BIOTIC

BIOTIC Species Information for Hydrobia ulvae
All Taxonomy Biology Distribution Reproduction

Researched by	Lizzie Tyler	Data supplied by	University of Sheffield
Refereed by	This information is not refereed.
Distribution and Habitat
Distribution in Britain & Ireland	Found on all British and Irish coasts
Global distribution	Atlantic, English Channel, North Sea and Baltic. Insufficient detail available to map distribution.
Biogeographic range	Not researched	Depth range	0 - 20 m
Migratory	Non-migratory / Resident
Distribution Additional Information	Often found as high as the high level strand line in a dried blanket of green algae. They appear to be dead but rapidly revive when returned to more suitable conditions. Hydrobia ulvae does not undertake any true migration but considerable dispersal is possible through floating at the surface using a mucous raft. A cycle of climbing, floating and crawling up and down the shore has been hypothesised. Work by Barnes (1981) suggests however that climbing is simply part of normal browsing behaviour.

Substratum preferences	Sandy mud Muddy sand Mud	Physiographic preferences	Open coast Sealoch Ria / Voe Estuary Isolated saline water (Lagoon) Enclosed coast / Embayment
Biological zone	Upper Littoral Fringe Lower Littoral Fringe Upper Eulittoral Mid Eulittoral Lower Eulittoral Sublittoral Fringe Upper Infralittoral Lower Infralittoral	Wave exposure	Sheltered Very Sheltered Extremely Sheltered Ultra Sheltered
Tidal stream strength/Water flow	Moderately Strong (1-3 kn) Weak (<1 kn) Very Weak (negligible)	Salinity	Variable (18-40 psu) Low (<18 psu) Full (30-40 psu) Reduced (18-30 psu)
Habitat Preferences Additional Information
Distribution References	Graham, 1988, Fretter & Graham, 1994, Clay, 1960, Barnes, 1981, Anderson, 1971, Hayward & Ryland, 1990,