Ulva compressa Linnaeus
Formerly widely known as Enteromorpha compressa.
Description: Compressed, elongated, hollow fronds with a green colour.
Habitat: Rock pools and sandy rocks, particularly in places with widely varying salinities such as upper-shore pools (below). Extremely tolderant to widely varying salinities and temperatures. Bubbles of oxygen (from photosynthesis) often apparent in the tubular fronds.
Distribution: Common through Britain and Ireland, and seemingly world-wide.
Similar species: Ulva (Enteromorpha) intestinalis which tends to be more tubular. Usage: Used dried in cooking, particularly with hens' eggs.
Photographs © M.D. Guiry