The Marine Life Information Network

Substratum loss

Benchmark. All of the substratum occupied by the species or biotope under consideration is removed. A single event is assumed for sensitivity assessment. Once the activity or event has stopped (or between regular events) suitable substratum remains or is deposited. Species or community recovery assumes that the substratum within the habitat preferences of the original species or community is present. Further details

Evidence

Pentapora foliacea is permanently attached to the seabed so substratum loss would result in death. Although being quite long-lived (10+ years) Pentapora fascialis is noted as having good reproductive and recolonization abilities, quite fast growth rates and gaining reproductive competency at an early stage (Cocito et al., 1998(b)). However, as the larval stage is potentially very short lived, dispersal distances may be limited (Keough & Chernoff, 1987). Local position of the adults can strongly affect the spatial pattern of larval settlement (Cocito et al 1998(b)). Following the almost total loss of a small population, Cocito et al., 1998(b)) recorded recovery and growth to original colony sizes taking only 3.5 years. In this case, reproductive adults remained nearby. If there are no remaining nearby adult populations then recovery may take much longer and so is assessed as moderate.

Smothering

Benchmark. All of the population of a species or an area of a biotope is smothered by sediment to a depth of 5 cm above the substratum for one month. Impermeable materials, such as concrete, oil, or tar, are likely to have a greater effect. Further details.

Evidence

Pentapora foliacea is permanently attached to the seabed and so would be unable to avoid smothering. Although colonies of this species may reach considerable heights (50 cm in the Mediterranean), the sheet-like-structure is likely to retain any smothering sediment. Smaller colonies may be entirely killed whereas larger colonies that protrude through the smothering layer may lose only part of the colony. Smothering by encrusting epibiotic species may also occur (Cocoito et al. (1998(a)) recorded epibionts present on 50 % of the area of study quadrats in the Mediterranean). Epibionts can cause partial mortality of colonies. This effect is size dependent - proportions affected by epibionts is greater in larger colonies. Although being quite long-lived (10+ years) Pentapora fascialis is noted as having good reproductive and recolonization abilities, quite fast growth rates and gaining reproductive competency at an early stage (Cocito et al., 1998(b)). However, as the larval stage is potentially very short lived, dispersal distances may be limited (Keough & Chernoff, 1987). Local position of the adults can strongly affect the spatial pattern of larval settlement (Cocito et al 1998(b)). Following the almost total loss of a small population, Cocito et al., 1998(b)) recorded recovery and growth to original colony sizes taking only 3.5 years. In this case, reproductive adults remained nearby. If there are no remaining nearby adult populations then recovery may take much longer. Some evidence is available regarding the ability of this species to repair damage to colonies by epibiont smothering by regrowth of new zooids and strengthening of the base by thickening of lower zooid walls (Hayward and Ryland, 1979).

Increase in suspended sediment

Benchmark. An arbitrary short-term, acute change in background suspended sediment concentration e.g., a change of 100 mg/l for one month. The resultant light attenuation effects are addressed under turbidity, and the effects of rapid settling out of suspended sediment are addressed under smothering. Further details

Evidence

Siltation has been recorded as causing partial colony mortality in populations of Pentapora fascialis in the Mediterranean. Increases in siltation rate may cause loss of part of a population. Although being quite long-lived (10+ years) Pentapora fascialis is noted as having good reproductive and recolonization abilities, quite fast growth rates and gaining reproductive competency at an early stage (Cocito et al., 1998(b)). However, as the larval stage is potentially very short lived, dispersal distances may be limited (Keough & Chernoff, 1987). Local position of the adults can strongly affect the spatial pattern of larval settlement (Cocito et al., 1998(b)). Following the almost total loss of a small population, Cocito et al., 1998(b)) recorded recovery and growth to original colony sizes taking only 3.5 years. In this case, reproductive adults remained nearby. If there are no remaining nearby adult populations then recovery may take much longer. Some evidence is available regarding the ability of this species to repair damage to colonies by siltation by regrowth of new zooids and strengthening of the base by thickening of lower zooid walls (Hayward and Ryland, 1979).

Decrease in suspended sediment

Benchmark. An arbitrary short-term, acute change in background suspended sediment concentration e.g., a change of 100 mg/l for one month. The resultant light attenuation effects are addressed under turbidity, and the effects of rapid settling out of suspended sediment are addressed under smothering. Further details

Evidence

Desiccation

1. A normally subtidal, demersal or pelagic species including intertidal migratory or under-boulder species is continuously exposed to air and sunshine for one hour.
2. A normally intertidal species or community is exposed to a change in desiccation equivalent to a change in position of one vertical biological zone on the shore, e.g., from upper eulittoral to the mid eulittoral or from sublittoral fringe to lower eulittoral for a period of one year. Further details.

Evidence

The species is entirely subtidal and exposure to desiccating influences is likely to cause death. Although being quite long-lived (10+ years) Pentapora fascialis is noted as having good reproductive and recolonization abilities, quite fast growth rates and gaining reproductive competency at an early stage (Cocito et al., 1998(b)). However, as the larval stage is potentially very short lived, dispersal distances may be limited (Keough & Chernoff, 1987). Local position of the adults can strongly affect the spatial pattern of larval settlement (Cocito et al., 1998(b)). Following the almost total loss of a small population, Cocito et al., 1998(b)) recorded recovery and growth to original colony sizes taking only 3.5 years. In this case, reproductive adults remained nearby. If there are no remaining nearby adult populations then recovery may take much longer and so is assessed as moderate.

Increase in emergence regime

Benchmark. A one hour change in the time covered or not covered by the sea for a period of one year. Further details

Evidence

The species is entirely subtidal and a period of emergence is likely to cause death. Although being quite long-lived (10+ years) Pentapora fascialis is noted as having good reproductive and recolonization abilities, quite fast growth rates and gaining reproductive competency at an early stage (Cocito et al., 1998(b)). However, as the larval stage is potentially very short lived, dispersal distances may be limited (Keough & Chernoff, 1987). Local position of the adults can strongly affect the spatial pattern of larval settlement (Cocito et al., 1998(b)). Following almost total loss of a small population, Cocito et al., 1998(b)) recorded recovery and growth to original colony sizes taking only 3.5 years. In this case, reproductive adults remained nearby. If there are no remaining nearby adult populations then recovery may take much longer.

Decrease in emergence regime

Benchmark. A one hour change in the time covered or not covered by the sea for a period of one year. Further details

Evidence

Increase in water flow rate

A change of two categories in water flow rate (view glossary) for 1 year, for example, from moderately strong (1-3 knots) to very weak (negligible). Further details

Evidence

The species inhabits environments with considerable water flow and is often found in areas scoured by sand. Decreases in water flow rate may interfere with feeding efficiency. Recovery of condition on the resumption of normal conditions should not take too long.

Decrease in water flow rate

A change of two categories in water flow rate (view glossary) for 1 year, for example, from moderately strong (1-3 knots) to very weak (negligible). Further details

Evidence

Increase in temperature

1. A short-term, acute change in temperature; e.g., a 5°C change in the temperature range for three consecutive days. This definition includes ‘short-term’ thermal discharges.
2. A long-term, chronic change in temperature; e.g. a 2°C change in the temperature range for a year. This definition includes ‘long term’ thermal discharges.

For intertidal species or communities, the range of temperatures includes the air temperature regime for that species or community. Further details

Evidence

Pentapora foliacea is found in warmer waters as far south the north coast of Morocco. The northernmost limits of the distribution are in the Minch off western Scotland. Once established, colonies are most likely able to withstand occasional lower or higher than normal temperatures, but long term decreases in temperature may cause distribution range to shrink. Although being quite long-lived (10+ years) Pentapora fascialis is noted as having good reproductive and recolonization abilities, quite fast growth rates and gaining reproductive competency at an early stage (Cocito et al., 1998(b)). However, as the larval stage is potentially very short lived, dispersal distances may be limited (Keough & Chernoff, 1987). Local position of the adults can strongly affect the spatial pattern of larval settlement (Cocito et al., 1998(b)). Following the almost total loss of a small population, Cocito et al., 1998(b)) recorded recovery and growth to original colony sizes taking only 3.5 years. In this case, reproductive adults remained nearby. If there are no remaining nearby adult populations then recovery may take much longer. Some evidence is available regarding the ability of this species to repair damage to the colony by regrowth of new zooids and strengthening of the base by thickening of lower zooid walls (Hayward and Ryland, 1979).

Decrease in temperature

1. A short-term, acute change in temperature; e.g., a 5°C change in the temperature range for three consecutive days. This definition includes ‘short-term’ thermal discharges.
2. A long-term, chronic change in temperature; e.g. a 2°C change in the temperature range for a year. This definition includes ‘long term’ thermal discharges.

For intertidal species or communities, the range of temperatures includes the air temperature regime for that species or community. Further details

Evidence

Increase in turbidity

1. A short-term, acute change; e.g., two categories of the water clarity scale (see glossary) for one month, such as from medium to extreme turbidity.
2. A long-term, chronic change; e.g., one category of the water clarity scale (see glossary) for one year, such as from low to medium turbidity. Further details

Evidence

The species has very low or no ability for visual perception and is unlikely to be sensitive to changes in turbidity.

Decrease in turbidity

1. A short-term, acute change; e.g., two categories of the water clarity scale (see glossary) for one month, such as from medium to extreme turbidity.
2. A long-term, chronic change; e.g., one category of the water clarity scale (see glossary) for one year, such as from low to medium turbidity. Further details

Evidence

Increase in wave exposure

A change of two ranks on the wave exposure scale (view glossary) e.g., from Exposed to Extremely exposed for a period of one year. Further details

Evidence

The species can occur in fairly exposed conditions. However, extreme wave action, as in storms, has been noted to cause widespread destruction of colonies (Cocito et al., 1998(a)). Therefore, increases in wave exposure may cause damage to colonies. Although being quite long-lived (10+ years) Pentapora fascialis is noted as having good reproductive and recolonization abilities, quite fast growth rates and gaining reproductive competency at an early stage (Cocito et al., 1998(b)). However, as the larval stage is potentially very short lived, dispersal distances may be limited (Keough & Chernoff, 1987). Local position of the adults can strongly affect the spatial pattern of larval settlement (Cocito et al., 1998(b)). Following the almost total loss of a small population, Cocito et al. (1998(b)) recorded recovery and growth to original colony sizes taking only 3.5 years. In this case, reproductive adults remained nearby. If there are no remaining nearby adult populations then recovery may take much longer. Some evidence is available regarding the ability of this species to repair damage to the colony by regrowth of new zooids and strengthening of the base by thickening of lower zooid walls (Hayward and Ryland, 1979).

Decrease in wave exposure

A change of two ranks on the wave exposure scale (view glossary) e.g., from Exposed to Extremely exposed for a period of one year. Further details

Evidence

Noise

1. Underwater noise levels e.g., the regular passing of a 30-metre trawler at 100 metres or a working cutter-suction transfer dredge at 100 metres for one month during important feeding or breeding periods.
2. Atmospheric noise levels e.g., the regular passing of a Boeing 737 passenger jet 300 metres overhead for one month during important feeding or breeding periods. Further details

Evidence

It is unlikely that Pentapora fascialis has a particular intolerance to noise vibrations.

Visual presence

Benchmark. The continuous presence for one month of moving objects not naturally found in the marine environment (e.g., boats, machinery, and humans) within the visual envelope of the species or community under consideration. Further details

Evidence

The species has very low or no ability for visual perception and is unlikely to be sensitive to changes in visual perception.

Abrasion & physical disturbance

Benchmark. Force equivalent to a standard scallop dredge landing on or being dragged across the organism. A single event is assumed for assessment. This factor includes mechanical interference, crushing, physical blows against, or rubbing and erosion of the organism or habitat of interest. Where trampling is relevant, the evidence and trampling intensity will be reported in the rationale. Further details.

Evidence

The 'leaves' of a Pentapora foliacea colony are highly calcified and brittle. Physical abrasion can easily cause damage. Pentapora foliacea is noted as being tolerant of regular medium intensity disturbances (such as winter storms) but low frequency, high intensity disturbances such as freak storms cause mortality, particularly in shallower waters (Cocito et al., 1998(b)). The effects of diver frequentation have been monitored for Pentapora fascialis populations in the Mediterranean (Sala et al., 1996). Areas with heavy diving activity have greatly reduced densities of Pentapora fascialis and remaining colonies are frequently smaller and highly damaged. Colonies only survive in more protected locations such as under overhangs. In addition, Pentapora foliacea was reported to be damaged by scallop dredges and mobile fishing gear, pots and creels (Bullimore, 1985; DWT, 1993; Eno et al., 1996). Mobile gears also result in modification of the substratum, including removal of shell debris, cobbles and rocks, and the movement of boulders (Bullimore, 1985; Jennings & Kaiser, 1998). Therefore, intolerance has been assessed as high.

Although being quite long-lived (10+ years) Pentapora fascialis is noted as having good reproductive and recolonization abilities, quite fast growth rates and gaining reproductive competency at an early stage (Cocito et al., 1998b). However, as the larval stage is potentially very short lived, dispersal distances may be limited (Keough & Chernoff, 1987). Local position of the adults can strongly affect the spatial pattern of larval settlement (Cocito et al., 1998b). Following almost total loss of a small population, Cocito et al., 1998b) recorded recovery and growth to original colony sizes taking only 3.5 years. In this case, reproductive adults remained nearby. If there are no remaining nearby adult populations then recovery may take much longer.

Displacement

Benchmark. Removal of the organism from the substratum and displacement from its original position onto a suitable substratum. A single event is assumed for assessment. Further details

Evidence

The colonies of Pentapora fascialis are permanently attached to the substratum. If displaced, the colony in not able to reform the attachment and death occurs. No information is available regarding the reproduction or dispersal abilities of this species so no assessment of recoverability can be made. However, the species may be quite long lived (10+ years) and slow growing (2 cm per year). Following loss of a population, growth to original colony sizes, after recolonization, may take some years.

Synthetic compound contamination

Sensitivity is assessed against the available evidence for the effects of contaminants on the species (or closely related species at low confidence) or community of interest. For example:

• evidence of mass mortality of a population of the species or community of interest (either short or long term) in response to a contaminant will be ranked as high sensitivity;
• evidence of reduced abundance, or extent of a population of the species or community of interest (either short or long term) in response to a contaminant will be ranked as intermediate sensitivity;
• evidence of sub-lethal effects or reduced reproductive potential of a population of the species or community of interest will be assessed as low sensitivity.

The evidence used is stated in the rationale. Where the assessment can be based on a known activity then this is stated. The tolerance to contaminants of species of interest will be included in the rationale when available; together with relevant supporting material. Further details.

Evidence

Insufficient
information

Heavy metal contamination

Evidence

Insufficient
information

Hydrocarbon contamination

Evidence

Insufficient
information

Radionuclide contamination

Evidence

Insufficient
information

Changes in nutrient levels

Evidence

Insufficient
information

Increase in salinity

1. A short-term, acute change; e.g., a change of two categories from the MNCR salinity scale for one week (view glossary) such as from full to reduced.
2. A long-term, chronic change; e.g., a change of one category from the MNCR salinity scale for one year (view glossary) such as from reduced to low. Further details.

Evidence

The species only inhabits fully saline waters (Patzold et al., 1987) and exposure to salinity conditions outside of this range would probably result in death. Although being quite long-lived (10+ years) Pentapora fascialis is noted as having good reproductive and recolonization abilities, quite fast growth rates and gaining reproductive competency at an early stage (Cocito et al., 1998(b)). However, as the larval stage is potentially very short lived, dispersal distances may be limited (Keough & Chernoff, 1987). Local position of the adults can strongly affect the spatial pattern of larval settlement (Cocito et al., 1998(b)). Following the almost total loss of a small population, Cocito et al., 1998(b)) recorded recovery and growth to original colony sizes taking only 3.5 years. In this case, reproductive adults remained nearby. If there are no remaining nearby adult populations, as is likely with changes in salinity, then recovery may take much longer.

Decrease in salinity

1. A short-term, acute change; e.g., a change of two categories from the MNCR salinity scale for one week (view glossary) such as from full to reduced.
2. A long-term, chronic change; e.g., a change of one category from the MNCR salinity scale for one year (view glossary) such as from reduced to low. Further details.

Evidence

Changes in oxygenation

Benchmark.  Exposure to a dissolved oxygen concentration of 2 mg/l for one week. Further details.

Evidence

There is no information regarding the tolerance of Pentapora fascialis to changes in oxygen concentration. However, Cole et al., (1999) suggest possible adverse effects on marine species below 4 mg/l and probable adverse effects below 2mg/l. Although being quite long-lived (10+ years) Pentapora fascialis is noted as having good reproductive and recolonization abilities, quite fast growth rates and gaining reproductive competency at an early stage (Cocito et al., 1998(b)). However, as the larval stage is potentially very short lived, dispersal distances may be limited (Keough & Chernoff, 1987). Local position of the adults can strongly affect the spatial pattern of larval settlement (Cocito et al., 1998(b)). Following almost total loss of a small population, Cocito et al., 1998(b)) recorded recovery and growth to original colony sizes taking only 3.5 years. In this case, reproductive adults remained nearby. If there are no remaining nearby adult populations then recovery may take much longer. Some evidence is available regarding the ability of this species to repair damage to the colony by regrowth of new zooids and strengthening of the base by thickening of lower zooid walls (Hayward and Ryland, 1979).

Introduction of microbial pathogens/parasites

Benchmark. Sensitivity can only be assessed relative to a known, named disease, likely to cause partial loss of a species population or community. Further details.

Evidence

Insufficient
information

Introduction of non-native species

Sensitivity assessed against the likely effect of the introduction of alien or non-native species in Britain or Ireland. Further details.

Evidence

Insufficient
information

Extraction of this species

Benchmark. Extraction removes 50% of the species or community from the area under consideration. Sensitivity will be assessed as 'intermediate'. The habitat remains intact or recovers rapidly. Any effects of the extraction process on the habitat itself are addressed under other factors, e.g. displacement, abrasion and physical disturbance, and substratum loss. Further details.

Evidence

The species has no commercial value (Sala et al., 1996) and is highly unlikely to be extracted.

Extraction of other species

Benchmark. A species that is a required host or prey for the species under consideration (and assuming that no alternative host exists) or a keystone species in a biotope is removed. Any effects of the extraction process on the habitat itself are addressed under other factors, e.g. displacement, abrasion and physical disturbance, and substratum loss. Further details.

Evidence

Pentapora fascialis has no known obligate relationships. Extraction of other species is not likely to have any effect on Pentapora fascialis colonies.