Country diary: The hard, heavy work of harvesting seaweed | Plants

Great olive-brown fankles of knotted wrack (Ascophyllum nodosum) swell up from the stony seabed. The fronds lift on faint ripples, rolling out from the boat bobbing nearby. Alexander, a local crofter, has been out since before low tide, moving laboriously up the shoreline, working the exposed seaweed.

Stooped over, he pulls long lengths of bladderwrack up from the water, then slices it with his sickle, leaving the holdfasts rooted to allow regrowth. Each cut handful is tossed into the net strung across the small bay behind. Round and back on repeat, pulling, grabbing, squatting, cutting. This is hard, heavy work.

Later, back at the shore, he cups a knotted tangle to show me. It has a clean, fecund smell, and a shine of slime that slips against the skin. The bladders are rubbery, strong enough to withstand the pressure of the sea, like the orange floats holding up his net.

Seaweed harvesting has always been a part of a crofter’s arsenal of survival. It can be applied straight to soil as a potassium-rich fertiliser, or rotted down with farmyard manure. I gather seaweed from our own shore for the polytunnel, collecting at most a tonne over the winter months, Alex will work this stretch on Loch Euport all summer, pulling six or seven tonnes a day.

Mechanised seaweed harvesting that rips out roots is heavily restricted here, but the small industry of human hands working in intertidal zones is centuries old. When crofts were created in the late 1700s, crofters also had to labour for whatever industry the landowner deemed profitable. Here, seaweed was harvested for the manufacture of soap and glass.

Whether kelp on the west coast, or bladderwrack on the east, crofters were paid by the tonne, as Alex is today. The difference now is that Alex sells to a local company that produces sustainable animal feed and fertiliser – from sea to land, as crofters have always done.

If he’s clever, he says, he can finish an hour before high tide. The full net is pulled tight and tied to the back of his wee wooden boat to be towed to the stone jetty. Engine droning across the evening water, lit violet and gold by the sunset, he rides the rising tide towards home.