RX Seaweeds checklist
A provisional and simplified Checklist of the commoner and larger seaweeds recorded or likely to occur in the wider coastal area of East Sussex to Kent – from the Atlas of British Seaweeds.
Most microscopic as well as larger species are included and are listed below alphabetically under the three Families. Rhodophyceae, Phaeophyceae and Chlorophyceae. Some have common names which are given.
Much more recording needs to be done to have an up-to-date account of the species and status of Seaweeds along the Hastings coast.
Seaweed species are highly adapted to particular niches and there are many species. Seaweeds are algae, primitive plants some of which are associated with the microscopic phytoplankton of the sea while others are larger and attached to physical surfaces in or near the sea by means of holdfasts. These basal structures act as physical anchors for the plant but they do not take in water or nutrients and therefor are not roots as such. However as plants they have chlorophyll and produce energy by photosynthesis in the same manner as do plants on the land. Carbon dioxide and water are synthesised into glucose – and oxygen is released as a part of the process.
Seaweeds are highly adapted to a stressful environment influenced by the gravitational effect of the Moon on the sea. There is a community ecology with zonation of seaweed types depending on the environmental conditions on any part of the coast. This in turn provides many types of habitat for other marine life.
Seaweeds reproduce themselves in a complex life history, with a tiny stage and a larger spore-producing stage.
Rhodophyceae (Red Seaweeds) have green chlorophyll mixed with phycoerythrin, a red pigmentation.
Phaeophycea (Brown Seaweeds) contain the pigment fucoxanthin.
Chlorophyceae (Green Seaweeds) have green chlorophyll.
Calliblepharis ciliata Widespread.
Ceramium virgatum Distinctive. Grows on other seaweeds.
Chondrus crispus Irish Moss. Rocks and pools of the lower shore. Widespread.
Corallina officinalis Coral Weed. Pink chalky red.
Delesseria sanguinea Sea Beech. Shape of a red Beech tree leaf attached to rock.
Dilsea carnosa Red Rags. Distinctive bright red.
Dumontia contorta Long, twisted fronds. Widespread.
Furcellaria lumbricalis Many branced tufts of reddish-brown fronds.
Halurus equisetifolius Sea Mare’s-tail.
Halurus flosculosus Tufted fronds of stiff hairs.
Lomentaria articulata Bead-weed.
Mastocarpus stellatus Grape Pip Weed.
Osmundea pinnatifida Pepper Dulse. Fern-like with strongly built fronds.
Palmaria palmata Dulse. Distinctive broad fronds and small holdfast.
Phymatolithon laevigatum Maerl. Unattached coralline.
Phymatolithon lenormandii Maerl. Unattached coralline.
Plumaria plumosa Feathery branches.
Polysiphonia lanosa An epiphyte, growing on Egg Wrack.
Porphyra leucosticta Laver.
Porphyra linearis Laver.
Porphyra purpurea Laver.
Porphyra umbilicalis Laver.
Pterothamnion plumula Whorles of divided branches on fronds.
Ascophyllum nodosum Egg Wrack. Grows on other seaweeds. Widespread.
Cladostephus spongiosus Slender fronds and branchlets. Widespread.
Dictyota dichotoma Yellowish flattened ribbon fronds with forked tips. Widespread.
Fucus serratus Serrated Wrack. Widespread with distinctive serrate fronds.
Fucus spiralis Spiral Wrack. Widespread. An upper shore seaweed.
Fucus vesiculosus Bladder Wrack. Sheltered rocky shores. Widespread.
Halidrys siliquosa Sea Oak. Distinctive fronds. Widespread.
Laminaria digitata Kelp. Conspicuous shiny brown frons. Widespread.
Laminaria hyperborea Cuvie.A large seaweed commonest in the southwest.
Leathesia difformis Punctured Ball Weed. Spherical yellow-brown on rocks and other seaweeds.
Pelvetia canaliculata Channel Wrack. Mainly in Western Britain.
Petalonia fascia Distinctively twisted fronds. Grows on rocks.
Sargassum muticum Wireweed. Slender branched with round bladders. Introduced.
Scytosiphon lomentaria Beanweed. Tubular fronds with constrictions are distinctive.
Stypocaulon scoparium Sea Flaxweed. Tufted brown on lower shores.
Bryopsis plumosa Hen Pen. Feathery tufted green seaweed quite widespread.
Chaetomorpha linum Delicate tangled tufts in rockpools. Widespread.
Cladophora rupestris Cladophora. Rock pools as a mat of delicate tufted strands.
Enteromorpha intestinalis Gutweed. Widespread on rock pools.
Rhizoclonium riparium Dense springy carpets of threads.
Ulva lactuca Sea Lettuce. Attached to rocks in sheltered areas and can be found on the beach.