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

As Funiculina quadrangularis lives in the substratum, substratum loss will lead to loss of the population. Therefore, intolerance has been recorded as high.
A recoverability of low has been recorded, thus sensitivity is assessed as high (see additional information below).

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

Smothering would be expected to be caused by high levels of siltation. Funiculina quadrangularis is very tall and would protrude above the sediment, therefore an intolerance of low as been recorded. Recoverability would be expected to be immediate, therefore the species is assessed as not sensitive.

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

The effect of an increased deposit of fine silt is unclear but it is possible that feeding structures may become clogged (Jones et al., 2000). Kinnear et al. (1996) found that mud particles adhering to Funiculina quadrangularis were quickly removed due to large amounts of mucus produced. Also, an increase in suspended sediment may provide an increase in food availiabity for Funiculina quadrangularis. Therefore an intolerance of low has been recorded. Recovery on return to normal conditions is likely to be immediate, therefore the species is assessed as not sensitive.

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

The effects of a decrease in suspended sediment levels are unclear. It is possible that this factor may reduce the amount of particulate matter available as food for Funiculina quadrangularis, which may affect viability but is unlikely to be fatal at the level of the benchmark. Therefore an intolerance of low has been recorded. Recovery on return to normal conditions is likely to be immediate, therefore the species is assessed as not sensitive.

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

Funiculina quadrangularis is a sub-tidal species and is therefore likely to be highly intolerant of desiccation. However, the species is found in the circalittoral zone (below 20 m) where desiccation is unlikely to occur, so not relevant has been recorded.

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

Funiculina quadrangularis is a sub-tidal species and is therefore likely to be highly intolerant of emergence. However, the species is found in the circalittoral zone (below 20 m) where any emergence is highly unlikely to occur, so not relevant has been recorded.

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

Funiculina quadrangularis is a sub-tidal species and is therefore likely to be highly intolerant of emergence. However, the species is found in the circalittoral zone (below 20 m) where any emergence is highly unlikely to occur, so not relevant has been recorded.

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

Areas where Funiculina quadrangularis is found tend to be physically sheltered with low or very low water flow rates. No information was found about effects of increased water flow rate on Funiculina quadrangularis. However, experiments on another sea pen (Virgularia mirabilis) showed that, as water flow increased, the polyps faced away from the current to face downstream. Increasing current led to the stalk bending over and the pinnae becoming pushed together, which may result in feeding inhibition. Eventually the sea pen withdrew into the sediment (Hiscock, 1983). Furthermore, Funiculina quadrangularis is large with a short peduncle and increased flow may drag the sea pen out of the sediment. If feeding was inhibited, or if the sea pen was displaced for an excessive amount of time, survival and distribution of Funiculina quadrangularis may be affected (Hiscock, 1983). Therefore intolerance has been recorded as high.
A recoverability of low has been recorded, resulting in a high sensitivity recording (see additional information below).

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

Areas where Funiculina quadrangularis is found tend to be physically sheltered with low or very low water flow rates, however, as this sea pen is a suspension feeder a decrease in water flow rate may effect feeding. Therefore an intolerance of intermediate has been recorded.
A recoverability of moderate has been recorded, hence sensitivity is moderate (see additional information below).

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

No information was found of the upper or lower thermal limits of Funiculina quadrangularis. Funiculina quadrangularis occurs in thermally stable conditions, with annual temperature variation between 5 - 15°C (Jones et al., 2001). This species is subtidal where wide variations in temperature are not common, so may be intolerant of short term changes in temperature. Therefore intolerance has been recorded as intermediate.
A recoverability of moderate has been recorded, and sensitivity is moderate (see additional information below). Also in the event of climate change, if larval dispersal is poor, colonization of suitable habitats at different latitudes is unlikely.

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

No information was found of the upper or lower thermal limits of Funiculina quadrangularis. Funiculina quadrangularis occurs in thermally stable conditions, with annual temperature variation between 5 - 15 (Jones et al., 2001). This species is subtidal where wide variations in temperature are not common, so may be intolerant of short term changes in temperature. Therefore intolerance has been recorded as intermediate.
A recoverability of moderate has been recorded, and sensitivity is moderate (see additional information below).

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

No information could be found about the sensitivity of Funiculina quadrangularis to light. Another sea pen Virgularia mirabilis, was not found to be sensitive to light (Hoare & Wilson, 1977).

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

No information could be found about the intolerance of Funiculina quadrangularis to light. Another sea pen Virgularia mirabilis was found to be insensitive to light (Hoare & Wilson, 1977).

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

Funiculina quadrangularis is found in areas with little or no wave exposure. Virgularia mirabilis was found to be smaller and less common where wave exposure increased (Hoare & Wilson, 1977). It is likely that an increase in exposure ranking of 2 or more would kill Funiculina quadrangularis. Therefore, an intolerance of high has been recorded.
A recoverability of low has been recorded, resulting in a high sensitivity assessment (see additional information below).

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

Funiculina quadrangularis is found in areas with little or no wave exposure so it is unlikely that a decrease in wave exposure would occur. Therefore, not relevant has been recorded.

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

Funiculina quadrangularis probably has a very limited if any ability for detection of noise vibrations, therefore tolerant has been recorded, and the species is assessed as not sensitive.

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

Funiculina quadrangularis probably has a very limited if any ability for visual perception, and is not known to be sensitive to light (Greathead et al., 2007). It is unlikely the sea pen will be sensitive to visual presence. Therefore tolerant has been recorded, and the species is assessed as not sensitive.

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

Sea pens project above the surface of the seabed and so are likely to be vulnerable to physical disturbance (Eno et al., 2001). Eno et al. (1996) dropped creels onto sea pens. They were seen to bend away in response to the pressure wave travelling ahead of the dropping creel, therefore reducing the chance the top of the sea pen would be struck causing fracture of the colony. Kinnear et al. (1996) conducted creel dragging experiments. The majority of Funiculina quadrangularis that were displaced from the sediment recovered after 72 hours. However, fishing gear such as a scallop dredge (see benchmark) or, more likely for this species, a Nephrops trawl, is likely to have a more severe impact. Sea pens are likely to be particularly vulnerable to damage from trawls, and have been reported as numerous in bycatch from otter trawls in the Bering sea (Brodeur 2001; Wilson et al., 2002). It is possible that the apparent absence of Funiculina quadrangularis from many open coast Nephrops grounds may be a consequence of its susceptibility to trawl damage (Connor, pers. comm. in Hughes, 1998a). For example when the sea pen Halipteris willemoesi becomes entangled in prawn trapping gear, 50% of sea pen colonies are damaged (Troffe et al., 2005).
A damaged sea pen appeared to remain fully functional but if, as seems likely, the axis is broken, the sea pen will be unable to remain erect and will most likely die. Therefore, intolerance has been recorded as high. A recoverability of moderate has been recorded, resulting in a moderate sensitivity value (see additional information below).

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

Funiculina quadrangularis can not retract into the sediment so it is likely to be removed from the seabed by the action of fishing gear. Removal experiments by Kinnear et al. (1996) showed when a sea pen was displaced it could reburrow as long as its foot remains in contact with the mud. Therefore, intolerance has been recorded as low. Recovery would take less that 72 hrs, so recoverability is recorded as immediate, yielding a sensitivity value of not sensitive.

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

No information was found for Funiculina quadrangularis in relation to intolerance to radionuclides. However another species, Virgularia mirabilis, occurred in high density (10/m) at a sampling station immediately offshore from the Sellafield outfall pipeline in the Irish Sea (Hughes & Atkinson, 1997). Bottom sediments in this area contains particles of long half life radionuclides from liquid effluent, so intolerance has been recorded as low. Recovery is likely to be high, therefore the species is assessed as low sensitivity.

Changes in nutrient levels

Evidence

A low level of nutrient enrichment is likely to be beneficial to Funiculina quadrangularis. However, because the distribution of the species is limited to relatively small areas within semi-enclosed water bodies, organic encrichment is expected to have adverse effects (Hughes, 1998). Jones et al. (2000) found Funiculina quadrangularis absent from de-oxygenated areas which are characterised by nutrient enrichment resulting in a hypoxic bacterial community. Salmon farming has been identified as the greatest source of organic pollution in Scottish sea lochs (Hiscock et al., 2005). Therefore intolerance has been recorded as intermediate. Recovery is recorded as high, hence a low sensitivity value.

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

Funiculina quadrangularis is found in fully saline conditions and it is unlikely that it would be exposed to hypersaline conditions, therefore, not relevant has been recorded.

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

Funiculina quadrangularis is found only in fully saline conditions so it is likely that the sea pen would be intolerant of a decrease in salinity. Therefore an intolerance of high has been recorded.
A recoverability of low has been recorded, hence sensitivity is high (see additional information below).

Changes in oxygenation

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

Evidence

Funiculina quadrangularis is found in sea lochs where stratification of the water column is likely to occur during warm temperatures so it may be able to tolerate some reduction in oxygenation. However, Jones et al. (2000) found the sea pen absent from de-oxygenated areas which are characterised by nutrient enrichment resulting in a hypoxic bacterial community. Therefore intolerance has been recorded as intermediate.
A recoverability of moderate has been recorded, hence sensitivity is moderate (see additional information below).

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

No information was found on diseases of Funiculina quadrangularis.

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

Funiculina quadrangularis is unlikely to be subject to extraction, therefore, this factor has been assessed as not relevant. This sea pen can not retract into the sea bed which may mean it can be extracted through dredging activity.

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

Trawling for the Norway lobster (Nephrops norvegicus) in the open sea and more accessible sea lochs may have removed populations of Funiculina quadrangularis. Large quantities of Funiculina quadrangularis axis have been observed below Dunstaffnage pier, presumably discarded bycatch (Hiscock, pers comm.). Other species of sea pen have also been recorded as numerous bycatch in trawls from the Bering sea (Brodeur 2001; Wilson et al., 2002). It is likely that physical disturbance from demersal fishing activities poses the greatest threat to Funiculina quadrangularis, (Greathead et al., 2007), and due to the fragmented distribution and possibly limited larval dispersal, recovery if unlikely (Hughes, 1998a).
In the isolated sea lochs where Funiculina quadrangularis is found, creeling for lobsters traditionally occurs. Studies indicate that this has a less damaging effect than trawling as the sea pen has the ability to right itself if hit by a creel pot (Eno et al., 1996). Nevertheless, due to its potential vulnerability to trawling, an intolerance of high has been recorded. A recoverability of low has been recorded, so sensitivity is high (see additional information below).