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

Brissopsis lyrifera is an infaunal species burrowing to a depth of up to 10 cm. It is not sufficiently mobile to avoid substratum removal. Thus removal of the substratum would also remove the resident population of Brissopsis lyrifera and intolerance has been assessed to be high. However, Brissopsis lyrifera is likely to repopulate rapidly, 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

Brissopsis lyrifera lives buried in muddy sediments up to 2-5 cm deep. As an urchin adapted for burrowing it is unlikely that it will be intolerant of additional sediment at the benchmark level and intolerance has been assessed to be low. However, it should be remembered that smothering by impermeable or viscous materials are likely to have some effect upon the animal, e.g. by causing deoxygenation.

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

Brissopsis lyrifera is a non-selective deposit feeder and therefore does not rely on suspended food. However, for most benthic deposit feeders, food is suggested to be a limiting factor for body and gonad growth, at least between events of sedimentation of fresh organic matter (Hargrave, 1980; Tenore, 1988). Consequently, an increase in the suspended matter settling out from the water column to the substratum will be utilizable by Brissopsis lyrifera as a food resource. Although characteristically a sub-surface deposit feeder, Brissopsis lyrifera has been observed to increase its surface feeding (apical tuft becomes visible) activity after addition of organic matter to the sediment surface and utilized the material for growth (Hollertz et al., 1998; Hollertz, 1998). This suggests that an increase in siltation may be beneficial to the population and the species has been assesses as tolerant.

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

Brissopsis lyrifera is a non-selective deposit feeder and therefore does not rely on suspended food. However, for most benthic deposit feeders, food is suggested to be a limiting factor for body and gonad growth, at least between events of sedimentation of fresh organic matter (Hargrave, 1980; Tenore, 1988). A decrease in siltation will increase competition for food resources and consequently impair growth. Intolerance has been assessed to be low. Recovery is likely to be rapid once food availability increases.

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

Populations of Brissopsis lyrifera are subtidal and are not likely to be affected by desiccation. Where Brissopsis lyrifera occurs in coastal marine inlets and sealochs it is protected from desiccation because it inhabits a burrow in sediments to a depth of up to 10 cm. However, Brissopsis lyrifera is likely to be intolerant of continuous exposure to air and sunshine for one hour, e.g. as a result of by-catch and surface exposure.

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

An assessment of this factor is not relevant for Brissopsis lyrifera as the species lives subtidally.

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

An assessment of this factor is not relevant for Brissopsis lyrifera as the species lives subtidally.

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

Brissopsis lyrifera is characteristic of offshore muddy sedimentary habitats exposed to only weak or very weak currents. The species is likely to be intolerant of the benchmark increase in water flow rate. Increased currents may wash out some of the sediments in which it burrows and decrease siltation of suspended organic matter to the sediment surface. The combination of a reduction in habitat and reduced food supply is likely to affect the viability of the population for a period of a year, so intolerance has been assessed to be intermediate. Brissopsis lyrifera is likely to recover rapidly, 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

Brissopsis lyrifera is characteristic of offshore and shallower, stable muddy habitats exposed to only weak or very weak currents. Sediments may become muddier due to increased settlement of silt if current strength declines. However, at the level of the benchmark it is not expected that populations will be affected. Thus Brissopsis lyrifera was assessed to be tolerant of a decrease in water flow rate.

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 specifically concerning the temperature tolerances of Brissopsis lyrifera was found. The geographic range of the species suggests that Brissopsis lyrifera is tolerant to a range of temperatures and a long term chronic increase of 2°C is unlikely to have adverse effects on populations around Britain and Ireland. Brissopsis lyrifera is an infaunal species that burrows up to 10 cm in depth, thus the burrow may offer some initial protection to an acute increase in water temperature. Furthermore, burrowing itself has been found to be significantly affected by temperature. Hollertz & Duchêne, (2001) found that Brissopsis lyrifera reworked almost double the amount of sediment per hour at 14 °C compared to activity at 7 °C (see adult general biology). However, Brissopsis lyrifera maintains a continuous contact with the overlying water column through the funnel (Hollertz, 2002). Increased water temperature may enhance microbial decomposition within the muddy sediments and promote deoxygenation to which Brissopsis lyrifera is intolerant. It is likely that Brissopsis lyrifera would be intolerant of an acute short term temperature increase and intolerance is assessed as intermediate. Brissopsis lyrifera has a high capacity for recovery, please see additional information below.

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 specifically concerning the temperature tolerances of Brissopsis lyrifera was found. The geographic range of the species suggests that Brissopsis lyrifera is tolerant to a range of temperatures and a long term chronic decrease is unlikely to have adverse effects on populations around Britain and Ireland. Brissopsis lyrifera is an infaunal species that burrows up to 10 cm in depth, thus the burrow may offer some protection to acute decreases in temperature. Furthermore, Brissopsis lyrifera populations live in deep water so that events such as a very cold winter is unlikely to affect the temperature of these deeper waters. However, burrowing itself has been found to be significantly affected by temperature. Hollertz & Duchêne, (2001) found that Brissopsis lyrifera reworked almost half the amount of sediment per hour at 7 °C compared to activity at 14 °C (see adult general biology). Furthermore, Brissopsis lyrifera maintains a continuous contact with the overlying water column through the funnel (Hollertz, 2002). Very low water temperatures have caused mass mortalities of other similar echinoderms, such as Echinocardium cordatum. In the severe winter of 1962-63 masses of dead Echinocardium cordatum were observed in regions of the North Sea and English Channel (Crisp (ed.), 1964), although it was reported that living specimens were obtained easily enough by digging (Moyse & Nelson-Smith, 1964 in Crisp (ed.), 1964). Intolerance of Brissopsis lyrifera to acute decreases in temperature has been assessed to be intermediate. Brissopsis lyrifera has a high capacity for recovery, 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

Brissopsis lyrifera is likely to have a poor facility for perception of irradiance and consequently is likely to be tolerant of an increase in turbidity. However, an increase in turbidity may be indicative of a potential increase in the supply of organic matter that may settle upon the sediment surface and be utilized as a food resource by Brissopsis lyrifera (Hollertz, 1998).

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

Brissopsis lyrifera is likely to have a poor facility for perception of irradiance and consequently is probably tolerant of a decrease in turbidity. A decrease in turbidity may be indicative of a reduced supply of organic matter eventually falling to the sediment surface which the species can utilize as a food resource (see changes in siltation). Reduced growth and fecundity may result.

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

Brissopsis lyrifera is characteristic of offshore and stable muddy nearshore habitats, where wave exposure is negligible. Populations of Brissopsis lyrifera occurring offshore at depths greater than 60 m would not be subjected to exposure from wave action, as the effects are attenuated with increasing depth. Populations situated in normally sheltered stable habitats at shallower depths may experience some disturbance to the sediment surface. However, as Brissopsis lyrifera burrows in the sediment to a depth of 10 cm, it is unlikely that turnover and displacement would occur to an extent where the population is significantly reduced. Intolerance has been assessed to be low.

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

Brissopsis lyrifera is characteristic of offshore and stable muddy nearshore habitats where wave exposure is negligible. Thus an assessment for decreased wave exposure was not considered relevant.

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

No information concerning sound or vibration reception in echinoids was found.

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

Some response to visual disturbance has been detected in echinoderms. However, Brissopsis lyrifera lives buried in muddy substrates up to 10 cm deep thus visual disturbance was not considered relevant to this species.

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

Brissopsis lyrifera has a fragile test that is likely to be damaged by an abrasive force, such as movement of trawling gear. In areas of the North Sea where heavy demersal fishing for Nephrops norvegicus occurs, populations of Brissopsis lyrifera may be reduced owing to damage inflicted to the 'test' by the fishing gear. Broken tests may be seen on the seabed (E.I.S. Rees, M. Costello, pers comm. to Connor et al., 1997). Intolerance has been assessed to be intermediate as some individuals of the species may be destroyed by the abrasive factor. Populations of Brissopsis lyrifera are likely to recover from effects of physical disturbance rapidly as the species is fecund and recruits annually with pelagic larva.

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

If displaced to the substratum surface Brissopsis lyrifera is potentially exposed to an increased risk of predation, but is capable of re-burrowing into the sediment. In the laboratory, animals left on the sediment surface were all observed to have buried themselves within a few hours (Hollertz, 2002). Intolerance is assessed to be low. Echinocardium cordatum can re-burrow into the sediment within 20 minutes, and as a similar specialized burrower it is also likely that Brissopsis lyrifera will submerge as rapidly, thus recovery has been assessed to be immediate.

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

Dahllöf et al., (1999) studied the long term effects of tri-n-butyl-tin (TBT) on the function of a marine sediment system. TBT spiked sediment was added to a sediment that already had a TBT background level of approximately 27 ng g^-1 and contained the following fauna: Amphiura spp., Brissopsis lyrifera and several species of polychaete. Within two days of treatment with a TBT concentration above 13.7 µmol /m² all species except the polychaetes had crept up to the surface and after six weeks these fauna had started to decay. Thus contamination from TBT is likely to result cause death of this species. Detergents used to disperse oil from the Torrey Canyon oil spill caused mass mortalities of a similar species, Echinocardium cordatum (Smith, 1968). Sea-urchins, especially the eggs and larvae are used for toxicity testing and environmental monitoring (reviewed by Dinnel et al., 1998). It is likely therefore, that Brissopsis lyrifera and its larvae are highly intolerant of organic compounds. Brissopsis lyrifera populations would probably recover rapidly assuming deterioration of contaminants, see additional information below.

Heavy metal contamination

Evidence

Information concerning the effects of heavy metals on echinoderms is limited and no information specific to Brissopsis lyrifera was found.

Hydrocarbon contamination

Evidence

No information directly concerning the intolerance of Brissopsis lyrifera to hydrocarbons was found. Suchanek (1993), proposed that echinoderms would be especially sensitive to the toxic effects of oil, owing to the exposure of the epidermis. However, as Brissopsis lyrifera burrows in muddy sediments to a depth of up to 10 cm, the likely route of exposure to the animal will arise from its feeding method. As a non-selective deposit feeder Brissopsis lyrifera is likely to ingest contaminated sediments. Intolerance has been assessed to be intermediate owing to a range of effects reported in other echinoderms (mortalities, feeding and growth inhibition, embryological abnormalities) reviewed by Suchanek (1993). Brissopsis lyrifera is likely to recover from this factor, see additional information below.

Radionuclide contamination

Evidence

Insufficient
information.

Changes in nutrient levels

Evidence

Brissopsis lyrifera is characteristic of muddy sediments with significant organic matter content and is a non-selective deposit feeder. For most benthic deposit feeders, food is suggested to be a limiting factor for body and gonad growth, at least between events of sedimentation of fresh organic matter (Hargrave, 1980; Tenore, 1988). An increase in nutrient availability is likely to promote pelagic productivity and increase the amount of organic matter reaching the sea bed. Hollertz (1998) demonstrated that such organic matter is utilizable by Brissopsis lyrifera as a food resource for gonad growth. Thus Brissopsis lyrifera may benefit from some nutrient enrichment. However, an excess of nutrients (eutrophication) facilitating a high pelagic production, in combination with thermal stratification of the water column in summer is likely to cause mortality of Brissopsis lyrifera indirectly, owing to the effects of hypoxia. Refer to 'changes in oxygenation' for a separate assessment of intolerance.

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

Echinoderms are stenohaline owing to the lack of an excretory organ and a poor ability to osmo- and ion-regulate (Stickle & Diehl, 1987). The inability of echinoderms to osmoregulate extracellularly causes body fluid volume to increase or decrease when individuals are exposed to higher salinity. No information concerning the specific tolerance of Brissopsis lyrifera to changes in salinity was found. However, the preferred habitat of Brissopsis lyrifera is found in waters of full salinity where an increase of salinity is not likely to occur.

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

Echinoderms are stenohaline owing to the lack of an excretory organ and a poor ability to osmo- and ion-regulate (Stickle & Diehl, 1987). The inability of echinoderms to osmoregulate extracellularly causes body fluid volume to or decrease when individuals are exposed to lower salinities. However, no information concerning the specific tolerance of Brissopsis lyrifera to a decrease in salinity was found. Populations that occur in sheltered nearshore situations, such as sealochs, which periodically receive inputs of freshwater are unlikely to experience the reduced salinities recorded at the surface. Furthermore, the muddy sediment in which Brissopsis lyrifera burrows may offer some protection. However, as a species with an apparent preference for fully saline conditions it is likely to be intolerant of a decrease in salinity.

Changes in oxygenation

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

Evidence

Brissopsis lyrifera is reported as a species sensitive to hypoxia (Diaz & Rosenberg, 1995). Demersal trawling in hypoxic areas has shown that large numbers of infaunal species in areas of high abundance and biomass leave their positions in the sediment and lie exposed on the bottom. At a bottom water oxygen concentration of ca. 1 ml/l (15% saturation) in the Kattegat, Baden et al., (1990) caught no fishes, but 200-400 kg per hour of benthic invertebrates that included the echinoderms Brissopsis lyrifera and Echinocardium cordatum. Similar mass migration of benthic infauna (including Brissopsis lyrifera) to the sediment surface was recorded during trawling in the North Sea with low values of oxygen (ca 2 ml/l) recorded (Dyer et al., 1983). Hollertz (2002) reported that Brissopsis lyrifera could tolerate ca 4 ml/l (ca 5.6 mg/l) for at least 15 hours in the laboratory and that the animals recovered quickly. However, this is a much higher oxygen concentration than that in the benchmark. Recovery of Brissopsis lyrifera has been assessed to be moderate. Recovery of 'mature' equilibrium dominants eliminated by hypoxia appears to be a process requiring more than two years (Diaz & Rosenberg, 1995). In the Gullmarsfjord (where Brissopsis lyrifera is reported; Brattström, 1946; Vasseur & Carlsen, 1949), the 1980/1981 hypoxia, ca 0.2 ml/l, eliminated all the macrobenthic fauna below 115 m depth. The recovery sequence was slow and communities were not re-established eighteen months after the collapse (Josefson & Widbom, 1988).

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

The occurrence of the ascothoracidan parasite Ulophysema öresundense (Brattström) has been observed in the body cavity of Brissopsis lyrifera (Brattström, 1946). This parasite may cause sexual castration but no further information concerning the effect of this parasite on the population was found.

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

No alien or non-native species are known to compete with Brissopsis lyrifera.

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

Brissopsis lyrifera is not a targeted species for harvest, but it may be affected by the extraction of other species, please refer to 'Extraction of other species'.

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

Mud in deep offshore waters may be characterized by urchin Brissopsis lyrifera and brittle star Amphiura chiajei, communities. In certain sea areas around the British Isles, e.g. northern Irish Sea, this community may also contain the Norway lobster, Nephrops norvegicus. Nephrops norvegicus is one of the most important fisheries in Scotland and the community can consequently become the focus for fishing activity (Mackie, Oliver & Rees, 1995). Where heavy demersal fishing occurs populations of Brissopsis lyrifera may be reduced owing to damage inflicted to the 'test' by the fishing gear. Broken tests may be seen on the sea bed (E.I.S. Rees, M. Costello pers. Comm. In Connor et al., 1997). The impact of pots/creels on the sea bed and non-target species is considered to be slight. Brissopsis lyrifera is likely to recover from fishing impacts as the species is fecund and recruits annually with pelagic larva.