|Basic Information||Biotope classification||Ecology||Habitat preferences and distribution||Species composition||Sensitivity||Importance|
Image Keith Hiscock - Steep bedrock shore with Corallina officinalis (ELR.Coff). Image width ca 1 m.
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LR.ELR.FR.Coff recorded () and expected () distribution in Britain and Ireland (see below)
Coralline turf communities are described in detail by Hagerman (1968), Dommasnes (1968, 1969), Hicks (1985), Grahame & Hanna (1989), Crisp & Mwaiseje (1989), Bamber (1988) and Bamber & Irving ( 1993). The following information is based the above references and lists of species in the MNCR database (JNCC 1999). Macroalgae including Corallina officinalis, Mastocarpus stellatus, Osmundea pinnatifida and Lomentaria articulata, provide primary productivity either directly to grazing fish and invertebrates or indirectly, to detritivores and decomposers, in the form of detritus and drift algae or as dissolved organic material and other exudates.
Macroalgal species compete for light, space and, to a lesser extent, nutrients, depending on the growth rates, size and reproductive pattern of each species. However, Corallina officinalis probably has a competitive advantage in wave exposed habitats due to their robust coralline fronds and resistant vegetative crustose bases (see Littler & Kauker, 1986).
Corallina officinalis provides substratum for spirorbid worms (e.g. Spirorbis corallinae), epiphytes and periphyton, depending on location, including microflora (e.g. bacteria, blue green algae, diatoms and juvenile larger algae), and interstices and refuges from predation for a variety of small invertebrates (see habitat complexity below).
Amphipods (e.g. Parajassa pelagica and Stenothoe monoculoides), isopods (e.g. Idotea pelagica and Jaera albifrons) and other mesoherbivores graze the epiphytic flora and senescent macroalgal tissue, which may benefit the macroalgal host, and may facilitate dispersal of the propagules of some macroalgal species (Brawley, 1992b; Williams & Seed, 1992). Mesoherbivores also graze the macroalgae but do not normally adversely affect the canopy (Brawley, 1992b).
Grazers of periphyton (bacteria, blue-green algae and diatoms) or epiphytic algae include harpacticoid copepods, small gastropods (e.g. Rissoa spp. and Littorina neglecta.
Coralline algae are probably relatively grazing resistant (Littler & Kauker, 1984) and few species graze the corallines directly except perhaps chitons and limpets of the genus Tectura. Grazers probably benefit the coralline turf by removing epiphytic and ephemeral algae (e.g. Ulva), which could potentially smother the turf.
Suspension feeders include Semibalanus balanoides, the spirorbid Spirorbis corallinae, the sponge Halichondria panicea, juvenile bivalves and interstitial bivalves such as Lasaea adansoni and Turtonia minuta, and the tubiculous amphipod Parajassa pelagica.
Turbellarians, nematodes and halacarid mites are probably interstitial predators on other nematodes, mites, and harpacticoid copepods (Hicks, 1985).
When the biotope is covered by the tide, intertidal fish such as gobies, blennies and clingfish, and the juveniles of larger inshore fish are probably active predators of amphipods, isopod, ostracods and harpacticoid copepods. The physical complexity of the Corallina officinalis turf was reported to offer a refuge from predation for epiphytic invertebrates (Coull & Wells, 1983; Hicks, 1985). Choat & Kingett (1982) did not detect any significant effect on fish predation in exclusion experiments. In harpacticoid copepods, although large numbers were consumed by fish little effect on the population resulted (Hicks, 1980). However, Hicks (1985) noted that considerable evidence of predators regulating prey abundance was available.
The brittlestar Amphipholis squamata probably is a detritivore within the turf.
Choat & Kingett (1982) reported that the abundance of amphipods in a New Zealand coralline turf habitat peaked in summer and declined to a low in winter, while polychaetes showed a peak of abundance in winter decreasing in summer. But ostracods showed a relatively low abundance throughout the sampling period (Choat & Kingett, 1982). Bamber (1993) examined coralline turf dominated runoffs in the Bristol Channel, and noted that the amphipod Melita palmata and the brittlestar Amphipholis squamata recruited after the summer growth of the coralline turf reaching a peak abundance in autumn. But the small isopod Jaera albifrons recruited to the turf in late winter and the polychaete Platynereis dumerilii showed an erratic pattern of abundance (Bamber & Irving, 1993). However, Bamber & Irving (1983) noted considerable variation in seasonal abundance between sites (runoffs) on the same shore.
Secondary productivity of the invertebrate fauna may be high and coralline turf may support high abundances of invertebrates. For example, Choat & Kingett (1982) recorded the following numbers of epiphytic fauna: amphipods 1038 / 0.01m²; ostracods 219 /0.01m², and polychaetes 134 /0.01m².
The propagules of most macroalgae tend to settle near the parent plant (Schiel & Foster, 1986; Norton, 1992; Holt et al., 1997). For example, the propagules of fucales are large and sink readily and red algal spores and gametes and immotile. Norton (1992) noted that algal spore dispersal is probably determined by currents and turbulent deposition (zygotes or spores being thrown against the substratum). For example, spores of Ulva sp. (as Ulva) have been reported to travel 35km, Phycodrys rubens 5km and Sargassum muticum up to 1km, although most Sargassum muticum spores settle within 2m. The reach of the furthest propagule and useful dispersal range are not the same thing and recruitment usually occurs on a local scale, typically within 10m of the parent plant (Norton, 1992). In clearance studies in the subtidal Kain (1975) noted that on a single block cleared every two months, most biomass belonged to Rhodophyceae in winter, Phaeophyceae in spring and Chlorophyceae in late summer, and concluded that recruitment was dependant on spore availability. For example, spore production in Mastocarpus stellatus is maximum between September to December (Dixon & Irvine, 1977), spores of Osmundea pinnatifida are present in October and December to June (Maggs & Hommersand, 1993), while the spores of Lomentaria articulata are available all year round with a peak in summer (Irvine, 1983).
Recruitment of Patella vulgata fluctuates from year to year and from place to place (Bowman, 1981). Fertilization is external and the larvae are pelagic for up to two weeks before settling on rock at a shell length of about 0.2mm. Winter breeding occurs only in southern England, in the north of Scotland it breeds in August and in north-east England in September. Reproduction is probably similar in Patella ulyssiponensis, except that it may be a protandrous hermaphrodite, spawning in October in south-west Ireland (Fish & Fish, 1996). The larvae of the blue-rayed limpet Helcion pellucidum settle on encrusting corallines and migrate to Mastocarpus stellatus as they grow and finally to Laminaria spp. via Himanthalia elongata (McGrath, 1992; see MarLIN review).
Barnacle recruitment can be very variable because it is dependent on a suite of environmental and biological factors, such as wind direction and success depends on settlement being followed by a period of favourable weather. Long term surveys have produced clear evidence of barnacle populations responding to climatic changes. During warm periods Chthamalus spp. predominate, whilst Semibalanus balanoides does better during colder spells (Hawkins et al., 1994). Release of Semibalanus balanoides larvae takes place between February and April with peak settlement between April and June.
Many species of mobile epifauna, such as polychaetes have long lived pelagic larvae and/or are highly motile as adults. Gammarid amphipods brood their embryos and offspring but are highly mobile as adults and probably capable of colonizing new habitats from the surrounding area (e.g. see Hyale prevosti review). Similarly, isopods such as Idotea species and Jaera species brood their young. Idotea species are mobile and active swimmers and probably capable to recruiting to new habitats from the surrounding area by adult migration. Jaera albifrons, however, is small and may take longer to move between habitats, and Carvalho (1989) suggested that under normal circumstances movement was probably limited to an area of less than 2m. Hicks (1985) noted that epiphytic harpacticoid copepods lack planktonic dispersive larval stages but are active swimmers, which is therefore the primary mechanism for dispersal and colonization of available habitats. Some species of harpacticoids are capable to moving between low and mid-water levels on the shore with the tide, while in other colonization rates decrease with increasing distance form resident population. Overall immigration and in situ reproduction were thought to maintain equilibrium populations exposed to local extinction, although there may be local spatial variation in abundance (see Hicks, 1985).
The small littorinids Littorina saxatilis and Littorina neglecta are ovoviviparous, releasing miniature adults. Therefore, local recruitment is probably good, whereas long distance recruitment is probably poor. The interstitial bivalve Lasaea adansoni also broods its eggs, releasing miniature adults. However, Martel & Chia (1991b) reported bysso-pelagic or mucus rafting in small bivalves and gastropods in the intertidal, and suggested that drifting may be an effective mean of dispersal at the local scale, even for species that produce miniature adult offspring. The gastropod Rissoa parva lays eggs capsules, from which hatch veliger larvae with a prolonged pelagic life and potentially good dispersal capability (Fish & Fish, 1996).
This review can be cited as follows:
Tyler-Walters, H. 2005. Corallina officinalis on very exposed lower eulittoral rock. Marine Life Information Network: Biology and Sensitivity Key Information Sub-programme [on-line]. Plymouth: Marine Biological Association of the United Kingdom. [cited 12/12/2013]. Available from: <http://www.marlin.ac.uk/habitatecology.php?habitatid=130&code=1997>
Corallina officinalis on very exposed lower eulittoral rock
Corallina officinalis on very exposed lower eulittoral rock