Distribution data supplied by the Ocean Biodiversity Information System (OBIS). To interrogate UK data visit the NBN Atlas.Map Help
Researched by | Nicola White | Refereed by | This information is not refereed |
Authority | (Lightfoot) Batters, 1902 | ||
Other common names | - | Synonyms | Saccorhiza bulbosa (Lightfoot) Batters, 1902, Laminaria polyschides |
Saccorhiza polyschides is kelp species with a distinctive large warty holdfast and a flattened stipe with a frilly margin. The stipe is twisted at the base and widens to form a large flat lamina, which is divided into ribbon-like sections. The species is an annual, and very fast growing. It is opportunistic and colonizes available hard substrata in the sublittoral.
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Phylum | Ochrophyta | Brown and yellow-green seaweeds |
Class | Phaeophyceae | |
Order | Tilopteridales | |
Family | Phyllariaceae | |
Genus | Saccorhiza | |
Authority | (Lightfoot) Batters, 1902 | |
Recent Synonyms | Saccorhiza bulbosa (Lightfoot) Batters, 1902Laminaria polyschides |
Typical abundance | Moderate density | ||
Male size range | |||
Male size at maturity | |||
Female size range | Large(>50cm) | ||
Female size at maturity | |||
Growth form | Forest | ||
Growth rate | 145mm/week | ||
Body flexibility | |||
Mobility | |||
Characteristic feeding method | Autotroph | ||
Diet/food source | |||
Typically feeds on | |||
Sociability | |||
Environmental position | Epilithic | ||
Dependency | Independent. | ||
Supports | No information | ||
Is the species harmful? | No |
Physiographic preferences | Open coast, Offshore seabed, Strait / sound, Sea loch / Sea lough, Ria / Voe |
Biological zone preferences | Sublittoral fringe, Upper infralittoral |
Substratum / habitat preferences | Bedrock, Cobbles, Large to very large boulders, Pebbles, Small boulders |
Tidal strength preferences | Moderately Strong 1 to 3 knots (0.5-1.5 m/sec.), Strong 3 to 6 knots (1.5-3 m/sec.), Very Strong > 6 knots (>3 m/sec.), Very Weak (negligible), Weak < 1 knot (<0.5 m/sec.) |
Wave exposure preferences | Extremely sheltered, Moderately exposed, Sheltered, Ultra sheltered, Very sheltered |
Salinity preferences | Full (30-40 psu) |
Depth range | 0 -35m |
Other preferences | No text entered |
Migration Pattern | Non-migratory / resident |
Reproductive type | Alternation of generations | |
Reproductive frequency | Semelparous / monotely | |
Fecundity (number of eggs) | No information | |
Generation time | <1 year | |
Age at maturity | 8-14 months | |
Season | October - May | |
Life span | <1 year |
Larval/propagule type | - |
Larval/juvenile development | Spores (sexual / asexual) |
Duration of larval stage | < 1 day |
Larval dispersal potential | 100 -1000 m |
Larval settlement period | Insufficient information |
The MarLIN sensitivity assessment approach used below has been superseded by the MarESA (Marine Evidence-based Sensitivity Assessment) approach (see menu). The MarLIN approach was used for assessments from 1999-2010. The MarESA approach reflects the recent conservation imperatives and terminology and is used for sensitivity assessments from 2014 onwards.
Intolerance | Recoverability | Sensitivity | Evidence/Confidence | |
High | High | Moderate | Moderate | |
Saccorhiza polyschides is permanently attached to the substratum so will be removed upon substratum loss. Experiments have shown that Saccorhiza polyschides colonizes cleared areas of the substratum within 26 weeks. However, if clearance takes place in August, when no spores of the species are released, the substratum may become colonized by red algae potentially blocking colonization by Saccorhiza polyschides (Kain, 1975). | ||||
Low | Immediate | Not sensitive | Low | |
Smothering could reduce light availability and therefore lower growth rates of the sporophyte but would not damage the plant. The microscopic sporophytes and gametophytes are likely to be more intolerant and if smothered growth would be inhibited, except on vertical surfaces where development appears to be unaffected (Norton, 1978). | ||||
Intermediate | High | Low | Low | |
Siltation is unlikely to affect the adult sporophytes but microscopic juvenile stages may be harmed. Norton (1978) observed that when spores settled on silt they continued development but failed to form attachments and would be easily washed off. Silt settling out on already attached spores prevented the formation of gametophytes and sporophytes. However, Birkett et al. (1998b), states that the species is found in areas of siltation and Santos (1993) observed that Saccorhiza polyschides is abundant in areas of high siltation, so the species may tolerate siltation. Recovery should be high because experiments have shown that Saccorhiza polyschides colonizes cleared areas of the substratum within 26 weeks. However, if clearance takes place in August, when no spores of the species are released the substratum may become colonized by red algae (Kain, 1975). | ||||
No information | ||||
High | High | Moderate | Moderate | |
The species is intolerant of desiccation. Norton (1970) observed that when sporophytes were exposed to air by an extreme low water springs on a hot summers day, they rapidly dried out and died. An increase in the level of desiccation would depress the upper limit of the species distribution. Recovery should be high because experiments have shown that Saccorhiza polyschides colonizes cleared areas of the substratum within 26 weeks and it has a very fast growth rate. However, if clearance takes place in August, when no spores of the species are released the substratum may become colonized by red algae (Kain, 1975). | ||||
High | High | Moderate | Moderate | |
Saccorhiza polyschides is intolerant of aerial exposure. Norton (1970) observed that when sporophytes were exposed to air by an extreme low water spring tide on a hot summers day, they rapidly dried out and died. An increase in the period of emersion would depress the upper limit of the species distribution. Recovery should be high because experiments have shown that Saccorhiza polyschides colonizes cleared areas of the substratum within 26 weeks and it has a very fast growth rate. However, if clearance takes place in August, when no spores of the species are released the substratum may become colonized by red algae (Kain, 1975). | ||||
No information | ||||
Low | High | Low | Moderate | |
Saccorhiza polyschides occurs in a wide range of water flow rates. It is found in areas of high water flow such as rapids in Lough Hyne (Ine), Ireland, but also grows in almost stationary water, where it can form extensive loose-lying populations in the absence of turbulence (Norton, 1978). The species is therefore unlikely to be affected by a change in water flow. | ||||
No information | ||||
Intermediate | High | Low | Moderate | |
The minimum temperature required for growth and reproduction of Saccorhiza polyschides is 5 degrees C and the maximum temperature is 23 degrees C. The 'northern lethal boundary' of the species occurs where the temperature falls below 4 degrees C for a period of 2 months and the southern lethal boundary occurs where temperatures rise above 25 degrees C for more than a few weeks (Hoek van den, 1982). The species is in the middle of its geographic range in the UK so is unlikely to be affected by a change of 2 degrees C for a year. However, a change in 5 degrees may put the species outside its lethal limits damaging the plant. Recovery should be high because the species has a fast growth rate and rapidly colonizes cleared areas of the substratum. | ||||
No information | ||||
Low | High | Low | Low | |
Light penetration influences the depth at which kelps can grow. An increase in turbidity would reduce light available for photosynthesis, lower growth rates and result in a decrease of the maximum depth at which it could grow. A reduction in the turbidity levels would allow Saccorhiza polyschides to grow at greater depths but the upper limit of the species distribution would be depressed due to increased competition with Laminaria hyperborea. On return to normal turbidity levels the growth rate and depth distribution would be quickly resumed | ||||
No information | ||||
Tolerant | Not relevant | Not sensitive | Moderate | |
Saccorhiza polyschides is found at all wave exposures (Hawkins & Jones, 1992) so is not likely to be intolerant of this factor. Increases in wave exposure which cause substrata to be mobilized and for abrasion to occur might be favourable to Saccorhiza. | ||||
No information | ||||
Tolerant | Not relevant | Not sensitive | Moderate | |
Seaweeds have no known mechanism for the perception of noise. | ||||
Tolerant | Not relevant | Not sensitive | Moderate | |
Seaweeds have no known mechanism for visual perception. | ||||
Intermediate | High | Low | Moderate | |
The fronds of Saccorhiza polyschides could be damaged by abrasion and gametophytes could be crushed. A passing scallop dredge or anchor is likely to rip off the plant and its holdfast, and remove a proportion of the population. Therefore, intolerance has been assessed as intermediate. However, the species has a fast growth rate, settles and grows to full size annually and, therefore, recovers very quickly from disturbance. | ||||
Low | Very high | Very Low | Moderate | |
Transplantation experiments have shown that plants can be transplanted to other sites with the rocks that they are attached to, with no adverse effects (Norton, 1978). The species could not tolerate displacement if the attachment to the rock was broken. |
Intolerance | Recoverability | Sensitivity | Evidence/Confidence | |
Intermediate | High | Low | Very low | |
The effects of chemicals on Saccorhiza polyschides have not been studied. Laminaria hyperborea, a related species of kelp, is thought to be fairly robust in terms of chemical pollution (Holt et al., 1995). Both species contain alginates which seem capable of storing chemicals in inert forms. However, it is likely that the gametophytes and very young sporophytes are more intolerant. Hopkin & Kain (1978) observed that growth of gametophytes and very young sporophytes of Laminaria hyperborea was inhibited at low levels of atrazine, sodium pentachlorophenate and phenol. | ||||
Intermediate | High | Low | Very low | |
The effects of heavy metals on Saccorhiza polyschides have not been studied. Laminaria hyperborea, a related species of kelp, is thought to be fairly robust in terms of chemical pollution (Holt et al., 1995). Both species contain alginates which seem capable of storing metals in inert forms. However, it is likely that the gametophytes and very young sporophytes are more intolerant. Hopkin & Kain (1978) observed that growth of gametophytes and very young sporophytes of Laminaria hyperborea was inhibited at low levels of mercury, cadmium, copper and zinc. | ||||
Low | High | Low | Very low | |
A number of workers have reported little effect of oil on sublittoral kelp, due to the lack of penetration of oil into the water column (Holt et al., 1995). Drew et al. (1967) recorded that the kelp forest escaped undamaged after the 'Torrey Canyon' oil spillage. Kelp may also be protected by the mucilaginous slime which covers the frond, by preventing damage from coating by oil (Birkett et al., 1998b). No studies have been carried out specifically on the impact on Saccorhiza polyschides but the alga is probably tolerant of this factor. Recovery rates would be high due to the fast growth rate of the species and its ability to rapidly colonize cleared areas of the substratum. | ||||
No information | Not relevant | No information | Not relevant | |
Insufficient information | ||||
Low | High | Low | Very low | |
Nutrients are required for algal growth. A slight increase in nutrient levels may enhance growth rates but a large increase may have a detrimental effect. Eutrophication could reduce the lower depth limit of the species distribution by reducing light penetration through an increase in turbidity. There may also be increased competition with mussels for available substratum space and plants may be overgrown by ephemeral green algae (Birkett et al.,1998b). However, Saccorhiza polyschides has a very fast growth rate and can probably effectively compete with these species, so it is only has low intolerance to this factor and recovery rates would be high. | ||||
High | High | Moderate | High | |
Saccorhiza polyschides is not found in areas of reduced salinity. In culture, lowered salinities have been found to reduce growth rate and development is irreversibly inhibited below 9 psu (Norton & South, 1969), so the species is regarded as highly intolerant of this factor. Recovery rates should be high because the species has a high growth rate and quickly colonizes cleared areas of the substratum (Kain, 1975). | ||||
No information | ||||
Low | High | Low | Very low | |
The effect of low oxygen levels on kelp is poorly studied. Saccorhiza polyschides can grow in almost stationary water (Norton, 1978) and can generate its own oxygen by photosynthesis, so it is likely to tolerate changes in this factor. The species can quickly recover from disturbance as it has a fast growth rate and rapidly colonizes cleared areas of the substratum (Kain, 1975). |
Intolerance | Recoverability | Sensitivity | Evidence/Confidence | |
No information | Not relevant | No information | Not relevant | |
Insufficient information | ||||
Intermediate | High | Low | Low | |
The Japanese kelp Undaria pinnatifida has recently spread to the south coast of England from Brittany, where it was introduced for aquaculture. It is thought that Undaria may compete with Saccorhiza polyschides (Birkett et al., 1998b). The potential introduction of Macrocystis spp. from America could have an enormous impact on native kelps due to the very fast growth rate of the species. | ||||
Intermediate | Very high | Low | Moderate | |
Saccorhiza polyschides has a fast growth rate and rapidly colonizes cleared areas of the substratum, so it would be able to quickly recover from harvesting. | ||||
Tolerant* | Not relevant | Not sensitive* | Moderate | |
Grazing urchins, such as Echinus esculentus and Paracentrotus lividus are important in determining the lower depth limit of Saccorhiza polyschides. The removal of these species may enable Saccorhiza to grow at greater depths, for example Kain & Jones (1966) found that removal of grazing urchins at Port Erin, Isle of Man, enabled Saccorhiza polyschides to extend its depth range by 3 m. Likewise, the upper limit of the species distribution is related to Laminaria hyperborea and the extraction of this species would enable Saccorhiza to grow in shallower water. Where beds of Laminaria hyperborea or Laminaria digitata have been cleared, they are usually replaced by Saccorhiza polyschides (Norton, 1970). |
- no data -
National (GB) importance | - | Global red list (IUCN) category | - |
Native | - | ||
Origin | - | Date Arrived | - |
Birkett, D.A., Maggs, C.A., Dring, M.J. & Boaden, P.J.S., 1998b. Infralittoral reef biotopes with kelp species: an overview of dynamic and sensitivity characteristics for conservation management of marine SACs. Natura 2000 report prepared by Scottish Association of Marine Science (SAMS) for the UK Marine SACs Project., Scottish Association for Marine Science. (UK Marine SACs Project, vol VI.), 174 pp. Available from: http://ukmpa.marinebiodiversity.org/uk_sacs/pdfs/reefkelp.pdf
Ebling, F.J., Kitching, J.A., Purchon, R.D. & Bassingdale, R., 1948. The ecology of Lough Ine rapids with special reference to water currents. 2. The fauna of the Saccorhiza canopy. Journal of Animal Ecology, 17, 223-244.
Guiry, M.D. & Blunden, G., 1991. Seaweed Resources in Europe: Uses and Potential. Chicester: John Wiley & Sons.
Guiry, M.D. & Nic Dhonncha, E., 2002. AlgaeBase. World Wide Web electronic publication http://www.algaebase.org,
Hardy, F.G. & Guiry, M.D., 2003. A check-list and atlas of the seaweeds of Britain and Ireland. London: British Phycological Society
Hawkins, S. J. & Jones, H. D., 1992. Rocky Shores. London: Immel.
Hopkin, R. & Kain, J.M., 1978. The effects of some pollutants on the survival, growth and respiration of Laminaria hyperborea. Estuarine and Coastal Marine Science, 7, 531-553.
Kain, J.M. & Jones, N.S., 1966. Algal colonisation after removal of Echinus. Proceedings of the International Seaweed Symposium, 8, 139-140.
Kain, J.M., 1975a. Algal recolonization of some cleared subtidal areas. Journal of Ecology, 63, 739-765.
McKenzie, J.D. & Moore, P.G., 1981. The microdistribution of animals associated with the bulbous holdfasts of Saccorhiza polyschides (Phaeophyta). Ophelia, 20, 201-213.
Norton, T.A. & Burrows, E.M., 1969. Studies on marine algae of the British Isles. 7. Saccorhiza polyschides (Lightf.) Batt. British Phycological Journal, 4, 19-53.
Norton, T.A. & South, G.R., 1969. Influence of reduced salinity on the distribution of two laminarian algae. Oikos, 20, 320-326
Norton, T.A., 1970. Synopsis of biological data on Saccorhiza polyschides. FAO Fisheries Synopsis, No. 83, 1-35.
Norton, T.A., 1978. The factors influencing the distribution of Saccorhiza polyschides in the region of Lough Ine. Journal of the Marine Biological Association of the United Kingdom, 58, 527-536.
Santos, R., 1993. A multivariate study of biotic and abiotic relationships in a subtidal algal stand. Marine Ecology Progress Series, 94, 181-190.
Van den Hoek, C., 1982. The distribution of benthic marine algae in relation to the temperature regulation of their life histories. Biological Journal of the Linnean Society, 18, 81-144.
Centre for Environmental Data and Recording, 2018. Ulster Museum Marine Surveys of Northern Ireland Coastal Waters. Occurrence dataset https://www.nmni.com/CEDaR/CEDaR-Centre-for-Environmental-Data-and-Recording.aspx accessed via NBNAtlas.org on 2018-09-25.
Cofnod – North Wales Environmental Information Service, 2018. Miscellaneous records held on the Cofnod database. Occurrence dataset: https://doi.org/10.15468/hcgqsi accessed via GBIF.org on 2018-09-25.
Fenwick, 2018. Aphotomarine. Occurrence dataset http://www.aphotomarine.com/index.html Accessed via NBNAtlas.org on 2018-10-01
Manx Biological Recording Partnership, 2017. Isle of Man wildlife records from 01/01/2000 to 13/02/2017. Occurrence dataset: https://doi.org/10.15468/mopwow accessed via GBIF.org on 2018-10-01.
Manx Biological Recording Partnership, 2018. Isle of Man historical wildlife records 1990 to 1994. Occurrence dataset:https://doi.org/10.15468/aru16v accessed via GBIF.org on 2018-10-01.
Manx Biological Recording Partnership, 2018. Isle of Man historical wildlife records 1995 to 1999. Occurrence dataset: https://doi.org/10.15468/lo2tge accessed via GBIF.org on 2018-10-01.
National Trust, 2017. National Trust Species Records. Occurrence dataset: https://doi.org/10.15468/opc6g1 accessed via GBIF.org on 2018-10-01.
NBN (National Biodiversity Network) Atlas. Available from: https://www.nbnatlas.org.
OBIS (Ocean Biodiversity Information System), 2023. Global map of species distribution using gridded data. Available from: Ocean Biogeographic Information System. www.iobis.org. Accessed: 2023-06-03
Outer Hebrides Biological Recording, 2018. Non-vascular Plants, Outer Hebrides. Occurrence dataset: https://doi.org/10.15468/goidos accessed via GBIF.org on 2018-10-01.
Royal Botanic Garden Edinburgh, 2018. Royal Botanic Garden Edinburgh Herbarium (E). Occurrence dataset: https://doi.org/10.15468/ypoair accessed via GBIF.org on 2018-10-02.
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Last Updated: 29/05/2008