BBC Countryfile Magazine
COMMON SEAWEEDS OF THE BRITISH COAST
From microscopic phytoplankton to forests of kelp, seaweed is a valuable food source for wildlife and provides important shelter for many marine creatures. A late winter’s walk is the perfect time to get to know these nine species.
OARWEED Laminaria digitata
The most common kelp species in the UK, oarweed can grow more than two metres long, at depths reaching 10 metres.
SPIRAL WRACK Fucus spiralis
Common just below the high waterline on rocky shores, it has no bladders. It produces a mucus and curls up to conserve moisture.
THONGWEED Himanthalia elongata
Also called sea spaghetti, this is one of the UK’s longest native seaweeds. It grows close to the low tidemark on rocky shores.
TOOTHED WRACK Fucus serratus
Grows just above the low tidemark. Brown seaweeds are high in vitamin C and iodine. Dried toothed wrack is used as a condiment.
CHANNELED WRACK Pelvetia canaliculata
This wrack is found at the top of rocky shores and can survive up to eight days out of water. It curls at the sides, creating channels.
GUTWEED Ulva intestinalis
Found in many habitats, including rock pools, sand and mud. Dense mats of gutweed form valuable shelter for marine creatures.
BLADDER WRACK Fucus vesiculosus
Growing in the inter-tidal area, this wrack has pairs of round bladders that help it float. Boiled bladder wrack can ease swollen joints.
KNOTTED WRACK Acophylym nodosum
Another common brown seaweed dominant on sheltered rocky shores, this wrack has large egg-shaped air bladders to help it float.
SEA LETTUCE Ulva lactua
Grows in sheets in inter-tidal parts of rocky shores and estuaries and is the most tender UK seaweed. Can be deep fried to make crisps!