BIOTIC Species Information for Alaria esculenta
Researched byDr Harvey Tyler-Walters Data supplied byMarLIN
Refereed byDr Stefan Kraan
General Biology
Growth formStraplike / Ribbonlike
Feeding methodPhotoautotroph
Mobility/MovementPermanent attachment
Environmental positionEpifloral
Typical food typesNot relevant HabitAttached
BioturbatorNot relevant FlexibilityHigh (>45 degrees)
FragilityRobust SizeLarge(>50cm)
Height Growth Rate20 cm/month
Adult dispersal potentialNone DependencyIndependent
General Biology Additional Information
  • Alaria esculenta forms the main canopy in exposed rocky areas.
  • Alaria esculenta is a colonizing species that will occur in recently denuded rock surfaces in exposed to sheltered situations.
  • Maximum growth rates in the field (20 cm/month) occur in April and May (Isle of Man). Plants on adjacent rope aquaculture system had an average growth rate of 5 cm per day (Birkett et al., 1999b). Kain & Dawes (1987) reported growth rates of 10 cm per day during one spring growth period on a rope aquaculture system in the Isle of Man. However, fields trials with different strains of Alaria esculenta resulted in highest growth rates of 25 cm/month and lowest rates of 5 cm/month (Kraan pers. comm.).
  • In June and July growth slows and the blade becomes eroded and damaged by wave action depending on depth. Alaria esculenta in the lower eulittoral and upper sublittoral will erode away completely due to higher summer water temperatures and bleaching by sunlight. Populations at 2 m or more below low water survive (Kraan pers. comm.).
  • In strong currents and low wave action the blade may reach 4 m in length (e.g. Aran Islands, Ireland; Guiry, 1997).
  • A short stipe and narrow lamina base is characteristic of exposed conditions whereas in sheltered conditions the stipe is long and the lamina base wider (Widdowson, 1971).
Biology References Birkett et al., 1998b, Lüning, 1990, Connor et al., 1997(a), Lobban & Harrison, 1997, Dring, 1982, Hoek van den et al., 1995, Guiry, 1997, Widdowson, 1971, Kain & Dawes, 1987,
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