Biodiversity & Conservation

LR.LR.Rkp.Cor

Explanation of sensitivity and recoverability


Physical Factors

Substratum Loss
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Removal of the substratum would result in loss of the coralline turf and its associated community. Therefore an intolerance of high has been recorded. Recoverability is likely to be high (see additional information below).
Smothering
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Corallina spp. accumulate more sediment than any other alga (Hicks, 1985). Significant sediment cover of the middle to lower intertidal in a South Californian shore, resulting from fresh water runoff, caused substantial decline in Corallina spp. cover as the fronds died back (Seapy & Littler, 1982). Although the fronds of Corallina officinalis may be intolerant of, rapid recovery will result from the resistant crustose bases (see additional information below). Encrusting coralline algae are frequently subject to cover by sediment and appear to survive well.
Faunal components of the biotope may be more intolerant of smothering than algae. If Littorina littorea cannot regain the surface then death may occur. Smothering of limpets by 5cm of sediment for one month is likely to interfere with locomotion, grazing and respiration. Mobile epifauna, such as amphipods and isopods are likely to be able to move through the sediment or debris to escape smothering. The species food source may be affected because smothering can reduce photosynthesis but Hyale prevostii for instance may migrate to alternative food sources on other parts of the shore. At the benchmark, level intolerance to smothering has been assessed to be intermediate as important structural species may be lost. Recoverability has been assessed to be high. For instance, Littorina littorea is an iteroparous breeder with high fecundity that lives for several (at least 4) years. Breeding can occur throughout the year. The planktonic larval stage is long (up to 6 weeks) although larvae do tend to remain in waters close to the shore so recruitment rates should be good.
Increase in suspended sediment
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Corallina species accumulate more sediment than any other alga (Hicks, 1985). Hence an increase in suspended sediment is likely to accumulate in the coralline turf. A significant increase may result in smothering (see above). An accumulation of sediment within the turf may attract more sediment dwelling interstitial invertebrates such as nematodes, harpacticoids and polychaetes, although in more wave exposed locations accumulation of sediment is likely to be minimal. Increased suspended sediment may also result in increased scour, which may adversely affect the fleshy red algae, and interfere with settling spores and recruitment if the factor is coincident with their major reproductive period. However, coralline algae, especially the crustose forms are thought to be resistant of sediment scour (Littler & Kauker, 1984), and will probably not be adversely affected at the benchmark level. Therefore, an increase in suspended sediment may reduce the epiphytic species diversity in the immediacy, and adversely affect the cover of fleshy red algae and an intolerance of intermediate has been recorded. Recoverability is likely to be very high as species are likely to remain in situ from which recruitment can occur.
Decrease in suspended sediment
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This community is unlikely to be dependant on suspended sediment. Although accumulated sediment within coralline turf habitats is likely to increase the species diversity of the epiphytic fauna, in very wave exposed locations, accumulated sediment in the habitat is likely to be minimal. A reduction in suspended sediment will probably reduce the risk of scour, and reduce food availability for the few suspension feeding species in the biotope (e.g. barnacles and spirorbids present). Therefore not sensitive has been recorded.
Desiccation
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Corallina officinalis inhabits damp or wet gullies and rock pools and does not inhabit open rock in the upper shore. Fronds are highly intolerant of desiccation and do not recover from a 15%water loss, which might occur within 40-45 minutes during a spring tide in summer (Wiedemann, 1994). Occurrence of encrusting coralline algae seems to be critically determined by exposure to air and sunlight. Colonies survive in damp conditions under algal canopies or in pools but not on open rock where desiccation effects are important. An intolerance assessment of high has been made owing to the fact that should a rockpool community dominated by coralline algae 'loose its water' and be subject to continuous emersion for an hour and hence desiccation it is likely that the key structuring species will suffer loss. Mobile epifauna are likely to seek shelter elsewhere and species such as Patella vulgata found throughout the intertidal zone are likely to tolerate a desiccation event to some extent. On return to prior conditions, recoverability of the key structuring species has been assessed to be very high (see additional information below).
Increase in emergence regime
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Bleached corallines were observed 15 months after the 1964 Alaska earthquake which elevated areas in Prince William Sound by 10 m. Similarly, increased exposure to air caused by upward movement of 15 cm due to nuclear tests at Armchitka Island, Alaska adversely affected Corallina pilulifera (Johansen, 1974). However, the upper extent of £LR.Coff£ is determined by the availability of rock pools and wet gullies. An increase in emergence and concomitant increase in desiccation on the open shore is of lesser importance where moisture is provided by standing water and shade. An increase in emergence will, however, expose the rockpool to increased evaporation, rainfall, and heating or cooling, so that some adverse effects on the fauna and flora are likely. Therefore, an intolerance of intermediate has been recorded. Recovery of the coralline algal community is likely to be very high (see additional information below).
Decrease in emergence regime
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A greater period of immersion will lessen the physico-chemical extremes that prevent the colonization of the mid to upper shore by species more typical of the lower shore. Desiccation stress will be lessened and temperature and salinity changes less severe. Thus the LR.Cor community has been assessed to have a high intolerance to decreased emergence as it will probably allow the 'up-lift' of lower shore species into the biotope and will it begin to change to another biotope. On return to prior conditions, it is likely that species which entered the biotope would be lost owing to intolerance, and recoverability has been assessed to be high to indicate that colonizing species may persist for a period but disappear as the biotope community re-stabilizes.
Increase in water flow rate
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Water flow rate in this biotope is typically only that of the ebb and flood tide speed, which hardly affects intertidal habitats and is far exceeded by the strength of wave action. An increase in water flow rate is therefore considered not relevant.
Decrease in water flow rate
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Wave action is far more important than tidal flow so not relevant has been recorded.
Increase in temperature
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In general, the water temperature of rockpools follows that of the air more closely than that of the sea and throughout any 24 hour period dramatic changes in temperature may be observed. For instance, Pyefinch (1943) plotted diurnal changes in a pool lying above mean high water during July. When the pool was out of contact with the sea, water temperature increased by 5 °C from 14 to 19 °C over a three hour period, and decreased suddenly to 14 °C within 1.5 hours when the incoming tide reached it. Hence, the community that inhabits such environments needs to be especially tolerant of acute temperature changes. Mobile species (e.g. littorinids, isopods and intertidal fish) will exhibit physiological and behavioural adaptations to temperature change and will probably migrate to deeper water within the rockpool if possible, or migrate to the surrounding rock surface to escape extreme temperatures, while fixed species such as macroalgae will need to tolerate the temperature change (see Newell, 1979).

Lüning (1990) reported that Corallina officinalis from Helgoland survived one week exposure to temperatures between 0 °C and 28 °C. An abrupt increase in temperature of 10 °C caused by the hot, dry 'Santa Anna' winds (between January -and February) in Santa Cruz, California resulted in die back of several species of algae exposed at low tide (Seapy & Littler, 1984). Although fronds of Corallina spp. dramatically declined, summer regrowth resulted in dense cover by the following October, suggesting that the crustose bases survived. Severe damage was noted in Corallina officinalis as a result of desiccation during unusually hot and sunny weather in summer 1983 (an increase of between 4.8 and 8.5 °C) (Hawkins & Hartnoll 1985). Littler & Kauker (1984) suggested that the crustose base was more resistant of desiccation or heating than fronds.

Most of the other species within the biotope are distributed to the north and south of Britain and Ireland and unlikely to be adversely affected by long-term temperature change. But Hawkins & Hartnoll (1985) suggested that typical understorey red algae were susceptible to hot dry weather and that occasional damaged specimens of Palmaria palmata, Osmundea pinnatifida and Mastocarpus stellatus were observed after the hot summer of 1983.

It is likely that Corallina officinalis fronds are intolerant of abrupt short term temperature increase although they may not be affected by long term chronic change and the crustose bases are probably less intolerant of than fronds. Epifaunal species will decline due to loss of coralline turf cover. Similarly, acute increases in temperature will probably reduce the cover of the characterizing red algae. The rockpool community is probably tolerant of a short term 5 °C change in temperature (see benchmark) and under normal circumstances the body of water protects species from the immediate effects of desiccation. But a long term increase in average temperature may expose the community to extremes of temperature above the tolerance limits, resulting in loss of some species, especially red algae and a reduced abundance of coralline algae. Therefore, an intolerance of intermediate has been recorded. Recoverability is probably very high (see additional information below).

Decrease in temperature
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In general, the water temperature of rockpools follows that of the air more closely than that of the sea and dramatic temporal changes in temperature may be observed. Under extremely low temperatures, components of the community demonstrate tolerance. Lüning (1990) reported that Corallina officinalis from Helgoland survived 0 °C when exposed for one week. New Zealand specimens were found to tolerate -4 °C (Frazer et al., 1988). Lüning (1990) suggested that most littoral algal species were tolerant of cold and freezing. For example, the photosynthetic rate of Chondrus crispus recovered after 3hrs at -20 °C but not after 6hrs (Dudgeon et al., 1990). The photosynthetic rate of Mastocarpus stellatus higher on the shore fully recovered from 24hrs at -20 °C. Littorina littorea is a hardy intertidal species and can tolerate long periods of exposure to the air and consequently wide variations in temperature. Adult snails can easily tolerate sub-zero temperatures and the freezing of over 50% of their extracellular body fluids (English & Storey, 1998). Adults of Patella vulgata are also largely unaffected by short periods of extreme cold. Ekaratne & Crisp (1984) found adult limpets continuing to grow over winter when temperatures fell to -6 °C, and stopped only by still more severe weather. However, loss of adhesion after exposure to -13 °C has been observed with limpets falling off rocks and therefore becoming easy prey to crabs or birds (Fretter & Graham, 1994). However, in the very cold winter of 1962-3 when temperatures repeatedly fell below 0 °C over a period of 2 months large numbers of Patella vulgata were found dead (Crisp, 1964). Nevertheless, the community has been assessed not sensitive to decreased temperature at the benchmark level.
Increase in turbidity
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The biotope essentially occur in shallow waters where light attenuation due to increase turbidity is probably low. Red algae and coralline algae especially are known to be shade tolerant and are common components of the understorey on seaweed dominated shores. Therefore, a decrease in light intensity is unlikely to adversely affect the biotope.
Decrease in turbidity
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An increase in light intensity is unlikely to adversely affect the biotope.
Increase in wave exposure
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The biotope may occur on the upper shore in locations with varying wave exposures (very exposed to sheltered) (Connor et al., 1997b). The effects of wave exposure upon rockpool communities high on the shore are likely to depend on tidal amplitude as within a shore, and where the tidal amplitude is significant, the time for which organisms are subjected to wave action will vary along the intertidal gradient. For instance, during neap tide periods, mid and higher shore rockpools may remain isolated from the main body of the sea for several days or weeks in succession. During such times, wave action is unlikely to be of direct influence other than generating a spray, whilst during periods of tidal immersion wave action may directly affect the community. The changes in community composition that occur with increased wave exposure are accompanied by striking changes in the vertical levels of zones on the shore. In north-west Europe, all the zones become greater in vertical extent as wave exposure increases, and thus are found at greater heights above chart datum (Little & Kitching, 1996). In balance, over a year it is likely that as a result of increased wave action the vertical extent of the biotope up the shore will increase with no major changes in community composition occurring, so an assessment of not sensitive has been made.
Decrease in wave exposure
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The biotope may occur on the upper shore in locations with varying wave exposures (very exposed to sheltered) (Connor et al., 1997b). A decrease in wave action (directly effective only when the biotope is immersed) may mean that siltation and smothering of epifauna may occur and remain in the long term (see smothering above). Overall, only limited adverse effects are likely and an intolerance assessment of low has been made. However, in situations where the biotope occurs on the upper shore due to wave splash, and reduction in wave exposure may result in loss these examples of the biotope.
Noise
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None of the species in this biotope are know to respond to noise or vibration at the benchmark level, an assessment of not sensitive has been made.
Visual Presence
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The mobile invertebrates are probably capable of responding to localized shading, experienced by the approach of a predator. But their visual acuity is likely to be low and they are unlikely to respond to visual disturbance at the benchmark level.
Abrasion & physical disturbance
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Abrasion by an anchor or mooring may remove some fronds of the foliose red algae and scrape coralline turf, although most species would grow back from their remaining holdfasts. Trampling may be more damaging (see £ELR.Coff£) but is likely to be less significant in rockpool than on open rock surfaces. Therefore an intolerance assessment of intermediate has been made.
Displacement
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The majority of the characterizing fauna, such as the limpets, winkles, top shells isopods, amphipods and harpacticoid copepods are either highly mobile or would be able to re-attach to the substratum if undamaged, and are unlikely to be adversely affected by displacement. But the dominant macroalgae are permanently attached to the substratum and if removed will be lost, resulting in loss of the biotope overall. If their holdfasts and bases are also removed then recovery will be prolonged but still relatively rapid

Chemical Factors

Synthetic compound contamination
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Smith (1968) reported that oil and detergent dispersants from the Torrey Canyon spill affected high water plans of Corallina officinalis more than low shore plants and some plants were protected in deep pools. In areas of heavy spraying, however, Corallina officinalis was killed (Smith, 1968). Regrowth of fronds had begun within two months after spraying ceased (Smith, 1968). O'Brien & Dixon (1976) suggested that red algae were the most sensitive group of algae to oil or dispersant contamination, possibly due to the susceptibility of phycoerythrins to destruction. They also reported that red algae are effective indicators of detergent damage since they undergo colour changes when exposed to relatively low concentration of detergent. However, Smith (1968) reported that red algae such as Chondrus crispus, Mastocarpus stellatus, and Laurencia pinnatifida were amongst the algae least affected by detergents. Laboratory studies by Grandy (1984) on the effects of oil and dispersants on several red algal species concluded that they were all sensitive to oil/dispersant mixtures, with little difference between adults, sporelings, diploid or haploid life stages.

Cole et al. (1999) suggested that herbicides were (not surprisingly) very toxic to algae and macrophytes. Hoare & Hiscock (1974) noted that with the exception of Phyllophora species, all red algae including encrusting coralline forms, were excluded from the vicinity of an acidified halogenated effluent discharge in Amlwch Bay, Anglesey and that intertidal populations of Corallina officinalis occurred in significant amounts only 600m east of the effluent. Chamberlain (1996) observed that although Lithophyllum incrustans was quickly affected by oil during the Sea Empress spill, recovery occurred within about a year. The oil was found to have destroyed about one third of the thallus thickness but regeneration occurred from thallus filaments below the damaged area.

Most pesticides and herbicides were suggested to be very toxic for invertebrates, especially crustaceans (amphipods isopods, mysids, shrimp and crabs) and fish (Cole et al., 1999).

intolerance to synthetic chemicals has been assessed to be high, owing to the likely loss of key structural and important characterizing as well as other red foliose algae from the rockpools. On return to prior conditions, recoverability has been assessed to be high (see additional information below).

Heavy metal contamination
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Little information was found concerning the effects of heavy metals on turf forming and encrusting coralline algae. However, Bryan (1984) suggested that the general order for heavy metal toxicity in seaweeds is: organic Hg> inorganic Hg > Cu > Ag > Zn> Cd>Pb.
Most of the information available suggests that adult gastropod molluscs are rather tolerant of heavy-metal toxicity (Bryan, 1984). Winkles may absorb metals from the surrounding water by absorption across the gills or from their diet, and evidence from experimental studies on Littorina littorea suggest that diet is the most important source (Bryan et al., 1983). The species has been suggested as a suitable bioindicator species for some heavy metals in the marine environment. Bryan et al. (1983) suggested that the species is a reasonable indicator for Ag, Cd, Pb and perhaps As. In the Fal estuary Patella vulgata occurs at, or just outside, Restronguet Point, at the end of the creek where metal concentrations are in the order: Zinc (Zn) 100-2000 µg/l, copper (Cu) 10-100µg/l and cadmium (Cd) 0.25-5µg/l (Bryan & Gibbs, 1983). However, in the laboratory Patella vulgata was found to be intolerant of small changes in environmental concentrations of Cd and Zn by Davies (1992). At concentrations of 10µg/l pedal mucus production and levels of activity were both reduced, indicating a physiological response to metal concentrations. Exposure to Cu at a concentration of 100 µg/l for one week resulted in progressive brachycardia (slowing of the heart beat) and the death of limpets. Zn at a concentration of 5500 µg/l produced the same effect (Marchan et al., 1999).
An intolerance assessment of intermediate has been made as evidence suggests that important grazers in the biotope would be adversely affected by heavy metal pollution of the biotope. Recruitment patterns of such species suggest that recoverability would be high.
Hydrocarbon contamination
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Where exposed to direct contact with fresh hydrocarbons, encrusting coralline algae appear to have a high intolerance. Crump et al. (1999) described "dramatic and extensive bleaching" of 'Lithothamnia' following the Sea Empress oil spill. Observations following the Don Marika oil spill (K. Hiscock, pers. comm.) were of rockpools with completely bleached coralline algae. However, Chamberlain (1996) observed that although Lithophyllum incrustans was affected in a short period of time by oil during the Sea Empress spill, recovery occurred within about a year. The oil was found to have destroyed about one third of the thallus thickness but regeneration occurred from thallus filaments below the damaged area.

Following the Torrey Canyon oil spill in 1967, oil and detergent dispersants affected high shore specimens of Corallina officinalis more than low shore specimens. Plants in deep pools were afforded some initial protection, although probably later affected by contaminated runoff. In areas of heavy spraying, however, Corallina officinalis was killed. (Smith 1968). Intolerance to hydrocarbon pollution has been assessed to be high, as key structural and important characterizing coralline algal species will be lost and the biotope not be recognized in their absence. Recoverability of the key structural and important characterizing turf forming and encrusting coralline algae has been assessed to be high (see additional information below).

Radionuclide contamination
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Insufficient information.
Changes in nutrient levels
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Corallines seem to be tolerant and successful in polluted waters. Kindig & Littler (1980) demonstrated that Corallina officinalis var. chilensis in South California showed equivalent or enhanced health indices, highest productivity and lowest moralities (amongst the species examined) when exposed to primary or secondary sewage effluent. Little difference in productivity was noted in chlorinated secondary effluent or pine oil disinfectant. However, specimens from unpolluted areas were less tolerant, suggesting physiological adaptation to sewage pollution (Kindig & Littler 1980). Also, increased nutrients may result in overgrowth of coralline algae by other epiphytic algae. Grazers in the biotope may benefit from increase availability of food resources. An intolerance assessment of low has been made as key structural and important characterizing species may experience reduced viability. On return to prior conditions, recovery has been assessed to be very high as, although the biotope will recover to typical abundances, some species may remain abnormally abundant for a period whilst the biotope community re-stabilizes.
Increase in salinity
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Conditions within rockpools are the consequence of prolonged separation from the main body of the sea, and physico-chemical parameters within them fluctuate dramatically (Huggett & Griffiths, 1986). Small and shallow pools are especially influenced by insolation, air temperature and rainfall, the effects of which become more significant towards the high shore, where pools may be isolated from the sea for a number of days or weeks (Lewis, 1964). Rockpools in the mid eulittoral are likely to experience lesser changes in salinity than those of the supralittoral, littoral fringe and upper eulittoral which are liable to gradually changing salinities followed by days of fully marine or fluctuating salinity at times of spring tide (Lewis, 1964). The community has been assessed to be not sensitive to increased salinity at the benchmark level because it represents a lesser change in salinity than the community might normally be expected to experience and the community persists owing to the tolerance of species to short-term acute changes.
Decrease in salinity
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Conditions within rockpools are the consequence of prolonged separation from the main body of the sea, and physico-chemical parameters within them fluctuate dramatically (Huggett & Griffiths, 1986). Small and shallow pools are especially influenced by insolation, air temperature and rainfall, the effects of which become more significant towards the high shore, where pools may be isolated from the sea for a number of days or weeks (Lewis, 1964). Rockpools in the mid eulittoral are likely to experience lesser changes in salinity than those of the supralittoral, littoral fringe and upper eulittoral which are liable to gradually changing salinities followed by days of fully marine or fluctuating salinity at times of spring tide (Lewis, 1964). Salinity values ranging from 5-30 psu have been recorded in upper shore rockpools over a period of 24 hrs (Ranade, 1957). The community has been assessed to be not sensitive to decreased salinity at the benchmark level because it represents a lesser change in salinity than the community might normally be expected to experience and the community persists owing to the tolerance of species to short-term acute changes.
Changes in oxygenation
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Oxygenation of the rockpool is usually high due to photosynthetic activity and frequent water exchange. During the day, algae within rockpools produce oxygen by photosynthesis, and oxygen concentrations may rise to three times the saturation value, so that it is released as bubbles. The effect of oxygen production is to increase the pH of water in the pool owing to utilization of carbon dioxide. At night, when photosynthesis has ceased, algal respiration may utilize much of the available oxygen and minimum values of 1-5 % saturation of oxygen have been recorded in situ (Morris & Taylor, 1983). The algal component of the biotope may be intolerance of reduced oxygen concentration in darkness when they can only respire. However, corallines may be more tolerant than most algae due to their low rates of respiration (see Littler & Kauker 1984 for values).

Littorina littorea can endure long periods of oxygen deprivation. The snails can tolerate anoxia by drastically reducing their metabolic rate (down to 20% of normal) (MacDonald & Storey, 1999). However, this reduces feeding rate and thus the viability of a population may be reduced. Patella vulgata was assessed to have an intermediate intolerance to low oxygen concentrations (see MarLIN review). At the benchmark level, the community has been assessed to have a low intolerance to reduced oxygenation of the water. Mobile species are likely to leave unfavourable locations, whilst immobile species are likely to suffer an energy expenditure, e.g. owing to changes in metabolism, in order to survive. On return to optimal conditions, recoverability has been assessed to be very high.

Biological Factors

Introduction of microbial pathogens/parasites
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Several coralline and non-coralline species are epiphytic on Corallina officinalis. Irvine & Chamberlain (1994) cite tissue destruction caused by Titanoderma corallinae. However, no information on pathogenic organisms in the British Isles was found. In Rhodophycota, viruses have been identified by means of electron microscopy (Lee, 1971) and they are probably widespread. However, nothing is known of their effects on growth or reproduction in red algae and experimental transfer from an infected to an uninfected specimen has not been achieved (Dixon & Irvine, 1977). Overall, insufficient information was found to make an assessment
Introduction of non-native species
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The non-native wireweed Sargassum muticum may occur extensively in examples of this biotope. But the biotope persists, probably because of the small area of basal attachment of Sargassum. Sargassum probably competes with other macroalgae for light and nutrients so an intolerance of low has been recorded.
Extraction
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Corallina officinalis was used in Europe as a vermifuge although it no longer seems to be collected for this purpose (Guiry & Blunden, 1991). Corallina officinalis is collected for medical purposes; the fronds are dried and converted to hydroxyapatite and used as bone forming material (Ewers et al., 1987). It is also sold as a powder for use in the cosmetic industry. An European research proposal for cultivation of Corallina officinalis is pending as of May 2000 (Wiedemann pers. comm.). Littorina littorea may also be collected. Both Chondrus crispus and Mastocarpus stellatus, although not species indicative of sensitivity, are collected as 'carragheen' by hand picking and racking in Europe (Guiry & Blunden, 1991). However, as long as holdfasts remain recovery will probably be rapid. Overall, intermediate intolerance has been suggested to reflect the fact that some species may experience a small decline. Recovery is likely to be very high (see additional information).

Additional information icon Additional information

Recoverability:
Corallina officinalis probably has good recruitment and settled on artificial substances within 1 week of their placement in the intertidal in New England summer (Harlin & Lindbergh, 1977). New fronds of Corallina officinalis appeared on sterilized plots within six months and 10% cover was reached with 12 months (Littler & Kauker, 1984). Bamber & Irving (1993) reported that new plants grew back in scraped transects within 12 months, although the resistant crustose bases were probably not removed. Similarly, in experimental plots, up to 15% cover of Corallina officinalis fronds returned within 3 months after removal of fronds and all other epiflora/fauna but not the crustose bases (Littler & Kauker, 1984). Although new crustose bases may recruit and develop quickly the formation of new fronds from these bases and recovery of original cover may take longer, and it is suggested that a population is likely to recover within a few years.

Chamberlain (1996) observed that although Lithophyllum incrustans was quickly affected by oil during the Sea Empress spill, recovery occurred within about a year. The oil was found to have destroyed about one third of the thallus thickness but regeneration occurred from thallus filaments below the damaged area. A recoverability of high is therefore suggested. If colonies were completely destroyed new growth would be slow and, because of low growth rates, recoverability would be low. If death occurred, recoverability will be slow. Spores will settle and new colonies will arise rapidly on bare substratum but growth rate is slow (2-7 mm per annum - see Irvine & Chamberlain 1994).

Recolonization of Patella vulgata on rocky shores is rapid as seen by the appearance of limpet spat 6 months after the Torrey Canyon oil spill reaching peak numbers 4-5 years after the spill (Southward & Southward, 1978). The epifauna are mainly composed of mobile species that will recruit quickly from surrounding habitats, and will therefore, recover quickly once the coralline turf has developed.

This review can be cited as follows:

Budd, G.C. 2002. Corallina officinalis and coralline crusts in shallow eulittoral rockpools.. Marine Life Information Network: Biology and Sensitivity Key Information Sub-programme [on-line]. Plymouth: Marine Biological Association of the United Kingdom. [cited 28/11/2014]. Available from: <http://www.marlin.ac.uk/habitatbenchmarks.php?habitatid=240&code=1997>