Seaweed descriptions and pictures of Seweeds of the Noth-east Atlantic

Here is a selection of 250 or so of the larger seaweeds from the north-eastern Atlanic, many of which occur in Norway, Britain, Ireland, Atlantic France and Spain, and in Portugal. Web pages have so far been completed for those with links (underlined). Please be patient while the descriptions and pictures are refined. It is also intended to provide a synoptic, interactive key later. Suggestions for additions and corrections to Michael Guiry. Where there is no common name in brackets, we have not discovered as suitable one.

Identification guide for selected marine non-native species (National Museum Wales). (Download free PDF, about 3.5 Mb).

Brown algae (Kelps, wracks, etc.)

*=adventive (introduced) species

Red algae (Dulse, Carrageen Moss, etc.)

*=adventive (introduced) species


Patella vulgata © M.D. Guiry

Green algae (Sea Lettuce, etc.)

*=adventive (introduced) species


Zostera marina © M.D. Guiry

Seagrasses (A flowering plant, not an alga)

Photographs on this page © M.D. Guiry

Last modified: October 20 2022