Researched by | Dr Harvey Tyler-Walters & Jacqueline Hill & Dr Samantha Garrard | Refereed by | Dr David Hughes |
---|
Stable muds, occasionally with small stones, with a high proportion of fine material (typically greater than 80%) may contain the opisthobranch Philine quadripartita and the sea pen Virgularia mirabilis. These muds typically occur in shallow water down to about 12-15 m where significant seasonal variation in temperature is presumed to occur. This habitat is restricted to the most sheltered basins in, for example, sea lochs. Although most records suggest full salinity conditions are prevalent, some sites may be subject to variable salinity. Philine quadripartita is the most characteristic species of this habitat, occurring in high densities at many sites, whilst Virgularia mirabilis, a species found more widely in muddy sediments, appears to reach its highest densities in this shallow mud but may not be present in all examples of this biotope. Other conspicuous species found in this shallow muddy habitat include Cerianthus lloydii, Pagurus bernhardus, Sagartiogeton spp. and Hydractinia echinata. Burrowing crustacean megafauna, characteristic of deeper mud, are rare or absent from this shallow sediment although Nephrops norvegicus may sometimes be recorded. This biotope has been primarily recorded on the basis of its epifauna and a few conspicuous infauna. Little data exists on the infaunal component of this biotope but it may include Nephtys spp., spionid polychaetes, Ampelisca spp. and the bivalves Nucula spp., Thyasira flexuosa, Kurtiella bidentata and Abra spp. In the south of Great Britain, the polychaete Sternaspis scutata is also characteristic of this biotope. This polychaete is rare in Great Britain (Sanderson 1996). This southern variant of the biotope is very restricted in the UK to Portland Harbour but is known to occur further south in the Gulf of Gascony and the Mediterranean. (Information from Connor et al., 2004; JNCC, 2015).
Records of Philine quadripartita in the British Isles were misidentified as Philine aperta (Price et al., 2011). Outwardly, most species of Philine are very similar in morphology and a detailed examination of their internal anatomy, especially the shape of the internal shell, gizzard and penial papilla, is required to differentiate the species (Price et al., 2011). Philine aperta is recorded from South Africa and Mozambique while Philine quadripartita is recorded from the North East Atlantic and the Mediterranean.
No text entered
Depth Range | 5-10 m, 10-20 m |
---|---|
Water clarity preferences | |
Limiting Nutrients | Nitrogen (nitrates), Phosphorus (phosphates) |
Salinity preferences | Full (30-40 psu) |
Physiographic preferences | Enclosed coast / Embayment |
Biological zone preferences | Infralittoral |
Substratum/habitat preferences | Mud |
Tidal strength preferences | Very Weak (negligible) |
Wave exposure preferences | Extremely sheltered, Very sheltered |
Other preferences |
Philine quadripartita and Virgularia mirabilis are the main important characterizing species, giving the name to the biotope. Cerianthus lloydii is another characteristic member of the epifauna. Amphiura filiformis may be abundant but reaches higher abundance in SMU.IFiMu.BriAchi. Other members of the infauna are probably found in a range of other biotope in similar sediments, while the other species are mobile (e.g. crabs and hermit crabs) or restricted to stones or shells (e.g. Hydractinia). Connor et al. (2004) note that this biotope might represent a temporal variant of similar SMU biotopes as the abundance of Philine quadripartita may vary from year to year.
Therefore, the assessment of sensitivity is based on the important characterizing species Philine quadripartita and Virgularia mirabilis and the mud habitat. The sensitivity of other species is discussed where relevant.
Philine quadripartita (studies as aperta) is a simultaneous hermaphrodite, capable of producing both eggs and sperm (Lancaster, 1983). In Britain, spawning is thought to occur between April and September (Thompson, 1976; Lancaster, 1983). It lays eggs in flask-shaped eggs in masses of up to 50,000. Eggs hatch within 3.5 to 8 days depending on temperature. The veliger larvae are ready for metamorphosis and settlement within 30-40 days (in the laboratory) (Thompson, 1976; Lancaster, 1983; Thompson, 1988; Hansen, 1991; Hansen & Ockelmann, 1991). It has a lifespan of 3-4 years (Thompson, 1976). Philine quadripartita is widely distributed around the coasts of Britain.
Little evidence was found to support this resilience assessment for Cerianthus lloydii. MES (2010) suggested that the genus Cerianthus would be likely to have a low recovery rate following physical disturbance based on long lifespan and slow growth rate. The MES (2010) review also highlighted that there were gaps in information for this species and that age at sexual maturity and fecundity is unknown although the larvae are pelagic (MES 2010). No empirical evidence was found for recovery rates following perturbations for Cerianthus lloydii. This species has limited horizontal mobility and re-colonization via adults is unlikely (Tillin & Tyler-Walters, 2014).
Little information on the reproduction and life history of Virgularia mirabilis was found. Edwards & Moore (2009) noted that many sea pens exhibited similar characteristics. Recent studies of oogenesis in Funiculina. quadrangularis and Pennatula phosphorea in Loch Linnhe, Scotland, demonstrated that they were dioecious, with 1:1 sex ratios, highly fecund, with continuous prolonged oocyte development and annual spawning (Edwards & Moore 2008; Edwards & Moore 2009). In Pennatula phosphorea, oogenesis exceeded 12 months in duration, with many small oocytes of typically 50 per polyp giving an overall fecundity of ca 40,000 in medium to large specimens, depending on size. However, <30% matured (synchronously) and were spawned in summer (July-August). Mature oocytes were large (>500µm) which suggested a lecithotrophic larval development (Edwards & Moore, 2008). In Funiculina. quadrangularis fecundity was again high, expressed as 500-2000 per 1 cm midsection, but not correlated with size, and again, only a small proportion of the oocytes (<10%) matured. Unlike Pennatula phosphorea, annual spawning occurred in autumn or winter (between October and January). Also the mature oocytes were very large (>800µm), which suggested a lecithotrophic larval development (Edwards &Moore, 2009). In a study of the intertidal Virgularia juncea fecundity varied with length (46,000 at 50 cm and 87,000 at 70 cm), reached a maximum size of 200-300 µm in May and were presumed to be spawned between August and September (Soong, 2005). Birkland (1974) found the lifespan of Ptilosarcus gurneyi to be 15 years, reaching sexual maturity between the ages of 5 and 6 years; while Wilson et al. (2002) noted that larger specimens of a tall sea pen (Halipteris willemoesi) in the Bering Sea were 44 years old, with a growth rate of 3.6 - 6.1cm/year.
Hughes (1998a) suggested that patchy recruitment, slow growth and long lifespan were typical of sea pens. Larval settlement is likely to be patchy in space and highly episodic in time with no recruitment to the population taking place for some years. Greathead et al. (2007) noted that patchy distribution is typical for sea pen populations. In Holyhead harbour, for example, animals show a patchy distribution, probably related to larval settlement (Hoare and Wilson, 1977).
Virgularia mirabilis was found to withdraw into its burrow rapidly (ca 30 seconds) and could not be uprooted by dragged creels (Hoare and Wilson, 1977; Eno et al., 2001; Ambroso et al., 2013). In summary, British sea pen species have been found to recover rapidly from the effects of dragging, uprooting and smothering (Eno et al., 2001). Recovery from effects that remove a proportion of the sea pen population (e.g. bottom gears, hydrographic changes) will depend on recruitment processes and little is known about the life history and population dynamics of sea pens (Hughes, 1998a).
Resilience assessment. No information on the population dynamics of Philine quadripartita was found. However, it is highly fecund, with high potential larval dispersal range so that recruitment is probably good, and it is a mobile species, capable of recolonizing the affected area adjacent populations, especially as it is common in British waters. Therefore, Philine quadripartita population s would probably recover within a couple of years (resilience is ‘High’). However, there is little information regarding the resilience of Cerianthus lloydii. A resilience of ‘Medium’ (2 – 10 years) is suggested for all resistance levels (‘None’, ‘Low’, ‘Medium’ or ‘High’) based on expert judgement. Where Virgularia mirabilis survive impact undamaged, that is resistance is ‘High’, recovery is likely to be rapid; a resilience of ‘High’ (<2 years). Where a proportion of the population is removed or killed, then the species has a high dispersal potential and long-lived benthic larvae, but larval recruitment is probably sporadic and patchy and growth is slow, suggesting that recovery may take many years: a resilience of ‘Low’ (>10 years). Therefore, the resilience of the biotope is likely to be Low (>10 years) as Virgularia mirabilis and Cerianthus lloydii are likely to take many years to recover. An exception is made for permanent or ongoing (long-term) pressures where recovery is not possible as the pressure is irreversible, in which case resilience is assessed as ‘Very low’ by default. The assessment is based on the reproduction and life history characteristics of the important characteristic species, or similar species, rather than direct evidence. Therefore, while confidence in the quality of the evidence and its concordance is Medium, confidence its application in Low.
Use / to open/close text displayed | Resistance | Resilience | Sensitivity |
High | High | Not sensitive | |
Q: Low A: NR C: NR | Q: High A: High C: High | Q: Low A: Low C: Low | |
Understanding the true biogeographic distribution of Philine quadripartita is difficult due to the number of published misidentifications of the Philine genus up until the present day (Crocetta & Tringali, 2018). Philine quadripartita was initially identified as Philine aperta and was thought to have a distribution from Europe to Africa, These species have now been separated and the European species Philine quadripartita is thought to have a biogeographic distribution around the UK and in the Mediterranean (Price et al., 2011, Crocetta & Tringali, 2018). Spawning, hatching, and time to metamorphosis are all temperature dependent in Philine quadripartita (as aperta). In the UK spawning occurs during the warmest months of the year (April to August) (Lancaster, 1983). Laboratory results showed hatching occurred after 3.5 days at 23°C and 8 days at 13°C (Thompson, 1976) and time to metamorphosis occurred after 35-40 days at 12-13°C and 30 days at 15°C (Hansen & Ockelmann, 1991). Virgularia mirabilis is common to all coasts of the UK, although less common in the south (Greathead et al., 2007). This species is abundant across the northwest European Shelf and in the Mediterranean and occurs throughout the North Atlantic possibly as far as North America (Hughes, 1998a). Whilst no upper thermal limit is available for this species, its occurrence in the Mediterranean suggests that it is likely to be tolerant of some degree of temperature increase. Cerianthus lloydii adults are locally abundant in many localities on all coasts of the British Isles and in some areas are common on the shore. This species occurs on all western coasts of Europe from Greenland and Spitzbergen south to the Bay of Biscay. Larvae, but not adults, have been recorded from the Mediterranean. However, no further information on the temperature tolerance of Cerianthus lloydii was found. Sensitivity assessment. This biotope occurs around the coast of the UK, although it is common in sea lochs. The key characterizing species of this biotope (Philine quadripartita and Virgularia mirabilis) both occur in the Mediterranean, where sea surface temperatures can often reach 28°C (www.seatemperature.org), suggesting that they will be tolerant of an increase in temperatures. Cerianthus lloydii may struggle to adapt to rising temperatures, as its southerly limit is the Bay of Biscay, although if this species is lost, the biotope may become impoverished but will remain the same. Under the middle and high emission and extreme scenarios seawater temperatures are expected to temperatures rise by 3-5°C to potential southern summer temperatures of 22-24°C. Philine quadripartita and Virgularia mirabilis are likely to be able to tolerate the predicted temperature increases. Therefore, for all three scenarios (middle and high emission and extreme scenarios) resistance is assessed as ‘High’, and resilience is assessed as ‘High’, as no recovery is deemed necessary. This biotope is assessed as being ‘Not sensitive’ to ocean warming under all three scenarios, albeit with ‘Low’ confidence. | |||
High | High | Not sensitive | |
Q: Low A: NR C: NR | Q: High A: High C: High | Q: Low A: Low C: Low | |
Understanding the true biogeographic distribution of Philine quadripartita is difficult due to the number of published misidentifications of the Philine genus up until the present day (Crocetta & Tringali, 2018). Philine quadripartita was initially identified as Philine aperta and was thought to have a distribution from Europe to Africa, These species have now been separated and the European species Philine quadripartita is thought to have a biogeographic distribution around the UK and in the Mediterranean (Price et al., 2011, Crocetta & Tringali, 2018). Spawning, hatching, and time to metamorphosis are all temperature dependent in Philine quadripartita (as aperta). In the UK spawning occurs during the warmest months of the year (April to August) (Lancaster, 1983). Laboratory results showed hatching occurred after 3.5 days at 23°C and 8 days at 13°C (Thompson, 1976) and time to metamorphosis occurred after 35-40 days at 12-13°C and 30 days at 15°C (Hansen & Ockelmann, 1991). Virgularia mirabilis is common to all coasts of the UK, although less common in the south (Greathead et al., 2007). This species is abundant across the northwest European Shelf and in the Mediterranean and occurs throughout the North Atlantic possibly as far as North America (Hughes, 1998a). Whilst no upper thermal limit is available for this species, its occurrence in the Mediterranean suggests that it is likely to be tolerant of some degree of temperature increase. Cerianthus lloydii adults are locally abundant in many localities on all coasts of the British Isles and in some areas are common on the shore. This species occurs on all western coasts of Europe from Greenland and Spitzbergen south to the Bay of Biscay. Larvae, but not adults, have been recorded from the Mediterranean. However, no further information on the temperature tolerance of Cerianthus lloydii was found. Sensitivity assessment. This biotope occurs around the coast of the UK, although it is common in sea lochs. The key characterizing species of this biotope (Philine quadripartita and Virgularia mirabilis) both occur in the Mediterranean, where sea surface temperatures can often reach 28°C (www.seatemperature.org), suggesting that they will be tolerant of an increase in temperatures. Cerianthus lloydii may struggle to adapt to rising temperatures, as its southerly limit is the Bay of Biscay, although if this species is lost, the biotope may become impoverished but will remain the same. Under the middle and high emission and extreme scenarios seawater temperatures are expected to temperatures rise by 3-5°C to potential southern summer temperatures of 22-24°C. Philine quadripartita and Virgularia mirabilis are likely to be able to tolerate the predicted temperature increases. Therefore, for all three scenarios (middle and high emission and extreme scenarios) resistance is assessed as ‘High’, and resilience is assessed as ‘High’, as no recovery is deemed necessary. This biotope is assessed as being ‘Not sensitive’ to ocean warming under all three scenarios, albeit with ‘Low’ confidence. | |||
High | High | Not sensitive | |
Q: Low A: NR C: NR | Q: High A: High C: High | Q: Low A: Low C: Low | |
Understanding the true biogeographic distribution of Philine quadripartita is difficult due to the number of published misidentifications of the Philine genus up until the present day (Crocetta & Tringali, 2018). Philine quadripartita was initially identified as Philine aperta and was thought to have a distribution from Europe to Africa, These species have now been separated and the European species Philine quadripartita is thought to have a biogeographic distribution around the UK and in the Mediterranean (Price et al., 2011, Crocetta & Tringali, 2018). Spawning, hatching, and time to metamorphosis are all temperature dependent in Philine quadripartita (as aperta). In the UK spawning occurs during the warmest months of the year (April to August) (Lancaster, 1983). Laboratory results showed hatching occurred after 3.5 days at 23°C and 8 days at 13°C (Thompson, 1976) and time to metamorphosis occurred after 35-40 days at 12-13°C and 30 days at 15°C (Hansen & Ockelmann, 1991). Virgularia mirabilis is common to all coasts of the UK, although less common in the south (Greathead et al., 2007). This species is abundant across the northwest European Shelf and in the Mediterranean and occurs throughout the North Atlantic possibly as far as North America (Hughes, 1998a). Whilst no upper thermal limit is available for this species, its occurrence in the Mediterranean suggests that it is likely to be tolerant of some degree of temperature increase. Cerianthus lloydii adults are locally abundant in many localities on all coasts of the British Isles and in some areas are common on the shore. This species occurs on all western coasts of Europe from Greenland and Spitzbergen south to the Bay of Biscay. Larvae, but not adults, have been recorded from the Mediterranean. However, no further information on the temperature tolerance of Cerianthus lloydii was found. Sensitivity assessment. This biotope occurs around the coast of the UK, although it is common in sea lochs. The key characterizing species of this biotope (Philine quadripartita and Virgularia mirabilis) both occur in the Mediterranean, where sea surface temperatures can often reach 28°C (www.seatemperature.org), suggesting that they will be tolerant of an increase in temperatures. Cerianthus lloydii may struggle to adapt to rising temperatures, as its southerly limit is the Bay of Biscay, although if this species is lost, the biotope may become impoverished but will remain the same. Under the middle and high emission and extreme scenarios seawater temperatures are expected to temperatures rise by 3-5°C to potential southern summer temperatures of 22-24°C. Philine quadripartita and Virgularia mirabilis are likely to be able to tolerate the predicted temperature increases. Therefore, for all three scenarios (middle and high emission and extreme scenarios) resistance is assessed as ‘High’, and resilience is assessed as ‘High’, as no recovery is deemed necessary. This biotope is assessed as being ‘Not sensitive’ to ocean warming under all three scenarios, albeit with ‘Low’ confidence. | |||
High | High | Not sensitive | |
Q: Low A: NR C: NR | Q: High A: High C: High | Q: Low A: Low C: Low | |
Marine heatwaves due to increased air-sea heat flux are predicted to occur more frequently, last for longer and at increased intensity by the end of this century under both middle and high emission scenarios (Frölicher et al., 2018). There are no laboratory studies on the upper thermal limit of Philine quadripartita and Virgularia mirabilis but both species occur in the Mediterranean suggesting some thermal tolerance. Furthermore, laboratory experiments showed egg hatching time of UK populations of Philine quadripartita increased from 8 days at 13°C to 3.5 days at 23°C (Thompson, 1976), suggesting a benefit of an increase in temperature for this species. Sensitivity Assessment. Under the middle emission scenario, if heatwaves occurred every three years, with a maximum intensity of 2°C for 80 days by the end of this century, this could lead to summer sea temperatures reaching up to 24°C in southern England. Under the high emission scenario, if heatwaves occur every two years by the end of this century, reaching a maximum intensity of 3.5°C for 120 days, this could lead to the heatwave lasting the entire summer with temperatures reaching up to 26.5°C. It is likely that this biotope can tolerate heatwaves of these magnitudes, as this species is known to occur around the Mediterranean, where sea surface temperatures can reach 28°C in the summer months (www.seatemperature.org) and therefore, resistance has been assessed as ‘High’. As no recovery is likely necessary, resilience has been assessed as ‘High’, leading to an assessment of ‘Not sensitive’ for this biotope under the middle and high emission scenarios. | |||
High | High | Not sensitive | |
Q: Low A: NR C: NR | Q: High A: High C: High | Q: Low A: Low C: Low | |
Marine heatwaves due to increased air-sea heat flux are predicted to occur more frequently, last for longer and at increased intensity by the end of this century under both middle and high emission scenarios (Frölicher et al., 2018). There are no laboratory studies on the upper thermal limit of Philine quadripartita and Virgularia mirabilis but both species occur in the Mediterranean suggesting some thermal tolerance. Furthermore, laboratory experiments showed egg hatching time of UK populations of Philine quadripartita increased from 8 days at 13°C to 3.5 days at 23°C (Thompson, 1976), suggesting a benefit of an increase in temperature for this species. Sensitivity Assessment. Under the middle emission scenario, if heatwaves occurred every three years, with a maximum intensity of 2°C for 80 days by the end of this century, this could lead to summer sea temperatures reaching up to 24°C in southern England. Under the high emission scenario, if heatwaves occur every two years by the end of this century, reaching a maximum intensity of 3.5°C for 120 days, this could lead to the heatwave lasting the entire summer with temperatures reaching up to 26.5°C. It is likely that this biotope can tolerate heatwaves of these magnitudes, as this species is known to occur around the Mediterranean, where sea surface temperatures can reach 28°C in the summer months (www.seatemperature.org) and therefore, resistance has been assessed as ‘High’. As no recovery is likely necessary, resilience has been assessed as ‘High’, leading to an assessment of ‘Not sensitive’ for this biotope under the middle and high emission scenarios. | |||
Medium | Very Low | Medium | |
Q: Low A: NR C: NR | Q: High A: High C: High | Q: Low A: Low C: Low | |
Increasing levels of CO2 in the atmosphere have led to the average pH of sea surface waters dropping from 8.25 in the 1700s to 8.14 in the 1990s (Jacobson, 2005). Evidence of the effect of ocean acidification on Philine quadripartita is lacking although by the end of a long-term (9 month) mesocosm experiment in Hawaii, a large biomass of opisthobranch molluscs, gastropod molluscs, crabs, amphipods and polychaete herbivores had developed in acidified (0.3 unit decrease in pH) mesocosms (Jokiel et al., 2008), suggesting some species of opisthobranch will be tolerant of future decreases in pH. There is also some evidence of sensitivity in opisthobranch molluscs, and experimental acidification to a pH of 7.67 slowed embryonic development and led to a decrease in larval hatchling shell length in the tropical opisthobranch Stylocheilus striatus (Allen, 2012). Sea pens are colonial octocorals from the order Pennutulacea. Research on octocorals, suggests that most species of octocoral will be tolerant of ocean acidification at levels expected for the end of this century under both the middle emission and high emission scenario (Gabay et al., 2013, Gabay et al., 2014, Enochs et al., 2015, Gomez et al., 2018). Whereas sea pens generally have a calcareous rod, formed from sclerites, the ability of octocorals to tolerate low pH may be because their fleshy tissue may act as a barrier, protecting the organism from low external pH (Gabay et al., 2013, Gabay et al., 2014). An exception to this is the octocoral Corallium rubrum. The octocoral Corallium rubrum is unusual in that it is highly calcified compared to other species of octocoral. In response to experimental acidification, this species has been shown to exhibit a decrease in feeding activity and calcification (Cerrano et al., 2013). Sensitivity Assessment. Direct evidence of the impact of ocean acidification on Philine quadripartita and Virgularia mirabilis is lacking. In general, lightly calcified, fleshy octocorals such as sea pens appear to be tolerant, although Philine quadripartita may show some sensitivity to this climate change pressure. Therefore, based on the evidence available and taking a precautionary approach, resistance has been assessed as ‘Medium’, whilst resilience is assessed as ‘Very Low’ due to the long term nature of ocean acidification. Under the middle and high emission scenario, sensitivity to ocean acidification is assessed as ‘Medium’, albeit it with 'Low' confidence. | |||
Medium | Very Low | Medium | |
Q: Low A: NR C: NR | Q: High A: High C: High | Q: Low A: Low C: Low | |
Increasing levels of CO2 in the atmosphere have led to the average pH of sea surface waters dropping from 8.25 in the 1700s to 8.14 in the 1990s (Jacobson, 2005). Evidence of the effect of ocean acidification on Philine quadripartita is lacking although by the end of a long-term (9 month) mesocosm experiment in Hawaii, a large biomass of opisthobranch molluscs, gastropod molluscs, crabs, amphipods and polychaete herbivores had developed in acidified (0.3 unit decrease in pH) mesocosms (Jokiel et al., 2008), suggesting some species of opisthobranch will be tolerant of future decreases in pH. There is also some evidence of sensitivity in opisthobranch molluscs, and experimental acidification to a pH of 7.67 slowed embryonic development and led to a decrease in larval hatchling shell length in the tropical opisthobranch Stylocheilus striatus (Allen, 2012). Sea pens are colonial octocorals from the order Pennutulacea. Research on octocorals, suggests that most species of octocoral will be tolerant of ocean acidification at levels expected for the end of this century under both the middle emission and high emission scenario (Gabay et al., 2013, Gabay et al., 2014, Enochs et al., 2015, Gomez et al., 2018). Whereas sea pens generally have a calcareous rod, formed from sclerites, the ability of octocorals to tolerate low pH may be because their fleshy tissue may act as a barrier, protecting the organism from low external pH (Gabay et al., 2013, Gabay et al., 2014). An exception to this is the octocoral Corallium rubrum. The octocoral Corallium rubrum is unusual in that it is highly calcified compared to other species of octocoral. In response to experimental acidification, this species has been shown to exhibit a decrease in feeding activity and calcification (Cerrano et al., 2013). Sensitivity Assessment. Direct evidence of the impact of ocean acidification on Philine quadripartita and Virgularia mirabilis is lacking. In general, lightly calcified, fleshy octocorals such as sea pens appear to be tolerant, although Philine quadripartita may show some sensitivity to this climate change pressure. Therefore, based on the evidence available and taking a precautionary approach, resistance has been assessed as ‘Medium’, whilst resilience is assessed as ‘Very Low’ due to the long term nature of ocean acidification. Under the middle and high emission scenario, sensitivity to ocean acidification is assessed as ‘Medium’, albeit it with 'Low' confidence. | |||
High | High | Not sensitive | |
Q: Low A: NR C: NR | Q: High A: High C: High | Q: Low A: Low C: Low | |
Sea level rise is occurring through a combination of thermal expansion and ice melt. Sea levels have risen 1-3 mm/yr. in the last century (Cazenave & Nerem, 2004, Church et al., 2004, Church & White, 2006). This biotope is recorded between 5 –20 m depth, although Virgularia mirabilis is known to reside at depths of up to 800 m (Bastari et al., 2018). Philine quadripartita appears to be more of a shallow-water species, which has been found at depths of up to 36 m in Malta (Ballesteros et al., 2013). Therefore, an increase in depth of 50 – 107 cm is unlikely to have large implications for these characterizing species. However, this biotope occurs on sheltered, stable mud and any increase in exposure or tidal energy occurring through sea-level rise may lead to negative impacts. Understanding of how sea-level rise will affect exposure or the tide-swept nature of a habitat, is fraught with uncertainty, although evidence appears to suggest that any alterations will be non-linear (Pickering et al., 2012, Li et al., 2016). Modelling potential outcomes of sea-level rise on the tidal and residual currents in the Bohai Sea, China showed effects were site dependent, with energy either increasing or decreasing (Li et al., 2016). Similarly, Pickering et al. (2012) found a similar pattern around the UK for tidal amplitude. The effects of sea-level rise and increased wave action may be increased further due to storms and storm surges. IPCC (2019) note that the frequency of extreme sea-level events (e.g. due to storms) are predicted to increase as sea-level rises, however, there is no consensus on the future storm and, hence, wave climate around UK coasts (Mossman et al., 2015, Lowe et al., 2018, Palmer et al., 2018). Sensitivity assessment. This habitat occurs from 5-20 m, although both characterizing species are known to occur at deeper depths. However, the habitat is only found in sheltered conditions and any change in exposure cannot be evaluated at the current time, as evidence suggests that any changes in relation to sea-level rise will be site-specific. Therefore, under the available evidence, resistance to sea-level rise has been assessed as ‘High’ for both the middle (50 cm) and high (70 cm) emission scenario, and the extreme scenario (107 cm). As no recovery is deemed necessary, resilience has been assessed as ‘High’ and, therefore, this biotope has been assessed as ‘Not sensitive’ to sea-level rise at each of the benchmarks albeit with ‘Low’ confidence. | |||
High | High | Not sensitive | |
Q: Low A: NR C: NR | Q: High A: High C: High | Q: Low A: Low C: Low | |
Sea level rise is occurring through a combination of thermal expansion and ice melt. Sea levels have risen 1-3 mm/yr. in the last century (Cazenave & Nerem, 2004, Church et al., 2004, Church & White, 2006). This biotope is recorded between 5 –20 m depth, although Virgularia mirabilis is known to reside at depths of up to 800 m (Bastari et al., 2018). Philine quadripartita appears to be more of a shallow-water species, which has been found at depths of up to 36 m in Malta (Ballesteros et al., 2013). Therefore, an increase in depth of 50 – 107 cm is unlikely to have large implications for these characterizing species. However, this biotope occurs on sheltered, stable mud and any increase in exposure or tidal energy occurring through sea-level rise may lead to negative impacts. Understanding of how sea-level rise will affect exposure or the tide-swept nature of a habitat, is fraught with uncertainty, although evidence appears to suggest that any alterations will be non-linear (Pickering et al., 2012, Li et al., 2016). Modelling potential outcomes of sea-level rise on the tidal and residual currents in the Bohai Sea, China showed effects were site dependent, with energy either increasing or decreasing (Li et al., 2016). Similarly, Pickering et al. (2012) found a similar pattern around the UK for tidal amplitude. The effects of sea-level rise and increased wave action may be increased further due to storms and storm surges. IPCC (2019) note that the frequency of extreme sea-level events (e.g. due to storms) are predicted to increase as sea-level rises, however, there is no consensus on the future storm and, hence, wave climate around UK coasts (Mossman et al., 2015, Lowe et al., 2018, Palmer et al., 2018). Sensitivity assessment. This habitat occurs from 5-20 m, although both characterizing species are known to occur at deeper depths. However, the habitat is only found in sheltered conditions and any change in exposure cannot be evaluated at the current time, as evidence suggests that any changes in relation to sea-level rise will be site-specific. Therefore, under the available evidence, resistance to sea-level rise has been assessed as ‘High’ for both the middle (50 cm) and high (70 cm) emission scenario, and the extreme scenario (107 cm). As no recovery is deemed necessary, resilience has been assessed as ‘High’ and, therefore, this biotope has been assessed as ‘Not sensitive’ to sea-level rise at each of the benchmarks albeit with ‘Low’ confidence. | |||
High | High | Not sensitive | |
Q: Low A: NR C: NR | Q: High A: High C: High | Q: Low A: Low C: Low | |
Sea level rise is occurring through a combination of thermal expansion and ice melt. Sea levels have risen 1-3 mm/yr. in the last century (Cazenave & Nerem, 2004, Church et al., 2004, Church & White, 2006). This biotope is recorded between 5 –20 m depth, although Virgularia mirabilis is known to reside at depths of up to 800 m (Bastari et al., 2018). Philine quadripartita appears to be more of a shallow-water species, which has been found at depths of up to 36 m in Malta (Ballesteros et al., 2013). Therefore, an increase in depth of 50 – 107 cm is unlikely to have large implications for these characterizing species. However, this biotope occurs on sheltered, stable mud and any increase in exposure or tidal energy occurring through sea-level rise may lead to negative impacts. Understanding of how sea-level rise will affect exposure or the tide-swept nature of a habitat, is fraught with uncertainty, although evidence appears to suggest that any alterations will be non-linear (Pickering et al., 2012, Li et al., 2016). Modelling potential outcomes of sea-level rise on the tidal and residual currents in the Bohai Sea, China showed effects were site dependent, with energy either increasing or decreasing (Li et al., 2016). Similarly, Pickering et al. (2012) found a similar pattern around the UK for tidal amplitude. The effects of sea-level rise and increased wave action may be increased further due to storms and storm surges. IPCC (2019) note that the frequency of extreme sea-level events (e.g. due to storms) are predicted to increase as sea-level rises, however, there is no consensus on the future storm and, hence, wave climate around UK coasts (Mossman et al., 2015, Lowe et al., 2018, Palmer et al., 2018). Sensitivity assessment. This habitat occurs from 5-20 m, although both characterizing species are known to occur at deeper depths. However, the habitat is only found in sheltered conditions and any change in exposure cannot be evaluated at the current time, as evidence suggests that any changes in relation to sea-level rise will be site-specific. Therefore, under the available evidence, resistance to sea-level rise has been assessed as ‘High’ for both the middle (50 cm) and high (70 cm) emission scenario, and the extreme scenario (107 cm). As no recovery is deemed necessary, resilience has been assessed as ‘High’ and, therefore, this biotope has been assessed as ‘Not sensitive’ to sea-level rise at each of the benchmarks albeit with ‘Low’ confidence. |
Use / to open/close text displayed | Resistance | Resilience | Sensitivity |
High | High | Not sensitive | |
Q: Medium A: Low C: Medium | Q: High A: High C: High | Q: Medium A: Low C: Medium | |
In shallow sea lochs, sedimentary biotopes typically experience seasonal changes in temperature between 5°C and 15°C (10°C) (Hughes, 1998a). Although, unusually warm summers or cold winters may change the temperatures outside this range, benthic burrowing species will be buffered from extremes by their presence in the sediment. Spawning, hatching, and time to metamorphosis are all temperature dependent in Philine quadripartita (as aperta). Spawning occurs during the warmest months of the year (April to August) (Lancaster, 1983). Laboratory results showed hatching occurred after 3.5 days at 23°C and 8 days at 13°C (Thompson, 1976) and time to metamorphosis occurred after 35-40 days at 12-13°C and 30 days at 15°C (Hansen & Ockelmann, 1991). Philine quadripartita is widely distributed around the coasts of Britain, south to the Mediterranean (Thompson, 1976). Sea pens can withdraw into their burrows for protection. No information was found on the upper limit of sea pens tolerance to temperature. Virgularia mirabilis is recorded from western Europe, the Mediterranean, from Norway and Iceland to Africa in the North Atlantic, and to the Gulf of Mexico in North America (Hughes, 1998a; OBIS 2015). Jones et al. (2000) suggested that Virgularia mirabilis was probably more tolerant of temperature change than other British sea pen species due to its abundance in shallow waters. Cerianthus lloydii adults are locally abundant in many localities on all coasts of the British Isles and in some areas are common on the shore. This species occurs on all western coasts of Europe from Greenland and Spitzbergen south to Biscay. Larvae, but not adults, have been recorded from the Mediterranean. However, no further information on the temperature tolerance of Cerianthus lloydii was found. The distribution of Virgularia mirabilis, Cerianthus lloydii, and Philine quadripartita suggest that they are probably resistant of 2°C change in temperature for a year. Exposure to short-term acute change of 5°C may interfere with reproduction in Philine quadripartita and may cause Virgularia mirabilis, Cerianthus lloydii to withdraw into their burrows temporarily. However, there is no evidence to suggest that mortality would result. Therefore, a resistance of High is suggested but with Low confidence. Therefore, resilience is High, so that the biotope is probably Not sensitive at the benchmark level. | |||
High | High | Not sensitive | |
Q: Medium A: Low C: Medium | Q: High A: High C: High | Q: Medium A: Low C: Medium | |
In shallow sea lochs, sedimentary biotopes typically experience seasonal changes in temperature between 5°C and 15°C (10°C) (Hughes, 1998a). Although, unusually warm summers or cold winters may change the temperatures outside this range, benthic burrowing species will be buffered from extremes by their presence in the sediment. Spawning, hatching, and time to metamorphosis are all temperature dependent in Philine quadripartita (as aperta). Spawning occurs during the warmest months of the year (April to August) (Lancaster, 1983). Laboratory results showed hatching occurred after 3.5 days at 23°C and 8 days at 13°C (Thompson, 1976) and time to metamorphosis occurred after 35-40 days at 12-13°C and 30 days at 15°C (Hansen & Ockelmann, 1991). Philine quadripartita is widely distributed around the coasts of Britain, south to the Mediterranean (Thompson, 1976). Sea pens can withdraw into their burrows for protection. No information was found on the upper limit of sea pens tolerance to temperature. Virgularia mirabilis is recorded from western Europe, the Mediterranean, from Norway and Iceland to Africa in the North Atlantic, and to the Gulf of Mexico in North America (Hughes, 1998a; OBIS 2015). Jones et al. (2000) suggested that Virgularia mirabilis was probably more tolerant of temperature change than other British sea pen species due to its abundance in shallow waters. Cerianthus lloydii adults are locally abundant in many localities on all coasts of the British Isles and in some areas are common on the shore. This species occurs on all western coasts of Europe from Greenland and Spitzbergen south to Biscay. Larvae, but not adults, have been recorded from the Mediterranean. Crisp (1964) reported that Cerianthus lloydii in North Wales were apparently unaffected by the severe winter of 1962/63. However, no further information on the temperature tolerance of Cerianthus lloydii was found. The distribution of Virgularia mirabilis, Cerianthus lloydii, and Philine quadripartita suggest that they are probably resistant of 2°C change in temperature for a year. Exposure to short-term acute change of 5°C may interfere with reproduction in Philine quadripartita and may cause Virgularia mirabilis, Cerianthus lloydii to withdraw into their burrows temporarily. However, there is no evidence to suggest that mortality would result. Therefore, a resistance of High is suggested but with Low confidence. Therefore, resilience is High, so that the biotope is probably Not sensitive at the benchmark level. | |||
Low | Medium | Medium | |
Q: Low A: NR C: NR | Q: Medium A: Low C: Medium | Q: Low A: Low C: Low | |
No information on the salinity tolerance of the important characterizing species was found. Cerianthus lloydii may be recorded from the intertidal at LWST, but is probably protected from changes in salinity due to its infaunal habitat, buffered by the salinity of the interstitial water of the sediment. Greathead et al. (2007) demonstrated that Virgularia mirabilis was the most ubiquitous of all three of the sea pens in Scotland, found in habitats nearer coastal areas and inner sea lochs. Jones et al. (2000) suggested that Virgularia mirabilis was more tolerant of reduced salinity than other British sea pens due to its distribution in shallower waters. No information on the salinity preferences of Philine quadripartita was found. An increase in salinity at the benchmark level, would result in a salinity of >40 psu, and as hypersaline water is likely to sink to the seabed, the biotope may be affected by hypersaline effluents. Ruso et al. (2007) reported that changes in the community structure of soft sediment communities due to desalinisation plant effluent in Alicante, Spain. In particular, in close vicinity to the effluent, where the salinity reached 39 psu, the community of polychaetes, crustaceans and molluscs was lost and replaced by one dominated by nematodes. Roberts et al. (2010b) suggested that hypersaline effluent dispersed quickly but was more of a concern at the seabed and in areas of low energy where widespread alternations in the community of soft sediments were observed. In several studies, echinoderms and ascidians were amongst the most sensitive groups examined (Roberts et al., 2010b). Sensitivity assessment. This biotope (IFiMu.PhiVir) is recorded from full and variable salinity regimes. However, although the biotope might occur in sea lochs subject to variable salinity, the benthos may not experience variable salinity at depth, and infauna are protected from short-term changes in salinity due to the salinity of the interstitial waters. An increase in salinity at the benchmark level would result in a salinity of >40 psu. However, hypersaline effluent is likely to sink to the seabed and may affect the community. Based on the evidence from Ruso et al. (2007) and Roberts et al. (2010b) it is likely that the community will be degraded and, especially, Philine quadripartita will leave the affected area or be killed. The effect on sea pens and anemones is unknown. Therefore, a resistance of Low is suggested with Low confidence. Resilience is probably Medium so that the sensitivity is assessed as Medium. | |||
Low | Low | High | |
Q: Low A: NR C: NR | Q: Medium A: Low C: Medium | Q: Low A: Low C: Low | |
No information on the salinity tolerance of the important characterizing species was found. Cerianthus lloydii may be recorded form the intertidal at LWST, but is probably protected from changes in salinity due to its infaunal habitat, buffered by the salinity of the interstitial water of the sediment. Greathead et al. (2007) demonstrated that Virgularia mirabilis was the most ubiquitous of all three of the sea pens in Scotland, found in habitats nearer coastal areas and inner sea lochs. Jones et al. (2000) suggested that Virgularia mirabilis was more tolerant of reduced salinity than other British sea pens due to its distribution in shallower waters. No information on the salinity preferences of Philine quadripartita was found. Sensitivity assessment. This biotope (IFiMu.PhiVir) is recorded from full and variable salinity regimes. However, although the biotope might occur in sea lochs subject to variable salinity, the benthos may not experience variable salinity at depth, and infauna are protected from short-term changes in salinity due to the salinity of the interstitial waters. A decrease in salinity at the benchmark level, would result in a reduced salinity regime. The majority of the characterizing species are only found in full salinity conditions. Therefore, such a reduction in salinity probably results in mobile species leaving the biotope, the death of species that could not relocate, and a marked reduction in species richness. Therefore, a resistance of Low is recorded based on expert judgement. Resilience is probably also Low so that sensitivity is assessed as High. | |||
Low | Low | High | |
Q: Medium A: Medium C: Medium | Q: Medium A: Low C: Medium | Q: Medium A: Low C: Medium | |
The biotope (IFiMu.PhiVir) occurs in low energy environments with weak (<0.5 m/sec.) to very weak tidal streams (Connor et al. 2004), which are a prerequisite for the fine mud sediments characteristic of the biotope. Virgularia mirabilis is also recorded from coarser sandier muds with small stones and shell fragments e.g. SS.SMu.CSaMu.VirOphPmax (Hughes, 1998a; Greathead et al. 2007), and is probably more tolerant of current or wave induced flow than other British sea pens. Hiscock (1983) examined the effects of water flow on Virgularia mirabilis. As water flow rates increase, Virgularia mirabilis first responds by swinging polyps around the axial rod to face away from the current (at 0.12 m/s), then polyps face downstream. With further increase in flow, the stalk bends over and the pinnae are pushed together to an increasing amount with increasing velocity of flow (at 0.33 m/s). Finally, tentacles retract and at water speeds greater than 0.5 m/s (i.e. 1 knot) the stalk retracts into the mud (Hiscock, 1983). If water speeds remain at this level or above the sea-pen will be unable to extend above the sediment, unable to feed and could die (Hill & Wilson, 2000). Cerianthus lloydii is recorded from biotopes with a wide range of water flow regimes, from very weak to strong flow and in muddy to mixed or coarse sediments (Connor et al., 1997a).Therefore, it is likely to tolerate changes in water flow regimes. However, Philine quadripartita is recorded from mud, muddy sand and sand (Thompson, 1976; Connor et al., 1997a). Sensitivity assessment. This biotope is only recorded in muds and in weak or very weak flow (Connor et al., 2004), so that a further decrease in flow is not relevant. Increased flow has the potential to modify the sediment, especially at the surface. A significant increase in water flow may winnow away the mud surface or even remove the mud habitat and hence the biotope if prolonged. An increase of 0.2 m/s may begin to erode the mud surface where the site is already subject to flow (e.g. weak flow at the seabed), based on sediment erosion deposition curves (Wright, 2001). However, given the depth of mud that characterizes the biotope only the surface of the mud may be removed within a year. Cerianthus lloydii is unlikely to be impacted by a change in the sediment, and is a passive predator. Philine quadripartita is also found in coarser sediments but reaches a high abundance in this biotope, presumably due to the abundance of prey and or habitat stability. Virgularia mirabilis may be directly affected by an increase in flow, especially if it exceeds 0.5 m/s. Therefore, modification of the sediment, coupled with a reduction in the Virgularia mirabilis abundance may result in a loss this biotope as described by the classification. Therefore, a resistance of Low is recorded. Resilience is probably also Low so that sensitivity is 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 | |
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 | |
The biotope (IFiMu.PhiVir) occurs in low energy environments sheltered or extremely sheltered from wave action (Connor et al. 2004), which are a prerequisite for the fine mud sediments characteristic of the biotope. Virgularia mirabilis occurs in coastal areas and inner sea lochs but these areas are still sheltered from wave action, and in sandier muds (e.g. the biotope SS.SMu.CSaMu.VirOphPmax) (Hughes, 1998a; Greathead et al. 2007), wave exposure was not recorded to be more than ‘sheltered’. Cerianthus lloydii is recorded from biotopes from wave exposed to extremely sheltered muddy to mixed or coarse sediments (Connor et al., 1997b). Therefore, it is likely to tolerate changes in wave action. However, Philine quadripartita is recorded from mud, muddy sand, and sand and very to extremely wave sheltered biotopes (Thompson, 1976; Connor et al., 1997b). Sensitivity assessment. A decrease in wave exposure is unlikely in the sheltered habitats they inhabit. An increase in wave exposure is likely to affect Virgularia mirabilis and Philine quadripartita species adversely, limiting or removing the shallower proportion of the population, and potentially modifying sediment and therefore habitat preferences in the longer-term. However, a 3-5% increase in significant wave height (the benchmark) is unlikely to be significant. The benchmark level of change may be no more than expected during winter storms even in the sheltered waters favoured by this biotope. Therefore, resistance is recorded as High at the benchmark level. Hence, resilience is High and the biotope is assessed as Not sensitive at the benchmark level. |
Use / to open/close text displayed | Resistance | Resilience | Sensitivity |
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 | |
This pressure is Not assessed but evidence is presented where available. | |||
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 | |
This pressure is Not assessed but evidence is presented where available. | |||
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 | |
This pressure is Not assessed but evidence is presented where available. | |||
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 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 | |
This pressure is Not assessed. | |||
Low | Low | High | |
Q: High A: High C: Medium | Q: Medium A: Low C: Medium | Q: Medium A: Low C: Medium | |
Virgularia mirabilis is often found in sea lochs so may be able to tolerate some reduction in oxygenation. However, Jones et al. (2000) reported that sea pen communities were absent from areas which are deoxygenated and characterized by a distinctive bacterial community and Hoare & Wilson (1977) reported that Virgularia mirabilis was absent from sewage related anoxic areas of Holyhead harbour. Nilsson & Rosenberg (1994) examined the effects of hypoxia on muddy sediment cores in mesocosm experiments. Both moderate (ca 1 mg O2/l) and severe (ca 0.5 mg O2/l) hypoxia resulted in a significant reduction in species abundance after 6-7 days of hypoxia. Amphiura filiformis left the sediment as hypoxia increases, followed by Kurtiella bidentata (as Mysella bidentata (0.5-2 days later), Echinocardium cordatum left the sediment before moderate hypoxia was reached, and all Labidoplax buskii left the sediment at 1.6 mg O2/l, while Nephtys hombergii was the last species to leave the sediment. Almost all the Philine quadripartita (studied as aperta) left the sediment at both levels of hypoxia, and even escaped the experimental sediment cores, or died at the sediment surface. In moderate hypoxia most individuals survived but at severe hypoxia treatment only two individuals survived. Diaz & Rosenberg (1995) noted that anemones include species that were reported to be particularly tolerant of hypoxia (e.g. Cerianthus sp and Epizoanthus erinaceus). A major hypoxic event due a pyncocline in the Gulf of Trieste resulted in a mass mortality of benthos between 12 and 26th September 1983 (Stachowitsch, 1992), during which the oxygen levels fell below 4.2 mg/l, became anoxic, and hydrogen sulphide and ammonia were released (Faganeli et al., 1985). Amongst the epifauna, the even hypoxia resistant polychaetes and bivalves died after 4-5 days and the only organism to survive after one week were the anemones Cerianthus sp and Epizoanthus erinaceus, the gastropods Aporrhais pespelecani and Trunculariopsis trunculus and the sphinuculid Sipunculus nudis (Stachowitsch, 1992). Sensitivity assessment. The evidence suggests that severe hypoxic or anoxic conditions are likely to be detrimental to sea pen and Philine quadripartita, while Cerianthus lloydii may survive even anoxic conditions for a week. Sea pens might be resistant of short-term hypoxia due to their presence at depth in sheltered sea lochs but severe hypoxia may be detrimental. However, a reduction in oxygen levels to below 2 mg/l for a week will probably force Philine quadripartita to leave the affected area, and result in a significant reduction in its abundance and the abundance of other infauna. Therefore, a resistance of Low is suggested to represent to loss of a small proportion of the sea pen population but a significant proportion of the Philine quadripartita population. Resilience is probably Low due to time required for the sea pen population to recover, although the Philine quadripartita population would probably recover rapidly (< 2 years). Therefore, sensitivity is assessed as High. | |||
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 | |
Hoare & Wilson (1977) noted that Virgularia mirabilis was absent from part of the Holyhead Harbour heavily affected by sewage pollution. However, the species was abundant near the head of Loch Harport, Skye, close to a distillery outfall discharging water enriched in malt and yeast residues and other soluble organic compounds (Nickell & Anderson, 1977; cited in Hughes, 1998a), where the organic content of the sediment was up to 5%. Virgularia mirabilis was also present in Loch Sween in Scotland in sites where organic content was as high as 4.5% (Atkinson, 1989). No information was available on the effect of nutrient enrichment on Cerianthus lloydii or Philine quadripartita. Borja et al. (2000) and Gittenberger and van Loon (2011) both assigned Cerianthus lloydii to their Ecological Group I, ‘species very sensitive to organic enrichment and present under unpolluted conditions (initial state)’ in of the AZTI Marine Biotic Index (AMBI) index to assess disturbance (including organic enrichment). The basis for their assessment and relation to the pressure benchmark is not clear. Sensitivity assessment. Sublittoral muds may be expected to be high in organic nutrients, and the presence of Virgularia mirabilis in areas of up to 4.5% organic carbon (Atkinson, 1989) suggest a resistance to organic enrichment at the benchmark level. The high organic content suggests that nutrients are not limiting. But no evidence on the direct effects of nutrients in the form of nitrates, phosphates and silicates was found. Algal mats are associated with nutrient enrichment, but only in shallow waters but the biotope could be affected by the algal blooms that sink to the bottom when they die, although the main effects are organic enrichment and hypoxia. However, the biotope is assessed as Not sensitive at the pressure benchmark of compliance with good status as defined by the WFD. | |||
Medium | Low | Medium | |
Q: Low A: NR C: NR | Q: Medium A: Low C: Medium | Q: Low A: Low C: Low | |
Hoare & Wilson (1977) noted that Virgularia mirabilis was absent from part of the Holyhead Harbour heavily affected by sewage pollution. However, the species was abundant near the head of Loch Harport, Skye, close to a distillery outfall discharging water enriched in malt and yeast residues and other soluble organic compounds (Nickell & Anderson, 1977; cited in Hughes, 1998a), where the organic content of the sediment was up to 5%. Virgularia mirabilis was also present in Loch Sween in Scotland in sites where organic content was as high as 4.5% (Atkinson, 1989). No information was available on the effect of organic enrichment on Philine quadripartita. Cerianthus lloydii was found near the centre of sewage sludge dumping groups at ca 10% organic carbon but was more abundant at intermediate nutrient enrichment (Hughes, 1998a). But Borja et al. (2000) and Gittenberger & van Loon (2011) both assigned Cerianthus lloydii to their Ecological Group I, ‘species very sensitive to organic enrichment and present under unpolluted conditions (initial state)’ in of the AZTI Marine Biotic Index (AMBI) index to assess disturbance (including organic enrichment). The basis for their assessment and relation to the pressure benchmark is not clear. Sensitivity assessment. Sublittoral muds may be expected to be high in organic nutrients, and the presence of Virgularia mirabilis in areas of up to 4.5% organic carbon (Atkinson, 1989) suggest a resistance to organic enrichment at the benchmark level. Therefore, a precautionary resistance of Medium is suggested but with Low confidence, and as resilience is probably Low, a sensitivity of Medium is recorded. |
Use / to open/close text displayed | Resistance | Resilience | Sensitivity |
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 sedimentary substrata were replaced with rock substrata the biotope would be lost, as it would no longer be a sedimentary habitat and would no longer support sea pens and burrowing megafauna. Sensitivity assessment. Resistance to the pressure is considered ’None‘, and resilience ’Very low‘ or ‘None’ (as the pressure represents a permanent change) and the sensitivity of this biotope is assessed as ’High’. | |||
None | Very Low | High | |
Q: High A: High C: High | Q: High A: High C: High | Q: High A: High C: High | |
Virgularia mirabilis occurs in a number of biotopes, on substrata ranging from mud, sandy mud, and gravelly mud, with or with shell fragments or stones (Connor et al., 2004). Greathead et al. (2007) suggested that the muscular peduncle of Virgularia mirabilis allowed it to occupy coarser muds than the other sea pens, and explained its presence in the Moray Firth and Firth of Forth, and its wider distribution in Scotland. Greathead et al. (2007) noted that Pennatula phosphorea was absent in the North Minch while Funiculina quadrangularis and Virgularia mirabilis were present, but that Pennatula phosphorea was abundant in soft, adhesive mud with high silt-clay content in Loch Broom. This may suggest a preference for fine muds. The MNCR only recorded Pennatula phosphorea from biotopes in ‘mud’. Greathead et al. (2007) also noted that Funiculina quadrangularis had the most restricted distribution, probably due to a preference of depth and soft deep muds of sheltered loch basins, where it was abundant. Again, the MNCR only recorded Funiculina quadrangularis from biotopes in ‘mud’. However, it was also recorded from areas of muddy sand in the South and North Minches and in the Fladen Grounds but in deep water. In addition, a 'mud' subtratum was the most important factor in a habitat suitability index model for sea pens developed by Greathead et al. (2015). In their model, habitat suitability for Funiculina quadrangularis increased with mud content up to a maximum at 90-100% mud. Pennatula phosphorea and Virgularia mirabilis also had their maximum habitat suitability at 100% mud. All three species had zero habitat suitability at 0% mud. However, gravel content was also important. Virgularia mirabilis was the most tolerant of gravel content and was still recorded at 50% gravel while the were no records of Pennatula phosporea and Funiculina quadrangularis above 40% and 30% gravel respectively (Greathead et al., 2015). Cerianthus lloydii is recorded from biotopes in muddy to mixed or coarse sediments (Connor et al., 1997b). Therefore, it is likely to tolerate changes in sediment type. Philine quadripartita is recorded from mud, muddy sand and sand (Thompson, 1976; Connor et al., 1997b). Sensitivity assessment. While the important characteristic species are recorded from a range of sediment types, this biotope (IFiMU.PhiVir) is defined by its occurrence in mud. Therefore, a change in sediment type by one Folk class (see Long, 2006), e.g. from mud to sandy mud and sand would result in loss of the biotope. Therefore, a resistance of None is recorded. As the change is permanent, resilience is Very low and sensitivity is assessed as High. | |||
None | Low | High | |
Q: Low A: NR C: NR | Q: Medium A: Low C: Medium | Q: Low A: Low C: Low | |
Benthic trawls (e.g. rock hopper ground gear, otter trawls) will remove and capture sea pens (Tuck et al., 1998; Kenchington et al., 2011), albeit with limited efficiency. Nevertheless, dredging and suction dredging penetrates to greater depth and are likely to remove sea pens. Although Virgularia mirabilis will not be able to avoid activities that penetrate into the sediment. Assuming their burrows are only deep enough to hold the entire animal (see Greathead et al., 2007), then Virgularia mirabilis burrows are up to 40 cm deep. Cerianthus lloydii can also withdraw into the sediment, and its burrow is up to 40 cm deep. However, Philine quadripartita feeds at the surface and burrows to find prey (Thompson, 1976). Sensitivity assessment. Extraction of sediment to 30 cm (the benchmark) could remove most of the resident sea pens present, the burrowing sea anemones, mobile epifauna, and Philine quadripartita from the affected area. Hence, the resistance is probably None. Resilience is probably Low, resulting in a sensitivity of High. | |||
Medium | Medium | Medium | |
Q: High A: High C: Medium | Q: Medium A: Low C: Medium | Q: Medium A: Low C: Medium | |
Stable sedimentary habitats, such as mud were amongst the most vulnerable to fishing activities, e.g. otterboard trawling (Ball et al., 2000b; Collie et al., 2000). Tracks left by otterboards were visible 18 months after experimental trawls in Gareloch (Ball et al., 2000b). Ball et al., (2000b) concluded that trawling modified the benthic community due to an increase in opportunistic polychaetes. However, Kaiser et al. (2006) concluded that otterboards had a significant initial effect on muddy sands and muds, but that the effects were short-lived in mud habitats. In experimental studies (Kinnear et al. 1996; Eno et al. 2001) sea pens were found to be largely resilient to smothering, dragging or uprooting by creels or pots. Virgularia mirabilis withdrew very quickly into the sediment when exposed to pots or creels so that it was difficult to determine their response. However, all sea pens recovered from being dragged over by pots or creels within 24-72 h, with exception of one individual Funiculina quadrangularis. In Virgularia mirabilis withdrawal from physical stimulus is rapid (ca 30 seconds) (Hoare & Wilson, 1977; Ambroso et al., 2013). Birkland (1974) maintained that the only way to capture all of the sea pens in an area (quadrat) was to remove them slowly by hand until no more emerged. But several studies note that their ability to withdraw into the sediment in response to bottom towed or dropped gear (e.g. creels, pots, camera/video mounted towed sleds, experimental grab, trawl, or dredge) means that sea pen abundance can be difficult to estimate (Birkeland, 1974; Eno et al., 2001; Greathead et al., 2007; Greathead et al., 2011). The ability to withdraw also suggests that sea pens can avoid approaching demersal trawls and fishing gear. This was suggested as the explanation for the similarity in the densities of Virgularia mirabilis in trawled and untrawled sites in Loch Fyne, and the lack of change in sea pen density observed after experimental trawling (using modified rock hopper ground gear) over a 18 month period in Loch Gareloch (Howson & Davies 1991; Hughes 1998a; Tuck et al. 1998). Kenchington et al. (2011) estimated the gear efficiency of otter trawls for sea pens (Anthoptilum and Pennatula) to be in the range of 3.7 – 8.2%, based on estimates of sea pen biomass from (non-destructive) towed camera surveys. However, species obtained by dredges were invariably damaged (Hoare & Wilson, 1977). Hoare & Wilson (1977) noted that Virgularia was absent for areas of Holyhead Harbour disturbed by dragging or boat mooring, although no causal evidence was given (Hughes, 1998a). Sea pens are potentially vulnerable to long lining. Munoz et al. (2011) noted that small numbers of Pennatulids (inc. Pennatula sp.) were retrieved from experimental long-lining around the Hatton Bank in the north east Atlantic, presumably either attached to hooks or wrapped in line as it passed across the sediment. Hixon & Tissot (2007) noted that sea pens (Stylatula sp.) were four times more abundant in untrawled areas relative to trawled areas in the Coquille Bank, Oregon, although no causal relationship was shown. No information on the effects of abrasion or penetrative gear on Cerianthus lloydii or Philine quadripartita was found. Greathead et al. (2011) was not able to conclude if the variation in Cerianthus abundance in the Fladden Grounds was due to miscounting, its patchy distribution or fishing activity. Sensitivity assessment. The reviews by Ball et al. (2000), Collie et al. (2000) and Kasier et al. (2006) suggest that stable sediments, e.g. muds are likely to be vulnerable to fishing activities. The evidence for Virgularia mirabilis suggests that its ability to withdraw into the sediment quickly would avoid surface abrasion from creels and pots but that dragging and mooring lines may be damaging, and individuals may be caught and removed by fishing lines (e.g. long-lines). Philine quadripartita feeds at the surface and burrows to find prey (Thompson, 1976) so that it might be susceptible to damage from passing gear or moorings. Therefore, a resistance of Medium is recorded due to the potential disturbance to the biotope as a whole. As the impact may be limited (see Kenchington et al., 2011), a resilience of Medium is suggested and sensitivity is assessed as Medium. | |||
Medium | Low | Medium | |
Q: High A: High C: Medium | Q: Medium A: Low C: Medium | Q: Medium A: Low C: Medium | |
Stable sedimentary habitats, such as mud were amongst the most vulnerable to fishing activities, e.g. otter trawling (Ball et al., 2000; Collie et al., 2000). Tracks left by otter were visible 18 months after experimental trawls in Gareloch (Ball et al., 2000). Ball et al., (2000) concluded that trawling modified the benthic community due to an increase in opportunistic polychaetes. However, Kaiser et al. (2006) concluded that otter trawls had a significant initial effect on muddy sands and muds, but that the effects were short-lived in mud habitats. In Virgularia mirabilis withdrawal from the physical stimulus is rapid (ca 30 seconds) (Hoare & Wilson, 1977; Ambroso et al., 2013). Birkland (1974) maintained that the only way to capture all of the sea pens in an area (quadrat) was to remove them slowly by hand until no more emerged. But several studies note that their ability to withdraw into the sediment in response to bottom towed or dropped gear (e.g. creels, pots, camera/video mounted towed sleds, experimental grab, trawl, or dredge) means that sea pen abundance can be difficult to estimate (Birkeland, 1974; Eno et al., 2001; Greathead et al., 2007; Greathead et al., 2011). The ability to withdraw also suggests that sea pens can avoid approaching demersal trawls and fishing gear. This was suggested as the explanation for the similarity in the densities of Virgularia mirabilis in trawled and untrawled sites in Loch Fyne, and the lack of change in sea pen density observed after experimental trawling (using modified rock hopper ground gear) over a 18 month period in Loch Gareloch (Howson & Davies 1991; Hughes 1998a; Tuck et al. 1998). Kenchington et al. (2011) estimated the gear efficiency of otter trawls for sea pens (Anthoptilum and Pennatula) to be in the range of 3.7 – 8.2%, based on estimates of sea pen biomass from (non-destructive) towed camera surveys. However, species obtained by dredges were invariably damaged (Hoare & Wilson, 1977). Hoare & Wilson (1977) noted that Virgularia was absent for areas of Holyhead Harbour disturbed by dragging or boat mooring, although no causal evidence was given (Hughes, 1998a). Sea pens are potentially vulnerable to long lining. Munoz et al. (2011) noted that small numbers of Pennatulids (inc. Pennatula sp.) were retrieved from experimental long-lining around the Hatton Bank in the north east Atlantic, presumably either attached to hooks or wrapped in line as it passed across the sediment. Hixon & Tissot (2007) noted that sea pens (Stylatula sp.) were four times more abundant in untrawled areas relative to trawled areas in the Coquille Bank, Oregon, although no causal relationship was shown. No information on the effects of abrasion or penetrative gear on Cerianthus lloydii or Philine quadripartita was found. Greathead et al. (2011) were not able to conclude if the variation in Cerianthus abundance in the Fladden Grounds was due to miscounting, its patchy distribution or fishing activity. Sensitivity assessment. The reviews by Ball et al. (2000), Collie et al. (2000) and Kasier et al. (2006) suggest that stable sediments, e.g. muds are likely to be vulnerable to fishing activities. The evidence for Virgularia mirabilis suggests that its ability to withdraw into the sediment quickly would avoid surface abrasion from creels and pots but that dragging and mooring lines may be damaging, individuals may be caught and removed by fishing lines (e.g. long-lines), and penetrative gear is likely to remove a proportion of the population. Philine quadripartita feeds at the surface and burrows to find prey (Thompson, 1976) so that it might be susceptible to damage from passing gear or moorings. Therefore, a resistance of Medium is recorded due to the potential disturbance to the biotope as a whole. The resilience is probably Low so that sensitivity is assessed as Medium. | |||
High | High | Not sensitive | |
Q: Low A: NR C: NR | Q: High A: High C: High | Q: Low A: Low C: Low | |
The sea pen species assessed live in sheltered areas, in fine sediments, subject to high suspended sediment loads. The effect of increased deposition of fine silt is uncertain but it is possible that feeding structures may become clogged. When tested, Virgularia mirabilis quickly seized and rejected inert particles (Hoare & Wilson, 1977). Hiscock (1983) observed Virgularia mirabilis secretes copious amounts of mucus which could keep the polyps clear of silt. Kinnear et al. (1996) noted that another species of sea pen, Funiculina quadrangularis, was quick to remove any adhering mud particles by the production of copious quantities of mucus. Virgularia mirabilis is also likely to be able to self-clean (Hiscock, 1983). No indication of the suspended sediment load was given in any evidence found. An increase in suspended sediment is unlikely to interfere with feeding in either Cerianthus lloydii or Philine quadripartita. Cerianthus lloydii is a passive predator while Philine quadripartita is an active predator that ploughs through the surface of the substratum looking for prey. Other members of the infaunal community are deposit feeders, predators or omnivores and unlikely to be affected. However, an increase in turbidity and increased ,light attenuation may reduce the prevalence of microphytobenthos diatoms. If sea pen feeding is reduced by increases in suspended sediment the viability of the population will be reduced. Once siltation levels return to normal, feeding will be resumed therefore recovery will be rapid. Overall, resistance is probably High, hence, resilience is also ‘High, and the biotope is probably Not sensitive at the benchmark level. | |||
High | High | Not sensitive | |
Q: Low A: NR C: NR | Q: High A: High C: High | Q: Low A: Low C: Low | |
Natural accretion rates are potentially high in the sheltered muddy habitats. Hiscock (1983) observed Virgularia mirabilis secretes copious amounts of mucus, which could keep the polyps clear of silt and is also likely to be able to self-clean. Kinnear et al. (1996) noted that Funiculina quadrangularis was quick to remove any adhering mud particles by the production of copious quantities of mucus, once the source of smothering (in this case potting) was removed. Virgularia mirabilis can burrow and move into and out of their own burrows. It is probable therefore that deposition of 5 cm of fine sediment will have little effect other than to temporarily suspend feeding and the energetic cost of burrowing. In normal accretion, Cerianthus lloydii keeps pace with the accretion and, as a result, develops burrows much larger than the animal itself (Schäfer, 1972; Bromley, 2012). Schäfer (1972) reported that an increase in depositional rate led to an avoidance behaviour in Cerianthus lloydii. The organism ceases tube building activity and instead the animal bunches its tentacles and intrudes its way up to the new surface, where it establishes a new burrow. However, no information on the depth of material through which is can burrow was given. Philine quadripartita ploughs through the surface of the substratum and creates furrows in its wake. Thompson (1976) suggested that it only burrowed into the substratum in pursuit of prey. Sensitivity assessment. The deposition of 5 cm of fine sediment is unlikely to affect the community adversely. Both Virgularia and Cerianthus can withdraw into their tube and can probably re-emerge through 5 cm of fines. Philine aperta is a large opisthobranch (up to 7 cm in length) that could probably move through a deposit of only 5 cm. The remaining infauna of polychaetes and bivalves are adapted to accreting environments and may be unaffected. However, no direct evidence was found. Therefore, a resistance of High is suggested, resulting in a resilience of High, so that the biotope is probably ‘Not sensitive’ at the benchmark level. | |||
Low | High | Low | |
Q: Low A: NR C: NR | Q: Medium A: Low C: Medium | Q: Low A: Low C: Low | |
Natural accretion rates are potentially high in the sheltered muddy habitats. Hiscock (1983) observed Virgularia mirabilis secretes copious amounts of mucus, which could keep the polyps clear of silt and is also likely to be able to self-clean. Kinnear et al. (1996) noted that Funiculina quadrangularis was quick to remove any adhering mud particles by the production of copious quantities of mucus, once the source of smothering (in this case potting) was removed. Virgularia mirabilis can burrow and move into and out of their own burrows. It is probable therefore that deposition of 5 cm of fine sediment will have little effect other than to temporarily suspend feeding and the energetic cost of burrowing. In normal accretion, Cerianthus lloydii keeps pace with the accretion and, as a result, develops burrows much larger than the animal itself (Schäfer, 1972; Bromley, 2012). Schäfer (1972) reported that an increase in depositional rate led to an avoidance behaviour in Cerianthus lloydii. The organism ceases tube building activity and instead the animal bunches its tentacles and intrudes its way up to the new surface, where it establishes a new burrow. However, no information on the depth of material through which is can burrow was given. Philine quadripartita ploughs through the surface of the substratum and creates furrows in its wake. Thompson (1976) suggested that it only burrowed into the substratum in pursuit of prey. Sensitivity assessment. The deposition of 30 cm of fine sediment is may affect the community adversely. Virgularia mirabilis and Cerianthus lloydii can burrow and move into and out of their own burrows, which can be up to 40 cm deep. It is probable, therefore, that deposition of 30 cm of fine sediment will have little effect other than to suspend feeding temporarily and the energetic cost of burrowing. However, Philine aperta lives primarily at the surface of the sediment, so that a sudden deposit of 30 cm of fine sediment may result in mortality of the opisthobranch, However, no direct evidence was found. Therefore, a resistance of Low is suggested due to the potential mortality of Philine aperta but with Low confidence. The resilience is probably High based on the recovery of Philine quadripartita population so that the biotope is probably Low at the benchmark level. | |||
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 | |
Not assessed. | |||
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 relevant (NR) | |
Q: NR A: NR C: NR | Q: NR A: NR C: NR | Q: NR A: NR C: NR | |
Some of the characterizing species associated with this biotope, in particular, the sea pens, may respond to sound vibrations and can withdraw into the sediment. Feeding will resume once the disturbing factor has passed. However, most of the species are infaunal and unlikely respond to noise disturbance at the benchmark level. Therefore, this pressure is probably Not relevant in this biotope. | |||
High | High | Not sensitive | |
Q: Low A: NR C: NR | Q: High A: High C: High | Q: Low A: Low C: Low | |
Shallow examples of this biotope develop a cover of microphytobenthic diatoms. so as increase in incident light may encourage their growth, while shading will inhibit their growth. Nevertheless, this biotope is dominated by deposit feeders and predators, so that the majority of the productivity is secondary. Therefore, the biotope is probably Not sensitive (resistance and resilience are 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–this pressure is considered applicable to mobile species, e.g. fish and marine mammals rather than seabed habitats. Physical and hydrographic barriers may limit the dispersal of seed. But seed dispersal is not considered under the pressure definition and benchmark. | |||
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. | |||
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 | |
Most species within the biotope are burrowing and have no or poor visual perception and are unlikely to be affected by visual disturbance such as shading. Epifauna such as crabs have well developed visual acuity and are likely to respond to movement in order to avoid predators. However, it is unlikely that the species will be affected by visual disturbance at the benchmark level. |
Use / to open/close text displayed | Resistance | Resilience | Sensitivity |
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 of genetic modification, breeding, or translocation was found. | |||
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 | |
In southern Britain, Sternapsis scutata is characterstic of this biotope (Connor et al., 2004). Sternapsis scutata is a non-native polychaete that has extended its range in inshore muddy sediments in the south west of the UK (Shelley et al., 2008). However, in mesocosm experiments, little effect on biological functioning was detected after the introduction of the polychaete and a doubling of its biomass (Shelley et al., 2008). No direct evidence on the effect of non-native species on mud communities was found. However, this assessment should be revisited in the light of new evidence. | |||
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 available on the effect of microbial pathogens on Cerianthus lloydii or Philine quadripartita or sea pens. | |||
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 this biotope are currently directly targeted in the UK and hence this pressure is considered to be ‘Not relevant’. | |||
Medium | Low | Medium | |
Q: Low A: NR C: NR | Q: Medium A: Low C: Medium | Q: Low A: Low C: Low | |
The physical effects of fisheries or dredging activities are addressed under abrasion, penetration and extraction pressures above. No clear biological relationships between the important characteristic species were found. Therefore, removal of any one species may not affect other members of the community adversely. However, is the important characterizing species were removed as by-catch, the character of the biotope would change. A significant decline in the abundance of either Philine quadripartita or Virgularia mirabilis would result in loss of the biotope as recognised by the habitat classification. Therefore, a resistance of Medium is recorded, albeit at Low confidence. As resilience is probably Low, sensitivity is assessed as Medium. |
Ambroso, S., Dominguez-Carrió, C., Grinyó, J., López-González, P., Gili, J.-M., Purroy, A., Requena, S. & Madurell, T., 2013. In situ observations on withdrawal behaviour of the sea pen Virgularia mirabilis. Marine Biodiversity, 43 (4), 257-258.
Ball, B., Munday, B. & Tuck, I., 2000b. Effects of otter trawling on the benthos and environment in muddy sediments. In: Effects of fishing on non-target species and habitats, (eds. Kaiser, M.J. & de Groot, S.J.), pp 69-82. Oxford: Blackwell Science.
Ballesteros, M., Madrenas, E. & Pontes, M., 2013. Philine quadripartita OPK-Opistobranquis, VIMAR 2012-2020. (27/01/2020). https://opistobranquis.info/en/5CL0i
Bastari, A., Pica, D., Ferretti, F., Micheli, F. & Cerrano, C., 2018. Sea pens in the Mediterranean Sea: habitat suitability and opportunities for ecosystem recovery. ICES Journal of Marine Science, 75 (5), 1722-1732. DOI https://doi.org/10.1093/icesjms/fsy010
Birkeland, C., 1974. Interactions between a seapen and seven of its predators. Ecological Monographs, 44, 211-232. DOI https://doi.org/10.2307/1942312
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.
Bromley, R.G., 2012. Trace Fossils: Biology, Taxonomy and Applications: Routledge.
Cazenave, A. & Nerem, R.S., 2004. Present-day sea-level change: Observations and causes. Reviews of Geophysics, 42 (3). DOI https://doi.org/10.1029/2003rg000139
Cerrano, C., Cardini, U., Bianchelli, S., Corinaldesi, C., Pusceddu, A. & Danovaro, R., 2013. Red coral extinction risk enhanced by ocean acidification. Scientific Reports, 3 (1), 1457. DOI https://doi.org/10.1038/srep01457
Chia, F.S. & Crawford, B.J., 1973. Some observations on gametogenesis, larval development and substratum selection of the sea pen Ptilosarcus guerneyi. Marine Biology, 23, 73-82. DOI https://doi.org/10.1007/BF00394113
Church, J.A. & White, N.J., 2006. A 20th century acceleration in global sea-level rise. Geophysical Research Letters, 33 (1). DOI https://doi.org/10.1029/2005gl024826
Church, J.A., White, N.J., Coleman, R., Lambeck, K. & Mitrovica, J.X., 2004. Estimates of the Regional Distribution of Sea Level Rise over the 1950–2000 Period. Journal of Climate, 17 (13), 2609-2625.
Collie, J.S., Hall, S.J., Kaiser, M.J. & Poiner, I.R., 2000. A quantitative analysis of fishing impacts on shelf-sea benthos. Journal of Animal Ecology, 69 (5), 785–798.
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. ISBN 1 861 07561 8. In JNCC (2015), The Marine Habitat Classification for Britain and Ireland Version 15.03. [2019-07-24]. Joint Nature Conservation Committee, Peterborough. Available from https://mhc.jncc.gov.uk/
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.
Crocetta, F. & Tringali, L.P., 2018. Remarks on Philine striatula Monterosato, 1874 ex Jeffreys ms., with a survey on Philinidae J.E. Gray, 1850 (1815) sensu lato (Gastropoda: Cephalaspidea) recently ascribed to the Mediterranean fauna. Marine Biodiversity, 48 (3), 1499-1510. DOI https://doi.org/10.1007/s12526-017-0652-0
Dauwe, B., Herman, P.M.J. & Heip, C.H.R., 1998. Community structure and bioturbation potential of macrofauna at four North Sea stations with contrasting food supply. Marine Ecology Progress Series, 173, 67-83.
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.
Edwards, C.B. & Moore, C.G., 2008. Reproduction in the sea pen Pennatula phosphorea (Anthozoa: Pennatulacea) from the west coast of Scotland Marine Biology 155:303–314
Edwards, D.C.B. & Moore, C.G., 2009. Reproduction in the sea pen Funiculina quadrangularis (Anthozoa: Pennatulacea) from the west coast of Scotland. Estuarine, Coastal and Shelf Science, 82, 161-168.
Eno, N.C., MacDonald, D.S., Kinnear, J.A.M., Amos, C.S., Chapman, C.J., Clark, R.A., Bunker, F.S.P.D. & Munro, C., 2001. Effects of crustacean traps on benthic fauna ICES Journal of Marine Science, 58, 11-20. DOI https://doi.org/10.1006/jmsc.2000.0984
Enochs, I.C., Manzello, D.P., Wirshing, H.H., Carlton, R. & Serafy, J., 2015. Micro-CT analysis of the Caribbean octocoral Eunicea flexuosa subjected to elevated pCO2. ICES Journal of Marine Science, 73 (3), 910-919. DOI https://doi.org/10.1093/icesjms/fsv159
Frölicher, T.L., Fischer, E.M. & Gruber, N., 2018. Marine heatwaves under global warming. Nature, 560 (7718), 360-364. DOI https://doi.org/10.1038/s41586-018-0383-9
Gabay, Y., Benayahu, Y. & Fine, M., 2013. Does elevated pCO2 affect reef octocorals? Ecology and Evolution, 3 (3), 465-473. DOI https://doi.org/10.1002/ece3.351
Gabay, Y., Fine, M., Barkay, Z. & Benayahu, Y., 2014. Octocoral Tissue Provides Protection from Declining Oceanic pH. PLoS ONE, 9 (4), e91553. DOI https://doi.org/10.1371/journal.pone.0091553
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. DOI: 10.13140/RG.2.1.3135.7521
Gomez, C., Wickes, L., Deegan, D., Etnoyer, P. & Cordes, E., 2018. Growth and feeding of deep-sea coral Lophelia pertusa from the California margin under simulated ocean acidification conditions. PeerJ, 6, e5671. DOI https://doi.org/10.7717/peerj.5671
Greathead, C., Demain, D., Dobby, H., Allan, L. & Weetman, A., 2011. Quantitative assessment of the distribution and abundance of the burrowing megafauna and large epifauna community in the Fladen fishing ground, northern North Sea. Scottish Government: Edinburgh (UK).
Greathead, C., González-Irusta, J.M., Clarke, J., Boulcott, P., Blackadder, L., Weetman, A. & Wright, P.J., 2015. Environmental requirements for three sea pen species: relevance to distribution and conservation. ICES Journal of Marine Science: Journal du Conseil, 72 (2), 576-586.
Greathead, C.F., Donnan, D.W., Mair, J.M. & Saunders, G.R., 2007. The sea pens Virgularia mirabilis, Pennatula phosphorea and Funiculina quadrangularis: distribution and conservation issues in Scottish waters. Journal of the Marine Biological Association, 87, 1095-1103. DOI https://doi.org/10.1017/S0025315407056238
Greathead, C.F., Donnan, D.W., Mair, J.M. & Saunders, G.R., 2007. The sea pens Virgularia mirabilis, Pennatula phosphorea and Funiculina quadrangularis: distribution and conservation issues in Scottish waters. Journal of the Marine Biological Association, 87, 1095-1103. DOI https://doi.org/10.1017/S0025315407056238
Hall, S.J., 1994. Physical disturbance and marine benthic communities: life in unconsolidated sediments. Oceanography and Marine Biology: an Annual Review, 32, 179-239.
Hansen, B. & Ockelmann, K.W., 1991. Feeding behaviour in larvae of the opisthobranch Philine aperta. I. Growth and functional response at the different developmental stages. Marine Biology, 111, 255-261.
Hansen, B., 1991. Feeding behaviour in larvae of the opisthobranch Philine aperta. II. Food size spectra and particle selectivity in relation to larval behaviour and morphology of the velar structures. Marine Biology, 111, 263-270.
Hill, J.M. & Wilson, E. 2000. Virgularia mirabilis Slender sea pen. 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. [cited 31-03-2020]. Available from: https://www.marlin.ac.uk/species/detail/1396
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.
Hixon, M.A. & Tissot, B.N., 2007. Comparison of trawled vs untrawled mud seafloor assemblages of fishes and macroinvertebrates at Coquille Bank, Oregon. Journal of Experimental Marine Biology and Ecology, 344 (1), 23-34. DOI https://doi.org/10.1016/j.jembe.2006.12.026
Hoare, R. & Wilson, E.H., 1977. Observations on the behaviour and distribution of Virgularia mirabilis O.F. Müller (Coelenterata: Pennatulacea) in Holyhead harbour. In Proceedings of the Eleventh European Symposium on Marine Biology, University College, Galway, 5-11 October 1976. Biology of Benthic Organisms, (ed. B.F. Keegan, P.O. Ceidigh & P.J.S. Boaden, pp. 329-337. Oxford: Pergamon Press. Oxford: Pergamon Press.
Howson, C.M. & Davies, L.M., 1991. Marine Nature Conservation Review, Surveys of Scottish Sea Lochs. A towed video survey of Loch Fyne. Vol. 1 - Report. Report to the Nature Conservancy Council from the University Marine Biological Station, Millport.
Howson, C.M., Connor, D.W. & Holt, R.H.F., 1994. The Scottish sealochs - an account of surveys undertaken for the Marine Nature Conservation Review. Joint Nature Conservation Committee Report, No. 164 (Marine Nature Conservation Review Report MNCR/SR/27)., Joint Nature Conservation Committee Report, No. 164 (Marine Nature Conservation Review Report MNCR/SR/27).
Hughes, D.J., 1998a. Sea pens & burrowing megafauna (volume III). An overview of dynamics and sensitivity characteristics for conservation management of marine SACs. Natura 2000 report prepared for Scottish Association of Marine Science (SAMS) for the UK Marine SACs Project., Scottish Association for Marine Science. (UK Marine SACs Project). Available from: http://ukmpa.marinebiodiversity.org/uk_sacs/pdfs/seapens.pdf
Hughes, D.J., 1998a. Sea pens & burrowing megafauna (volume III). An overview of dynamics and sensitivity characteristics for conservation management of marine SACs. Natura 2000 report prepared for Scottish Association of Marine Science (SAMS) for the UK Marine SACs Project., Scottish Association for Marine Science. (UK Marine SACs Project). Available from: http://ukmpa.marinebiodiversity.org/uk_sacs/pdfs/seapens.pdf
Hughes, D.J., 1998b. Subtidal brittlestar beds. An overview of dynamics and sensitivity characteristics for conservation management of marine SACs. Natura 2000 report prepared for Scottish Association of Marine Science (SAMS) for the UK Marine SACs Project., Scottish Association for Marine Science. (UK Marine SACs Project, Vol. 3). Available from: http://ukmpa.marinebiodiversity.org/uk_sacs/pdfs/britstar.pdf
Jacobson, M.Z., 2005. Studying ocean acidification with conservative, stable numerical schemes for nonequilibrium air-ocean exchange and ocean equilibrium chemistry. Journal of Geophysical Research: Atmospheres, 110 (D7). DOI https://doi.org/10.1029/2004JD005220
JNCC (Joint Nature Conservation Committee), 2022. The Marine Habitat Classification for Britain and Ireland Version 22.04. [Date accessed]. Available from: https://mhc.jncc.gov.uk/
JNCC (Joint Nature Conservation Committee), 2022. The Marine Habitat Classification for Britain and Ireland Version 22.04. [Date accessed]. Available from: https://mhc.jncc.gov.uk/
Jones, L.A., Hiscock, K. & Connor, D.W., 2000. Marine habitat reviews. A summary of ecological requirements and sensitivity characteristics for the conservation and management of marine SACs. Joint Nature Conservation Committee, Peterborough. (UK Marine SACs Project report.). Available from: http://ukmpa.marinebiodiversity.org/uk_sacs/pdfs/marine-habitats-review.pdf
Kaiser, M., Clarke, K., Hinz, H., Austen, M., Somerfield, P. & Karakassis, I., 2006. Global analysis of response and recovery of benthic biota to fishing. Marine Ecology Progress Series, 311, 1-14.
Kenchington, E., Murillo, F.J., Cogswell, A. & Lirette, C., 2011. Development of encounter protocols and assessment of significant adverse impact by bottom trawling for sponge grounds and sea pen fields in the NAFO Regulatory Area. NAFO, Dartmouth, NS, Canada, 51 pp. Available from https://archive.nafo.int/open/sc/2011/scr11-075.pdf
Kinnear, J.A.M., Barkel, P.J., Mojseiwicz, W.R., Chapman, C.J., Holbrow, A.J., Barnes, C. & Greathead, C.F.F., 1996. Effects of Nephrops creels on the environment. Fisheries Research Services Report No. 2/96, 24 pp. Available from https://www2.gov.scot/Uploads/Documents/frsr296.pdf
Lancaster, S.M., 1983. The biology and reproductive ecology of Philine aperta (Opisthobranchia: Bullomorpha) in Oxwich Bay. Journal of Molluscan Studies, Suppl. 12A, 82-88.
Li, Y., Zhang, H., Tang, C., Zou, T. & Jiang, D., 2016. Influence of Rising Sea Level on Tidal Dynamics in the Bohai Sea. 74 (SI), 22-31. DOI https://doi.org/10.2112/si74-003.1
Lowe, J., Bernie, D., Bett, P., Bricheno, L., Brown, S., Calvert, D., Clark, R.T., Eagle, K.E., Edwards, T., Fosser, G., Fung, F., Gohar, L., Good, P., Gregory, J., Harris, G.R., Howard, T., Kaye, N., Kendon, E.J., Krijnen, J., Maisey, P., McDonald, R.E., McInnes, R.N., McSweeney, C.F., Mitchell, J.F.B., Murphy, J.M., Palmer, M., Roberts, C., Rostron, J.W., Sexton, D.M.H., Thornton, H.E., Tinker, J., Tucker, S., Yamazaki, K. & Belcher, S., 2018. UKCP18 Science Overview Report. Meterological Office, Hadley Centre, Exeter, UK, 73 pp. Available from https://www.metoffice.gov.uk/research/approach/collaboration/ukcp/index
MES, 2010. Marine Macrofauna Genus Trait Handbook. Marine Ecological Surveys Limited. http://www.genustraithandbook.org.uk/
Moore, P.G. & Cameron, K.S., 1999. A note on a hitherto unreported association between Photis longicaudata (Crustacea: Amphipoda) and Cerianthus lloydii (Anthozoa: Hexacorallia). Journal of the Marine Biological Association of the United Kingdom, 79, 369-370.
Mossman, H.L., Grant, A., Lawrence, P.J. & Davy, A.J., 2015. Biodiversity climate change impacts report card technical paper 10. Implications of climate change for coastal and inter-tidal habitats of the UK. Biodiversity climate change impacts, Living With Environmental Change, NERC, UKRI, 26 pp. Available from https://nerc.ukri.org/research/partnerships/ride/lwec/report-cards/biodiversity-source10/
Munoz, D.P., Murillo, F.J., Sayago-Gil, M., Serrano, A., Laporta, M., Otero, I. & Gomez, C., 2011. Effects of deep-sea bottom longlining on the Hatton Bank fish communities and benthic ecosystem, north-east Atlantic. Journal of the Marine Biological Association of the United Kingdom, 91 (4), 939-952.
Nilsson, H.C. & Rosenberg, R., 1994. Hypoxic response of two marine benthic communities. Marine Ecology Progress Series, 115, 209-217.
Palmer, M., Howard, T., Tinker, J., Lowe, J., Bricheno, L., Calvert, D., Edwards, T., Gregory, J., Harris, G., Krijnen, J., Pickering, M., Roberts, C. & Wolf, J., 2018. UKCP18 Marine Report. Met Office, The Hadley Centre, Exeter, UK, 133 pp. Available from https://www.metoffice.gov.uk/pub/data/weather/uk/ukcp18/science-reports/UKCP18-Marine-report.pdf
Pickering, M.D., Wells, N.C., Horsburgh, K.J. & Green, J.A.M., 2012. The impact of future sea-level rise on the European Shelf tides. Continental Shelf Research, 35, 1-15. DOI https://doi.org/10.1016/j.csr.2011.11.011
Price, R.M., Gosliner, T.M. & Valdes, A., 2011. Systematics and phylogeny of Philine (Gastropoda: Opisthobranchia), with emphasis on the Philine aperta species complex. Veliger, 51 (2), 1-58.
Roberts, D.A., Johnston, E.L. & Knott, N.A., 2010b. Impacts of desalination plant discharges on the marine environment: A critical review of published studies. Water Research, 44 (18), 5117-5128.
Rosenberg, R., 1995. Benthic marine fauna structured by hydrodynamic processes and food availability. Netherlands Journal of Sea Research, 34, 303-317.
Rowden, A.A., Jago, C.F. & Jones, S.E., 1998b. Influence of benthic macrofauna on the geotechnical and geophysical properties of surficial sediment, North Sea. Continental Shelf Research, 18, 1347-1363.
Ruso, Y.D.P., la Ossa Carretero, J.A.D., Casalduero, F.G. & Lizaso, J.L.S., 2007. Spatial and temporal changes in infaunal communities inhabiting soft-bottoms affected by brine discharge. Marine environmental research, 64 (4), 492-503.
Schäfer, W., 1972. Ecology and palaeoecology of marine environments, 568 pp. Edinburgh: Oliver & Boyd.
Shelley, R., Widdicombe, S., Woodward, M., Stevens, T., McNeill, C.L. & Kendall, M.A. 2008. An investigation of the impacts on biodiversity and ecosystem functioning of soft sediments by the non-native polychaete Sternaspis scutata (Polychaeta: Sternaspidae). Journal of Experimental Marine Biology and Ecology, 366, 146-150.
Soong, K., 2005. Reproduction and colony integration of the sea pen Virgularia juncea. Marine Biology, 146 (6), 1103-1109.
Stachowitsch, M., 1992b. Benthic communities: eutrophication's memory mode. In The Response of marine transitional systems to human impact: problems and perspectives for restoration Proceedings of an International Conferencee, Bologna, Italy, 21-24 March, 1990, (ed. R.A. Vollenweider, R. Marchetti, & R. Viviani), pp.1017-1028. Amsterdam: Elsevier.
Thompson, T.E., 1976. Biology of Opisthobranch Molluscs, vol. 1. London: The Ray Society.
Thompson, T.E., 1988. Molluscs: Benthic Opisthobranchs. London: Bath Press. [Synopses of the British Fauna New Series), (ed. Doris M. Kermack & R.S.K. Barnes), no. 8 (second Edition)].
Tillin, H. & Tyler-Walters, H., 2014b. 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. Available from: www.marlin.ac.uk/publications
Tuck, I.D., Hall, S.J., Robertson, M.R., Armstrong, E. & Basford, D.J., 1998. Effects of physical trawling disturbance in a previously unfished sheltered Scottish sea loch. Marine Ecology Progress Series, 162, 227-242.
Wilson, M.T., Andrews, A.H., Brown, A.L. & Cordes, E.E., 2002. Axial rod growth and age estimation of the sea pen, Halipteris willemoesi Kölliker Hydrobiologia, 471, 133-142.
Wright, J., Colling, A., Park, D. & Open University Oceanography Course Team, 2001. Waves, Tides, and Shallow-water Processes. Oxford: Butterworth-Heinemann.
This review can be cited as:
Last Updated: 28/01/2020
Tags: Slender sea pen seapen lobe shell