The coast of the Falkland Islands is practically surrounded by kelp beds. The fringe can be up to a mile wide (1.6km). Offshore to depths of up to 30m (98ft) giant kelp Macrocystis pyrifera and tree kelp Lessonia flavicans grow. The shallower fringe zone between the low water mark and to around 12ft (3 to 4m) supports two large species of Lessonia and two of Durvillea. On the intertidal middle shore between high and low water levels there can be found smaller marine algae e.g. Sea lettuce Ulva sp.
Many invertebrates depend on kelp as a habitat and these in turn are depended upon for food for fish and birds, logger ducks being one of these. Early navigators knew that kelp was an unerring symbol of rocks under water. Lives have been lost because it is almost impossible to swim through a kelp bed to get to shore after a boat has overturned. Sometimes Falkland’s people are called 'kelpers'.
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Offshore to depths of up to 30m (98ft)
Giant and Basket Kelp Macrocystis pyrifera
Giant kelp has a root system of much tangled and woven fibres by which it attaches itself to rock on the sea bed. When these root systems wash ashore and dry out they resemble baskets. Hence it is often called ‘Basket Kelp’. Strands can grow to 60m (197ft). The golden brown fronds or ‘leaves’ are kept afloat and held up to the sun by small gas-filled bladders. They are long with wrinkly surfaces and serrated edges. Found offshore to depths of up to 30m (98ft).
Tree Kelp Lessonia sp
The Falklands are known to have 3 species of Lessonia L. Flavicans can be found in deep water offshore up to 30m (98 ft.), along with Giant kelp. Lessonia sp. is common on most open coasts. Its holdfast is branched and it often has a bare stem like a tree. Fronds or ‘leaves’ lack air sacs.
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Shallower water to around 3-4m (12ft)
The shallower fringe zone between the low water mark and to around 12ft (3 to 4m) supports two large species of Lessonia and two of Durvillea.
Durvillaea antarctica
This alga has large fronds, a leathery texture, and is greenish- gold brown. It does not have air bladders but floats because of its unique honeycomb structure within the alga’s blades. Durvillaea attaches itself to rocky shores with a strong round holdfast which is very strong but can fail due to molluscs and worms feeding on it. Due to its novel ability to float it is thought that it Durvillaea colonises other shores in this manner, sometimes carrying communities of invertebrates on it. Dried pieces can be found on Falkland beaches.
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The Intertidal middle shore zone between high and low water levels
Here the bright green Sea Lettuce Ulva sp grows. It is thin and fragile, almost transparent. It generally grows around 10 to 12 inches (25-30cm) but may reach up to 20 inches (50cm). It is food for Kelp Geese but can be cooked and eaten. Other seaweeds include the red Callophyllis sp and Iridaea sp which often forms dense patches of dark fronds. Several semi-circular crinkled leaves may be attached to a short stem; the entire seaweed might achieve a height of up to 16 inches (40cm). This seaweed too is grazed by Kelp Geese and might be fried and eaten. Seaweeds in this zone are important as they provide a habitat and/or food source for a wide range of marine fauna including Kelp geese, Steamer ducks, crustaceans, cephalopods and fish.
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Sources include:,Falkland Islands State of the Environment Report 2008 Otley H, Munro G, Clausen A, Ingham B. Wikipedia, Falklands Conservation, A Field Guide to the Wildlife of The Falkland Islands and South Georgia - Ian J Strange
Photographic credits: Header- Robert Maddocks
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