The Marine Life Information Network

Temperature increase (local)

Benchmark. A 5°C increase in temperature for one month, or 2°C for one year. Further detail

Evidence

No direct evidence was found on the effect of changes in local temperature at the benchmark level on the biotope. The only evidence found on the temperature range of the biotope was from Graves (in prep). This study predicted the distribution of Caryophyllia smithii and Actinauge richardi across the UK and Irish waters using habitat suitability modelling. From their biotope distribution data, Graves (in prep) characterized the thermal niche of Caryophyllia smithii and Actinauge richardi assemblages across the UK and Ireland as 7.38 to 9.38°C.

Caryophyllia smithii is found throughout the UK and has been recorded in Greece (Koukouras, 2010). It is therefore unlikely to be significantly affected by an increase in temperature at the benchmark level. Caroselli et al. (2017) reported that over one year, Caryophyllia inornata – a species similar to Caryophyllia smithii – was exposed to temperatures ranging from 11.8-22.8°C in Elba Sands (northwest Mediterranean Sea). However, Tranter et al. (1982) suggested Caryophyllia smithii reproduction was cued by seasonal increases in seawater temperature. Although, it is worth noting this observation was made in aquaria using individuals collected within Plymouth Sound (coastal) and were not from deeper waters. Nonetheless, it may still be that unseasonal increases in temperature may disrupt natural reproductive processes and negatively influence recruitment patterns.

No direct evidence was found on Actinauge richardi sensitivity to changes in local temperature. However, the distribution of Actinauge richardi is large, from Norway to Western Africa and across the Mediterranean Sea, as well as occupying a wide depth range (70-2,000 m). It is therefore likely that Actinauge richardi also occupies a relatively wide thermal niche. Within UK waters, Gates et al. (2019) reported the presence of Actinauge richardi on the protective structures of wellheads in the North Sea at a temperature of 10.32°C.

It is worth noting that this biotope occurs at the deeper end of the two species’ distribution (200-1,100 m), particularly Caryophyllia smithii. Although the temperature of deeper waters tends to be less variable, the biotope is distributed within the permanent thermocline, 600-1000 m (White & Dorschel, 2010) and will, therefore, still experience some seasonal temperature variations.

Sensitivity assessment. It is unlikely that Caryophyllia smithii and Actinauge richardi will be significantly impacted by an increase in temperature at the benchmark level. Therefore, resistance has been assessed as ‘High’, resilience assessed as ‘High’ and sensitivity assessed as ‘Not sensitive’.

Temperature decrease (local)

Benchmark. A 5°C decrease in temperature for one month, or 2°C for one year. Further detail

Evidence

No direct evidence was found on the effect of changes in local temperature at the benchmark level on the biotope. The only evidence found on the temperature range of the biotope was from Graves (in prep). This study predicted the distribution of Caryophyllia smithii and Actinauge richardi across the UK and Irish waters using habitat suitability modelling. From their biotope distribution data, Graves (in prep) characterized the thermal niche of Caryophyllia smithii and Actinauge richardi assemblages across the UK and Ireland as 7.38-9.38°C.

Caryophyllia smithii is found throughout the UK and has been recorded in Greece (Koukouras, 2010), at a maximum depth of 1,100 m. At the depth distribution of this biotope (200-1,100 m), Caryophyllia smithii is likely at the very lower limit of its temperature range. Therefore, a decrease in temperature at the benchmark level may cause mortality in Caryophyllia richardi.

No direct evidence was found on Actinauge richardi sensitivity to changes in local temperature. The distribution of Actinauge richardi is vast, from Norway to Western Africa and across the Mediterranean Sea, as well as occupying a wide depth range (70-2,000 m). It is therefore likely that Actinauge richardi also occupies a relatively wide thermal niche. Within UK waters, Gates et al. (2019) reported the presence of Actinauge richardi on the protective structures of wellheads in the North Sea at a temperature of 10.32°C.

Sensitivity assessment. A decrease in temperature at the benchmark level may cause mortality in Caryophyllia richardi. Although it is likely Actinauge richardi would be unaffected, the mortality of Caryophyllia smithii would result in the loss of a characterizing feature. Therefore, resistance has been assessed as ‘Low’, resilience assessed as ‘Medium’ and sensitivity assessed as ‘Medium’.

Salinity increase (local)

Benchmark. A increase in one MNCR salinity category above the usual range of the biotope or habitat. Further detail

Evidence

Caryophyllia smithii has a large depth distribution, from the intertidal, down to 1,100 m. Caryophyllia smithii has been reported in deep rock pools so is likely to have some tolerance to changes in salinity. However, Actinauge richardi is distributed between 70-2,000 m. In the North-East Atlantic, these depths are characterized by full salinity (30-35 psu). At these depths, Actinauge richardi is unlikely to experience natural changes in salinity.

Sensitivity assessment. Due to the relatively stable salinity conditions that Actinauge richardi, as a species, and the wider biotope occurs, a change in salinity due to human activities may cause mortality in Actinauge richardi. Therefore, resistance is assessed as ‘Low’, resilience assessed as ‘Medium’ and overall sensitivity as ‘Medium’.

Salinity decrease (local)

Benchmark. A decrease in one MNCR salinity category above the usual range of the biotope or habitat. Further detail

Evidence

Caryophyllia smithii has a large depth distribution, from the intertidal, down to 1,100 m. Caryophyllia smithii has been reported in deep rock pools so is likely to have some tolerance to changes in salinity. However, Actinauge richardi is distributed between 70-2,000 m. In the North-East Atlantic, these depths are characterized by full salinity (30-35 psu). At these depths, Actinauge richardi is unlikely to experience natural changes in salinity.

Sensitivity assessment. Due to the relatively stable salinity conditions that Actinauge richardi, as a species, and the wider biotope occurs in, a change in salinity due to human activities may cause mortality in Actinauge richardi. Therefore, resistance is assessed as ‘Low’, resilience assessed as ‘Medium’ and overall sensitivity as ‘Medium’.

Water flow (tidal current) changes (local)

Benchmark. A change in peak mean spring bed flow velocity of between 0.1 m/s to 0.2 m/s for more than one year. Further detail

Evidence

Caryophyllia smithii has been observed in the North Sea where the residual current speeds are between 0.02-0.08 m/s (Coolen et al., 2015). In a coastal setting, Caryophyllia smithii has also been reported by Bell & Turner (2000) to occur in areas of current speeds of up to 3.0 m/s at Whirlpool Cliff, Lough Hyne Marine Nature Reserve (Co. Cork, Ireland).

No evidence was found for Actinauge richardi resistance to changes in water flow, although it will have an impact. Current speeds that are too fast will cause the individuals to withdraw (reducing the ability to feed), and they may be severely damaged or dislodged. As a suspension feeder, if current speeds are too slow, the number of food particles delivered will be reduced. The coarse substrata that this biotope occurs on suggest that local currents must be relatively high compared to other substrata types, such as mud. In addition, Urra et al. (2021) reported that in the Gulf of Cadiz (Southern Spain and Portugal), Actinauge richardi occurs on rippled sand – an indicator of strong bottom currents. Furthermore, Urra et al. (2021) suggest that oceanographic, as well as trophic drivers, determine the spatial distribution of Actinauge richardi.

The change in water flow is most likely to have a bigger impact on the sediment, which characterizes the biotope, than the species alone. Although no direct evidence of current flow has been found, water flow in a suitable biotope habitat is likely to be between 0.1 and 1.0 m/s, based on the characteristic coarse sediment of the biotope and the Hjulstrom-Sundborg diagram (Earle, 2019).  Furthermore, this is more likely to be nearer the 1.0 m/s than 0.1 m/s given that the biotope is found at the Wyville Thomson Ridge – a bathymetric feature associated with high-energy currents (JNCC, 2010). Therefore, an increase in tidal flow at the benchmark will likely not affect the biotope. An increase in water flow will likely introduce more gravel and, therefore, increase the available suitable substrata for Caryophyllia smithii to settle. A decrease at the benchmark is also not likely to affect the biotope. Although a decrease will likely see an increase in coarse sand, gravel is still likely to remain.

Sensitivity assessment. A change in water flow at the benchmark is unlikely to affect the biotope. An increase or decrease in water current speed is not likely to change the substrata that characterize this biotope, and the habitat will remain suitable. It is also unlikely to adversely affect the characterizing species, Caryophyllia smithii or Actinauge richardi, themselves. Therefore, resistance is assessed as ‘High’ and resilience is assessed as ‘High’. This results in an overall sensitivity assessment of ‘Not sensitive’ at the benchmark level.  

Emergence regime changes

Benchmark.  1) A change in the time covered or not covered by the sea for a period of ≥1 year or 2) an increase in relative sea level or decrease in high water level for ≥1 year. Further detail

Evidence

Caryophyllia smithii and Actinauge richardi assemblages are found at upper bathyal depths; therefore, they will not be impacted by a change in emergence. As a result, this pressure is assessed as ‘Not relevant’.

Wave exposure changes (local)

Benchmark. A change in near shore significant wave height of >3% but <5% for more than one year. Further detail

Evidence

Caryophyllia smithii and Actinauge richardi assemblages are found at upper bathyal depths, therefore, they will not be impacted by wave exposure. As a result, this pressure is assessed as ‘Not relevant’.

Transition elements & organo-metal contamination

Benchmark. Exposure of marine species or habitat to one or more relevant contaminants via uncontrolled releases or incidental spills. Further detail

Evidence

Not assessed.

Hydrocarbon & PAH contamination

Benchmark. Exposure of marine species or habitat to one or more relevant contaminants via uncontrolled releases or incidental spills. Further detail

Evidence

Not assessed.

Synthetic compound contamination

Benchmark. Exposure of marine species or habitat to one or more relevant contaminants via uncontrolled releases or incidental spills. Further detail

Evidence

Not assessed.

Radionuclide contamination

Benchmark. An increase in 10µGy/h above background levels. Further detail

Evidence

 ‘No evidence’ was found.

Introduction of other substances

Benchmark. Exposure of marine species or habitat to one or more relevant contaminants via uncontrolled releases or incidental spills. Further detail

Evidence

Not assessed.

De-oxygenation

Benchmark. Exposure to dissolved oxygen concentration of less than or equal to 2 mg/l for one week (a change from WFD poor status to bad status). Further detail

Evidence

Limited direct evidence is currently available for the effect of dissolved oxygen concentration on either characterizing species. Bell (2002) reported that an oxycline at Lough Hyne (<5% surface concentration) limited vertical colonization by Caryophyllia smithii.  In addition, Hiscock & Hoare (1975) reported that Caryophyllia smithii was excluded from Abereiddy Quarry (Pembrokeshire) below 12 m, where oxygen levels fell below 5% saturation (ca 0.5 mg/l) in summer.

In general, respiration in most marine invertebrates does not appear to be significantly affected until very low concentrations of dissolved oxygen are reached. For many benthic invertebrates, this concentration is approximately 2 ml/l (ca 2.66 mg/l) (Herreid, 1980; Rosenberg et al., 1991; Diaz & Rosenberg, 1995). Cole et al. (1999) suggest possible adverse effects on marine species below 4 mg/l and probable adverse effects below 2 mg/l.

Sensitivity assessment. The characterizing species, Caryophyllia smithii and Actinauge richardi, of this biotope, may be affected by hypoxic events. Therefore, resistance is assessed as ‘Low’ and resilience assessed as ‘Medium’, resulting in an overall sensitivity score of ‘Medium’.

Nutrient enrichment

Benchmark. Compliance with WFD criteria for good status. Further detail

Evidence

Nutrient availability will be important to Caryophyllia smithii and Actinauge richardi, however, no evidence was found on the effect of nutrient enrichment on the biotope. Therefore, this pressure is recorded as ‘No evidence’.

Organic enrichment

Benchmark. A deposit of 100 gC/m²/yr. Further detail

Evidence

Particulate organic matter (POM) is a food source for Caryophyllia smithii and Actinauge richardi as passive suspension feeders. However, no evidence was found on the effect of organic enrichment at the level of the benchmark on Caryophyllia smithii and Actinauge richardi. Therefore, ‘No evidence’ is recorded.

Physical loss (to land or freshwater habitat)

Benchmark. A permanent loss of existing saline habitat within the site. Further detail

Evidence

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 available habitat (resilience is ‘Very low’). Caryophyllia smithii and Actinauge richardi assemblages are, therefore, considered to have ‘High’ sensitivity to this pressure.

Physical change (to another seabed type)

Benchmark. Permanent change from sedimentary or soft rock substrata to hard rock or artificial substrata or vice-versa. Further detail

Evidence

The larvae of Caryophyllia smithii require hard substrata for settlement, the absence of which makes the habitat unsuitable. The coarse substrata on which the biotope occurs is reliant upon the gravel within the gravelly sand, as it is this that larvae settle on.

Sensitivity assessment. This biotope occurs only on coarse sediments, not on rock (soft or hard) or artificial substrata. As a specific sediment type defines the biotope, a change in seabed type will result in a change in the biotope classification and, therefore, the loss of the original biotope. Therefore, resistance is assessed as ‘None’, resilience as ‘Very low’ and overall sensitivity as ‘High’.

Physical change (to another sediment type)

Benchmark. Permanent change in one Folk class (based on UK SeaMap simplified classification). Further detail

Evidence

The larvae of Caryophyllia smithii require hard substrata for settlement, the absence of which makes the habitat unsuitable. The coarse substrata on which the biotope occurs is reliant upon the gravel within the gravelly sand, as this is what the larvae settle on.

Sensitivity assessment. This biotope occurs only on coarse sediments. As a specific sediment type defines the biotope, a change in sediment type will result in a change in the biotope classification and therefore the loss of the original biotope. In addition, a change from gravelly sand to another sediment type, e.g. sand or mud, would make the habitat unsuitable for Caryophyllia. Therefore, resistance is assessed as ‘None’, resilience as ‘Very low’ and overall sensitivity as ‘High’.

Habitat structure changes - removal of substratum (extraction)

Benchmark. The extraction of substratum to 30 cm (where substratum includes sediments and soft rock but excludes hard bedrock). Further detail

Evidence

As Caryophyllia smithii and Actinauge richardi assemblages are characterized by sessile species, removal of the substratum at the benchmark level would destroy the biotope within the affected area. Therefore, the resistance of Caryophyllia smithii and Actinauge richardi assemblage is assessed as ‘None’, resilience as ‘Medium’ and overall sensitivity to the pressure is assessed as ‘Medium’.

Abrasion / disturbance of the surface of the substratum or seabed

Benchmark. Damage to surface features (e.g. species and physical structures within the habitat). Further detail

Evidence

The main sources of potential abrasion and disturbance relevant to Caryophyllia smithii and Actinauge richardi are from bottom fishing (e.g. beam trawls), deep-sea mining activity (e.g. mining vehicles) and from anchoring or positioning of offshore structures. No evidence was found of the direct impacts of abrasion on Caryophyllia smithii or Actinauge richardi. However, it is likely that bottom-fishing activities, e.g. trawling, would cause significant damage to both of the characterizing biotope species, particularly Actinauge richardi, which is soft-bodied. There is evidence from bycatch and scientific trawl data that both Caryophyllia smithii and Actinauge richardi are removed by bottom-trawling gear (Castro et al., 2012; Ordonez-Del Pazo et al., 2014; Terribilie et al., 2016; Waller et al., 2005).

Sensitivity assessment. No direct experimental studies on the effects of abrasion on Caryophyllia smithii and Actinauge richardi assemblages are available. However, comparative studies between disturbed and undisturbed areas indicate that abrasion and disturbance from bottom trawling on coarse gravels and sands, reduce the abundance of organisms, biomass and species diversity (Collie et al., 1997; Bradshaw et al., 2000).  In addition, evidence that both of the characteristic species are removed as bycatch suggests that trawling may result in significant damage.  Therefore, resistance is assessed as ‘Low’, resilience as ‘Medium’, and overall sensitivity is assessed as ‘Medium.’ 

Penetration or disturbance of the substratum subsurface

Benchmark. Damage to sub-surface features (e.g. species and physical structures within the habitat). Further detail

Evidence

Penetration and or disturbance of the substratum would result in similar, if not identical, results as abrasion or removal of Caryophyllia smithii and Actinauge richardi assemblages (see abrasion/disturbance).

Sensitivity assessment. A resistance of ‘Low’ has been suggested.  If the substratum were penetrated or disturbed, the overlying biotope would be significantly affected. Therefore, resilience has been assessed as ‘Medium’ resulting in sensitivity being ‘Medium’.

Changes in suspended solids (water clarity)

Benchmark. A change in one rank on the WFD (Water Framework Directive) scale e.g. from clear to intermediate for one year. Further detail

Evidence

Bell & Turner (2000) studied populations of Caryophyllia smithii at three sites of differing sedimentation regimes in Lough Hyne, Ireland. Calyx size was largest at the site of least sedimentation and smallest at the site of most sedimentation. In contrast, the height of individuals was greatest at the site of most sedimentation and smallest at the site of least sedimentation. The height of individuals correlated with the level of surrounding sediment. High density correlated with high sedimentation (Bell & Turner, 2000). Furthermore, Farrow et al. (1983) suggested that Caryophyllia smithii is ‘remarkably tolerant of high turbidity’ after it was found in a highly turbid fjord, Knight Inlet, in British Columbia. 

While siltation may inhibit the feeding of Actinauge richardi, the species has been reported by Gates et al. (2019) to colonize the protective structures of wellheads in the North Sea. Between the deployment and recovery of protective structures, drilling continued. During that period, Actinauge richardi colonized the structure and continued to persist. This suggests that Actinauge richardi has some resistance to periodic increases in suspended solids, i.e. drill cuttings.

Sensitivity assessment. From the limiting evidence available, the characterizing species of this biotope are likely to tolerate a change in suspended solids at the benchmark level. Resistance is assessed at ‘High’, resilience is assessed as ‘High’, giving an overall sensitivity of ‘Not sensitive’. 

Smothering and siltation rate changes (light)

Benchmark. ‘Light’ deposition of up to 5 cm of fine material added to the seabed in a single discrete event. Further detail

Evidence

Caryophyllia smithii is small (approx. 3 cm height) and would therefore likely be inundated in a 'light' sedimentation event. However, Bell & Turner (2000) reported Caryophyllia smithii was abundant at sites of 'moderate' sedimentation (7 mm ± 0.5 mm) in Lough Hyne. It is therefore likely that Caryophyllia smithii would be resistant to periodic sedimentation. If 5 cm of sediment were removed rapidly, via tidal currents, Caryophyllia smithii would likely remain within the biotope.  Burton et al. (2010) partly attributed fluctuations in Caryophyllia smithii abundance at Skomer Island to surface sediment cover.  Bell (2002) reported that juvenile Caryophyllia smithii are morphologically variable and initially undergo rapid growth with tall and thin forms in deeper, sheltered, relatively sedimented conditions near Lough Hyne, Ireland.  It was concluded that this was to escape the thin layer of sediment present.  Hiscock & Howlett (1976) reported that Caryophyllia smithii is sediment-tolerant because of its efficient sediment removal mechanisms.

No direct evidence was available on the effects of smothering and siltation on Actinauge richardi. However, the study by Durán-Fuentes et al. (2022) suggests that some anemone species are tolerant to high sedimentation. In their study, they found that at least four species of anemone occupy the area proximal to the Maddalena River mouth (Columbian Caribbean), and therefore experience high turbidity and sedimentation (143.9x10⁶ t per year). Actinauge richardi can likely withstand sedimentation at the benchmark level, particularly if the sediment is quickly removed, e.g. by tidal currents, and the biotope would remain, especially as Actinauge richardi can withdraw and protect its feeding apparatus.

Sensitivity assessment. With the limited available evidence, the biotope may not be significantly impacted at the benchmark level. Therefore, resistance is assessed as ‘High’ and resilience assessed as ‘High’, resulting in an overall sensitivity score of ‘Not sensitive’.

Smothering and siltation rate changes (heavy)

Benchmark. ‘Heavy’ deposition of up to 30 cm of fine material added to the seabed in a single discrete event. Further detail

Evidence

Caryophyllia smithii is small (approx. 3 cm height) and would therefore likely be inundated in a 'light' sedimentation event. However, Bell & Turner (2000) reported Caryophyllia smithii was abundant at sites of 'moderate' sedimentation (7 mm ± 0.5 mm) in Lough Hyne. It is therefore likely that Caryophyllia smithii would be resistant to periodic sedimentation. If 5 cm of sediment were removed rapidly, via tidal currents, Caryophyllia smithii would likely remain within the biotope.  Burton et al. (2010) partly attributed fluctuations in Caryophyllia smithii abundance at Skomer Island to surface sediment cover.  Bell (2002) reported that juvenile Caryophyllia smithii are morphologically variable and initially undergo rapid growth with tall and thin forms in deeper, sheltered, relatively sedimented conditions near Lough Hyne, Ireland.  It was concluded that this was to escape the thin layer of sediment present.  Hiscock & Howlett (1976) said that Caryophyllia smithii is sediment-tolerant because of its efficient sediment removal mechanisms.

No direct evidence is available on the effects of smothering and siltation on Actinauge richardi. However, the study by Durán-Fuentes et al. (2022) suggests that some anemone species are tolerant to high sedimentation. In their study, they found that at least four species of anemone occupy the area proximal to the Maddalena River mouth (Columbian Caribbean) and, therefore, experience high turbidity and sedimentation (143.9x10⁶ t per year).

Sensitivity assessment. Smothering by 30 cm of sediment will completely bury both Caryophyllia smithii and Actinauge richardi because of their small size. As this biotope is not characterized by fast tidal currents, it is also unlikely that the sediment will be quickly removed. It is therefore likely that the characterizing species will suffocate and/or starve.  As a result, resistance is assessed as ‘None’ and resilience assessed as ‘Medium’, giving an overall sensitivity score of ‘Medium’.

Litter

Benchmark. The introduction of man-made objects able to cause physical harm (surface, water column, seafloor or strandline). Further detail

Evidence

Actinauge richardi was observed in the Northern Tyrrhenian Sea (Italy) with a plastic bag incorporated into its basal disc (Macini et al., 2021).  However, this pressure is ‘Not assessed’.

Electromagnetic changes

Benchmark. A local electric field of 1 V/m or a local magnetic field of 10 µT. Further detail

Evidence

‘No evidence’ was found.

Underwater noise changes

Benchmark. MSFD indicator levels (SEL or peak SPL) exceeded for 20% of days in a calendar year. Further detail

Evidence

Whilst no evidence could be found on the effects of noise or vibrations on the characterizing species, it is unlikely that these species would be adversely affected by noise. This pressure ‘Not relevant’.

Introduction of light or shading

Benchmark. A change in incident light via anthropogenic means. Further detail

Evidence

Whilst no evidence could be found for the effect of light on the characterizing species of these biotopes, it is unlikely that these species would be impacted.  Although the biotope is characterized as ‘deep sea’, both of the characterizing species are found within the photic zone (< 200 m) independent of this biotope. If anthropogenic light, e.g. from oil and gas drilling or mining machinery, was introduced to the biotope, the characterizing species would not be detrimentally affected. Therefore, resistance to this pressure is assessed as 'High' and resilience as 'High'. This biotope is therefore considered to be 'Not sensitive' at the benchmark level.

Barrier to species movement

Benchmark. A permanent or temporary barrier to species movement over ≥50% of water body width or a 10% change in tidal excursion. Further detail

Evidence

Caryophyllia smithii and Actinauge richardi have a planktonic larval stage and therefore connectivity and recruitment could be affected by a permanent or temporary barrier to propagule dispersal. However, ‘No evidence is available to assess this pressure.

Death or injury by collision

Benchmark. Injury or mortality from collisions of biota with both static or moving structures due to 0.1% of tidal volume on an average tide, passing through an artificial structure. Further detail

Evidence

Caryophyllia smithii and Actinauge richardi assemblages are characterized by sessile invertebrates in deep water and are unlikely to be affected by an increased risk of collision as defined under the pressure. This pressure is therefore assessed as ‘Not relevant’.

Visual disturbance

Benchmark. The daily duration of transient visual cues exceeds 10% of the period of site occupancy by the feature. Further detail

Evidence

Caryophyllia smithii and Actinauge richardi assemblages are characterized by invertebrates that are not reliant on vision, as such, the biotope will not be affected by 'Visual disturbance'. This pressure is assessed as ‘Not relevant’.

Genetic modification & translocation of indigenous species

Benchmark. Translocation of indigenous species or the introduction of genetically modified or genetically different populations of indigenous species that may result in changes in the genetic structure of local populations, hybridization, or change in community structure. Further detail

Evidence

This pressure is not relevant to the characterizing species within this biotope. Therefore, an assessment of ‘Not relevant’ is recorded.

Introduction or spread of invasive non-indigenous species

Benchmark. The introduction of one or more invasive non-indigenous species (INIS). Further detail

Evidence

No alien or non-native species are known to compete with Caryophyllia smithii nor Actinauge richardi at upper bathyal depths.  As a result, this pressure is recorded as ‘Not relevant’.

Introduction of microbial pathogens

Benchmark. The introduction of relevant microbial pathogens or metazoan disease vectors to an area where they are currently not present (e.g. Martelia refringens and Bonamia, Avian influenza virus, viral Haemorrhagic Septicaemia virus). Further detail

Evidence

‘No evidence’ was found on diseases that may affect either of the characterizing species.

Removal of target species

Benchmark. Removal of species targeted by fishery, shellfishery or harvesting at a commercial or recreational scale. Further detail

Evidence

The characterizing species associated with the biotope are not commercially targeted. Therefore, this pressure is assessed as ‘Not relevant’.

Removal of non-target species

Benchmark. Removal of features or incidental non-targeted catch (by-catch) through targeted fishery, shellfishery or harvesting at a commercial or recreational scale. Further detail

Evidence

Although direct evidence was not found for Caryophyllia smithii, other Caryophyllidae solitary corals (Caryophyllia ambrosia, Caryophyllia cornuformis, Caryophyllia sequenzae) of similar size and morphology have been recorded in scientific trawls (Waller et al., 2005). Direct evidence is available for Actinauge richardi, which has been widely recorded in commercial trawl bycatch (Castro et al., 2012; Ordonez-Del Pazo et al., 2014) and scientific trawls (Terribilie et al., 2016).

Sensitivity assessment. The available evidence suggests that bottom-trawling activity readily removes the characterizing species of this biotope. Therefore, resistance is assessed as ‘Low’ and resilience as ‘Medium’, resulting in an overall sensitivity assessment of ‘Medium’.