It's said that an Uist man of old, looking out over the sea for signs of the longed-for seaweed floating in would say, 'How worthy is the ocean of honour', while his grandson by his side, also gazing, remarks, 'Not a blade of seaweed will we get till this wind changes.'
The Scots have always culled the maximum benefit from the land and sea for thousands of years. Of necessity, seaweed was once used in large quantities to enrich the soil - a yield of barley of from ten to thirty heads per single seed was not uncommon. As it drifted ashore, crofters would go to the beach to collect it bringing it back to their fields and then plough it into the earth. Seaweed's value didn't end with being a fine manure, in the days of the salt tax the ashes of seaweed replaced salt in preserving fish and sea-birds for the winter and from the mid-18th century on kelp was used extensively in making glass and soap. And two or three forms of seaweed are still eaten in the Isles and at least two other are known to be edible and have been used to offset famine.
As said, the value for 'kelp' is actually found in the residue of slowly burnt seaweed. Baleshare, a low-lying island to the west of North Uist in the Western Isles, was the first home of the kelp industry in Scotland. In 1735 Hugh Macdonald of Baleshare invited a man from Ireland to come and teach him and his people how to prepare the kelp. But as he first allowed the fire to become too hot and reduced the seaweed to useless ash so that he became known as Rhuary-na-Luahigh - Rory, Maker of Ashes - and Baleshare became Lord of the Ashes.
As an industrial alkali kelp became much in demand toward the turn of the eighteenth century. Initially £1 a ton at first, the price continued to rise until during the Napoleonic War, kelp from the Hebrides Islands, where the weed was richest in soda salts and iodine, was fetching as much as £30 per ton. The sudden demand for kelp led to smaller and smaller crop yields from the farms. There are a variety of reasons for this; historically the farmers used the kelp as a fertilizer for the fields and it was collected as a right, with the commercial value established lairds issued the order that it must be paid for and these same farmers were working to collect the seaweed to pay their rents. Because crop yields were diminishing and the population was simultaneously increasing, potatoes replaced the traditional grains of oats and barley as the crop requires less land to yield similar amounts of food. After the Napoleonic War, 1825, the kelp market crashed and farmers were without this source of income. Were it not for the potato blight in 1847 hitting the British Isles destroying the potato crop throughout Ireland and Scotland the failure of the kelp industry might not have been so devastating. When tenants couldn't pay their rent, they were evicted from their crofts and their lairds turned the land over to grazing sheep, (it's been said) a more profitable venture than people.