BIOTIC

BIOTIC Species Information for Laminaria digitata
All Taxonomy Biology Distribution Reproduction

Researched by	Jacqueline Hill	Data supplied by	MarLIN
Refereed by	This information is not refereed.
Distribution and Habitat
Distribution in Britain & Ireland	Most coasts of Britain and Ireland, including Rockall. Scarce along east coast of England, particularly between Ouse and Thames estuaries, due to turbidity and lack of hard substrata. Absent from Liverpool Bay and Severn estuary due to turbidity.
Global distribution	Recorded from the Atlantic coasts of Europe as far north as Novaya Zemlya and south to the Canary Islands, including Iceland. Also found in southern Greenland and east coast Canada, Quebec and North America from Hudson Straits to New York.
Biogeographic range	Not researched	Depth range	Lower intertidal to 20 m
Migratory	Non-migratory / Resident
Distribution Additional Information	There is a marked difference in the lower depth limit of Laminaria digitata between the various parts of its geographical range. Depth is determined by water clarity and competition. In the Isle of Man the lower limit is at 1-2m below the lowest astronomical tide and at Milford Haven it has been recorded at 5m. In the north of its range Laminaria digitata extends to depths of 15-20m (Birkett et al., 1998b). Where %Laminaria hyperborea% thrives it out-competes Laminaria digitata limiting the lower limit of Laminaria digitata (Kain 1975). The salinity optimum for Laminaria digitata is full salinity. However, on the Norwegian coast, subject to seasonal fluctuations in salinity, Sundene (1964) found healthy Laminaria digitata plants growing between 15 and 25psu.

Substratum preferences	Bedrock Large to very large boulders Small boulders Cobbles Pebbles Artificial (e.g. metal/wood/concrete)	Physiographic preferences	Open coast Strait / sound Ria / Voe Enclosed coast / Embayment
Biological zone	Sublittoral Fringe Lower Eulittoral Upper Infralittoral	Wave exposure	Very Exposed Exposed Moderately Exposed Sheltered
Tidal stream strength/Water flow	Very Strong (>6 kn) Strong (3-6 kn) Moderately Strong (1-3 kn) Weak (<1 kn)	Salinity	Full (30-40 psu)
Habitat Preferences Additional Information
Distribution References	Guiry & Blunden, 1991, Birkett et al., 1998b, Kain, 1979, Kain, 1975, Bolten & Lüning, 1982, Sundene, 1964, Bassindale et al., 1948, Hardy & Guiry, 2003, Guiry, 2006,