Jane’s Journal

The history of Scotland's kelp industry

When we think of the Industrial Revolution we tend to think of cities. That is how it is taught in schools – the dark satanic mills, the factories and urban development – but that is not the whole story. Where there were natural resources – and people – to exploit, industry rooted itself in rural areas too, changing the landscape, the ecology and society. One of the biggest and most important industries in C18th Scotland was kelp production – employing tens of thousands of people in Orkney and the Hebrides. All that survives today is the buildings – odd drystone structures on the beaches, low strip walls for drying kelp, stone sheds for storing it, often covered in generations of sand. In the late C18th, however, Stronsay in Orkney was described as looking like a volcano; with all the kelp burning, crops were contaminated, cattle and horses dying, limpets (the food of the crofters in hard times) falling dead from their rocks, workers going blind. Arsenic deposits - concentrated from the seaweed – can still be detected in kelp burning areas. Industrial contamination.

Why did kelp become important?

In the C18th landowners in Scotland began to look for more of a financial return from their land. The traditional farming system in many areas was open fields, divided into strips and allocated anew each year. They were drawn by lot and farmed individually, and managed by a middleman tacksman who paid rent to the landowner, keeping some profit for himself. The tacksman was usually related to the laird and the system shored up a landowner or clansman’s personal power and feudal connections, but was not financially efficient. During the C18th the tacksmen were removed from their positions and a new system of crofts replaced the earlier run-rigs. Crofts were individual tenancies, with rent directly payable by the crofter to the landowner, there were no tenants’ rights and the size of a croft was deliberately too small to allow self-sufficiency. Rent was usually to be paid in cash, rather than kind, and it was estimated that 200 days’ work off farm would be required for a family to survive.

One of the main reasons for the move to a croft system in Scotland’s islands was the need for a workforce that would process seaweed into kelp.

Seaweed, when burned into ash, provided the alkali for making soap and glass - especially valued for the fine window glass that had become popular in the mid C18th. It could also be further processed elsewhere to extract iodine and silver iodide. By the early C19th 60,000 people were working in kelp manufacture in Scotland and £70,000 profit was being made in the Hebrides alone. At its peak crofters on Orkney were producing 3000 tonnes of kelp ash a year - it was worth £22 a tonne. The crofters were paid £2 a tonne.

Making kelp ash

This was an activity for all the family, the men collecting the seaweed, the children dragging it to dry and the women tending the fires. To make a tonne of kelp ash you need to collect about 20 tonnes (dry weight) of seaweed. The kelp burning season was June to August, so the seaweed was collected from the winter and spring storms and dried out on low drystone walls (kelp ricks which were covered with a heather thatch to protect from rain) and then stored in rough stone buildings until the summer. Seaweed can grow 30cm a day in the summer and a summer crop would be cut from the rocks with sickles and dried. The best part was the stem of the weed and it was important that no sand got into the mix. When it was time to burn the seaweed, a pit would be dug in the sand to collect the oily ash, it would be lined with flat stones and an iron grid put over it. The kelp would go on top and be burned. It needed to be kept moving constantly while it burned, stirred with long iron poles – a job done mainly by women – it took 14-24 hours to burn down and it was a heavy, smoky, stinking job. The putrid oil would drip through the grid and gradually harden into a solid mass. This stage of the process affected people’s eyesight and could lead to blindness. The cooling of the oil into a grey blue solid took between a week and a month - depending on the size of the pit - and it would be chopped with a flat iron spade when still soft into foot square lumps that could be more easily chiseled out and transported.

The end of the industry

What eventually led to the decline of the kelp industry wasn’t the terrible working conditions though, it was purely economics. The whole industry had been sustained by high import duties and a war with France. By 1822 the war had finished and trade agreements changed, as a result he price of kelp ash fell from £22 a ton to £5 and the profit disappeared. Without the kelp industry, life on the coastal crofts became untenable and there was mass depopulation. Some crofters headed to Glasgow and Edinburgh, others to North America.

All that survives now is the kelp ricks where the seaweed used to dry.

The ones on Westray in Orkney are particularly beautiful – parallel lines of drystone walls like an Andy Goldsworthy sculpture, looking out over the sea.

Photo: Brian Yurasits

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