reefs—lower
infralittoral/
upper
circalittoral
Natural rock
reefs—
circalittoral
‘Scylla’,
upward facing
surfaces
(decks, not
including
shallowest
parts)
‘Scylla’, outward
facing external
surfaces (sides of
the hull and
super-structure)
‘Scylla’, internal
surfaces (walls of
and structures in
swim-throughs)
Algae
Bonnemaisonia asparagoides CF P- -
Brongniartella byssoides CF A- -
Calliblepharis ciliata O- -- -
Callophyllis lacineata O- F- -
Carpomitra costata O- -- -
Corallinacea indet (pink encr.) F F - - -
Cryptopleura ramosa (and as Acrosorium uncinatum)F O - - -
Delleseria sanguinea FO C- -
Desmarestia aculeata R- P- -
Dictyopteris polypodiodes FO O- -
Dictyota dichotoma OO O- -
Dilsea carnosa O- F- -
Drachiella spectabilis OO -- -
Halarachnion ligulatum OR -- -
Halopteris filicina F- F- -
Heterosiphonia plumosa F- A- -
Hypoglossum hypoglossoides -R F- -
Kallymenia reniformis OO C- -
Myriogramme heterocarpum O- -- -
?Myriogramme bonnemaisonii -O -- -
Phyllophora crispa OR P- -
Polyneura gmelinii FO -- -
Polyneura hilliae O- P- -
Pterothamnion plumula O- P- -
Rhodophyllis sp. F O - - -
Rhodymenia pseudopalmata OO -- -
Schottera nicaeensis OO -- -
Scinaia turgida -- C- -
Sponges
Amphilectus fucorum -O -- -
Axinella damicornis - O/F - - -
Axinella dissimilis - O/C - - -
Axinella infundibuliformis -O -- -
Ciocalypta penicillus -O -- -
Cliona celata RF -- -
Halichondria cf. bowerbankii -O -P -
Hemimycale columella OO -R -
Leucosolenia botryoides -O -O -
Oscarella lobularis -- -O R
Pachymatisma johnstonia -O -- -
Polymastia boletiformis - O/F - - -
Raspailia hispida -F -- -
Raspailia ramosa -O -- -
Stelligera stuposa -O -- -
Continued
92 keith hiscock et al.
Natural rock
reefs—lower
infralittoral/
upper
circalittoral
Natural rock
reefs—
circalittoral
‘Scylla’,
upward facing
surfaces
(decks, not
including
shallowest
parts)
‘Scylla’, outward
facing external
surfaces (sides of
the hull and
super-structure)
‘Scylla’, internal
surfaces (walls of
and structures in
swim-throughs)
Sycon ciliatum -R -O -
Tethya citrina -O -- -
Sea anemones and corals
Actinothoe
¨sphyrodeta OO -? -
Alcyonium digitatum F C F C/A F
Alcyonium glomeratum -O -R -
Caryophyllia smithii OF OR -
Corynactis viridis -F OF O
Eunicella verrucosa -A FC -
Metridium senile -- CS F
Parazoanthus axinellae -O -- -
Sagartia elegans -P FC -
Sagartiogeton laceratus -- FF F
Sagartia troglodytes O- OO O
Urticina felina -R OO-
Hydroids
Abietinaria abietina OO -- -
Aglaophenia tubulifera -F -- -
Ectopleura larynx - - (F) (F/C) (O)
Halecium halecinium O- -- -
Nemertesia antennina OF AO O
Nemertesia ramosa O F R/O - -
Obelia dichotoma -O PP -
Plumularia setacea -O PP -
Sertularia gayi -F -R -
Tubularia indivisa - R (O) (O) -
Polychaetes
Filograna implexa/Salmacina dysteri -O -- -
Hydroides norvegicus -P PC ?
Pomatoceros triquetor OO CF C
Protula tubularia -R -O R
Sabella pavonina -- -R O
Crustacea: Cirripedia
Verruca stroemia OO PP ?
Crustacea: Decapoda
Cancer pagurus -O R- R
Homarus gammarus RR -- -
Necora puber -R -- O
Maja squinado OO R- -
Palaemon serratus -P -- F
Crustacea: Amphipoda
Amphipoda indet. (tubes)/Jassa falcata - R (F) (F) -
Molluscs
Calliostoma zizyphinum -O -- -
Bryozoans
Alcyonidium diaphanum - O (R) - -
Bugula angustloba (¼B. flabellata)OO-R-
Bugula turbinata -P -R -
Chartella papyracea -O -R -
Crisiidae indet. - O - P -
Cellepora pumicosa F O F/C C/A C/A
Electra pilosa FO PP -
Omalosecosa ramulosa -O -R -
Parasmittina trispinosa OF -- -
Pentapora fascialis foliacea -F OO-
Schizomavella linearis O - ?F ?O -
Continued
colonization of an artificial reef in south-west england 93
Correspondence should be addressed to:
K. Hiscock
Marine Biological Association
Citadel Hill, Plymouth
PL1 2PB, UK
email: khis@mba.ac.uk
Natural rock
reefs—lower
infralittoral/
upper
circalittoral
Natural rock
reefs—
circalittoral
‘Scylla’,
upward facing
surfaces
(decks, not
including
shallowest
parts)
‘Scylla’, outward
facing external
surfaces (sides of
the hull and
super-structure)
‘Scylla’, internal
surfaces (walls of
and structures in
swim-throughs)
Scrupocellaria spp. - O - P -
Echinodermata
Antedon bifida -- FF C
Ascidia mentula -O -OO
Asterina gibbosa OO -- -
Asterias rubens FF AC O
Aslia lefevrei RO -- -
Echinus esculentus OC -R R
Henricea sp. - O - - -
Holothuria forskali -C -- -
Marthasterias glacialis OF OO -
Pawsonia saxicola -O -- -
Ascidiacea
Ascidiella aspersa -R OA C
Ascidia mentula -O -OO
Botryllus schlosseri RO OO O
Ciona intestinalis -- -F F
Clavelina lepadiformis OO -- -
Diplosoma sp./spongiforme -O OO O
Morchellium argus -O -- -
Stolonica socialis -F -R -
Styela clava -- -O -
Fish
Centrolabrus exoletus FF O- -
Ctenolabrus rupestris OO OO O
Labrus bergylta -O OO-
Labrus mixtus OF R- -
Pollachius pollachius OO CO -
Parablennius gattorugine -O -R R
Symphodus (¼Crenilabrus)melops R- O- -
Thorogobius ephippiatus -O -- R
Trisopterus luscus OO -- O
Trisopterus minutus -R -- F
94 keith hiscock et al.