MarLIN

information on the biology of species and the ecology of habitats found around the coasts and seas of the British Isles

Caryophyllia (Caryophyllia) smithii with faunal and algal crusts on moderately wave-exposed circalittoral rock

08-11-2016

Summary

UK and Ireland classification

UK and Ireland classification

Description

This biotope is typically found on the upper and vertical faces of exposed and moderately wave-exposed circalittoral rock, subject to very little water movement. Where this variant is found on slightly more wave-exposed sites, it tends to be found towards the bottom of its depth range. The rocky substratum has a grazed appearance, with encrusting red algae. Diversity of species is very low, possibly due to grazing pressure from the sea urchin Echinus esculentus. From afar, there is little evident epifauna attached to the rocks apart from the white, calcareous tubes of the polychaete Spirobranchus triqueter and the cup-coral Caryophyllia smithii. In addition, bryozoan crusts such as Parasmittina trispinosa are frequently seen. Under closer inspection, a few more species become apparent but few are typically characterising of this particular variant. The echinoderms Antedon bifida, Asterias rubens, Ophiothrix fragilis, Marthasterias glacialis, Ophiocomina nigra and Crossaster papposus are occasionally present. Sparse clumps of hydroids such as Halecium halecinum, Kirchenpaueria pinnata and Nemertesia antennina may be found attached to rocky outcrops or boulders. Small specimens of Alcyonium digitatum may be present. The ascidians Ciona intestinalis,Clavelina lepadiformis and Ascidia mentula also occur in this variant but are found in greater numbers in other biotopes. The top shells Calliostoma zizyphinum, Gibbula cineraria, and the saddle oyster Pododesmus patelliformis may be seen on the rock surface whilst the crab Cancer pagurus may be seen under boulders and in crevices. The anemone Metridium senile may be found under rocky overhangs and on the sides of boulders. (Information from Connor et al., 2004).

Depth range

10-20 m, 20-30 m

Additional information

-

Listed By

Listed By

- none -

Further information sources

Further information sources

Search on:

Sensitivity reviewHow is sensitivity assessed?

Sensitivity characteristics of the habitat and relevant characteristic species

CR.MCR.EcCr.FaAlCr.Adig, CR.MCR.EcCr.FaAlCr.Sec, CR.MCR.EcCr.FaAlCr.Pom & CR.MCR.EcCr.FaAlCr.Car are within the “Faunal and algal crusts on exposed to moderately wave-exposed circalittoral rock” FaAlCr habitat complex.  All these biotopes have a sparse appearance due to grazing, mainly by Echinus esculentus, which combined with water depth, is thought to be a limiting factor controlling the growth of algal and increasing the dominance of faunal turfs. Their sensitivities are probably similar. Therefore, they are reviewed as a group, and the resultant reviews and sensitivity assessments presented separately.

Alcyonium digitatum is common to all biotopes however colonies are generally smaller and have lower biomass within CR.MCR.EcCr.FaAlCr.Pom and CR.MCR.EcCr.FaAlCr.Car. Securiflustra securifrons is also an important erect faunal species within  CR.MCR.EcCr.FaAlCr.Sec. In CR.MCR.EcCr.FaAlCr.Car Caryophyllia smithii is an important characterizing species.  Encrusting fauna such as Spirobranchus triqueter (syn. Pomatoceros triqueter) and the bryozoan Parasmittina trispinosa are also important characterizing species across these biotopes (Connor et al., 2004).

For this sensitivity assessment, Alcyonium digitatum, Caryophyllia smithii, Echinus esculentus, the encrusting bryozoan Parasmittina trispinosa, Securiflustra securifrons and Spirobranchus triqueter and are the primary foci of research as the key characterizing species defining CR.MCR.EcCr.FaAlCr.Adig, CR.MCR.EcCr.FaAlCr.Sec, CR.MCR.EcCr.FaAlCr.Pom & CR.MCR.EcCr.FaAlCr.Car.  Grazing pressure is the most important structuring feature of the biotope after depth.  Therefore, the sensitivity of grazers, e.g. Echinus esculentus  is probably crucial to the sensitivity of the biotope. Other erect hydroids and bryozoans, e.g. Abietinaria abietina, Nemertesia antennina, Thuiaria thuja and Cellepora pumicosa are also thought important to the character of these biotopes, however, were not assessed within this review.

Resilience and recovery rates of habitat

Spirobranchus triqueter and Parasmittina trispinosa are two visually dominant encrusting species within CR.MCR.EcCr.FaAlCr.Car, CR.MCR.EcCr.FaAlCr.Sec, CR.MCR.EcCr.FaAlCr.Pom and CR.MCR.EcCr.FaAlCr.Adig. Spirobranchus triqueter is a species of serpulid worm which forms encrusting tubes, typically 2-3 cm long, on rock and shell surfaces. Once settled onto the substratum the worm forms a temporary delicate semi-transparent tube. Mature tubes are formed by a secretion of calcium carbonate. Growth rate was recorded by Dons (1927) to be 1.5 mm per month, although this varies with external conditions. Hayward & Ryland (1995a) and Dons (1927) stated that sexual maturity is reached in approximately 4 months. Spirobranchus triqueter is also a visually dominant species within mobile and/or disturbed biotopes e.g. SS.SCS.CCS.SpiB (Connor et al., 2004), indicating this species is either highly resilient to physical disturbance or has a rapid recolonization rate. In agreement, Hiscock (1983) noted that a community, under conditions of scour and abrasion from stones and boulders moved by storms, developed into a community consisting of fast growing species such as Spirobranchus triqueter. Off Chesil Bank, the epifaunal community dominated by Spirobranchus triqueter, Balanus crenatus and Electra pilosa, decreased in cover in October, was scoured away in winter storms, and was recolonized in May to June (Warner, 1985). Hayward & Ryland (1995a) noted that Spirobranchus triqueter lived approximately 1.5 years. Spirobranchus triqueter are broadcast spawners and are therefore likely to have large dispersal capacity. Larvae are pelagic for about 2-3 weeks in the summer, however, in the winter this amount of time increases to about 2 months (Hayward & Ryland, 1995a). The time of reproduction is variable, Hayward & Ryland (1995) and Segrove (1941) suggested that Spirobranchus triqueter reproduction probably took place throughout the year but peaked in spring and summer. However, Moore (1937) noted Spirobranchus triqueter breeding only took place in April in Port Erin, Isle of Man. Castric-Fey (1983) studied variations in settlement rate and concluded that, although the species settled all year round, very rare settlement was observed during winter and maximum settlement occurred in April, June, August and Sept-Oct. Studies in Bantry Bay  revealed a single peak in recruitment during summer (especially July and August) with very little recruitment at other times of the year (Cotter et al., 2003).Alcyonium digitatum is a colonial species of soft coral with a wide distribution in the North Atlantic, recorded from Portugal (41°N) to Northern Norway (70°N) as well as on the east coast of North America (Hartnoll, 1975; Budd, 2008). Colonies consist of stout “finger like” projections (Hartnoll, 1975) which can reach up to 20 cm tall (Budd, 2008) and can dominate circalittoral rock habitats (as in CR.HCR.FaT.CTub.Adig; Connor et al., 2004). Alcyonium digitatum colonies are likely to have a lifespan that exceeds 20 years as colonies have been followed for 28 years in marked plots (Lundälv, pers. comm., in Hartnoll, 1998).  Colonies that were 10-15 cm in height were aged at between 5 and 10 years old (Hartnoll, unpublished). Most colonies are unisexual, with the majority of individuals being female.  Sexual maturity is predicted to occur, at its earliest, when the colony reaches its second year of growth. However the majority of colonies are not predicted to reach maturity until their third year (Hartnoll, 1975).

Alcyonium digitatum spawns from December and January. Gametes are released into the water where fertilization occurs. The embryos are neutrally buoyant and float freely for seven days, when they give rise to actively swimming lecithotrophic planulae that may have an extended pelagic life before they eventually settle (usually within 1 or 2 further days) and metamorphose to polyps (Matthews, 1917; Hartnoll, 1975; Budd, 2008). In laboratory experiments, several larvae of Alcyonium digitatum failed to settle within 10 days, presumably finding the conditions unsuitable. These larvae were able to survive 35 weeks as non-feeding planulae. After 14 weeks some were still swimming and after 24 weeks the surface cilia were still active although they rested on the bottom of the tanks. By the end of the experiment, at 35 weeks the larvae had shrunk to a diameter of 0.3 mm. The ability to survive for long periods in the plankton may favour the dispersal and eventual discovery of a site suitable for settlement (Hartnoll, 1975).  The combination of spawning in winter and the long pelagic lifespan may allow a considerable length of time for the planulae to disperse, settle and metamorphose ahead of the spring plankton bloom. Young Alcyonium digitatum will consequently be able to take advantage of an abundant food resource in spring and be well developed before the appearance of other organisms that may otherwise compete for the same substrata.  In addition, because the planulae do not feed whilst in the pelagic zone they do not suffer by being released at the time of minimum plankton density.  They may also benefit by the scarcity of predatory zooplankton which would otherwise feed upon them (Hartnoll, 1975).

Caryophyllia smithii is a small (max 3 cm across) solitary coral common within tide swept sites of the UK (Wood, 2005), distributed from Greece (Koukouras, 2010) to the Shetland Islands and southern Norway (NBN, 2015). It was suggested by Fowler & Laffoley (1993) that Caryophyllia smithii was a slow growing species (0.5-1mm in horizontal dimension of the corallum per year) which in turn suggests that inter-specific spatial competition with colonial faunal or algae species are important factors in determining local abundance of Caryophyllia smithii (Bell & Turner, 2000). Caryophyllia smithii reproduces sexually; sessile polyps discharge gametes typically from January-April, gamete release is most likely triggered by seasonal temperature increases, gametes are fertilized in the water column and develop into a swimming planula that then settles onto suitable substrata. The pelagic stage of the larvae may last up to 10 weeks, which provides this species with a good dispersal capability (Tranter et al., 1982).

Whomersley & Picken (2003) documented epifauna colonization of offshore oil platforms in the North Sea from 1989-2000. On all platforms, Mytilus edulis dominated the near surface community. For the first three years, hydroids and tubeworms dominated the community below the mussel band. However, the hydroid community was later out-competed by other more climax communities.  Recruitment of Alcyonium digitatum and Metridium senile began at 2-5 years (dependent on the oil rig).  The community structure and zonation differed between the four rigs, however generally after four years Metridium senile had become the dominant organism below the mussel zone to approximately 60-80 m Below Sea Level (BSL). Zonation differed between oil rigs but Alcyonium digitatum was the dominant organism from approximately 60-90 m BSL.

The Scylla was intentionally sunk on the 27th March 2004 in Whitsand Bay, Cornwall to act as an artificial reef. Hiscock et al. (2010) recorded the succession of the biological community on the wreck for five years following the sinking of the ship. Initially, the wreck was colonized by opportunistic species /taxa; e.g. filamentous algae, hydroids, serpulid worms and barnacles. Tubularia sp. were early colonizers, appearing within a couple of months after the vessel was sunk. Metridium senile appeared late in the summer of the first year but didn’t become visually dominant until 2007 (three years after the vessel was sunk). Sagartia elegans was recorded within the summer of 2005, and by the end of 2006 was well established. Corynactis viridis was first recorded in the summer of the first year and quickly formed colonies via asexual reproduction. Urticina felina was first recorded at the end of august 2006 (two years after the vessel was sunk), and by summer 2008 had increased in abundance. Alcyonium digitatum was first recorded in early summer 2005, a year after the vessel was sunk.  Within one year of growth, colonies had grown to nearly full size but did not become a visually dominant component of the community until 2009 (five years after the vessel had been sunk). The authors noted that erect branching Bryozoa (such as Securiflustra securifrons) are not a common part of rocky reef communities to the west of Plymouth and had not colonized ‘Scylla’ to any great extent by the end of the study, although several species of erect bryozoans were recorded, which included Chartella papyracea in August 2006 (two years after the vessel was sunk). Caryophyllia smithii was noted to colonize the wreck a year after the vessel was sunk.

Parasmittina trispinosa is an encrusting bryozoan which is described as having a “cosmopolitan” distribution by Powell (1971). In the North East Atlantic, it is recorded from all coasts of the British Isles (NBN, 2015) to the Iberian Peninsula (Ramos, 2010). Parasmittina trispinosa is also recorded from the Panama Cana (Powell (1971) to the Gulf of Alaska (Soule & Soule, 2002) in the Pacific ocean. Little information regarding the life history traits of Parasmittina trispinosa was found. Eggleston (1972a) noted In the Isle of Man, a peak in reproductive and vegetative growth was not well marked in Parasmittina trispinosa, and the number of embryos present is fairly constant throughout the year (Eggleston, 1972a). Indicating that Parasmittina trispinosa could potentially reproduce annually within the UK. However, due to the lack of available literature regarding Parasmittina trispinosa, it’s resilience cannot be assessed with sufficient confidence.

Echinus esculentus is a sea urchin found within North East Atlantic, recorded from Murmansk Coast, Russia to Portugal (Hansson, 1998). Echinus esculentus is estimated to have a lifespan of 8-16 years (Nichols, 1979; Gage, 1992a) and reach sexual maturity within 1-3 years (Tyler-Walters, 2008). Maximum spawning occurs in spring although individuals may spawn over a protracted period throughout the year. Gonad weight is at its maximum in February/March in English Channel (Comely & Ansell, 1988) but decreases during spawning in spring and then increases again through summer and winter until the next spawning season. Spawning occurs just before the seasonal rise in temperature in temperate zones but is probably not triggered by rising temperature (Bishop, 1985). Echinus esculentus is a broadcast spawner, with a complex larval life history that includes a blastula, gastrula and a characteristic four armed echinopluteus stage, which forms an important component of the zooplankton. MacBride (1914) observed planktonic larval development could take 45-60 days in captivity. Recruitment is sporadic or variable depending on locality, e.g. Millport populations showed annual recruitment, whereas few recruits were found in Plymouth populations during Nichols studies between 1980-1981 (Nichols, 1984). Bishop & Earll (1984) suggested that the population of Echinus esculentus at St Abbs had a high density and recruited regularly whereas the Skomer population was sparse, ageing and had probably not successfully recruited larvae in the previous six years (Bishop & Earll, 1984). Comely & Ansell (1988) noted that the largest number of Echinus esculentus occurred below the kelp forest.

Echinus esculentus is a mobile species and could, therefore, migrate and re-populate an area quickly if removed.  For example, Lewis & Nichols (1979a) found that adults were able to colonize an artificial reef in small numbers within 3 months and the population steadily grew over the following year. If completely removed from a site and local populations are naturally sparse then recruitment may be dependent on larval supply which can be highly variable. As suggested by Bishop & Earll (1984) the Skomer, Wales Echinus esculentus population had most likely not successfully recruited for 6 years which would suggest the mature population would be highly sensitive to removal and may not return for several years. On 19th November 2002, the Prestige oil tanker spilt 63 000t of fuel 130 nautical miles off Galicia, Spain. High wave exposure and strong weather systems increased mixing of the oil to “some” depth within the water column, causing sensitive faunal communities to be effected. Preceding and for nine years following the oil spill, the biological community of Guéthary, France was monitored. Following the oil spill, taxonomic richness decreased significantly from 57 recorded species to 41, which included the loss of Echinus esculentus from the site. Post-spill taxonomic richness had increased to pre-spill levels within 2-3 years and Echinus esculentus had returned (Castège et al., 2014).

Resilience assessment. Spirobranchus triqueter can reportedly reach maturity within approximately four months and is often a dominant component of physically disturbed habitats, indicating rapid colonization rates (<1 year) and/or physical robustness. Echinus esculentus can reportedly reach sexual maturity within 1-2 years (Tyler-Walters, 2008), however, as highlighted by Bishop & Earll (1984) and Castège et al. (2014) recovery may take 2-6 years (possibly more if local recruitment is poor).  Alcyonium digitatum can recruit onto bare surfaces within two years, however, may take up to five years to become a dominant component of the community (Whomersley & Picken, 2003; Hiscock et al., 2010). Caryophyllia smithii colonized the wreck of the Scylla within a year, however, this may be due to the time of the vessel sinking and if removed recovery may take up to two years. If the community is completely removed from the habitat (resistance of 'None') resilience has been assessed as ‘Medium’, however, if resistance has been assessed as 'Low',  'Medium' or 'High' then resilience will be assessed as ‘High’.  Pressures that result in a significant reduction in (or loss of) the Echinus population would probably result in a change in the character (or loss) of the biotope due to the reduction in grazing pressure, in which case recovery of the biotope would depend on the recovery of the Echinus population.

Hydrological Pressures

 ResistanceResilienceSensitivity
Medium High Low
Q: Low
A: NR
C: NR
Q: High
A: High
C: High
Q: Low
A: Low
C: Low

The majority of the records of CR.MCR.EcCr.FaAlCr.Car occur in west Scotland, but numerous records occur in south-west Ireland and the south-west of England. Sea surface temperature across this distribution ranges from northern to southern Sea Surface Temperature (SST) of 8-16°C in summer and 6-13°C in winter (Beszczynska-Möller & Dye, 2013). Alcyonium digitatum is described as a northern species by Hiscock et al. (2004) but is distributed from Northern Norway (70°N) to Portugal (41°N) (Hartnoll, 1975; Budd, 2008). Securiflustra securifrons is recorded from Kongsfjorden, Svalbard (Gontar et al., 2001) to the Iberian peninsula in both Spain and Portugal (Ramos, 2010). Across this latitudinal gradient both species are likely to experience a range of temperatures from approximately 5-18°C (Seatemperature, 2015). Spirobranchus triqueter is described as a temperate species by Kupriyanova & Badyaev (1998). Spirobranchus triqueter is recorded as abundant in sub-tidal habitats of Trondheimsfjord (63°N) (Kukliński & Barnes, 2008); no survey reports could be found further north. The most southerly records are from the Iberian peninsula, Spain (Ramos, 2010) as well from the Alexandria coast of Egypt, Mediterranean Sea (Dorgham et al., 2013). Across this latitudinal gradient, Spirobranchus triqueter is likely to experience a range of temperatures from approximately 5-28°C (Seatemperature, 2015). Bishop (1985) suggested that Echinus esculentus cannot tolerate high temperatures for prolonged periods due to increased respiration rate and resultant metabolic stress. Ursin (1960) reported Echinus esculentus occurred at temperatures between 0-18°C in Limfjord, Denmark. Bishop (1985) noted that gametogenesis occurred at 11-19°C however, continued exposure to 19°C disrupted gametogenesis. Embryos and larvae developed abnormally after 24hr exposure to 15°C but normally at 4, 7 and 11°C (Tyler & Young, 1998). Mature examples of Caryophyllia smithii are recorded in Greece (Koukouras, 2010), and are, therefore, unlikely to be physically affected at the benchmark. However, Tranter et al. (1982) suggested Caryophyllia smithii reproduction was cued by seasonal increases in temperature. Therefore, unseasonal increases in temperature may disrupt natural reproductive processes and negatively influence recruitment patterns. Mature examples of Caryophyllia smithii were recorded in Greece.

Sensitivity assessment. Spirobranchus triqueter records from the Alexandria coast of Egypt, Mediterranean Sea (Dorgham et al., 2013) indicate the species is unlikely to be affected at the benchmark level. An increase in sea surface temperature of 2°C for a period of 1 year combined with high temperatures may approach the upper temperature threshold of Alcyonium digitatum, Echinus esculentus, and may, therefore, cause minor declines in abundance. There was insufficient evidence to assess the effect of a short-term increase in temperature of 5°C on Alcyonium digitatum however it may disrupt Echinus esculentus spawning in southern examples of this biotope. If reproduction in Caryophyllia smithii was disrupted by a short-term or long-term change in temperature then recruitment would be impaired for the affected period (one year) but recover subsequently as long as adults survived. Therefore, resistance has been assessed as ‘Medium’, resilience as ‘High’ and sensitivity has been assessed as ‘Low’.

Medium High Low
Q: Low
A: NR
C: NR
Q: High
A: High
C: High
Q: Low
A: Low
C: Low

The majority of the records of CR.MCR.EcCr.FaAlCr.Car occur in north-west Scotland, but numerous records occur in south-west Ireland and the south-west of England. Sea surface temperature across this distribution ranges from northern to southern Sea Surface Temperature (SST) of 8-16°C in summer and 6-13°C in winter (Beszczynska-Möller & Dye, 2013).

Alcyonium digitatum is described as a northern species by Hiscock et al. (2004) but is distributed from northern Norway (70°N) to Portugal (41°N) (Hartnoll, 1975; Budd, 2008). Across this latitudinal gradient, both species are likely to experience a range of temperatures from approximately 5-18°C. Alcyonium digitatum was also reported to be apparently unaffected by the severe winter of 1962-1963 where air temperature reached -5.8°C (Crisp, 1964). Securiflustra securifrons is recorded from Kongsfjorden, Svalbard (Gontar et al., 2001) to the Iberian peninsula in both Spain and Portugal (Ramos, 2010). Echinus esculentus has been recorded from the Murmansk Coast, Russia. Due to the high latitude at which Echinus esculentus can occur it is unlikely to be affected at the pressure benchmark. 

Spirobranchus triqueter is described as a temperate species by Kupriyanova & Badyaev (1998). Spirobranchus triqueter is recorded as abundant in subtidal habitats of Trondheimsfjord (63°N) (Kukliński & Barnes, 2008); no survey reports could be found further north. Averaged across several years the lowest winter temperature within Trondheimsfjord is 4.9°C (Seatemperature, 2015). Below 7°C Spirobranchus triqueter is unable to build calcareous tubes (Thomas, 1940). Mature adults may survive a decrease at the pressure benchmark, however, larvae may not be able to attach to the substratum (Riley & Ballerstedt, 2005) if a temperature decrease co-occurred with cold winter temperatures in the UK. However, settlement is reportedly low within winter (see resilience section), and therefore the effects on recruitment are likely to be minor.

Caryophyllia smithii has a northern range limit in the Shetland Isles and southern Norway (NBN, 2015), and may, therefore, be negatively affected by cold temperatures in northern examples of this biotope.

Sensitivity assessment. Alcyonium digitatum, Echinus esculentus have northern/boreal distributions and are unlikely to be affected at the benchmark level. Spirobranchus triqueter is unable to build calcareous tubes at low temperatures, however, during winter, this is unlikely to have any significant effects on recruitment. In addition, the depth of the biotope probably protects it from short-term acute decreases in temperature. The important characterizing Caryophyllia smithii is close to its northern distribution limit within the British Isles and a decrease at the benchmark level may result in some mortality in northern examples of the biotope.  Therefore, resistance is, therefore ‘Medium’, resilience is ‘High’ and sensitivity is ‘Low’.

Low High Low
Q: Low
A: NR
C: NR
Q: High
A: High
C: High
Q: Low
A: Low
C: Low

Lyster (1965) tested the tolerance of Spirobranchus triqueter larvae to various hyper and hypo salinity treatments. Larvae were placed in cultures ranging from 0-90‰ and notes were made on the time taken for larvae to die or begin displaying abnormal behaviour. Spirobranchus triqueter larvae were tolerant of salinities ranging from 20-50‰, above 50‰ caused high mortality. Spirobranchus triqueter is, therefore, unlikely to be affected at the pressure benchmark.

Echinoderms are generally stenohaline and possess no osmoregulatory organ (Boolootian, 1966). Therefore, an increase in salinity may cause Echinus esculentus mortality. Alcyonium digitatum’ distribution and the depth at which it occurs also suggest it would not likely experience regular salinity fluctuations and therefore tolerate significant increases in salinity. 

Sensitivity assessment. CR.MCR.EcCr.FaAlCr.Car is restricted to full salinity (Connor et al., 2004), therefore, it is likely that an increase in salinity to >40‰ (e.g. from hypersaline, brine effluents) may cause a decline in the abundance of Alcyonium digitatum and Echinus esculentus. A reduction in Echinus grazing is likely to alter the character of the biotope. Therefore, resistance has been assessed as ‘Low’, resilience as ‘High’. Sensitivity has been assessed as ‘Low’. Due to the lack of information regarding salinity effects on Alcyonium digitatum, Echinus esculentus Caryophyllia smithii confidence in this assessment has been assessed as 'Low'. 

Medium High Low
Q: Low
A: NR
C: NR
Q: High
A: High
C: High
Q: Low
A: Low
C: Low

Alcyonium digitatum does inhabit situations such as the entrances to sea lochs (Budd, 2008) or the entrances to estuaries (Braber & Borghouts, 1977) where salinity may vary occasionally. Furthermore,  Alcyonium digitatum is found within a number of variable salinity biotopes, e.g. MCR.ByH.Flu.Hocu. However, its distribution and the depth at which it occurs suggest that Alcyonium digitatum would not likely often experience salinity fluctuations and therefore unlikely to survive significant reductions in salinity (Budd, 2008).

Echinoderms are generally unable to tolerate low salinity (stenohaline) and possess no osmoregulatory organ (Boolootian, 1966). At low salinity, urchins gain weight, and the epidermis loses its pigment as patches are destroyed; prolonged exposure is fatal. However, within Echinus esculentus, there is some evidence to suggest intracellular regulation of osmotic pressure due to increased amino acid concentrations. Furthermore, Echinus esculentus is found within a number of variable and reduced salinity biotopes, e.g. IR.LIR.KVS.LsacPsaVS.

Lyster (1965) tested the tolerance of Spirobranchus triqueter larvae to various hyper and hypo salinity treatments. Larvae were placed in cultures ranging from 0-90‰ and notes were made on the time taken for larvae to die or begin displaying abnormal behaviour. Spirobranchus triqueter larvae can survive very well in salinities down to 20‰, and can tolerate salinities down to 10‰. Adults are tolerant of salinities as low as 3‰, and can be found in areas were salinity ranges from 18-23‰ (Alexander et al., 1935). No information on the salinity tolerance of Caryophyllia smithii was found. However, it is recorded from the CR.LCR.BrAs.NovPro.VS biotope that occurs in 'variable', 'reduced' and 'low' salinity regimes (Connor et al., 2004) but at lower abundance than in this biotope (FaAlCr.Car).

Sensitivity review. CR.MCR.EcCr.FaAlCr.Car is recorded exclusively in full marine conditions (30-40 ‰) (Connor et al., 2004).  Spirobranchus triqueter is likely to be able to tolerate reduced salinity. Records from the MNCR suggest that Caryophyllia smithii, Alcyonium digitatum and Echinus esculentus can occur in reduced salinity habitats. However, their abundance is likely to decrease is the salinity decreased to 'reduced' conditions.  Therefore, resistance has been assessed as ‘Medium’, resilience as ‘High’ and sensitivity has been assessed as ‘Low’.

High High Not sensitive
Q: Medium
A: High
C: High
Q: High
A: High
C: High
Q: Medium
A: High
C: High

CR.MCR.EcCr.FaAlCr.Car is recorded from weak to very weak (<0.5 m/sec) tidal streams and, although it also occurs in wave exposed to sheltered conditions it is characterized by very little water movement (Connor et al., 2004). Caryophyllia smithii is recorded from biotopes in moderately strong to very weak tidal streams. Alcyonium digitatum and Spirobranchus triqueter are suspension feeders relying on water currents to supply food. These taxa, therefore, thrive in conditions of vigorous water flow e.g. around Orkney and St Abbs, Scotland, where the community may experience tidal currents of 3 and 4 knots during spring tides (De Kluijver, 1993).Spirobranchus triqueter has been recorded in areas with very sheltered to exposed water flow rates (Price et al., 1980). Wood (1988) observed Spirobranchus sp. in strong tidal streams and Hiscock (1983) found that in strong tidal streams or strong wave action where abrasion occurs, fast growing species such as Spirobranchus triqueter occur. Echinus esculentus occurred in kelp beds on the west coast of Scotland in currents of about 0.5 m/sec. Outside the beds specimens were occasionally seen being rolled by the current (Comely & Ansell, 1988), which may have been up to 1.4 m/sec. Urchins are removed from the stipe of kelps by wave and current action. Echinus esculentus are also displaced by storm action. After disturbance Echinus esculentus migrates up the shore, an adaptation to being washed to deeper water by wave action (Lewis & Nichols, 1979a). Therefore, increased water flow may remove the population from the affected area, probably to deeper water, although individuals would probably not be killed in the process and could recolonize the area quickly.

Sensitivity assessment. CR.MCR.EcCr.FaAlCr.Car is recorded from weak to very weak (<0.5 m/sec) tidal streams and is characterized by very little water movement. A further decrease in tidal streams is 'not relevant'. However, an increase in flow of 0.1-0.2 m/s is also not likely to have a significant effect on the biological community as the important charactersitic species also occur in similar FaAlCr biotopes in stronger flow. Echinus esculentus may become dislodged but are unlikely to be killed and may recolonize quickly. Therefore, resistance has been assessed as ‘High’, resilience as ‘High’ and sensitivity has been assessed as ‘Not sensitive’ at the benchmark level.

Not relevant (NR) Not relevant (NR) Not relevant (NR)
Q: NR
A: NR
C: NR
Q: NR
A: NR
C: NR
Q: NR
A: NR
C: NR

Changes in emergence is Not relevant  fully subtidal/circalittoral biotopes. The pressure benchmark is relevant only to littoral and shallow sublittoral fringe biotopes.

High High Not sensitive
Q: Low
A: NR
C: NR
Q: High
A: High
C: High
Q: Low
A: Low
C: Low

CR.MCR.EcCr.FaAlCr.Car is recorded from wave exposed to sheltered sites (Connor et al., 2004). Alcyonium digitatum,  Spirobranchus triqueter are suspension feeders relying on water currents to supply food. These taxa, therefore, thrive in conditions of vigorous water flow.The depth at which this biotope is recorded (10-30 m)may therefore also negate the direct physical effects of a localised change in wave height; as wave attenuation is directly related to water depth (Hiscock, 1983).

Echinus esculentus occurred in kelp beds on the west coast of Scotland in currents of about 0.5 m/sec. Outside the beds specimens were occasionally seen being rolled by the current (Comely & Ansell, 1988), which may have been up to 1.4 m/sec. Urchins are removed from the stipe of kelps by wave and current action. Echinus esculentus are also displaced by storm action. After disturbance Echinus esculentus migrates up the shore, an adaptation to being washed to deeper water by wave action (Lewis & Nichols, 1979a). Keith Hiscock (pers. comm.) reported Echinus esculentus occurred in significant numbers as shallow as 15 m below low water at the extremely wave exposed site of Rockall, Scotland. Therefore, localised increases in wave height may remove the population from the affected area, probably to deeper water, although individuals would probably not be killed in the process and could recolonize the area quickly.

Sensitivity assessment. Wave action is a fundamental environmental variable controlling the biological community of sublittoral biotopes. A large and significant change in wave height may fundamentally alter the character of FaAlCr biotopes. However, a change in near shore significant wave height of 3-5% is not likely to have a significant effect on the biological community. Resistance has been assessed as ‘High’, resilience has been assessed as ‘High’. Sensitivity has been assessed as ‘Not sensitive’.

Chemical Pressures

 ResistanceResilienceSensitivity
Not relevant (NR) Not relevant (NR) Not sensitive
Q: NR
A: NR
C: NR
Q: NR
A: NR
C: NR
Q: NR
A: NR
C: NR

This biotope is considered to be 'Not sensitive' at the pressure benchmark, that assumes compliance with all relevant environmental protection standards.

No information on the direct biological effects of heavy metal contamination on Alcyonium digitatum. Possible sub-lethal effects of exposure to heavy metals may result in a change in morphology, growth rate or disruption of the reproductive cycle. The vulnerability of this species to concentrations of pollutants may also depend on variations in other factors e.g. temperature and salinity conditions outside the normal range. Based on the available evidence for several species Bryan (1984) suggested that polychaetes are fairly resistant to heavy metals. Bryozoans are common members of the fouling community and amongst those organisms most resistant to antifouling measures, such as copper containing anti-fouling paints (Soule & Soule, 1979; Holt et al., 1995). Bryozoans were shown to bio accumulate heavy metals to a certain extent (Holt et al., 1995). For example, Bowerbankia gracialis and Nolella pusilla accumulated Cd, exhibiting sublethal effects (reduced sexual reproduction and inhibited resting spore formation) between 10-100 µg Cd /l and fatality above 500 µg Cd/l (Kayser, 1990). Little is known about the effects of heavy metals on echinoderms. Bryan (1984) reported that early work had shown that echinoderm larvae were sensitive to heavy metals contamination, for example, Migliaccio et al. (2014) reported exposure of Paracentrotus lividis larvae to increased levels of cadmium and manganese caused abnormal larval development and skeletal malformations. Kinne (1984) reported developmental disturbances in Echinus esculentus exposed to waters containing 25 µg / l of copper (Cu).

Bryozoans are common members of the fouling community and amongst those organisms most resistant to antifouling measures, such as copper containing anti-fouling paints (Soule & Soule, 1979; Holt et al., 1995). Bryan & Gibbs (1991) reported that there was little evidence regarding TBT toxicity in bryozoa with the exception of the encrusting Schizoporella errata, which suffered 50% mortality when exposed for 63 days to 100 ng/l TBT. Rees et al. (2001) reported that the abundance of epifauna (including bryozoans) had increased in the Crouch estuary in the 5 years since TBT was banned from use on small vessels. This last report suggests that bryozoans may be at least inhibited by the presence of TBT.

Not relevant (NR) Not relevant (NR) Not sensitive
Q: NR
A: NR
C: NR
Q: NR
A: NR
C: NR
Q: NR
A: NR
C: NR

This biotope is considered to be 'Not sensitive' at the pressure benchmark, that assumes compliance with all relevant environmental protection standards.

CR.MCR.EcCr.FaAlCr biotopes are subtidal biotopes (Connor et al., 2004). Oil pollution is mainly a surface phenomenon its impact upon circalittoral turf communities is likely to be limited. However, as in the case of the Prestige oil spill off the coast of France, high swell and winds can cause oil pollutants to mix with the seawater and potentially negatively affect sublittoral habitats (Castège et al., 2014). Smith (1968) reported dead colonies of Alcyonium digitatum at a depth of 16 m in the locality of Sennen Cove, Cornwall, which was likely a result of toxic detergents sprayed along the shoreline to disperse oil from the Torrey Canyon tanker spill (Budd, 2008). Little information on the effects of hydrocarbons on bryozoans was found. Ryland & Putron (1998) did not detect adverse effects of oil contamination on the bryozoan Alcyonidium spp. in Milford Haven or St. Catherine's Island, south Pembrokeshire although it did alter the breeding period. Large numbers of dead polychaetes and other fauna were washed up at Rulosquet Marsh near the  Isle de Grand following the Amoco Cadiz oil spill in 1978 (Cross et al., 1978). However, no information was found relating to Spirobranchus triqueter in particular.

Echinus esculentus is subtidal and unlikely to be directly exposed to oil spills. However, as with the ‘Prestige’ oil spill rough seas can cause mixing with the oil and the seawater, and therefore sub-tidal habitats can be affected by the oil spill. Castège et al., (2014) recorded the recovery of rocky shore communities following the Prestige oil spill which impacted the French Atlantic coast. Rough weather at the time of the spill increased mixing between the oil and seawater, causing subtidal communities/habitats to be affected. The urchin Echinus esculentus was reported absent after the oil spill, however, returned after 2-5 years. Large numbers of dead Echinus esculentus were found between 5.5 and 14.5 m in the vicinity of Sennen cove, presumably due to a combination of wave exposure and heavy spraying of dispersants following the Torrey canyon oil spill (Smith, 1968). Smith (1968) also demonstrated that 0.5 -1 ppm of the detergent BP1002 resulted in developmental abnormalities in its echinopluteus larvae. Echinus esculentus populations in the vicinity of an oil terminal in A Coruna Bay, Spain, showed developmental abnormalities in the skeleton. The tissues contained high levels of aliphatic hydrocarbons, naphthalenes, pesticides and heavy metals (Zn, Hg, Cd, Pb, and Cu) (Gomez & Miguez-Rodriguez, 1999).

Not relevant (NR) Not relevant (NR) Not sensitive
Q: NR
A: NR
C: NR
Q: NR
A: NR
C: NR
Q: NR
A: NR
C: NR

This biotope is considered to be 'Not sensitive' at the pressure benchmark, that assumes compliance with all relevant environmental protection standards.

Smith (1968) reported dead colonies of Alcyonium digitatum at a depth of 16 m in the locality of Sennen Cove, Cornwall resulting from the offshore spread and toxic effect of detergents (a mixture of a surfactant and an organic solvent) e.g. BP 1002 sprayed along the shoreline to disperse oil from the Torrey Canyon tanker spill. Possible sub-lethal effects of exposure to synthetic chemicals may result in a change in morphology, growth rate or disruption of the reproductive cycle. The vulnerability of this species to concentrations of pollutants may also depend on variations in other factors e.g. temperature and salinity conditions outside the normal range (Budd, 2008).

Hoare & Hiscock (1974) suggested that polyzoa (bryozoa) were amongst the most intolerant species to acidified halogenated effluents in Amlwch Bay, Anglesey and reported that Flustra foliacea did not occur less than 165m from the effluent source. The evidence, therefore, suggests that Securiflustra securifrons would be sensitive to synthetic compounds.

Large numbers of dead Echinus esculentus were found between 5.5 and 14.5 m in the vicinity of Sennen, presumably due to a combination of wave exposure and heavy spraying of dispersants in that area following the Torrey Canyon oil spill (Smith 1968). Smith (1968) also demonstrated that 0.5 -1ppm of the detergent BP1002 resulted in developmental abnormalities in echinopluteus larvae of Echinus esculentus. Echinus esculentus populations in the vicinity of an oil terminal in A Coruna Bay, Spain, showed developmental abnormalities in the skeleton. The tissues contained high levels of aliphatic hydrocarbons, naphthalenes, pesticides and heavy metals (Zn, Hg, Cd, Pb, and Cu) (Gomez & Miguez-Rodriguez 1999).

No evidence (NEv) Not relevant (NR) No evidence (NEv)
Q: NR
A: NR
C: NR
Q: NR
A: NR
C: NR
Q: NR
A: NR
C: NR

No evidence was found

Not relevant (NR) Not relevant (NR) Not sensitive
Q: NR
A: NR
C: NR
Q: NR
A: NR
C: NR
Q: NR
A: NR
C: NR

No benchmark proposed therefore sensitivity assessment has been assessed as Not sensitive at the pressure benchmark that assumes compliance with all relevant environmental protection standards.

Low High Low
Q: Low
A: NR
C: NR
Q: High
A: High
C: High
Q: Low
A: Low
C: Low

In general, respiration in most marine invertebrates do not appear to be significantly affected until extremely low concentrations are reached. For many benthic invertebrates, this concentration is about 2 ml/l or even less (Herreid, 1980; Rosenberg et al., 1991; Diaz & Rosenberg, 1995).

Alcyonium digitatum mainly inhabits environments in which the oxygen concentration usually exceeds 5 ml/l and respiration is aerobic (Budd, 2008). In August 1978 a dense bloom of a dinoflagellate, Gyrodinium aureolum occurred surrounding Geer reef in Penzance Bay, Cornwall and persisted until September that year. Observations by local divers indicated a decrease in underwater visibility (<1 m) from below 8 m Below Sea Level. It was also noted that many of the faunal species appeared to be affected, e.g. no live Echinus esculentus were observed whereas on surveys prior to August were abundant, Alcyonium sp. and Bryozoans were also in an impoverished state. Caryophyllia smithii were also in a contracted state, apparently dead, and with Echinus esculentus were the worst affected species during the bloom.  During follow up surveys conducted in early September Alcyonium sp. were noted to be much healthier and feeding. It was suggested the decay of Gyrodinium aureolum either reduced oxygen levels or physically clogged faunal feeding mechanisms. Adjacent reefs where also surveyed during the same time period and the effects of the Gyrodinium aureolum bloom were less apparent. It was suggested that higher water agitation in shallow water on reefs more exposed to wave action were less affected by the phytoplankton bloom (Griffiths et al., 1979).

Sensitivity assessment. There is anecdotal evidence to suggest that Alcyonium digitatum, Caryophyllia smithii and Echinus esculentus are sensitive to hypoxic events.  Loss of the important characteristic species and the major grazer could result in a change in the biotope. Therefore, a resistance of Low is suggested. However, because the degree of deoxygenation wasn’t quantified the evidence cannot be compared to the pressure benchmark and confidence in the assessment is 'Low'. Resilience is probably High so that sensitivity is assessed as Low.

Not relevant (NR) Not relevant (NR) Not sensitive
Q: NR
A: NR
C: NR
Q: NR
A: NR
C: NR
Q: NR
A: NR
C: NR

This biotope is considered to be 'Not sensitive' at the pressure benchmark that assumes compliance with good status as defined by the WFD.

Alcyonium digitatum and Caryophyllia smithii are suspension feeders of phytoplankton and zooplankton. Nutrient enrichment of coastal waters that enhances the population of phytoplankton may be beneficial to Alcyonium digitatum and Caryophyllia smithii in terms of an increased food supply but the effects are uncertain (Hartnoll, 1998). The survival of Alcyonium digitatum and Caryophyllia smithii may be influenced indirectly. High primary productivity in the water column combined with high summer temperature and the development of thermal stratification (which prevents mixing of the water column) can lead to hypoxia of the bottom waters which faunal species are likely to be highly intolerant of (see de-oxygenation pressure).

Johnston & Roberts (2009) conducted a meta-analysis, which reviewed 216 papers to assess how a variety of contaminants (including sewage and nutrient loading) affected 6 marine habitats (including subtidal reefs). A 30-50% reduction in species diversity and richness was identified from all habitats exposed to the contaminant types.

It was suggested by Comely & Ansell (1988) that Echinus esculentus could absorb dissolved organic material for the purposes of nutrition. Nutrient enrichment may encourage the growth of ephemeral and epiphytic algae and therefore increase sea-urchin food availability. Lawrence (1975) reported that sea urchins had persisted over 13 years on barren grounds near sewage outfalls, presumably feeding on dissolved organic material, detritus, plankton and microalgae, although individuals died at an early age. 

Medium High Low
Q: Low
A: NR
C: NR
Q: High
A: High
C: High
Q: Low
A: Low
C: Low

Alcyonium digitatum and Caryophyllia smithii are suspension feeders of phytoplankton and zooplankton. Organic enrichment of coastal waters that enhances the population of phytoplankton may be beneficial to Alcyonium digitatum and Caryophyllia smithii in terms of an increased food supply but the effects are uncertain (Hartnoll, 1998). The survival of Alcyonium digitatum and Caryophyllia smithii may be influenced indirectly. High primary productivity in the water column combined with high summer temperature and the development of thermal stratification (which prevents mixing of the water column) can lead to hypoxia of the bottom waters which faunal species are likely to be highly intolerant of (see de-oxygenation pressure).

Johnston & Roberts (2009) conducted a meta-analysis, which reviewed 216 papers to assess how a variety of contaminants (including sewage and nutrient loading) affected 6 marine habitats (including subtidal reefs). A 30-50% reduction in species diversity and richness was identified from all habitats exposed to the contaminant types.

It was suggested by Comely & Ansell (1988) that Echinus esculentus could absorb dissolved organic material for the purposes of nutrition. Organic enrichment may encourage the growth of ephemeral and epiphytic algae and therefore increase sea-urchin food availability. Lawrence (1975) reported that sea urchins had persisted over 13 years on barren grounds near sewage outfalls, presumably feeding on dissolved organic material, detritus, plankton and microalgae, although individuals died at an early age.

Sensitivity assessment. Organic enrichment is not likely to directly negatively affect the characterizing species within this biotope, however, chronic organic enrichment may cause secondary effects such as hypoxia. Resistance has been assessed as ‘Medium’, resilience as ‘High’, and sensitivity has been assessed as ‘Low’.

Physical Pressures

 ResistanceResilienceSensitivity
None Very Low High
Q: High
A: High
C: High
Q: High
A: High
C: High
Q: High
A: High
C: High

All marine habitats and benthic species are considered to have a resistance of ‘None’ to this pressure and to be unable to recover from a permanent loss of habitat (resilience is ‘Very Low’). Sensitivity within the direct spatial footprint of this pressure is, therefore ‘High’. Although no specific evidence is described confidence in this assessment is ‘High’, due to the incontrovertible nature of this pressure.

None Very Low High
Q: High
A: High
C: High
Q: High
A: High
C: High
Q: High
A: High
C: High

If rock were replaced with sediment, this would represent a fundamental change to the physical character of the biotope and the species would be unlikely to recover. The biotope would be lost.

Sensitivity assessment. Resistance to the pressure is considered ‘None’, and resilience ‘Very low’. Sensitivity has been assessed as ‘High’.

Not relevant (NR) Not relevant (NR) Not relevant (NR)
Q: NR
A: NR
C: NR
Q: NR
A: NR
C: NR
Q: NR
A: NR
C: NR

Not relevant

Not relevant (NR) Not relevant (NR) Not relevant (NR)
Q: NR
A: NR
C: NR
Q: NR
A: NR
C: NR
Q: NR
A: NR
C: NR

The species characterizing this biotope are epifauna or epiflora occurring on rock and would be sensitive to the removal of the habitat. However, extraction of rock substratum is considered unlikely and this pressure is considered to be ‘Not relevant’ to hard substratum habitats.

Medium High Low
Q: High
A: High
C: High
Q: High
A: High
C: High
Q: High
A: High
C: High

CR.MCR.EcCr.FaAlCr biotopes are subtidal habitats (Connor et al., 2004). Therefore, abrasion is most likely to be a result of bottom or pot fishing gear, cable laying etc., which may cause localised mobility of the substrata and mortality of the resident community. The effect would be situation dependent, however, if bottom fishing gear were towed over a site it may mobilise a high proportion of the rock substrata and cause high mortality in the resident community.

Alcyonium digitatum, Echinus esculentus, and Caryophyllia smithii are sessile or slow moving species that might be expected to suffer from the effects of dredging. Boulcott & Howell (2011) conducted experimental Newhaven scallop dredging over a circalittoral rock habitat in the sound of Jura, Scotland and recorded the damage to the resident community. The results indicated that the sponge Pachymatisma johnstoni was highly damaged by the experimental trawl. However, only 13% of photographic samples showed visible damage to Alcyonium digitatum. Where Alcyonium digitatum damage was evident it tended to be small colonies that were ripped off the rock. The authors highlight physical damage to faunal turfs (erect bryozoans and hydroids) was difficult to quantify in the study. However, the faunal turf communities did not show large signs of damage and were only damaged by the scallop dredge teeth which was often limited in extent (approximately 2 cm wide tracts). The authors indicated that species such as Alcyonium digitatum and faunal turf communities were not as vulnerable to damage through trawling as sedimentary fauna and whilst damage to circalittoral rock fauna did occur it was of an incremental nature, with loss of species such as Alcyonium digitatum and faunal turf communities increasing with repeated trawls.

Species with fragile tests, such as Echinus esculentus were reported to suffer badly as a result of scallop or queen scallop dredging (Bradshaw et al., 2000; Hall-Spencer & Moore, 2000a). Kaiser et al. (2000) reported that Echinus esculentus were less abundant in areas subject to high trawling disturbance in the Irish Sea. Jenkins et al. (2001) conducted experimental scallop trawling in the North Irish sea and recorded the damage caused to several conspicuous megafauna species, both when caught as by-catch and when left on the seabed. The authors predicted 16.4% of Echinus esculentus were crushed/dead, 29.3% would have >50% spine loss/minor cracks, 1.1% would have <50% spine loss and the remaining 53.3% would be in good condition. Sea urchins can rapidly regenerate spines, e.g. Psammechinus miliaris were found to re-grow all spines within a period of 2 months (Hobson, 1930).  The trawling examples mentioned above were conducted on sedimentary habitats and thus the evidence is not directly relevant to the rock based biotopes, however, does indicate the likely effects of abrasion on Echinus esculentus.

Sensitivity assessment. Resistance has been assessed ‘Medium’, resilience has been assessed as ‘High’. Sensitivity has been assessed as ‘Low’. Please note, Boulcott & Howell (2011) did not mention the abrasion caused by fully loaded collection bags on the new haven dredges. A fully loaded Newhaven dredge may cause higher damage to the community as indicated in their study.

Not relevant (NR) Not relevant (NR) Not relevant (NR)
Q: NR
A: NR
C: NR
Q: NR
A: NR
C: NR
Q: NR
A: NR
C: NR

The species characterizing this biotope group are epifauna or epiflora occurring on rock which is resistant to subsurface penetration.  The assessment for abrasion at the surface only is therefore considered to equally represent sensitivity to this pressure. This pressure is not thought relevant to hard rock biotopes.

High High Not sensitive
Q: High
A: High
C: High
Q: High
A: High
C: High
Q: High
A: High
C: High

Alcyonium digitatum and Caryophyllia smithii are not thought highly susceptible to changes in water clarity due to the fact they are suspension feeding organisms and are not directly dependent on sunlight for nutrition. Alcyonium digitatum has been shown to be tolerant of high levels of suspended sediment. Hill et al. (1997) demonstrated that Alcyonium digitatum sloughed off settled particles with a large amount of mucous. Alcyonium digitatum is also known to inhabit the entrances to sea lochs (Budd, 2008) or the entrances to estuaries (Braber & Borghouts, 1977) where water clarity is likely to be highly variable.

Moore (1977a) suggested that Echinus esculentus was unaffected by turbid conditions. Echinus esculentus is an important grazer of red macro-algae within CR.MCR.EcCr. Increased turbidity and resultant reduced light penetration is likely to negatively affect algal growth. However, Echinus esculentus can feed on alternative prey, detritus or dissolved organic material (Lawrence, 1975, Comely & Ansell, 1988).

According to Bacescu (1972), sabellids are accustomed to turbidity and silt. Spirobranchus triqueter has also recently been recorded by De Kluijver (1993) from Scotland in the aphotic zone, indicating that the species would not be sensitive to light reduction due to an increase in turbidity. In addition, Spirobranchus triqueter is commonly found under boulders where sediment may accumulate.

Sensitivity assessment. Resistance has been assessed as ‘High’, resilience as ‘High’ and sensitivity has been assessed as ‘Not Sensitive’.

Low High Low
Q: Low
A: NR
C: NR
Q: High
A: High
C: High
Q: Low
A: Low
C: Low

Alcyonium digitatum and Caryophyllia smithii are sessile and thus would be unable to avoid the deposition of a smothering layer of sediment. Some Alcyonium digitatum colonies can attain a height of up to 20 cm (Budd, 2008), while Echinus esculentus are large globular urchins which can reach a diameter of 17 cm (Tyler-Walters, 2008). Spirobranchus triqueter are an encrusting species and would thus likely be smothered, and depending on sediment retention could block larval settlement.

Caryophyllia smithii is small (approx. <3 cm height from the seabed) and would therefore likely be inundated in a “light” sedimentation event. However, Bell & Turner (2000) reported that Caryophyllia smithii was abundant at sites of “moderate” sedimentation (7mm ± 0.5mm) in Lough Hyne. It is, therefore, likely that Caryophyllia smithii would be resistant to periodic sedimentation. If 5 cm of sediment were removed rapidly, via tidal currents, Caryophyllia smithii would likely remain within the biotope.

Comely & Ansell (1988) recorded large Echinus esculentus from kelp beds on the west coast of Scotland, in which, the substratum was seasonally covered with "high levels" of silt. This suggests that Echinus esculentus is unlikely to be killed by smothering, however, smaller specimens and juveniles may be less resistant. A layer of sediment may interfere with larval settlement.  If retained within the host biotope for extended periods a layer of 5 cm of the sediment may negatively affect successive recruitment events.

Sensitivity assessment. CR.MCR.EcCr.FaAlCr.Car is recorded from areas with very little water movement (Connor et al., 2004) so that any deposit of sediment is likely to remain for some time and only vertical surfaces escape smothering.  Echinus may be deterred from feeding but small encrusting forms (Caryophyllia smithii and Spirobranchus triqueter) may be smothered and prevented from feeding or exposed to anoxia. Resistance has been assessed as ‘Low’, resilience as ‘High’, and sensitivity has, therefore, been assessed as ‘Low’.

Low High Low
Q: Low
A: NR
C: NR
Q: High
A: High
C: High
Q: Low
A: Low
C: Low

Alcyonium digitatum and Caryophyllia smithii are sessile and thus would be unable to avoid the deposition of a smothering layer of sediment. Some Alcyonium digitatum colonies can attain a height of up to 20 cm (Budd, 2008), while Echinus esculentus are large globular urchins which can reach a diameter of 17 cm (Tyler-Walters, 2008). Spirobranchus triqueter are an encrusting species and would thus likely be smothered, and depending on sediment retention could block larval settlement.

Caryophyllia smithii is small (approx. <3 cm height from the seabed) and would therefore likely be inundated in a “light” sedimentation event. However, Bell & Turner (2000) reported that Caryophyllia smithii was abundant at sites of “moderate” sedimentation (7mm ± 0.5mm) in Lough Hyne. It is, therefore, likely that Caryophyllia smithii would be resistant to periodic sedimentation. If 5 cm of sediment were removed rapidly, via tidal currents, Caryophyllia smithii would likely remain within the biotope.

Comely & Ansell (1988) recorded large Echinus esculentus from kelp beds on the west coast of Scotland, in which, the substratum was seasonally covered with "high levels" of silt. This suggests that Echinus esculentus is unlikely to be killed by smothering, however, smaller specimens and juveniles may be less resistant. A layer of sediment may interfere with larval settlement.  If retained within the host biotope for extended periods a layer of 5 cm of the sediment may negatively affect successive recruitment events.

Sensitivity assessment. CR.MCR.EcCr.FaAlCr.Car is recorded from areas with very little water movement (Connor et al., 2004) so that any deposit of sediment is likely to remain for some time and only vertical surfaces escape smothering.  Echinus may be deterred from feeding but small encrusting forms (Caryophyllia smithii and Spirobranchus triqueter) may be smothered and prevented from feeding or exposed to anoxia. Resistance has been assessed as ‘Low’, resilience as ‘High’, and sensitivity has, therefore, been assessed as ‘Low’.

Not Assessed (NA) Not assessed (NA) Not assessed (NA)
Q: NR
A: NR
C: NR
Q: NR
A: NR
C: NR
Q: NR
A: NR
C: NR

There was no evidence on which to assess this pressure.

No evidence (NEv) Not relevant (NR) No evidence (NEv)
Q: NR
A: NR
C: NR
Q: NR
A: NR
C: NR
Q: NR
A: NR
C: NR

There was no evidence on which to assess this pressure. 

Not relevant (NR) Not relevant (NR) Not relevant (NR)
Q: NR
A: NR
C: NR
Q: NR
A: NR
C: NR
Q: NR
A: NR
C: NR

Alcyonium digitatum, Echinus esculentus and Caryophyllia smithii have no hearing perception but vibrations may cause an impact, however no studies exist to support an assessment.

High High Not sensitive
Q: High
A: High
C: High
Q: High
A: High
C: High
Q: High
A: High
C: High

There is no evidence to suggest that If exposed to anthropogenic light sources algal species would benefit. CR.MCR.EcCr.FaAlCr biotopes are circalittoral and are thus by definition naturally shaded environments with low light levels. Increased shading (e.g. by the construction of a pontoon, pier etc) could be beneficial to the characterizing species within these biotopes.

Sensitivity assessment. Resistance is probably 'High', with a 'High' resilience and a sensitivity of 'Not Sensitive'. 

Not relevant (NR) Not relevant (NR) Not relevant (NR)
Q: NR
A: NR
C: NR
Q: NR
A: NR
C: NR
Q: NR
A: NR
C: NR

Not relevant: barriers and changes in tidal excursion are not relevant to biotopes restricted to open waters.

Not relevant (NR) Not relevant (NR) Not relevant (NR)
Q: NR
A: NR
C: NR
Q: NR
A: NR
C: NR
Q: NR
A: NR
C: NR

Not relevant to seabed habitats.  NB. Collision by grounding vessels is addressed under ‘surface abrasion’.

Not relevant (NR) Not relevant (NR) Not relevant (NR)
Q: NR
A: NR
C: NR
Q: NR
A: NR
C: NR
Q: NR
A: NR
C: NR

Not relevant

Biological Pressures

 ResistanceResilienceSensitivity
No evidence (NEv) Not relevant (NR) No evidence (NEv)
Q: NR
A: NR
C: NR
Q: NR
A: NR
C: NR
Q: NR
A: NR
C: NR

Alcyonium digitatum, Securiflustra securifrons & Spirobranchus triqueter are not cultivated or translocated. Echinus esculentus was identified by Kelly & Pantazis (2001) as a species suitable for culture for the urchin Roe industry. However, no evidence could be found to suggest that significant Echinus esculentus mariculture was present in the UK. If industrially cultivated it is feasible that Echinus esculentus individuals could be translocated.

Translocation also has the potential to transport pathogens to uninfected areas (see pressure ‘introduction of microbial pathogens’). The sensitivity of the ‘donor’ population to harvesting to supply stock for translocation is assessed for the pressure ‘removal of target species’.

No evidence (NEv) Not relevant (NR) No evidence (NEv)
Q: NR
A: NR
C: NR
Q: NR
A: NR
C: NR
Q: NR
A: NR
C: NR

There was no evidence regarding known invasive species that may pose a threat to CR.MCR.EcCr.FaAlCr biotopes. Didemnum vexillum is an invasive colonial sea squirt native to Asia which was first recorded in the UK in Darthaven Marina, Dartmouth in 2005. Didemnum vexillum can form extensive mats over the substrata it colonizes; binding boulders, cobbles and altering the host habitat (Griffith et al., 2009). Didemnum vexillum can also grow over and smother the resident biological community. Recent surveys within Holyhead Marina, North Wales have found Didemnum vexillum growing on and smother native tunicate communities (Griffith et al., 2009). Due to the rapid-re-colonization of Didemnum vexillum eradication attempts have to date failed. 

Presently Didemnum vexillum is isolated to several sheltered locations in the UK (NBN, 2015), however, Didemnum vexillum has successfully colonized the offshore location of the Georges Bank, USA (Lengyel et al., 2009) which is more exposed than the locations that Didemnum vexillum has colonized in the UK. It is, therefore, possible that Didemnum vexillum could colonize more exposed locations within the UK and could, therefore, pose a threat to CR.MCR.EcCr.FaAlCr biotopes in the future.

No evidence (NEv) Not relevant (NR) No evidence (NEv)
Q: NR
A: NR
C: NR
Q: NR
A: NR
C: NR
Q: NR
A: NR
C: NR

No evidence was found to suggest that any of the characterizing species within CR.MCR.EcCr.FaAlCr biotopes are sensitive to current/known microbial pathogens.

Alcyonium digitatum acts as the host for the endoparasitic species Enalcyonium forbesiand and Enalcyonium rubicundum (Stock, 1988). Parasitisation may reduce the viability of a colony but not to the extent of killing them but no further evidence was found to substantiate this suggestion. Thomas (1940) recorded parasites of Spirobranchus triqueter. Trichodina pediculus (a ciliate) was observed in high numbers moving over the branchial crown. However, this relationship is symbiotic, not parasitic. Parasites found in the worm include gregarines & ciliated protozoa and parasites that had the appearance of sporozoan cysts. However, no information was found about the effects of microbial pathogens on Spirobranchus triqueter.

Echinus esculentus is susceptible to 'Bald-sea-urchin disease', which causes lesions, loss of spines, tube feet, pedicellariae, destruction of the upper layer of skeletal tissue and death. It is thought to be caused by the bacteria Vibrio anguillarum and Aeromonas salmonicida. Bald sea-urchin disease was recorded from Echinus esculentus on the Brittany Coast. Although associated with mass mortalities of Strongylocentrotus franciscanus in California and Paracentrotus lividus in the French Mediterranean it is not known if the disease induces mass mortality (Bower, 1996).

Not relevant (NR) Not relevant (NR) Not relevant (NR)
Q: NR
A: NR
C: NR
Q: NR
A: NR
C: NR
Q: NR
A: NR
C: NR

None of the characterizing species within CR.MCR.EcCr.FaAlCr biotopes are commercially exploited. This pressure is considered ‘Not Relevant’.

Low High Low
Q: Low
A: NR
C: NR
Q: High
A: High
C: High
Q: Low
A: Low
C: Low

Alcyonium digitatum and faunal turf communities  are probably resistant to abrasion through bottom fishing (see abrasion pressure). Alcyonium digitatum goes through an annual cycle, From February to July all Alcyonium digitatum colonies are feeding, from July to November, an increasing number of colonies stop feeding. During this period, a large number of polyps can retract and a variety of filamentous algae, hydroids and amphipods can colonize the surface of colonies epiphytically. From December to February, the epiphytic community is however sloughed off (Hartnoll, 1975). If Alcyonium digitatum were removed the epiphytic species would likely colonize rock surfaces and are therefore not dependent on Alcyonium digitatum.

Alcyonium digitatum and Caryophylia smithii, probably compete for space, however, there isn’t any evidence to suggest other interspecific relationships or dependencies between these species. Therefore, removal of one or a number of these species would provide colonization space and most likely benefit the species with rapid colonization rates (e.g. Spirobranchus triqueter). Echinus esculentus is an important red algal grazer  (Connor et al., 2004), without which the abundance of red algae may increase and possibly displace some of the faunal turf species.

Sensitivity assessment. If Alcyonium digitatum, Caryophylia smithii or Echinus were removed (e.g. as incidental by-catch) the character of the biotope would probably change. Therefore, resistance has been assessed as ‘Low’, resilience has been assessed as ’High’. Sensitivity has been assessed as ‘Low’.

Bibliography

  1. Alexander, W., Southgate, B.A. & Bassindale, R., 1935. Survey of the River Tees: The Estuary, Chemical and Biological. HM Stationery Office.

  2. Bacescu, M.C., 1972. Substratum: Animals. In: Marine Ecology: A Comprehensive Treatise on Life in Oceans and Coastal Waters. Volume 1 Environmental Factors Part 3. (ed. O. Kinne ). Chichester: John Wiley & Sons.

  3. Bell, J.J. & Turner, J.R., 2000. Factors influencing the density and morphometrics of the cup coral Caryophyllia smithii in Lough Hyne. Journal of the Marine Biological Association of the United Kingdom, 80, 437-441.

  4. Beszczynska-Möller, A., & Dye, S.R., 2013. ICES Report on Ocean Climate 2012. In ICES Cooperative Research Report, vol. 321 pp. 73.

  5. Bishop, G.M. & Earll, R., 1984. Studies on the populations of Echinus esculentus at the St Abbs and Skomer voluntary Marine Nature Reserves. Progress in Underwater Science, 9, 53-66.

  6. Bishop, G.M., 1985. Aspects of the reproductive ecology of the sea urchin Echinus esculentus L. Ph.D. thesis, University of Exeter, UK.

  7. Boolootian, R.A.,1966. Physiology of Echinodermata. (Ed. R.A. Boolootian), pp. 822-822. New York: John Wiley & Sons.

  8. Boulcott, P. & Howell, T.R.W., 2011. The impact of scallop dredging on rocky-reef substrata. Fisheries Research (Amsterdam), 110 (3), 415-420.

  9. Bower, S.M., 1996. Synopsis of Infectious Diseases and Parasites of Commercially Exploited Shellfish: Bald-sea-urchin Disease. [On-line]. Fisheries and Oceans Canada. [cited 26/01/16]. Available from: http://www.dfo-mpo.gc.ca/science/aah-saa/diseases-maladies/bsudsu-eng.html

  10. Braber, L. & Borghouts, C.H., 1977. Distribution and ecology of Anthozoa in the estuarine region of the rivers Rhine, Meuse and Scheldt. Hydrobiologia, 52, 15-21.

  11. Bradshaw, C., Veale, L.O., Hill, A.S. & Brand, A.R., 2000. The effects of scallop dredging on gravelly seabed communities. In: Effects of fishing on non-target species and habitats (ed. M.J. Kaiser & de S.J. Groot), pp. 83-104. Oxford: Blackwell Science.

  12. Bryan, G.W. & Gibbs, P.E., 1991. Impact of low concentrations of tributyltin (TBT) on marine organisms: a review. In: Metal ecotoxicology: concepts and applications (ed. M.C. Newman & A.W. McIntosh), pp. 323-361. Boston: Lewis Publishers Inc.

  13. Bryan, G.W., 1984. Pollution due to heavy metals and their compounds. In Marine Ecology: A Comprehensive, Integrated Treatise on Life in the Oceans and Coastal Waters, vol. 5. Ocean Management, part 3, (ed. O. Kinne), pp.1289-1431. New York: John Wiley & Sons.

  14. Budd, G.C. 2008. Alcyonium digitatum Dead man's fingers. In Tyler-Walters H. and Hiscock K. (eds) Marine Life Information Network: Biology and Sensitivity Key Information Reviews, [on-line]. Plymouth: Marine Biological Association of the United Kingdom. Available from: http://www.marlin.ac.uk/species/detail/1187

  15. Castège, I., Milon, E. & Pautrizel, F., 2014. Response of benthic macrofauna to an oil pollution: Lessons from the “Prestige” oil spill on the rocky shore of Guéthary (south of the Bay of Biscay, France). Deep Sea Research Part II: Topical Studies in Oceanography, 106, 192-197.

  16. Castric-Fey, A., 1983. Recruitment, growth and longevity of Pomatoceros triqueter and Pomatoceros lamarckii (Polychaeta, Serpulidae) on experimental panels in the Concarneau area, South Brittany. Annales de l'Institut Oceanographique, Paris, 59, 69-91.

  17. Comely, C.A. & Ansell, A.D., 1988. Invertebrate associates of the sea urchin, Echinus esculentus L., from the Scottish west coast. Ophelia, 28, 111-137.

  18. Connor, D.W., Allen, J.H., Golding, N., Howell, K.L., Lieberknecht, L.M., Northen, K.O. & Reker, J.B., 2004. The Marine Habitat Classification for Britain and Ireland. Version 04.05. Joint Nature Conservation Committee, Peterborough. www.jncc.gov.uk/MarineHabitatClassification.

  19. Cotter, E., O'Riordan, R.M & Myers, A.A. 2003. Recruitment patterns of serpulids (Annelida: Polychaeta) in Bantry Bay, Ireland. Journal of the Marine Biological Association of the United Kingdom, 83, 41-48.

  20. Crisp, D.J. (ed.), 1964. The effects of the severe winter of 1962-63 on marine life in Britain. Journal of Animal Ecology, 33, 165-210.

  21. Cross, F.A., Davis, W.P., Hoss, D.E. & Wolfe, D.A., 1978. Biological Observations, Part 5. In The Amoco Cadiz Oil Spill - a preliminary scientific report (ed. W.N.Ness). NOAA/EPA Special Report, US Department of Commerce and US Environmental Protection Agency, Washington.

  22. De Kluijver, M., 1993. Sublittoral hard-substratum communities off Orkney and St Abbs (Scotland). Journal of the Marine Biological Association of the United Kingdom, 73 (04), 733-754.

  23. Diaz, R.J. & Rosenberg, R., 1995. Marine benthic hypoxia: a review of its ecological effects and the behavioural responses of benthic macrofauna. Oceanography and Marine Biology: an Annual Review, 33, 245-303.

  24. Dons, C., 1927. Om Vest og voskmåte hos Pomatoceros triqueter. Nyt Magazin for Naturvidenskaberne, LXV, 111-126.

  25. Dorgham, M.M., Hamdy, R., El-Rashidy, H.H. & Atta, M.M., 2013. First records of polychaetes new to Egyptian Mediterranean waters. Oceanologia, 55 (1), 235-267.

  26. Eggleston, D., 1972a. Patterns of reproduction in marine Ectoprocta off the Isle of Man. Journal of Natural History, 6, 31-38.

  27. Fowler, S. & Laffoley, D., 1993. Stability in Mediterranean-Atlantic sessile epifaunal communities at the northern limits of their range. Journal of Experimental Marine Biology and Ecology, 172 (1), 109-127.

  28. Gage, J.D., 1992a. Growth bands in the sea urchin Echinus esculentus: results from tetracycline mark/recapture. Journal of the Marine Biological Association of the United Kingdom, 72, 257-260.

  29. Gommez, J.L.C. & Miguez-Rodriguez, L.J., 1999. Effects of oil pollution on skeleton and tissues of Echinus esculentus L. 1758 (Echinodermata, Echinoidea) in a population of A Coruna Bay, Galicia, Spain. In Echinoderm Research 1998. Proceedings of the Fifth European Conference on Echinoderms, Milan, 7-12 September 1998, (ed. M.D.C. Carnevali & F. Bonasoro) pp. 439-447. Rotterdam: A.A. Balkema.

  30. Griffith, K., Mowat, S., Holt, R.H., Ramsay, K., Bishop, J.D., Lambert, G. & Jenkins, S.R., 2009. First records in Great Britain of the invasive colonial ascidian Didemnum vexillum Kott, 2002. Aquatic Invasions, 4 (4), 581-590.

  31. Griffiths, A.B., Dennis, R. & Potts, G.W., 1979. Mortality associated with a phytoplankton bloom off Penzance in Mount's Bay. Journal of the Marine Biological Association of the United Kingdom, 59, 515-528.

  32. Hall-Spencer, J.M. & Moore, P.G., 2000a. Impact of scallop dredging on maerl grounds. In Effects of fishing on non-target species and habitats. (ed. M.J. Kaiser & S.J., de Groot) 105-117. Oxford: Blackwell Science.

  33. Hansson, H., 1998. NEAT (North East Atlantic Taxa): South Scandinavian marine Echinodermata Check-List. Tjärnö Marine Biological Assocation [On-line] [cited 26/01/16]. Available from: http://www.tmbl.gu.se/libdb/taxon/neat_pdf/NEAT*Echinodermata.pdf

  34. Hartnoll, R., 1998. Circalittoral faunal turf biotopes: An overview of dynamics and sensitivity characteristics for conservation management of marine SACs, Volume VIII. Scottish Association of Marine Sciences, Oban, Scotland.

  35. Hartnoll, R., 1975. The annual cycle of Alcyonium digitatum. Estuarine and coastal marine science, 3 (1), 71-78.

  36. Hayward, P.J. & Ryland, J.S. (ed.) 1995a. The marine fauna of the British Isles and north-west Europe. Volume 2. Molluscs to Chordates. Oxford Science Publications. Oxford: Clarendon Press.

  37. Herreid, C.F., 1980. Hypoxia in invertebrates. Comparative Biochemistry and Physiology Part A: Physiology, 67 (3), 311-320.

  38. Hill, A.S., Brand, A.R., Veale, L.O. & Hawkins, S.J., 1997. Assessment of the effects of scallop dredging on benthic communities. Final Report to MAFF, Contract CSA 2332, Liverpool: University of Liverpool

  39. Hiscock, K. & Wilson, E. 2007. Metridium senile Plumose anemone. In Tyler-Walters H. and Hiscock K. (eds) Marine Life Information Network: Biology and Sensitivity Key Information Reviews, [on-line]. Plymouth: Marine Biological Association of the United Kingdom. Available from: http://www.marlin.ac.uk/species/detail/1185

  40. Hiscock, K., 1983. Water movement. In Sublittoral ecology. The ecology of shallow sublittoral benthos (ed. R. Earll & D.G. Erwin), pp. 58-96. Oxford: Clarendon Press.

  41. Hiscock, K., 1985. Littoral and sublittoral monitoring in the Isles of Scilly. September 22nd to 29th, 1984. Nature Conservancy Council, Peterborough, CSD Report, no. 562., Field Studies Council Oil Pollution Research Unit, Pembroke.

  42. Hiscock, K., Sharrock, S., Highfield, J. & Snelling, D., 2010. Colonization of an artificial reef in south-west England—ex-HMS ‘Scylla’. Journal of the Marine Biological Association of the United Kingdom, 90 (1), 69-94.

  43. Hiscock, K., Southward, A., Tittley, I. & Hawkins, S., 2004. Effects of changing temperature on benthic marine life in Britain and Ireland. Aquatic Conservation: Marine and Freshwater Ecosystems, 14 (4), 333-362.

  44. Hoare, R. & Hiscock, K., 1974. An ecological survey of the rocky coast adjacent to the effluent of a bromine extraction plant. Estuarine and Coastal Marine Science, 2 (4), 329-348.

  45. Hobson, A., 1930. Regeneration of the Spines in Sea-Urchins. Nature, 125, 168.

  46. Holt, T.J., Jones, D.R., Hawkins, S.J. & Hartnoll, R.G., 1995. The sensitivity of marine communities to man induced change - a scoping report. Countryside Council for Wales, Bangor, Contract Science Report, no. 65.

  47. Jenkins, S.R., Beukers-Stewart, B.D. & Brand, A.R., 2001. Impact of scallop dredging on benthic megafauna: a comparison of damage levels in captured and non-captured organisms. Marine Ecology Progress Series, 215, 297-301.

  48. Johnston, E.L. & Roberts, D.A., 2009. Contaminants reduce the richness and evenness of marine communities: a review and meta-analysis. Environmental Pollution, 157 (6), 1745-1752.

  49. Kaiser, M.J., Ramsay, K., Richardson, C.A., Spence, F.E. & Brand, A.R., 2000. Chronic fishing disturbance has changed shelf sea benthic community structure. Journal of Animal Ecology, 69, 494-503.

  50. Kayser, H., 1990. Bioaccumulation and transfer of cadmium in marine diatoms, Bryozoa, and Kamptozoa. In Oceanic processes in marine pollution, vol. 6. Physical and chemical processes: transport and transformation (ed. D.J. Baumgartner & I.W. Duedall), pp. 99-106. Florida: R.E. Krieger Publishing Co.

  51. Kelly, M., Owen, P. & Pantazis, P., 2001. The commercial potential of the common sea urchin Echinus esculentus from the west coast of Scotland. Hydrobiologia, 465 (1-3), 85-94.

  52. Kinne, O. (ed.), 1984. Marine Ecology: A Comprehensive, Integrated Treatise on Life in Oceans and Coastal Waters.Vol. V. Ocean Management Part 3: Pollution and Protection of the Seas - Radioactive Materials, Heavy Metals and Oil. Chichester: John Wiley & Sons.

  53. Koukouras, A., 2010. Check-list of marine species from Greece. Aristotle University of Thessaloniki. Assembled in the framework of the EU FP7 PESI project

  54. Kukliński, P. & Barnes, D.K., 2008. Structure of intertidal and subtidal assemblages in Arctic vs temperate boulder shores. Pol. Polar Res, 29 (3), 203-218.

  55. Kupriyanova, E.K. & Badyaev, A.V., 1998. Ecological correlates of arctic Serpulidae (Annelida, Polychaeta) distributions. Ophelia, 49 (3), 181-193.

  56. Lawrence, J.M., 1975. On the relationships between marine plants and sea urchins. Oceanography and Marine Biology: An Annual Review, 13, 213-286.

  57. Lengyel, N.L., Collie, J.S. & Valentine, P.C., 2009. The invasive colonial ascidian Didemnum vexillum on Georges Bank - Ecological effects and genetic identification. Aquatic Invasions, 4(1), 143-152.

  58. Lewis, G.A. & Nichols, D., 1979a. Colonization of an artificial reef by the sea-urchin Echinus esculentus. Progress in Underwater Science, 4, 189-195.

  59. Lyster, I., 1965. The salinity tolerance of polychaete larvae. Journal of Animal Ecology, 34 (3), 517-527.

  60. MacBride, E.W., 1914. Textbook of Embryology, Vol. I, Invertebrata. London: MacMillan & Co.

  61. Matthews, A., 1917. The development of Alcyonium digitatum with some notes on early colony formation. Quarterly Journal of Microscopial Science, 62, 43-94.

  62. Migliaccio, O., Castellano, I., Romano, G. & Palumbo, A., 2014. Stress response to cadmium and manganese in Paracentrotus lividus developing embryos is mediated by nitric oxide. Aquatic Toxicology, 156, 125-134.

  63. Moore, H.B., 1937. Marine Fauna of the Isle of Man. Liverpool University Press.

  64. Moore, P.G., 1977a. Inorganic particulate suspensions in the sea and their effects on marine animals. Oceanography and Marine Biology: An Annual Review, 15, 225-363.

  65. NBN, 2015. National Biodiversity Network 2015(20/05/2015). https://data.nbn.org.uk/

  66. Nelson, M.L. & Craig, S.F., 2011. Role of the sea anemone Metridium senile in structuring a developing subtidal fouling community. Marine Ecology Progress Series, 421, 139-149.

  67. Nichols, D., 1979. A nationwide survey of the British Sea Urchin Echinus esculentus. Progress in Underwater Science, 4, 161-187.

  68. Nichols, D., 1984. An investigation of the population dynamics of the common edible sea urchin (Echinus esculentus L.) in relation to species conservation management. Report to Department of the Environment and Nature Conservancy Council from the Department of Biological Sciences, University of Exeter.

  69. Porter, J., 2012. Seasearch Guide to Bryozoans and Hydroids of Britain and Ireland.   Ross-on-Wye: Marine Conservation Society.

  70. Powell, N., 1971. The marine bryozoa near the Panama Canal. Bulletin of Marine Science, 21 (3), 766-778.

  71. Price, J.H., Irvine, D.E. & Farnham, W.F., 1980. The shore environment. Volume 2: Ecosystems. London Academic Press.

  72. Ramos, M., 2010. IBERFAUNA. The Iberian Fauna Databank, 2015(2015/12/21). http://iberfauna.mncn.csic.es/

  73. Rees, H.L., Waldock, R., Matthiessen, P. & Pendle, M.A., 2001. Improvements in the epifauna of the Crouch estuary (United Kingdom) following a decline in TBT concentrations. Marine Pollution Bulletin, 42, 137-144.

  74. Riley, K. & Ballerstedt, S., 2005. Pomatoceros triqueter. Marine Life Information Network: Biology and Sensitivity Key Information Sub-programme [on-line]. Plymouth: Marine Biological Association of the United Kingdom:. [cited 08/01/2016]. Available from:

  75. Rosenberg, R., Hellman, B. & Johansson, B., 1991. Hypoxic tolerance of marine benthic fauna. Marine Ecology Progress Series, 79, 127-131.

  76. Ryland, J.S. & De Putron, S., 1998. An appraisal of the effects of the Sea Empress oil spillage on sensitive invertebrate communities. Countryside Council for Wales Sea Empress Contract Report, no. 285, 97pp.

  77. SeaTemperature, 2015. World Sea Temperatures. (15/10/2015). http://www.seatemperature.org/

  78. Segrove, F., 1941. The development of the serpulid Pomatoceros triqueta L. Quarterly Journal of Microscopical Science, 82, 467-540.

  79. Smith, J.E. (ed.), 1968. 'Torrey Canyon'. Pollution and marine life. Cambridge: Cambridge University Press.

  80. Soule, D.F. & Soule, J.D., 2002. The eastern Pacific Parasmittina trispinosa complex (Bryozoa, Cheilostomatida): new and previously described species. Hancock Institute for Marine Studies, University of Southern California.

  81. Soule, D.F. & Soule, J.D., 1979. Bryozoa (Ectoprocta). In Pollution ecology of estuarine invertebrates (ed. C.W. Hart & S.L.H. Fuller), pp. 35-76.

  82. Stephenson, T.A., 1935. The British Sea Anemones, vol. 2. London: Ray Society.

  83. Stock, J.H., 1988. Lamippidae (Copepoda: Siphonostomatoida) parasitic in Alcyonium. Journal of the Marine Biological Association of the United Kingdom, 68 (02), 351-359.

  84. Svane, I. & Groendahl, F., 1988. Epibioses of Gullmarsfjorden: an underwater stereophotographical transect analysis in comparison with the investigations of Gislen in 1926-29. Ophelia, 28, 95-110.

  85. Thomas, J.G., 1940. Pomatoceros, Sabella and Amphitrite. LMBC Memoirs on typical British marine plants and animals no.33. University Press of Liverpool

  86. Tranter, P.R.G., Nicholson, D.N. & Kinchington, D., 1982. A description of spawning and post-gastrula development of the cool temperate coral, Caryophyllia smithi. Journal of the Marine Biological Association of the United Kingdom, 62, 845-854.

  87. Tyler, P.A. & Young, C.M., 1998. Temperature and pressures tolerances in dispersal stages of the genus Echinus (Echinodermata: Echinoidea): prerequisites for deep sea invasion and speciation. Deep Sea Research II, 45, 253-277

  88. Tyler-Walters, H., 2008. Echinus esculentus. Edible sea urchin. Marine Life Information Network: Biology and Sensitivity Key Information Sub-programme [on-line]. [cited 26/01/16]. Plymouth: Marine Biological Association of the United Kingdom. Available from: http://www.marlin.ac.uk/species/detail/1311

  89. Ursin, E., 1960. A quantitative investigation of the echinoderm fauna of the central North Sea. Meddelelser fra Danmark Fiskeri-og-Havundersogelser, 2 (24), pp. 204.

  90. Walsh, P. & Somero, G., 1981. Temperature adaptation in sea anemones: physiological and biochemical variability in geographically separate populations of Metridium senile. Marine Biology, 62 (1), 25-34.

  91. Warner, G.F., 1985. Dynamic stability in two contrasting epibenthic communities. In Proceedings of the 19th European Marine Biology Symposium, Plymouth, Devon, UK, 16-21 September, 1984 (ed. P.E. Gibbs), pp. 401-410.

  92. Whomersley, P. & Picken, G., 2003. Long-term dynamics of fouling communities found on offshore installations in the North Sea. Journal of the Marine Biological Association of the UK, 83 (5), 897-901.

  93. Wood, E. (ed.), 1988. Sea Life of Britain and Ireland. Marine Conservation Society. IMMEL Publishing, London

  94. Wood. C., 2005. Seasearch guide to sea anemones and corals of Britain and Ireland. Ross-on-Wye: Marine Conservation Society.

  95. Zintzen, V., Norro, A., Massin, C. & Mallefet, J., 2008. Temporal variation of Tubularia indivisa (Cnidaria, Tubulariidae) and associated epizoites on artificial habitat communities in the North Sea. Marine Biology, 153 (3), 405-420.

Citation

This review can be cited as:

Stamp, T.E., 2016. [Caryophyllia (Caryophyllia) smithii] with faunal and algal crusts on moderately wave-exposed circalittoral rock. In Tyler-Walters H. and Hiscock K. (eds) Marine Life Information Network: Biology and Sensitivity Key Information Reviews, [on-line]. Plymouth: Marine Biological Association of the United Kingdom. Available from: http://www.marlin.ac.uk/habitat/detail/1062

Last Updated: 11/01/2016