Horned wrack (Fucus ceranoides)
Fucus ceranoides.
Photographer: Keith Hiscock Copyright: Dr Keith Hiscock
Detail of frond of Fucus ceranoides.
Photographer: Keith Hiscock Copyright: Dr Keith Hiscock
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 | Dr Graham Scott |
| Authority | Linnaeus, 1753 | ||
| Other common names | - | Synonyms | - |
Summary
Description
A large brown intertidal seaweed, restricted to growing in estuaries or near freshwater streams on the shore. Fucus ceranoides does not have airbladders, but the side of the fronds are often inflated.
Recorded distribution in Britain and Ireland
All coasts of Britain and IrelandGlobal distribution
Spitsbergen, Iceland, Norway, Heligoland, Netherlands, Ireland, Britain, N. France, Portugal and Azores.Habitat
Fucus ceranoides is widely distributed in north-west Europe but is only common in brackish water. It is characteristic of estuaries and is often abundant where freshwater streams run onto the shore. The species is found on the middle part of the shore, where it attaches to stones, rocks or gravel.Depth range
Not relevantIdentifying features
- Frond thin with smooth margin.
- Frond fan shaped with prominent midrib.
- Without air bladders but frond on either side may be inflated.
- Reproductive bodies narrow, pointed fronds at ends of branches.
Additional information
No text entered
Listed by
- none -
Biology review
Taxonomy
| Phylum | Ochrophyta | Brown and yellow-green seaweeds |
| Class | Phaeophyceae | |
| Order | Fucales | |
| Family | Fucaceae | |
| Genus | Fucus | |
| Authority | Linnaeus, 1753 | |
| Recent Synonyms | ||
Biology
| Typical abundance | High density | ||
| Male size range | Up to 60cm | ||
| Male size at maturity | |||
| Female size range | Large(>50cm) | ||
| Female size at maturity | |||
| Growth form | Foliose | ||
| Growth rate | Data deficient | ||
| Body flexibility | |||
| Mobility | Not relevant | ||
| Characteristic feeding method | Autotroph | ||
| Diet/food source | |||
| Typically feeds on | Not relevant | ||
| Sociability | No information | ||
| Environmental position | Epifloral | ||
| Dependency | Independent. | ||
| Supports | No information | ||
| Is the species harmful? | Data deficient | ||
Biology information
Fucus ceranoides is physiologically adapted to brackish conditions. Suryono & Hardy (1997) found that growth rate was highest between 5 and 25 psu and growth was depressed at 0 and 35 psu. When cultured in high salinity they found that plant tissue decayed within 5 to 6 weeks. Khjafi & Norton (1979) recorded similar results but Baeck et al. (1992) found that Fucus ceranoides grew at full salinity for 11 weeks.
Habitat preferences
| Physiographic preferences | Open coast, Strait / sound, Sea loch / Sea lough, Ria / Voe, Estuary |
| Biological zone preferences | Mid eulittoral, Upper eulittoral |
| Substratum / habitat preferences | Bedrock, Cobbles, Gravel / shingle, 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 Weak (negligible), Weak < 1 knot (<0.5 m/sec.) |
| Wave exposure preferences | Sheltered, Very sheltered |
| Salinity preferences | Low (<18 psu), Reduced (18-30 psu) |
| Depth range | Not relevant |
| Other preferences | No text entered |
| Migration Pattern | Non-migratory / resident |
Habitat Information
The species is commonly found in the upper reaches of estuaries. It appears to be physiologically adapted to living in reduced salinity and exhibits its maximum growth rate at 11 psu. It is thought to be absent from fully saline sites due to an inability to compete with the faster growing fucoids, such as Fucus vesiculosus and a physiological intolerance of fully saline conditions. In areas of estuaries where salinity varies between 11 and 25 psu, Fucus ceranoides and Fucus vesiculosus can be found living together.Life history
Adult characteristics
| Reproductive type | Gonochoristic (dioecious) | |
| Reproductive frequency | Annual episodic | |
| Fecundity (number of eggs) | No information | |
| Generation time | Insufficient information | |
| Age at maturity | Insufficient information | |
| Season | May - August | |
| Life span | 2-5 years |
Larval characteristics
| Larval/propagule type | - |
| Larval/juvenile development | Not relevant |
| Duration of larval stage | No information |
| Larval dispersal potential | No information |
| Larval settlement period | Not relevant |
Life history information
The species is usually dioecious but monoecious plants have been recorded, although it has been suggested that these are hybrids. Well developed gametangia are present on plants in southern Norway from the end of May to December. Gametes are released on daytime high tides at about full and new moon. Germlings are found from the end of May to the beginning of August. Receptacles usually drop off by October or November.Sensitivity review
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.
Physical pressures
| Intolerance | Recoverability | Sensitivity | Evidence/Confidence | |
| High | Moderate | Moderate | Low | |
| Fucus ceranoides is permanently attached to the substratum, so would be removed upon substratum loss. In general, fucoids recruit rapidly to cleared areas, but populations of this species are restricted to brackish waters so new individuals may have to recruit in from some distance. | ||||
| High | Moderate | Moderate | Moderate | |
| If smothering occurred when the tide was out, the whole plant would be buried underneath the sediment, preventing photosynthesis and killing the plant. If smothering occurred when the plant was immersed, some of the frond may protrude above the sediment and not be affected. In general, fucoids recruit rapidly to cleared areas, but populations of this species are restricted to brackish waters so new individuals may have to recruit in from some distance. | ||||
| Tolerant | Not relevant | Not sensitive | Moderate | |
| Fucus ceranoides is a resident of estuaries, where high levels of siltation naturally occur, so is likely to be tolerant of this factor. | ||||
| No information | ||||
| High | Moderate | Moderate | Low | |
| An increase in the level desiccation may result in the upper limit of the species distribution on the shore becoming depressed. A decrease in the level of desiccation may allow the species to grow further up the shore. In general, fucoids recruit rapidly to cleared areas, but populations of this species are restricted to brackish waters so new individuals may have to recruit in from some distance. | ||||
| High | Moderate | Moderate | Low | |
| Fucus ceranoides would suffer desiccation and nutrient stress on increased exposure to air. An increase in the period of emersion would cause the upper limit of the population to be depressed. Reduced exposure to air would enable Fucus ceranoides to extend further up the shore. | ||||
| No information | ||||
| Intermediate | Moderate | Moderate | Moderate | |
| An increase in water flow rate may tear plants of the substratum or mobilise the substratum with the plants attached. The plants with substratum may be washed away to conditions unsuitable for the growth of the species. In general, fucoids recruit rapidly to cleared areas, but populations of this species are restricted to brackish waters so new individuals may have to recruit in from some distance. | ||||
| No information | ||||
| Low | Moderate | Low | Moderate | |
| Decreases in temperature are unlikely to have any effect as the species extends to Northern Norway where temperatures are much cooler. Fucus vesiculosus, a similar species, can withstand temperatures of up to 30 degrees C, so the species is also likely to be tolerant of increases in temperature. | ||||
| No information | ||||
| Low | Immediate | Not sensitive | Moderate | |
| The growth rate of Fucus ceranoides may be lowered due to a reduction in the light available for photosynthesis. On return to previous turbidity levels, the growth rate would quickly return to normal. | ||||
| No information | ||||
| Intermediate | Moderate | Moderate | Low | |
| An increase in wave exposure could cause the plants to be torn off the substratum or mobilise the substratum with the plants attached. The plants with substratum may be washed away to conditions unsuitable for the growth of the species. Increased exposure would also batter the fronds against the substratum subjecting them to abrasion. In general, fucoids recruit rapidly to cleared areas, but populations of this species are restricted to brackish waters so new individuals may have to recruit in from quite far away. | ||||
| No information | ||||
| Not relevant | Not relevant | Not relevant | Not relevant | |
| Seaweeds have no known mechanism for noise perception | ||||
| Not relevant | Not relevant | Not relevant | Not relevant | |
| Seaweeds have no known mechanism for visual perception | ||||
| Intermediate | Moderate | Moderate | Low | |
| Abrasion may damage and remove fronds and germlings. Abrasion may result from human trampling which can significantly reduce the cover of fucoid algae on a shore (Holt et al., 1997). In general, fucoids recruit rapidly to cleared areas but populations of this species are restricted to brackish waters. Where populations are restricted to the affected area, new individuals may have to recruit in from some distance. | ||||
| High | Moderate | Moderate | Moderate | |
| Fucus ceranoides is permanently attached to the substratum so once removed a plant cannot re-establish itself. In general, fucoids recruit rapidly to cleared areas, but populations of this species are restricted to brackish waters so new individuals may have to recruit in from some distance. | ||||
Chemical pressures
| Intolerance | Recoverability | Sensitivity | Evidence/Confidence | |
| No information | Not relevant | No information | Not relevant | |
| Insufficient information | ||||
| Low | Very high | Very Low | Low | |
| Fucus ceranoides accumulates heavy metals in its tissues (Barreiro et al., 1993). However, little is known of how heavy metals affect the species although fucoids are generally quite robust to chemical pollution and do not appear to be harmed by heavy metals (Holt et al., 1997). Intolerance is therefore, reported to be low. Recovery will be rapid as growth returns to normal. | ||||
| No information | Not relevant | No information | Not relevant | |
| Insufficient information | ||||
| No information | Not relevant | No information | Not relevant | |
| Insufficient information | ||||
| High | Moderate | Moderate | Moderate | |
| Fucus ceranoides was found to be absent from areas of high nutrient pollution in the Tyne estuary by Suryono & Hardy (1997). In low concentrations nutrients enhance the growth rate of the alga but in high concentrations growth is stopped. In general, fucoids recruit rapidly to cleared areas, but populations of this species are restricted to brackish waters so new individuals may have to recruit in from some distance. | ||||
| Intermediate | Moderate | Moderate | Moderate | |
| Fucus ceranoides is adapted to living in brackish waters. It grows fastest at 11 psu and will die when exposed to freshwater for several weeks. Suryono & Hardy (1997) and Khfaji & Norton (1979) both found that vegetative branches of Fucus ceranoides died within 5-6 weeks when grown in fully saline water. However, Baeck et al., (1992) found that Fucus ceranoides survived and grew for 11 weeks in salinities of up to 45 psu. | ||||
| No information | ||||
| No information | Not relevant | No information | Not relevant | |
| Insufficient information | ||||
Biological pressures
| Intolerance | Recoverability | Sensitivity | Evidence/Confidence | |
| No information | Not relevant | No information | Not relevant | |
| Insufficient information | ||||
| No information | Not relevant | No information | Not relevant | |
| Insufficient information | ||||
| No information | Not relevant | No information | Not relevant | |
| Insufficient information | ||||
| No information | Not relevant | No information | Not relevant | |
| Insufficient information | ||||
Additional information
Importance review
Policy/legislation
- no data -
Status
| National (GB) importance | - | Global red list (IUCN) category | - |
Non-native
| Native | - | ||
| Origin | - | Date Arrived | - |
Importance information
-none-Bibliography
Baeck, S., Collins, J.C. & Russell, G., 1992. Recruitment of the Baltic flora: the Fucus ceranoides enigma. Botanica Marina, 35, 53-59.
Barreiro, R., Real, C., Carballeira, A., 1993. Heavy-metal accumulation by Fucus ceranoides in a small estuary in north-west Spain. Marine Environmental Research, 36, 39-61.
Fish, J.D. & Fish, S., 1996. A student's guide to the seashore. Cambridge: Cambridge University Press.
Hardy, F.G. & Guiry, M.D., 2003. A check-list and atlas of the seaweeds of Britain and Ireland. London: British Phycological Society
Howson, C.M. & Picton, B.E., 1997. The species directory of the marine fauna and flora of the British Isles and surrounding seas. Belfast: Ulster Museum. [Ulster Museum publication, no. 276.]
JNCC (Joint Nature Conservation Committee), 1999. Marine Environment Resource Mapping And Information Database (MERMAID): Marine Nature Conservation Review Survey Database. [on-line] http://www.jncc.gov.uk/mermaid
Khfaji, A.K. & Norton, T.A., 1979. The effects of salinity on the distribution of Fucus ceranoides. Estuarine, Coastal and Shelf Science, 8, 433-439.
Lein, T.E., 1984. Distribution, reproduction and ecology of Fucus ceranoides L. (Phaeophyceae) in Norway. Sarsia, 60, 75-81.
Norton, T.A. (ed.), 1985. Provisional Atlas of the Marine Algae of Britain and Ireland. Huntingdon: Biological Records Centre, Institute of Terrestrial Ecology.
Suryono, C.A. & Hardy, F.G., 1997. Studies on the distribution of Fucus ceranoides L. (Phaeophyta, Fucales) in estuaries on the north-east coast of England. Transactions of the Natural History Society of Northumbria, 57, 153-168.
Datasets
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.
Environmental Records Information Centre North East, 2018. ERIC NE Combined dataset to 2017. Occurrence dataset: http://www.ericnortheast.org.ukl accessed via NBNAtlas.org on 2018-09-38
Fenwick, 2018. Aphotomarine. Occurrence dataset http://www.aphotomarine.com/index.html Accessed via NBNAtlas.org on 2018-10-01
Fife Nature Records Centre, 2018. St Andrews BioBlitz 2014. Occurrence dataset: https://doi.org/10.15468/erweal accessed via GBIF.org on 2018-09-27.
Fife Nature Records Centre, 2018. St Andrews BioBlitz 2016. Occurrence dataset: https://doi.org/10.15468/146yiz accessed via GBIF.org on 2018-09-27.
Lancashire Environment Record Network, 2018. LERN Records. Occurrence dataset: https://doi.org/10.15468/esxc9a accessed via GBIF.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 1995 to 1999. Occurrence dataset: https://doi.org/10.15468/lo2tge accessed via GBIF.org on 2018-10-01.
Merseyside BioBank., 2018. Merseyside BioBank (unverified). Occurrence dataset: https://doi.org/10.15468/iou2ld 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: 2023-03-31
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.
South East Wales Biodiversity Records Centre, 2018. SEWBReC Algae and allied species (South East Wales). Occurrence dataset: https://doi.org/10.15468/55albd accessed via GBIF.org on 2018-10-02.
South East Wales Biodiversity Records Centre, 2018. Dr Mary Gillham Archive Project. Occurance dataset: http://www.sewbrec.org.uk/ accessed via NBNAtlas.org on 2018-10-02
Citation
This review can be cited as:
Last Updated: 03/07/2007
