BIOTIC

BIOTIC Species Information for Saccharina latissima
All Taxonomy Biology Distribution Reproduction

Researched by	Nicola White and Charlotte Marshall	Data supplied by	MarLIN
Refereed by	Dr Joanna Jones
General Biology
Growth form	Foliose Forest	Feeding method	Photoautotroph
Mobility/Movement	See additional information Permanent attachment	Environmental position	Epilithic Epifloral See additional information
Typical food types	No text entered	Habit	See additional information
Bioturbator	Not relevant	Flexibility	High (>45 degrees)
Fragility	Intermediate	Size	Large(>50cm)
Height		Growth Rate	1.1 cm/day
Adult dispersal potential	Not relevant	Dependency	Independent
Sociability	Solitary
Toxic/Poisonous?	No
General Biology Additional Information	Growth Laminaria saccharina grows fastest from late winter to spring at a rate of about 1.1 cm/day although growth rates of up to 4.87 cm/day have been recorded. Growth then declines from June onwards and may cease in late summer. The reduction in summer growth rate is thought to be due to nitrate limitation (Sjøtun, 1993). The length:width ratio of newly grown lamina tissue varies throughout the year and is highest during the periods of fast growth, that is, December to June (Sjøtun, 1993). By shifting effort towards growth in width in late summer, it is possible that the plant can maximize the lamina area for autumn and winter and therefore increase the amount of stored carbon available for plants at this time (Sjøtun, 1993). The seasonal growth pattern results in annual growth rings or lines in the stipe, which can be used to age the plant. The species may occur as an annual opportunist. Morphology The shape of the frond can vary with environmental conditions. Gerard (1987) found that plants subjected to constant longitudinal tension (as would be expected in higher water flow rates) may become morphologically enhanced to a more streamlined shape. In laboratory simulations, he found that plants subjected to longitudinal stress had significantly narrower blades and a significantly higher rate of cell elongation at the end of the six week experiment, compared to those plants that had not experienced the same stress. Laminaria saccharina plants from wave exposed sites have short, solid stipes and short, narrow and thick tissued fronds with closely wrinkled blades (Lüning, 1990). In contrast, plants from sheltered sites have a broad thin blade with an undulate surface (Lüning, 1990). Mobility The majority of Laminaria saccharina plants are permanently attached to the substratum. This may include bedrock and large boulders down to pebbles. Even sand grains can provide an attachment sufficient enough to allow the young sporophytes to segment and develop into new plants (Burrows, 1958). However, Burrows (1958) also described large populations of 'loose lying' Laminaria saccharina in Port Erin Bay, Isle of Man, which showed no signs of ever having been attached. She concluded that, apart from at the earliest stages of sporophyte development, an attachment to the substratum is not essential for the growth of the plant.
Biology References