by John Wombell (NOSAS)
Intertidal track ways on the Caolas peninsular
This is the first time that I have been aware of such features anywhere in the highlands or on other Scottish islands. The Caolas track ways are all about 2m wide where stones have been shifted left and right through the intertidal boulder spreads and outcrops to avoid lengthy routes around the hags over the soft and fragile swards of the saltings on the high water mark.
On the east side of Fadamull islet which is connected to the main island by a tombolo (a gravel bar covered at high tide) we found 7 cleared boat landing places most of which were connected to a naturally clear beach where boats could be pulled right up out of the water by a cleared track way that ran parallel to the shore. Otherwise the cleared landing places stopped short of the high tide mark – all rather strange as we don’t know what they were for. There are more than a dozen short lengths of seaweed drying walls on the islet but only one possible burning pit. Our thinking meantime is that the cleared landings were used to beach heavily laden small boats stacked to the gunwales with seaweed after which they were unloaded into carts or panniers using the intertidal track way off the sterns of the boats. Smart thinking as taking heavy wet seaweed off the sides of a small boat and staggering up a rocky beach with it would not have been very efficient. Whether this arrangement was purely associated with burning seaweed to produce kelp (soda ash) or for landing seaweed to be used as manure we don’t know. A bit of both maybe? Possibly also associated with the time when the iodine factory was functioning and calling for large supplies of seaweed.
Seaweed use as a manure was very important well into the 20th century for many coastal communities. Seaweed provides a readily available source of nitrogen and potassium i.e. it isn’t locked up in an insoluble form, but there is next to no phosphorous in seaweed. Seaweed has no lasting manurial effect and must be applied annually. Animal dung is the best natural source of phosphorous and either the arable land had to be rested and grazed on rotation or dung spread periodically on the land to maintain levels of phosphorous essential for plant growth. Continued cereal cropping using seaweed as the only manure soon results in falling yields.
At several locations around the island we found plenty of drying wall evidence but few or no burning pits nearby. Maybe all traces of the pits had been removed during subsequent land improvement or the seaweed was being taken to a central township location for burning? Other places had pits by the dozen. Continue reading