Pomatoceros triqueter with barnacles and bryozoan crusts on unstable circalittoral cobbles and pebbles

24-11-2002
Researched byDr Harvey Tyler-Walters Refereed byThis information is not refereed.
EUNIS CodeA5.141 EUNIS NamePomatoceros triqueter with barnacles and bryozoan crusts on unstable circalittoral cobbles and pebbles

Summary

UK and Ireland classification

EUNIS 2008A5.141Pomatoceros triqueter with barnacles and bryozoan crusts on unstable circalittoral cobbles and pebbles
EUNIS 2006A5.141Pomatoceros triqueter with barnacles and bryozoan crusts on unstable circalittoral cobbles and pebbles
JNCC 2004SS.SCS.CCS.PomBPomatoceros triqueter with barnacles and bryozoan crusts on unstable circalittoral cobbles and pebbles
1997 BiotopeCR.ECR.EFa.PomByCPomatoceros triqueter, Balanus crenatus and bryozoan crusts on mobile circalittoral cobbles and pebbles

Description

Cobbles and pebbles with Balanus crenatus, Pomatoceros and a few bryozoan and coralline algal crusts are often found at the base of exposed cliff faces where scour action prevents colonization by more delicate species. Occasionally in tide-swept conditions tufts of hydroids such as Sertularia argentea and Hydrallmania falcata are present. This biotope often grades into MCR.Flu.SerHyd which is characterized by large amounts of the above hydroids on stones also covered in Pomatoceros and barnacles. The main difference here is that MCR.Flu.SerHyd seems to develop on more stable, consolidated cobbles and pebbles in moderate tides - these stones may be disturbed in the winter and therefore long-lived species are not found. (Information taken from the Marine Biotope Classification for Britain and Ireland, Version 97.06: Connor et al., 1997a, b).

Recorded distribution in Britain and Ireland

Scattered records from Fair Isle, Orkney; the rivers Teign and Dart, Devon; Lundy; the Bishops & Clerks, Skomer and off Dinas Head in Pembrokeshire; Cardigan Bay, Lleyn Peninsula, Bardsey and Menai Straits north Wales; Donlus Bay, south west Ireland; Tiree and Loch Roag, Isle of Lewis in west Scotland and St Kilda.

Depth range

-

Additional information

None entered.

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Habitat review

Ecology

Ecological and functional relationships

This biotope is characterized by an impoverished fauna, dominated by fast growing epifauna such as the tubeworms, encrusting bryozoans and barnacles. The dominant species probably compete for space on the available hard substrata. While Pomatoceros triqueter may overgrow encrusting bryozoans, encrusting bryozoans tolerate overgrowth and probably subsequently grow over the calcareous tube of Pomatoceros triqueter (Gordon, 1972; Rubin, 1985). Encrusting bryozoans and encrusting corallines also probably compete for space. But this biotope experiences seasonal and sporadic cycles of severe scour that will free space for colonization, so that competition is probably limited. Numerous species have been recorded within this biotope but most are probably opportunistic or are species that are fortunate to find temporary sheltered niches from scour, and the species present probably vary with location. Overall, the community is primarily opportunistic and ephemeral.
  • Primary productivity is provided by encrusting corallines although few species present can probably graze them and few other algae are likely to survive scour in the long term.
  • The dominant species are suspension feeders on phytoplankton, zooplankton and organic particulates, e.g. the tubeworm Pomatoceros triqueter, barnacles Balanus crenatus and Balanus balanus, encrusting bryozoans (e.g. Parasmittina trispinosa), occasional erect Bryozoa (e.g. Crissiidae, Flustra foliacea and Scrupocellaria species), and occasional hydroids e.g. Sertularia argentea, Nemertesia species and Hydrallmania falcata).
  • Where present, Urticina felina is a passive predator of zooplankton and small invertebrates.
  • Mobile predators on epifauna include the starfish Asterias rubens and occasional Echinus esculentus feeding on epifaunal crusts, encrusting corallines, hydroids and bryozoans.
  • Starfish and hermit crabs (e.g. Pagurus bernhardus) are probably generalist predators and scavengers within the biotope.

Seasonal and longer term change

This biotope probably experiences seasonal variation in scour, which is most severe in winter storms. Holme & Wilson (1985) suggested that the fauna of his Balanus-Pomatoceros assemblage in the central English Channel was restricted to rapid growing colonizers able to settle rapidly and utilize space in short periods of stability in the summer months. The biotope will probably exhibit spring and summer peaks in hydroids, erect bryozoa and fast growing ascidians. Species richness is probably highest in the spring and summer. Inter-annual variation in storms and wave action is likely to remove the majority of epifauna in some years but allow more species to become established in others. However, the biotope is dominated by opportunistic species and effectively annual and ephemeral. Off Chesil Bank, the epifaunal communities dominated by Pomatoceros 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). Warner (1985) reported that the community did not contain any persistent individuals, being dominated by rapidly colonizing organisms but, while larval recruitment was patchy and varied between the years studied, recruitment was sufficiently predictable to result in a dynamic stability and a similar community was present in 1979, 1980 and 1983.

Habitat structure and complexity

The surface of cobbles and pebbles support tubes of Pomatoceros species, encrusting coralline algae, encrusting bryozoans and barnacles. Boulders and more stable hard substrata may support more delicate species such as the hydroids, erect bryozoans (e.g. Bugula spp. and Flustra foliacea) and fast growing ascidians (e.g. Ascidiella species and Dendrodoa grossularia). Patches of gravel and sand overlying bedrock may support the large dahlia anemone Urticina felina. The sand and gravel infauna probably supports meiofauna and some polychaetes but no information was found. Mobile species such as squat lobster (e.g. Galathea spp.) may use spaces between boulders as temporary refuges. Brittlestars (e.g. Ophiocomina nigra and Ophiothrix fragilis) may utilize spaces between cobbles and pebbles. The biotope may be surrounded by more species rich biotopes. For example, the biotope may grade into MCR.Flu.SerHyd with increasing substratum stability (Connor et al., 1997a). Holmes & Wilson (1985) noted that raised bedrock, above the main area affected by scour, in the English Channel was characterized by Flustra foliacea communities (see MCR.Flu for more information).

Productivity

This biotope is dominated by secondary producers. Food in the form of phytoplankton, zooplankton and organic particulates from the water column together with detritus and abraded macroalgal particulates from shallow water ecosystems are supplied by water currents and converted into faunal biomass. Their secondary production supplies higher trophic levels such as mobile predators (e.g. starfish, sea urchins, and fish) and scavengers (e.g. starfish and crabs) and the wider ecosystem in the form of detritus (e.g. dead bodies and faeces). In addition, reproductive products (sperm, eggs, and larvae) also contribute to the zooplankton (Hartnoll, 1998). No estimates of productivity were found in the literature but the biotope is impoverished so that productivity is likely to be low.

Recruitment processes

Pomatoceros triqueter probably breeds throughout the year with a peak in spring and summer, although breeding was reported to only occur in April at Port Erin (Moore, 1937; Segrove, 1941; Hayward & Ryland, 1995). 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, 1995). Settlement was reported to be rare in winter but maximum settlement occurred in April, June, August and Sept-Oct (Castric-Fey, 1983). Once settled juveniles grow at about 1.5mm/month, and become sexually mature with about 4 months (see MarLIN review). Pomatoceros triqueter may live for up to 4 years, although 1.5-2.5 years is probably more usual and most die after reproduction (Castric-Fey, 1983; Hayward & Ryland, 1995), so that life span probably depends on location and environmental conditions. Dispersal potential is high, depending on local hydrographic condition, and tubeworms, such as spirorbids and Pomatoceros triqueter are commonly the initial recruits to new substrata (Sebens, 1985, 1986; Hatcher, 1998). For example, Pomatoceros triqueter colonized artificial reefs soon after deployment in summer (Jensen et al., 1994), settlement plates within 2-3.5 months and dominated spring recruitment (Hatcher, 1998). However, in the mobile stone communities of Chesil Bank, Warner (1985) suggested that Pomatoceros triqueter did not reach sexual maturity in the population he studied.

The barnacle Balanus crenatus reproduces between February and September, larvae settling in a peak from April to October. Once settled, Balanus crenatus matures within 4 months, so that April settled individuals can produce larvae by July, reaching full size before their first winter (Rainbow, 1984). Balanus crenatus has a life span of only 18 months so that the population requires continuous recruitment. Therefore, dispersal potential is high, depending on the local hydrographic regime. Balanus crenatus also colonized settlement plates or artificial reefs within 1-3 months of deployment in summer, (Brault & Bourget, 1985; Hatcher, 1998), and became abundant on settlement plates shortly afterwards (Standing, 1976; Brault & Bourget, 1985).

The brooded, lecithotrophic coronate larvae of many bryozoans (e.g. Flustra foliacea, Parasmittina trispinosa, and Bugula species), have a short pelagic life time of several hours to about 12 hours (Ryland, 1976). Recruitment is dependant on the supply of suitable, stable, hard substrata (Eggleston, 1972b; Ryland, 1976; Dyrynda, 1994). However, even in the presence of available substratum, Ryland (1976) noted that significant recruitment in bryozoans only occurred in the proximity of breeding colonies. Other species, such as Electra and Crisia release long-lived planktonic larvae. Electra pilosa has a planktonic larvae with a protracted life in the plankton and potentially extended dispersal and can colonize a wide variety of substrata. It is probably adapted to rapid growth and reproduction (r-selected), capable of colonizing ephemeral habitats, but may also be long lived in ideal conditions (Hayward & Ryland, 1998). In settlement studies, Electra crustulenta recruited to plates within 5 -6months of deployment (Sandrock et al., 1991). Jensen et al. (1994) reported that encrusting bryozoans colonized an artificial reef within 6-12months. Keough (1983) noted that Parasmittina raigii colonized settlement plates annually. Overall, encrusting bryozoans are probably rapid colonizers of available hard substrata.

Hydroids are often initial colonizing organisms in settlement experiments and fouling communities (Jensen et al., 1994; Gili & Hughes, 1995; Hatcher, 1998). The hydroids (e.g. Hydrallmania falcata and Sertularia argentea) lack a medusa stage, releasing planula larvae. Planula larvae swim or crawl for short periods (e.g. <24hrs) so that dispersal away from the parent colony is probably very limited (Sommer, 1992; Gili & Hughes, 1995). However, Nemertesia antennina releases planulae on mucus threads, that increase potential dispersal to 5 -50m, depending on currents and turbulence (Hughes, 1977). Most species of hydroid in temperate waters grow rapidly and reproduce in spring and summer. Few species of hydroids have specific substrata requirements and many are generalists. Hydroids are also capable of asexual reproduction and many species produce dormant, resting stages, that are very resistant of environmental perturbation (Gili & Hughes, 1995). But Hughes (1977) noted that only a small percentage of the population of Nemertesia antennina in Torbay developed from dormant, regressed hydrorhizae, the majority of the population developing from planulae as three successive generations. Rapid growth, budding and the formation of stolons allows hydroids to colonize space rapidly. Fragmentation may also provide another route for short distance dispersal. Hydroids may potentially disperse over a wide area in the long term as dormant stages, or reproductive adults, rafting on floating debris or hitch-hiking on ships hulls or in ballast water (Cornelius, 1992; Gili & Hughes, 1995).

Overall, the dominant species in the biotope, i.e. the tubeworms, encrusting bryozoans and barnacles, are good initial colonizers of hard substrata, capable of rapid growth and reproduction (r-selected) and adapted to ephemeral habitats.

Time for community to reach maturity

This biotope has a impoverished community consisting of rapid colonizing, rapid growing and reproducing species (see above). After winter storms or other severe disturbance, the dominant species would probably recolonize the habitat within a few months, and the community probably develops annually by recruitment from surviving individuals or colonies and recruitment from adjacent or upstream habitats. The biotope would probably be recognizable within less than 6 months. Hydroids and erect bryozoans may take longer to establish, probably from surviving fragments or hydrorhizae but would either regrow or re-colonize within 6-12 months in most cases. Holme & Wilson (1985) suggested that the fauna of his Balanus-Pomatoceros assemblage was restricted to rapid growing colonizers able to settle rapidly and utilize space in short periods of stability in the summer months, and develop within less than a year.

Additional information

None entered

Preferences & Distribution

Recorded distribution in Britain and IrelandScattered records from Fair Isle, Orkney; the rivers Teign and Dart, Devon; Lundy; the Bishops & Clerks, Skomer and off Dinas Head in Pembrokeshire; Cardigan Bay, Lleyn Peninsula, Bardsey and Menai Straits north Wales; Donlus Bay, south west Ireland; Tiree and Loch Roag, Isle of Lewis in west Scotland and St Kilda.

Habitat preferences

Depth Range
Water clarity preferences
Limiting Nutrients
Salinity
Physiographic
Biological Zone
Substratum
Tidal
Wave
Other preferences Mobile hard substrata and scour

Additional Information

This biotope characterizes hard mobile substrata such as cobbles, pebbles and boulders with sand or gravel in areas of considerable water movement either due to wave action or tidal streams. The biotope occurs in very wave exposed to moderately wave exposed habitats, and/or in areas of strong to very weak tidal streams (Connor et al., 1997a; JNCC, 1999). Scour of the cobbles, pebbles and boulders by sand, or by mobilization of the cobbles and pebbles themselves results in a scour resistant or ephemeral fauna. For example, in the mouth of the Teign, Devon, ECR.PomByC occurs on cobbles sitting on coarse sand and gravel in a scour pit. This biotope is probably very similar to the impoverished Balanus-Pomatoceros assemblage described on hard substrata subject to severe scour or deep submergence by sand or gravel reported by Holme & Wilson (1985) in tide-swept areas of the central English Channel.

Species composition

Species found especially in this biotope

Rare or scarce species associated with this biotope

-

Additional information

The MNCR recorded 265 species in 9 records of this biotope. But only a few dominant species occurred in any abundance and most species were only occasional or rare, and not all species occurred in all records of the biotope.

Sensitivity reviewHow is sensitivity assessed?

Explanation

The dominant characterizing species are Pomatoceros triqueter and Balanus crenatus which if lost would result in loss of the biotope as described. Reference was made to Electra pilosa to represent the sensitivity of encrusting bryozoans and to Nemertesia ramosa and Cordylophora caspia to represent the erect hydroids.

Species indicative of sensitivity

Community ImportanceSpecies nameCommon Name
Important characterizingBalanus crenatusAn acorn barnacle
Important characterizingPomatoceros triqueterA tubeworm

Physical Pressures

 IntoleranceRecoverabilitySensitivitySpecies RichnessEvidence/Confidence
High Very high Low Major decline Moderate
Removal of the substratum would result in loss of its associated community and an intolerance of high has, therefore, been recorded. The biotope is dominated by rapid colonizing species, so that recovery is likely to be very high (see additional information below).
High Very high Low Major decline Moderate
Pomatoceros triqueter, Balanus crenatus are encrusting Bryozoa are low lying epifauna and probably highly intolerant of smothering by 5 cm of sediment, due to clogging of filter-feeding and respiratory apparatus, localized anoxia and associated scour. Holme & Wilson (1985) suggested that scour or deep submergence with sediment probably depopulates the affected substrata. However, Urticina felina (where present) occurred in areas of the English Channel subject to a covering of ca 5cm of sand, and would probably survive where present. Overall, smothering by sediment would probably result in loss of the dominant characterizing species and an intolerance of high has been recorded, although subsequent recovery would probably be very high (see additional information below).
Low Immediate Not sensitive No change Low
A moderate increased in suspended sediment is likely to increase food availability for suspension feeders, while a significant increase may block filter feeding apparatus. Pomatoceros triqueter has been recorded from areas of high suspended sediment load such as Chichester Harbour (Stubbings & Houghton, 1964). It is also commonly found under boulders, where sediment is likely to settle and be re-suspended by water movement. Similarly, Balanus species are generally tolerant of moderate siltation but are intolerant of excessive siltation (Holt et al., 1995). Balanus crenatus is found in a wide variety of habitats including estuaries and on the carapace of crustaceans in sedimentary habitats, although increased sediment loads may reduce growth rates. Encrusting bryozoans may be more intolerant, although Electra pilosa is relatively tolerant of suspended sediment, for example Moore (1973c; 1977) regarded Electra pilosa to be ubiquitous with respect to turbidity in subtidal kelp holdfasts in north east England. Hydroids, if present may be intolerant, for example Sertularia operculata was reported to die within a few months when transplanted from Lough Ine rapids to sheltered water, due to the build up of a layer of silt (Round, et al., 1961).

While an increase in suspended sediment at the benchmark level for a month is likely to reduce the efficiency of filter feeding in suspension feeders most species are likely to survive for a month. If there is an associated increase in siltation, it is likely to interfere with larval growth and settlement if it coincided with the reproductive season. Therefore, an intolerance of low has been recorded.

Low Not relevant Not relevant
Pomatoceros triqueter has been reported to occur in areas where there is little or no silt present (Price et al., 1980). A decrease in suspended sediment loads may reduce food availability to suspension feeders within this biotope, e.g. Pomatoceros triqueter, Balanus crenatus and encrusting bryozoans. Rapid growth and reproduction is vitally important in this ephemeral biotope, so that a reduction in food supply affect subsequent recruitment. Therefore, an intolerance of low has been recorded at the benchmark level.
Not relevant Not relevant Not relevant Not relevant Not relevant
The majority of records of this biotope were recorded from 20-30m depth, while shallower example occurred at 5-10m (JNCC, 1999). Therefore, this biotope is unlikely to experience exposure to the air or desiccation.
Not relevant Not relevant Not relevant Not relevant Not relevant
This biotope occur in the circalittoral and is unlikely to be directly affected by an increase in emergence. However, increased emergence may indirectly affect the effective depth of the biotope potentially exposing it to greater wave action (see below).
Not sensitive* Not relevant
This biotope occur in the circalittoral and is unlikely to be directly affected by an decrease in emergence. However, decreased emergence may indirectly affect the effective depth of the biotope potentially exposing it to reduced wave action (see below).
Intermediate Very high Low Minor decline Low
Water movement is the most important structuring factor in this biotope. Wave action is probably the most important source of water movement, expect in the few wave sheltered records, and with increasing depth where currents and tidal flow become increasingly significant. In examples of this biotope in extremely exposed to wave exposed conditions, changes in water movement may not be significant. But in moderately exposed to wave sheltered sites water flow is likely to be more important in mobilization of the hard substrata. An increase in water flow from strong to very strong will result in increased scour, and possibly removal of the smaller pebbles cobbles and sands and hence some substratum loss. However, the biotope would probably develop on scoured bedrock although with reduced abundance of individual species. (see Holme & Wilson, 1985). Delicate species such as hydroids would be lost. Therefore, an intolerance of intermediate has been recorded with a recoverability of very high (see additional information below).
High Very high Low Rise Low
Water movement is the most important structuring factor in this biotope. Wave action is probably the most important source of water movement, expect in the few wave sheltered records, and with increasing depth where currents and tidal flow become increasingly significant. In examples of this biotope in extremely exposed to wave exposed conditions, changes in tidal flow may not be significant. But in moderately exposed to wave sheltered sites water flow is likely to be more important in mobilization of the hard substrata. In more wave sheltered sites a reduction in water flow from strong to weak (see benchmark) will stabilize the substratum, allowing more delicate species to colonize and increase in abundance, e.g. hydroids, erect bryozoans, and ascidians, and the biotope may be replaced by more stable epifaunal communities such as A5.444. Therefore, an intolerance of high has been recorded. Once prior conditions return recovery is likely to be rapid (see additional information below).
Low Immediate Not sensitive Minor decline Low
Maximum sea surface temperatures around the British Isles rarely exceed 20 °C (Hiscock, 1998). Pomatoceros triqueter occurs as far south as the Mediterranean, it will therefore be subject to a wider range of temperatures than experienced in the British Isles. Most of the encrusting bryozoan and hydroid species occurring in the biotope are distributed to the north and south of Britain and Ireland (e.g. the bryozoans Electra pilosa and Parasmittina trispinosa, and the hydroids, Sertularia argentea and Hydrallmania falcata) and are also unlikely to be affected by long term changes in temperature. But, acute temperature change may affect growth, feeding and hence reproduction in bryozoans (see Electra pilosa for discussion).

Balanus crenatus is a boreal species, and is intolerant of increases in water temperature. In Queens Dock, Swansea where the water was on average 10 °C higher than average due to the effects of a power station effluent, Balanus crenatus was replaced by the subtropical barnacle Balanus amphitrite. After the water temperature cooled, Balanus crenatus returned (Naylor, 1965). Balanus crenatus has a peak rate of cirral beating at 20 °C and all spontaneous activity ceases at about 25 °C (Southward, 1955). Gosse (1860) observed that Urticina felina (as Actinia crassicornis) was "one of the most difficult [anemones] to keep in an aquarium" and that "the heat of the summer is generally fatal to our captive specimens". It is therefore likely that local warming may adversely affect individuals and that some mortality might occur.

Overall, a long term change in temperature is unlikely to affect most members of the community, although Balanus crenatus may decrease in abundance in southern records. Several species may be more intolerant of acute temperature change, although this biotope is probably buffered and against acute change due to its depth. Therefore, an intolerance of low has been recorded. Recoverability is likely to be very rapid.
Intermediate Very high Low Decline Low
Minimum surface sea water temperatures rarely fall below 5 °C around the British Isles (Hiscock, 1998). Below a temperature of 7 °C Pomatoceros triqueter is unable to build calcareous tubes (Thomas, 1940). Intertidal populations of Pomatoceros triqueter were reported to suffer 50% mortality at Mumbles, on the Gower after the extreme winter of 1962-63 (Crisp, 1964). But the boreal barnacle Balanus crenatus was unaffected by the 1962-63 winter (Crisp, 1964). Although Urticina felina was apparently unaffected by the extremely cold winter of 1962-63 (Crisp, 1964), Gosse (1860) observed that "after the intense and protracted frost of February 1855, the shores of South Devon were strewn with dead and dying anemones, principally of this species". Most of the encrusting bryozoans and hydroids occur to the north of Britain and Ireland and are unlikely to be affected by long terms changes in temperature, although short term acute change may affect their growth and reproduction. This biotope is probably protected from acute temperature change by its depth. But decreased temperatures may adversely affect survival and larval settlement in Pomatoceros triqueter, and may partly explain why recruitment in rare in winter, possibly leading to a reduction in its abundance. Therefore, an intolerance of intermediate has been recorded, although recovery is likely to be rapid.
Tolerant Not relevant Not relevant Not relevant Not relevant
The only species in the biotope that are dependant on light are encrusting corallines. But encrusting coralline algae are amongst the deepest water species of macroalgae occurring in the circalittoral, at great depths, and a light levels as low as 0.05 -0.001% of surface incident light (Lüning, 1990). A reduction in light intensity may reduce their growth rates, especially in the deepest examples of the biotope. However, their extremely slow growth rates mean that the corallines will probably not be adversely affected for the duration of the benchmark. Therefore, not sensitive has been recorded.
Intermediate Very high Low Not relevant Very low
A increase in light reaching the biotope may benefit encrusting corallines and may encourage the growth of ephemeral algae, especially in the summer months. Hiscock (1986c) described ephemeral algal communities inhabiting pebbles off Skomer. Several species were only present in summer, while others were abundant in summer but survived as small creeping fragments or sporelings during winter (e.g. Polyneura gmelinii, Polysiphonia spp, Lomentaria orcadensis and Rhodophyllis divaricata). Other species, such as Cladophora spp., Bryopsis plumosa and Ulva spp. showed seasonal variation (Hiscock, 1986c). Decreased turbidity may allow similar ephemeral algal to colonize the biotope, especially in its more shallow extent. Therefore, the biotope may be altered and a proportion of the biotope as described lost. Therefore, an intolerance of intermediate has been recorded with very low confidence. Recoverability is likely to be very high.
Intermediate Very high Low Minor decline Low
Water movement is the most important structuring factor in this biotope. Mobilization of the stony substratum and associated sediment by wave action, especially in winter storms controls succession and hence the community structure. For example, winter storms were reported to de-populate cobbles off Chesil Bank (Warner, 1985), while severe scour by sand and gravel in the central English Channel depopulated hard substrata (see Holme & Wilson, 1985). However, seasonal depopulation of the biotope is part of the dynamic stability of the community (Warner, 1985). This biotope was reported from wave exposed to very wave exposed habitats. An increase in wave action to extremely wave exposed for a year will probably reduce the abundance of all species within the community, although some individuals will probably survive in the summer months, and the biotope would still be recognizable albeit with a reduced number of species (e.g. delicate hydroids and encrusting bryozoans). Therefore, an overall intolerance of intermediate has been recorded.
High Very high Low Rise Low
Water movement is the most important structuring factor in this biotope. Mobilization of the stony substratum and associated sediment by wave action, especially in winter storms, controls succession and hence the community structure. Wave action is of primary importance to generate water movement except in deeper examples of the biotope or examples in wave sheltered site where water flow is of increased importance (see above). Therefore, a decrease in wave action, e.g. from exposed to sheltered is likely to have significant effects on the biotope. Decreased wave exposure will reduce scour and stabilize the substratum, allowing more delicate and long-lived species (e.g. hydroids, erect bryozoans and ascidians) to colonize the habit. As a result the biotope will probably be replaced by communities characteristic of similar substrata but more stable condition e.g. MCR.Flu or A5.444. Therefore, an intolerance of high has been recorded, although recoverability is likely to be very high.
Tolerant Not relevant Not sensitive No change High
Tubeworms, barnacles, hydroids, and bryozoans are unlikely to be sensitive to noise or vibration at the benchmark level. Mobile fish or decapod species may be temporarily scared away from the areas but few if any adverse effects on the biotope are likely to result.
Tolerant Not relevant Not sensitive No change High
Many of the species within the biotope probably respond to light levels, detecting shade and shadow to avoid predators, and day length in their behavioural or reproduction. However, their visual acuity is probably very limited and they are unlikely to be sensitive to visual disturbance at the benchmark level.
Tolerant Not relevant Not sensitive No change High
Physical disturbance by water movement and abrasion due to scour are characteristic of this biotope. Additional abrasion due to anchoring or mobile fishing gear is unlikely to have any significant affect on the community. Mobile fishing gear may remove gravel and pebbles and move cobbles and stones, in which case the effects will be akin to substratum loss above. Overall, not sensitive has been recorded.
Intermediate Very high Low Minor decline Low
Removal of the epifauna, e.g. Pomatoceros triqueter, Balanus crenatus or encrusting bryozoans from their substratum is likely to be terminal. But displacement of the cobbles, stones or pebbles to which they are attached is far more likely. Some individuals will probably be killed by abrasion in the process of displacement but as long as they are displaced to a similar habitat then the majority would survive. However, displacement from the biotope would result in a reduction in their abundance within the biotope and an intolerance of intermediate has been recorded. Recoverability is probably very high (see additional information below).

Chemical Pressures

 IntoleranceRecoverabilitySensitivityRichnessEvidence/Confidence
Low Immediate Not sensitive Decline Low
Bryan & Gibbs (1991) suggest that little information was available on the intolerance of polychaetes to tributyl-tin (TBT). Hoare & Hiscock (1974) reported that Pomatoceros triqueter was present in the immediate vicinity of halogenated effluent in Amlwch Bay, suggesting tolerance of chemical contamination. Holt et al. (1995) suggested that barnacles are fairly sensitive to chemical pollution. But Balanus crenatus was the dominant species on pier pilings at a site subject to urban sewage pollution (Jakola & Gulliksen, 1987), while Hoare & Hiscock (1974) found that Balanus crenatus survived near to an acidified halogenated effluent discharge where many other species were killed, suggesting a high tolerance to chemical contamination. Hoare & Hiscock (1974) observed that Urticina felina also survived near to an acidified halogenated effluent discharge in a 'transition' zone where many other species were unable to survive but was absent from stations closest to the effluent which were dominated by pollution tolerant species such as polychaetes, suggesting a tolerance to chemical contamination. Bryozoans are common members of fouling communities, 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 100ng/l TBT. Hoare & Hiscock (1974) suggested that Polyzoa (Bryozoa) were amongst the most intolerant species to acidified halogenated effluents in Amlwch Bay, Anglesey, e.g. Electra pilosa occurred at low abundance on laminarian holdfasts within the bay, compared to sites outside the affected area. Rees et al. (2001) reported that the abundance of epifauna (including bryozoans) had increased in the Crouch estuary in the five 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.

Overall, Pomatoceros triqueter and Balanus crenatus may tolerate some forms of chemical contamination, while encrusting bryozoans may be more intolerant. Chemical contamination may remove some more intolerant species, resulting in a reduction in species richness, but the biotope will probably still be recognizable without loss of extent. Therefore, an intolerance of low has been suggested based on available evidence.

Heavy metal contamination
Low Immediate Not sensitive Minor decline Low
Bryan (1984) suggested that, on evidence available for several species, polychaetes are fairly resistant to heavy metals, although no evidence concerning tolerance in Pomatoceros triqueter was found. Barnacles accumulate heavy metals and store them as insoluble granules (Rainbow, 1987). Pyefinch & Mott (1948) recorded a median lethal concentration of 0.19 mg/l copper and 1.35 mg/l mercury, for Balanus crenatus over 24 hours. Barnacles may tolerate fairly high level of heavy metals in nature, for example they are found in Dulas Bay, Anglesey, where copper reaches concentrations of 24.5 µg/l, due to acid mine waste (Foster et al., 1978). Bryozoans are common members of fouling communities and amongst those organisms most resistant to antifouling measures, such as copper containing anti-fouling paints. Bryozoans were also shown to bioaccumulate heavy metals to a certain extent (Soule & Soule, 1979; Holt et al., 1995). Various heavy metals have been show to have sublethal effects on growth in the few hydroids studied experimentally (Stebbing, 1981; Bryan, 1984; Ringelband, 2001).

Overall, the dominant species within the biotope are probably tolerant of heavy metal contamination and no evidence of mortality in nature was found. Therefore, an intolerance of low has been recorded, albeit with low confidence.

Hydrocarbon contamination
Low Immediate Not sensitive Minor decline Very low
This biotope is protected from the direct effects of oil spills by its depth but may be affected by water soluble fractions of oils, PAHs, hydrocarbons adsorbed onto particulates or oils solublized by dispersants. For example, dispersants and oil from the Torrey Canyon oil spill affected organisms at a depth of 5.5 and 14.5 m in the vicinity of Sennen, an area affected by strong mixing due to heavy wave action.

No information on the effects of hydrocarbon contamination on Pomatoceros triqueter was found. Urticina felina was found to be one of the most resistant animals on the shore one month after the Torrey Canyon oil spill, being commonly found alive in pools between the tide-marks which appeared to be devoid of all other animals (Smith, 1968). Littoral barnacles generally have a high tolerance to oil (Holt et al., 1995) and were little impacted by the Torrey Canyon oil spill (Smith, 1968). Therefore, Balanus crenatus may be fairly resistant to hydrocarbon contamination. But bryozoans may be highly intolerant of the effects of oil spills and possibly hydrocarbons (see Electra pilosa and CR.Bug reviews).

Overall , if the physiology within different animals groups can be assumed to be similar, then bryozoans, may be highly intolerant of hydrocarbon contamination, while the other dominant species may be relatively tolerant. Therefore an intolerance of low has been recorded, albeit with very low confidence.

Radionuclide contamination
No information Not relevant No information Not relevant Not relevant
No information found
Changes in nutrient levels
Tolerant Not relevant Not relevant Not relevant Not relevant
Moderate nutrient enrichment may increase the food available to suspension feeders in this biotope. Eutrophication may increase the green of ephemeral algae in shallower examples of the biotope, although given the degree of scour, their growth is unlikely to adversely affect the biotope. Therefore not sensitive has been recorded. The biotope may be indirectly affected by the death of algal blooms and their subsequent settlement on the seabed but the biotope occurs in areas of strong water movement where the dead algae would be quickly removed.
Not relevant Not relevant Not relevant Not relevant Not relevant
This biotope occurs in deep waters in fully saline conditions and it unlikely to be affected by further increases in salinity.
Not sensitive* Not relevant
Pomatoceros triqueter occurs in fully saline coastal waters and has not been recorded from brackish or estuarine waters. It occurs under boulders in intertidal habitats where it is probably exposed to variable salinity due to evaporation of seawater or fresh water runoff. Dixon (1985) viewed the species as able to withstand significant reductions in salinity but did not provide quantitative data. Balanus crenatus occurs in upper estuaries and can tolerate salinities down to 14 psu if given time to acclimate (Foster, 1970). At salinities below 6 psu motor activity ceases, respiration falls and the animal falls in to a "salt sleep". In this state the animals may survive in fresh water for 3 weeks, enabling them to withstand changes in salinity over moderately long periods (Barnes, 1953). Most bryozoans and hydroids are stenohaline and limited to fully saline conditions (see CR.Bug for details). However, this biotope is probably protected from fresh water runoff by its depth, and unlikely to be subject to decreased salinity.
Not relevant Not relevant Not relevant Not relevant Not relevant
This biotope occurs in areas of strong water movement, where anoxic conditions are unlikely to occur.

Biological Pressures

 IntoleranceRecoverabilitySensitivityRichnessEvidence/Confidence
Low Immediate Not sensitive No change Low
The commensal ciliate Trichodina pediculus was observed in "fair numbers" moving over the branchial crown of Pomatoceros triqueter (Thomas, 1940). 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 these parasites on Pomatoceros triqueter. No information concerning parasites or diseases in the other dominant species was found. Overall, any parasitic burden is likely to affect growth and reproduction, both especially critical in this ephemeral biotope. Therefore an intolerance of low has been recorded.
No information Not relevant No information Insufficient
information
Not relevant
No information found.
Not relevant Not relevant Not relevant Not relevant Not relevant
It is extremely unlikely that any of the species indicative of sensitivity would be targeted for extraction and we have no evidence for the indirect effects of extraction of other species on this biotope. Urticina felina is not currently subject to extraction but if a cold water marine aquarium trade were to take-off, this species is likely to be collected. However, its loss form the biotope would probably not significantly affect the integrity of the biotope and not relevant has been recorded.
Not relevant Not relevant Not relevant Not relevant Not relevant

Additional information

Recoverability
The dominant species are rapid colonizers, capable of rapid growth and early reproduction. For example Pomatoceros triqueter colonized artificial reefs soon after deployment in summer (Jensen et al., 1994), settlement plates within 2-3.5 months and dominated spring recruitment (Hatcher, 1998). Similarly, Balanus crenatus also colonized settlement plates or artificial reefs within 1-3 months of deployment in summer, (Brault & Bourget, 1985; Hatcher, 1998), and became abundant on settlement plates shortly afterwards (Standing, 1976; Brault & Bourget, 1985). Sebens (1985, 1986) noted that calcareous tube worms, encrusting bryozoans and erect hydroids and bryozoans covered scraped areas within 4 months in spring, summer and autumn. Holme & Wilson (1985) suggested that the Pomatoceros-Balanus assemblage on severely scoured hard substrata probably developed rapidly, in less than a year. Tube worms, encrusting bryozoans and hydroids are generally considered to be early colonizers of available hard substrata and are common members of fouling communities (Rubin, 1980; Castric-Fey, 1983; Warner, 1985; Holme & Wilson, 1985; Sebens 1985, 1986; Jensen et al., 1994; Hatcher, 1998). In addition, most of the epifauna is probably subject to severe physical disturbance and scour during winter storms and probably develops annually, through recolonization from any surviving individuals and from adjacent habitats. Therefore, recovery is likely to be very high, the biotope developing within less than year and probably no more than 6 months in spring and summer.

Importance review

Policy/Legislation

Habitats of Principal ImportanceSubtidal sands and gravels
Habitats of Conservation ImportanceSubtidal sands and gravels
UK Biodiversity Action Plan PrioritySubtidal sands and gravels

Exploitation

None of the species occurring in this biotope are likely to be subject to exploitation.

Additional information

-

Bibliography

  1. Adey, W.H. & Adey, P.J., 1973. Studies on the biosystematics and ecology of the epilithic crustose corallinacea of the British Isles. British Phycological Journal, 8, 343-407.
  2. Airoldi, L., 2003. The effects of sedimentation on rocky coast assemblages. Oceanography and Marine Biology: An Annual Review, 41,161-236
  3. Airoldi, L., 2000. Responses of algae with different life histories to temporal and spatial variability of disturbance in subtidal reefs. Marine Ecology Progress Series, 195 (8), 81-92.
  4. Andersson, M.H., Berggren, M., Wilhelmsson, D. & Öhman, M.C., 2009. Epibenthic colonization of concrete and steel pilings in a cold-temperate embayment: a field experiment. Helgoland Marine Research, 63, 249-260.

  5. Arévalo, R., Pinedo, S. & Ballesteros, E., 2007. Changes in the composition and structure of Mediterranean rocky-shore communities following a gradient of nutrient enrichment: descriptive study and test of proposed methods to assess water quality regarding macroalgae. Marine Pollution Bulletin, 55 (1), 104-113.
  6. Balata, D., Piazzi, L., & Cinelli, F., 2007. Increase of sedimentation in a subtidal system: effects on the structure and diversity of macroalgal assemblages. Journal of Experimental Marine Biology and Ecology351(1), 73-82.

  7. Barnes, H. & Bagenal, T.B., 1951. Observations on Nephrops norvegicus and an epizoic population of Balanus crenatus. Journal of the Marine Biological Association of the United Kingdom, 30, 369-380.
  8. Barnes, H. & Barnes, M., 1974. The responses during development of the embryos of some common cirripedes to wide changes in salinity. Journal of Experimental Marine Biology and Ecology, 15 (2), 197-202.
  9. Barnes, H. & Barnes, M., 1968. Egg numbers, metabolic efficiency and egg production and fecundity; local and regional variations in a number of common cirripedes. Journal of Experimental Marine Biology and Ecology, 2, 135-153.
  10. Barnes, H. & Powell, H.T., 1953. The growth of Balanus balanoides and B. crenatus under varying conditions of submersion. Journal of the Marine Biological Association of the United Kingdom, 32, 107-127.
  11. Barnes, H., Finlayson, D.M. & Piatigorsky, J., 1963. The effect of desiccation and anaerobic conditions on the behaviour, survival and general metabolism of three common cirripedes. Journal of Animal Ecology, 32, 233-252.
  12. Boney, A.D., 1971. Sub-lethal effects of mercury on marine algae. Marine Pollution Bulletin, 2, 69-71.
  13. Borja, A., Franco, J. & Perez, V., 2000. A Marine Biotic Index to Establish the Ecological Quality of Soft-Bottom Benthos Within European Estuarine and Coastal Environments. Marine Pollution Bulletin, 40 (12), 1100-1114.
  14. Bradshaw, C., Veale, L.O., Hill, A.S. & Brand, A.R., 2002. The role of scallop-dredge disturbance in long-term changes in Irish Sea benthic communities: a re-analysis of an historical dataset. Journal of Sea Research, 47, 161-184.
  15. Brault, S. & Bourget, E., 1985. Structural changes in an estuarine subtidal epibenthic community: biotic and physical causes. Marine Ecology Progress Series, 21, 63-73.
  16. Brazier, D.P., Holt, R.H.F., Murray, E. & Nichols, D.M., 1999. Marine Nature Conservation Review Sector 10. Cardigan Bay and North Wales: area summaries. Peterborough: Joint Nature Conservation Committee. [Coasts and seas of the United Kingdom. MNCR Series.]
  17. 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.
  18. 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.
  19. Cadée, G.C., 2007. Balanuliths: Free-living clusters of the barnacle Balanus crenatus. Palaios, 22, 680-681.

  20. Campbell, D.A. & Kelly, M.S., 2002. Settlement of Pomatoceros triqueter (L.) in two Scottish lochs, and factors determining its abundance on mussels grown in suspended culture. Journal of Shellfish Research, 21, 519-528.

  21. 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.
  22. Chamberlain, Y.M., 1996. Lithophylloid Corallinaceae (Rhodophycota) of the genera Lithophyllum and Titausderma from southern Africa. Phycologia, 35, 204-221.
  23. Cole, S., Codling, I.D., Parr, W., Zabel, T., 1999. Guidelines for managing water quality impacts within UK European marine sites [On-line]. UK Marine SACs Project. [Cited 26/01/16]. Available from: http://www.ukmarinesac.org.uk/pdfs/water_quality.pdf

  24. Colhart, B.J., & Johanssen, H.W., 1973. Growth rates of Corallina officinalis (Rhodophyta) at different temperatures. Marine Biology, 18, 46-49.
  25. Connor, D., Allen, J., Golding, N., Howell, K., Lieberknecht, L., Northen, K. & Reker, J., 2004. The Marine Habitat Classification for Britain and Ireland Version 04.05 JNCC, Peterborough. ISBN 1 861 07561 8.

  26. Connor, D.W., Dalkin, M.J., Hill, T.O., Holt, R.H.F. & Sanderson, W.G., 1997a. Marine biotope classification for Britain and Ireland. Vol. 2. Sublittoral biotopes. Joint Nature Conservation Committee, Peterborough, JNCC Report no. 230, Version 97.06., Joint Nature Conservation Committee, Peterborough, JNCC Report no. 230, Version 97.06.
  27. Constantino, R., Gaspar, M., Tata-Regala, J., Carvalho, S., Cúrdia, J., Drago, T., Taborda, R. & Monteiro, C., 2009. Clam dredging effects and subsequent recovery of benthic communities at different depth ranges. Marine Environmental Research, 67, 89-99.

  28. Cornelius, P.F.S., 1992. Medusa loss in leptolid Hydrozoa (Cnidaria), hydroid rafting, and abbreviated life-cycles among their remote island faunae: an interim review.
  29. 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.
  30. Crisp, D.J., 1965. The ecology of marine fouling. In: Ecology and the Industrial Society, 5th Symposium of the British Ecological Society, 99-117 (ed. G.T. Goodman, R.W. Edwards & J.M. Lambert).
  31. Crump, R.G., Morley, H.S., & Williams, A.D., 1999. West Angle Bay, a case study. Littoral monitoring of permanent quadrats before and after the Sea Empress oil spill. Field Studies, 9, 497-511.
  32. Davenport, J., 1976. A comparative study of the behaviour of some balanomorph barnacles exposed to fluctuating sea water concentrations. Journal of the Marine Biological Association of the United Kingdom, 5, pp.889-907.
  33. Davenport, J. & Davenport, J.L., 2005. Effects of shore height, wave exposure and geographical distance on thermal niche width of intertidal fauna. Marine Ecology Progress Series, 292, 41-50.
  34. Davies, C.E. & Moss, D., 1998. European Union Nature Information System (EUNIS) Habitat Classification. Report to European Topic Centre on Nature Conservation from the Institute of Terrestrial Ecology, Monks Wood, Cambridgeshire. [Final draft with further revisions to marine habitats.], Brussels: European Environment Agency.
  35. de Kluijver, M.J.; Ingalsuo, S.S. & de Bruyne, 2016. Pomatoceros triqueter.

  36. Dethier, M.N., 1994. The ecology of intertidal algal crusts: variation within a functional group. Journal of Experimental Marine Biology and Ecology, 177 (1), 37-71.

  37. Devlin, M.J., Barry, J., Mills, D.K., Gowen, R.J., Foden, J., Sivyer, D. & Tett, P., 2008. Relationships between suspended particulate material, light attenuation and Secchi depth in UK marine waters. Estuarine, Coastal and Shelf Science, 79 (3), 429-439.

  38. Dixon, D.R., 1985. Cytogenetic procedures. Pomatoceros triqueter: A test system for environmental mutagenesis. In The effects of stress and pollution in marine animals.
  39. Donovan, S.K., 2011. Postmortem encrustation of the alien bivalve Ensis americanus (Binney) by the barnacle Balanus crenatus Brugière in the North Sea. Palaios, 26, 665-668.

  40. Dons, C., 1927. Om Vest og voskmåte hos Pomatoceros triqueter. Nyt Magazin for Naturvidenskaberne, LXV, 111-126.
  41. Dyrynda, P.E.J., 1994. Hydrodynamic gradients and bryozoan distributions within an estuarine basin (Poole Harbour, UK). In Proceedings of the 9th International Bryozoology conference, Swansea, 1992. Biology and Palaeobiology of Bryozoans (ed. P.J. Hayward, J.S. Ryland & P.D. Taylor), pp.57-63. Fredensborg: Olsen & Olsen.
  42. Eckman, J.E. & Duggins, D.O., 1993. Effects of flow speed on growth of benthic suspension feeders. Biological Bulletin, 185, 28-41.
  43. Edyvean, R.G.J.  & Ford, H., 1987. Growth rates of Lithophyllum incrustans (Corallinales, Rhodophyta) from south west Wales. British Phycological Journal, 22 (2), 139-146.

  44. Edyvean, R.G.J.  & Ford, H., 1984a. Population biology of the crustose red alga Lithophyllum incrustans Phil. 2. A comparison of populations from three areas of Britain. Biological Journal of the Linnean Society, 23 (4), 353-363.

  45. Edyvean, R.G.J. & Ford, H., 1984b. Population biology of the crustose red alga Lithophyllum incrustans Phil. 3. The effects of local environmental variables. Biological Journal of the Linnean Society, 23, 365-374.

  46. Edyvean, R.G.J. & Ford, H., 1986. Population structure of Lithophyllum incrustans (Philippi) (Corallinales Rhodophyta) from south-west Wales. Field Studies, 6, 397-405.
  47. Eggleston, D., 1972b. Factors influencing the distribution of sub-littoral ectoprocts off the south of the Isle of Man (Irish Sea). Journal of Natural History, 6, 247-260.
  48. Fernandez‐Leborans, G. & Gabilondo, R., 2006. Taxonomy and distribution of the hydrozoan and protozoan epibionts on Pagurus bernhardus (Linnaeus, 1758) (Crustacea, Decapoda) from Scotland. Acta Zoologica, 87, 33-48.

  49. Forbes, L., Seward, M.J. & Crisp, D.J., 1971. Orientation to light and the shading response in barnacles. In: Proceedings of the 4th European Marine Biology Symposium. Ed. Crisp, D.J., Cambridge University Press, Cambridge. pp 539-558.

  50. Foster, B.A., 1970. Responses and acclimation to salinity in the adults of some balanomorph barnacles. Philosophical Transactions of the Royal Society of London, Series B, 256, 377-400.
  51. Foster, P., Hunt, D.T.E. & Morris, A.W., 1978. Metals in an acid mine stream and estuary. Science of the Total Environment, 9, 75-86.
  52. Gili, J-M. & Hughes, R.G., 1995. The ecology of marine benthic hydroids. Oceanography and Marine Biology: an Annual Review, 33, 351-426.
  53. Gittenberger, A. & Van Loon, W.M.G.M., 2011. Common Marine Macrozoobenthos Species in the Netherlands, their Characterisitics and Sensitivities to Environmental Pressures. GiMaRIS report no 2011.08.

  54. Gontar, V.I. & Denisenko, N.V., 1989. Arctic Ocean Bryozoa. In The Arctic Seas. Climatology, oceanography, geology, and biology (ed. Y. Herman), pp.341-371. New York: Van Nostrand Reinhold Co.
  55. Gordon, D.P., 1972. Biological relationships of an intertidal bryozoan population. Journal of Natural History, 6, 503-514.
  56. Gorzula, S., 1977. A study of growth in the brittle-star Ophiocomina nigra. Western Naturalist, 6, 13-33.

  57. Guarnieri, G., Terlizzi, A., Bevilacqua, S. & Fraschetti, S., 2012. Increasing heterogeneity of sensitive assemblages as a consequence of human impact in submarine caves. Marine Biology, 159 (5), 1155-1164.

  58. Guiry, M.D. & Guiry, G.M. 2015. AlgaeBase [Online], National University of Ireland, Galway [cited 30/6/2015]. Available from:
  59. Harms, J. & Anger, K., 1983. Seasonal, annual, and spatial variation in the development of hard bottom communities. Helgoländer Meeresuntersuchungen, 36, 137-150.
  60. Hartnoll, R.G., 1998. Volume VIII. Circalittoral faunal turf biotopes: An overview of dynamics and sensitivity characteristics for conservation management of marine SACs. Scottish Association of Marine Sciences, Oban, Scotland. [UK Marine SAC Project. Natura 2000 reports.]
  61. Hatcher, A.M., 1998. Epibenthic colonization patterns on slabs of stabilised coal-waste in Poole Bay, UK. Hydrobiologia, 367, 153-162.
  62. Hayward, P.J. & Ryland, J.S. 1998. Cheilostomatous Bryozoa. Part 1. Aeteoidea - Cribrilinoidea. Shrewsbury: Field Studies Council. [Synopses of the British Fauna, no. 10. (2nd edition)]
  63. Hayward, P.J. & Ryland, J.S. (ed.) 1995b. Handbook of the marine fauna of North-West Europe. Oxford: Oxford University Press.
  64. Heath, D., 1976. The distribution and orientation of epizoic barnacles on crabs. Zoological Journal of the Linnean Society, 59, 59-67.

  65. 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.
  66. Hiscock, S., 1986c. Skomer Marine Nature Reserve subtidal monitoring project. Algal results. August 1984 to February 1986. Nature Conservancy Council, Peterborough, CSD Report no. 620., Peterborough, Nature Conservancy Council. (CSD Report No. 620.)
  67. 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.

  68. Holme, N.A. & Wilson, J.B., 1985. Faunas associated with longitudinal furrows and sand ribbons in a tide-swept area in the English Channel. Journal of the Marine Biological Association of the United Kingdom, 65, 1051-1072.
  69. 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.
  70. Houghton, J.P., Lees, D.C., Driskell, W.B., Lindstrom & Mearns, A.J., 1996. Recovery of Prince William Sound intertidal epibiota from Exxon Valdez oiling and shoreline treatments, 1989 through 1992. In Proceedings of the Exxon Valdez Oil Spill Symposium. American Fisheries Society Symposium, no. 18, Anchorage, Alaska, USA, 2-5 February 1993, (ed. S.D. Rice, R.B. Spies, D.A., Wolfe & B.A. Wright), pp.379-411.
  71. Hughes, R.G., 1977. Aspects of the biology and life-history of Nemertesia antennina (L.) (Hydrozoa: Plumulariidae). Journal of the Marine Biological Association of the United Kingdom, 57, 641-657.
  72. Huthnance, J., 2010. Ocean Processes Feeder Report. London, DEFRA on behalf of the United Kingdom Marine Monitoring and Assessment Strategy (UKMMAS) Community.

  73. Hyman, L.V., 1959. The Invertebrates, vol. V. Smaller coelomate groups. New York: McGraw-Hill.
  74. Irvine, L. M. & Chamberlain, Y. M., 1994. Seaweeds of the British Isles, vol. 1. Rhodophyta, Part 2B Corallinales, Hildenbrandiales. London: Her Majesty's Stationery Office.
  75. Jakola, K.J. & Gulliksen, B., 1987. Benthic communities and their physical environment to urban pollution from the city of Tromso, Norway. Sarsia, 72, 173-182.
  76. Jensen, A.C., Collins, K.J., Lockwood, A.P.M., Mallinson, J.J. & Turnpenny, W.H., 1994. Colonization and fishery potential of a coal-ash artificial reef, Poole Bay, United Kingdom. Bulletin of Marine Science, 55, 1263-1276.
  77. JNCC (Joint Nature Conservation Committee), 1999. Marine Environment Resource Mapping And Information Database (MERMAID): Marine Nature Conservation Review Survey Database. [on-line] http://www.jncc.gov.uk/mermaid,
  78. Kain, J.M., 1982. The reproductive phenology of nine species of the Rhodophycota in the subtidal region of the Isle of Man. British Phycological Journal, 17, 321-331.
  79. Kain, J.M., 1987. Photoperiod and temperature as triggers in the seasonality of Delesseria sanguinea. Helgolander Meeresuntersuchungen, 41, 355-370.
  80. Kaiser, M.J., Cheney, K., Spence, F.E., Edwards, D.B. & Radford, K., 1999. Fishing effects in northeast Atlantic shelf seas: patterns in fishing effort, diversity and community structure VII. The effects of trawling disturbance on the fauna associated with the tubeheads of serpulid worms. Fisheries Research (Amsterdam), 40, 195-205.

  81. Kendrick, G.A., 1991. Recruitment of coralline crusts and filamentous turf algae in the Galapagos archipelago: effect of simulated scour, erosion and accretion. Journal of Experimental Marine Biology and Ecology, 147 (1), 47-63

  82. Kenny, A.J. & Rees, H.L., 1994. The effects of marine gravel extraction on the macrobenthos: early post dredging recolonisation. Marine Pollution Bulletin, 28, 442-447.
  83. Keough, M.J., 1983. Patterns of recruitment of sessile invertebrates in two subtidal habitats. Journal of Experimental Marine Biology and Ecology, 66, 213-245.
  84. Kitching, J.A., 1937. Studies in sublittoral ecology. II Recolonization at the upper margin of the sublittoral region; with a note on the denudation of Laminaria forest by storms. Journal of Ecology, 25, 482-495.
  85. Littler, M. & Littler, D.S. 2013. The nature of crustose coralline algae and their interactions on reefs. Smithsonian Contributions to the Marine Sciences, 39, 199-212

  86. Littler, M.M., 1973. The population and community structure of Hawaiian fringing-reef crustose Corallinaceae (Rhodophyta, Cryptonemiales). Journal of Experimental Marine Biology and Ecology, 11 (2), 103-120.

  87. Littler, M.M. & Littler, D.S., 1995. Impact of CLOD pathogen on Pacific coral reefs. Science, 267, 1356-1356.

  88. Littler, M.M., Littler, D.S. & Brooks, B.L. 2007.Target phenomena on south Pacific reefs: strip harvesting by prudent pathogens? Reef Encounter, 34, 23-24

  89. Meadows, P.S., 1969. Sublittoral fouling communities on northern coasts of Britain. Hydrobiologia, 34 (3-4), pp.273-294.

  90. Menon, N.R., 1972. Heat tolerance, growth and regeneration in three North Sea bryozoans exposed to different constant temperatures. Marine Biology, 15, 1-11.
  91. Miron, G., Bourget, E. & Archambault, P., 1996. Scale of observation and distribution of adult conspecifics: their influence in assessing passive and active settlement mechanisms in the barnacle Balanus crenatus (Brugière). Journal of Experimental Marine Biology and Ecology, 201 (1), 137-158.

  92. Mohammad, M-B.M., 1974. Effect of chronic oil pollution on a polychaete. Marine Pollution Bulletin, 5, 21-24.
  93. Moore, H.B., 1937. Marine Fauna of the Isle of Man. Liverpool University Press.
  94. Moore, J., Smith, J. & Northen, K.O., 1999. Marine Nature Conservation Review Sector 8. Inlets in the western English Channel: area summaries. Peterborough: Joint Nature Conservation Committee. [Coasts and seas of the United Kingdom. MNCR Series.]
  95. Moore, P.G., 1973c. Bryozoa as a community component on the northeast coast of Britain. In Living and fossil Bryozoa. Recent advances in research (ed. G.P. Larwood), pp. 21-36.
  96. Naylor, E., 1965. Effects of heated effluents upon marine and estuarine organisms. Advances in Marine Biology, 3, 63-103.
  97. Newman, W. A. & Ross, A., 1976. Revision of the Balanomorph barnacles including a catalogue of the species. San Diego Society of Natural History Memoirs, 9, 1–108.

  98. OECD (ed.), 1967. Catalogue of main marine fouling organisms. Vol. 3: Serpulids. Paris: Organisation for Economic Co-operation and Development.
  99. Picton, B.E. & Costello, M.J., 1998. BioMar biotope viewer: a guide to marine habitats, fauna and flora of Britain and Ireland. [CD-ROM] Environmental Sciences Unit, Trinity College, Dublin., http://www.itsligo.ie/biomar/
  100. Price, J.H., Irvine, D.E. & Farnham, W.F., 1980. The shore environment. Volume 2: Ecosystems. London Academic Press.
  101. Pyefinch, K.A. & Mott, J.C., 1948. The sensitivity of barnacles and their larvae to copper and mercury. Journal of Experimental Biology, 25, 276-298.
  102. Rainbow, P.S., 1984. An introduction to the biology of British littoral barnacles. Field Studies, 6, 1-51.
  103. Rainbow, P.S., 1987. Heavy metals in barnacles. In Barnacle biology. Crustacean issues 5 (ed. A.J. Southward), 405-417. Rotterdam: A.A. Balkema.
  104. 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:

  105. Rubin, J.A., 1985. Mortality and avoidance of competitive overgrowth in encrusting Bryozoa. Marine Ecology Progress Series, 23, 291-299.
  106. 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.
  107. Ryland, J.S., 1970. Bryozoans. London: Hutchinson University Library.
  108. Ryland, J.S., 1976. Physiology and ecology of marine bryozoans. Advances in Marine Biology, 14, 285-443.
  109. Salman, S., 1982. Seasonal and short-term variations in abundance of barnacle larvae near the south-west of the Isle of Man. Estuarine, Coastal and Shelf Science, 15 (3), 241-253.

  110. Sandrock, S., Scharf, E-M., von Oertzen, J.A., 1991. Short-term changes in settlement of micro- and macro-fouling organisms in brackish waters. Acta Ichthyologica et Piscatoria, 21(Suppl.), 221-235.
  111. Sebens, K.P., 1985. Community ecology of vertical rock walls in the Gulf of Maine: small-scale processes and alternative community states. In The Ecology of Rocky Coasts: essays presented to J.R. Lewis, D.Sc. (ed. P.G. Moore & R. Seed), pp. 346-371. London: Hodder & Stoughton Ltd.

  112. Sebens, K.P., 1986. Spatial relationships among encrusting marine organisms in the New England subtidal zone. Ecological Monographs, 56, 73-96.

  113. Segrove, F., 1941. The development of the serpulid Pomatoceros triqueta L. Quarterly Journal of Microscopical Science, 82, 467-540.
  114. Smith, J.E. (ed.), 1968. 'Torrey Canyon'. Pollution and marine life. Cambridge: Cambridge University Press.
  115. Sommer, C., 1992. Larval biology and dispersal of Eudendrium racemosum (Hydrozoa, Eudendriidae). Scientia Marina, 56, 205-211. [Proceedings of 2nd International Workshop of the Hydrozoan Society, Spain, September 1991. Aspects of hydrozoan biology (ed. J. Bouillon, F. Cicognia, J.M. Gili & R.G. Hughes).]
  116. 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.
  117. Southward, A.J. & Southward, E.C., 1978. Recolonisation of rocky shores in Cornwall after use of toxic dispersants to clean up the Torrey Canyon spill. Journal of the Fisheries Research Board of Canada, 35, 682-706.
  118. Southward, A.J., 1955. On the behaviour of barnacles. I. The relation of cirral and other activities to temperature. Journal of the Marine Biological Association of the United Kingdom, 34, 403-432.
  119. Standing, J.D., 1976. Fouling community structure: effect of the hydroid Obelia dichotoma on larval recruitment. In Coelenterate ecology and behaviour (ed. G.O. Mackie), pp. 155-164. New York: Plenum Press.
  120. Stubbings, H.G. & Houghton, D.R., 1964. The ecology of Chichester Harbour, south England, with special reference to some fouling species. Internationale Revue der Gesamten Hydrobiologie, 49, 233-279.
  121. Thomas, J.G., 1940. Pomatoceros, Sabella and Amphitrite. LMBC Memoirs on typical British marine plants and animals no.33. University Press of Liverpool
  122. Tillin, H. & Tyler-Walters, H., 2014. Assessing the sensitivity of subtidal sedimentary habitats to pressures associated with marine activities. Phase 2 Report – Literature review and sensitivity assessments for ecological groups for circalittoral and offshore Level 5 biotopes. JNCC Report No. 512B,  260 pp.
  123. UKTAG, 2014. UK Technical Advisory Group on the Water Framework Directive [online]. Available from: http://www.wfduk.org
  124. 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.
  125. Watson, D.I., O'Riordan, R.M., Barnes, D.K. & Cross, T., 2005. Temporal and spatial variability in the recruitment of barnacles and the local dominance of Elminius modestus Darwin in SW Ireland. Estuarine, Coastal and Shelf Science, 63 (1), pp.119-131.

  126. Witt, J., Schroeder, A., Knust, R. & Arntz, W.E., 2004. The impact of harbour sludge disposal on benthic macrofauna communities in the Weser estuary. Helgoland Marine Research, 58 (2), 117-128.
  127. Witte, S., Buschbaum, C., van Beusekom, J.E. & Reise, K., 2010. Does climatic warming explain why an introduced barnacle finally takes over after a lag of more than 50 years? Biological Invasions, 12 (10), 3579-3589.

Citation

This review can be cited as:

Tyler-Walters, H., 2002. Pomatoceros triqueter with barnacles and bryozoan crusts on unstable circalittoral cobbles and pebbles. 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/177

Last Updated: 24/11/2002