Kelp Forests - Scottish Natural Heritage

Uses of kelp
Cast kelp or ‘tangle’ has been utilised by generations of
Scots industrialists, farmers and crofters for manufacturing
and agricultural purposes, especially in the Highlands and
Islands.
The very name ‘kelp’ was first coined to mean the ash
produced after tangle burning, and only later came to refer
to the seaweed itself. This ash was first produced on a large
scale, particularly in Orkney and the Western Isles, in the
early 18th century; its high potash and soda content were
used in glass and soap manufacture. At its peak, between
1780 and 1830, the industry employed several thousand
people. The bulk of the ash was exported south for further
processing. With the discovery of other sources of potash
and soda, the industry declined.
Burning kelp, Birsay, Orkney (1880s)
Collected tangle set out to dry, Birsay, Orkney
It revived on a smaller scale, however, with the discovery in
the 19th century that iodine could be extracted from
laminarian ash, a practice which continued until the 1930s.
At that time imports of cheaper iodine extracted from
Chilean nitrate deposits ended the Scottish kelp industry.
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