Don't be tempted to stray towards commercial foraging, even if you do it out of generosity, not for payment. That's something that could lead to over-exploitation and impact the wider ecosystem.
At high tide limpets use their feet to wander from their rock to get their radulas into seaweed. The seaweeds that limpets graze upon are autotrophs or primary producers, at the base of the food chain.
They provide food and habitat for an array of herbivores. Snails, sea urchins, crabs, limpets, abalone and seals are all seaweed gourmands. And to this list, we should add an increasing number of human enthusiasts.
I live on the Outer Hebridean Isle of South Uist, where at times, the white sandy beaches are strewn with waist high tangles of storm wrecked seaweed.
Growing vegetables on a windswept Isle is a labour of love and heavily dependent on access to shelter. Some Islanders enjoy the fruits of their labours ... but I rely on the Island's one supermarket. However the terrestrial vegetables on display often look weary after transport across the Minch and down the Isles.
And in stormy weather the supermarket shelves may well end up bare. In a moment of needs-must I turned to the 'sea vegetables' on my local beach. There was no looking back. Since then I have experimented with numerous varieties - all evoking the sea in their scent and flavour, but each distinct, different, and delicious, at least when prepared correctly.
Keep it a personal pleasure ...
Sea vegetables should be cut from their hold fast where they bind to the rock or seabed. A plant has roots; marine algae have holdfasts. Pick a little here and there, no more than a sixth of any individual plant - and don't pick for the neighbourhood, just for yourself.
What of this current chic trend for us top consumers to get in on the seaweed act too? Not only do kelp 'forests' provide the habitat for a wide range of species but they also reduce the wave force on many exposed shores.
So don't be tempted to stray towards commercial foraging, even if you do it out of generosity, not for payment. That's something that could lead to over-exploitation and impact the wider ecosystem. 'Need not greed' is the best motto for seaweed foragers.
An accidental science project revealed how crucial sea otters are to kelp forests - precisely by keeping herbivores at bay. When Jim Estes arrived on the Aleutian Islands (Alaska) in 1970, he noticed that where sea otters inhabited islands there were kelp forests. The islands without sea otters were carpeted by sea urchins but not kelp. The sea urchins had flourished unrestricted, at the expense of the kelp.
What to look for at a low spring or big tide - maximum exposure:
My hint is to use a separate bag for each species you collect. Seaweed foraging is an occasion when a plastic bag is recycled with good conscience. Cotton or other material bags have no merit; some seaweeds are veritable sponges.
Although storm cast dulse, growing as an epiphyte, may glisten in the sun, storm damaged seaweed is not fit for eating - but is fine for crafting, herbarium-style.
Carrageen: this may be Chodrus crispus or Grape Pip Weed Mastocarpus stellatus both work as a setting agent. The Grape Pip Weed, in my opinion, gives a better set - and Dickensian Aberdonian sellers concurred. Think of carrageen as vegan gelatine. There's a recipe for marshmallows in Seaweed in the Kitchen. It gives a shine to casseroles too. There is certainly more to carrageen than the Hebridean milk pudding. That said carrageen does show a particular reaction with milk: if you use milk in your recipe you will need less carrageen.
Dulse: Palmaria palmata, a red seaweed, has been heralded as the new bacon by researchers at Oregon State University; a point of interest to those averse to washing bacon grill pans. Dulse is also a thickener, adding texture to soups and sauces.
Laver: Porphyra spp. is excellent for novice seaweed cooks to try out. It is similar to the nori you find in sushi bars. Nori is farmed and comes from a species of the genus Pyropia, typically Pyropia yezoensis or P. tenera. This latter species is probably non existent in the wild. Laver, however, is available, and in the intertidal zone which is useful because you can find and harvest it on a low, sluggish neap tide. In comparison with some seaweeds, its taste is mild.
Sea lettuce: Ulva lactuca looks like common or garden lettuce and, in my view, can be a bully to other ingredients, if not added wisely. It likes human effluent so pick it in rock pools, not close to suspect freshwater drains.
Sugar kelp: Saccharina latissima is a crinkly brown seaweed that reminds me of a mermaid's tail. It can grow to bath mat size but pick it when it is young and tender. Washed and shredded it will cook in the same time as a root vegetable.
Dabberlocks: Alaria esculenta is my current favourite, especially the smaller succulent 'wings'. Its botanical name (Latin for edible wings) gives it the food thumbs up - it was deemed to be food by Linnaeus.
What to do with seaweed in the kitchen:
Wash seaweed well and in the case of laver, wash it again. Laver retains both sand and water - like a sponge. Allow laver extra time to relax in the colander too. Place a jug underneath and expect to collect copious amounts of red sea stock.
Laver is a red seaweed but may appear olive or even bin liner black. A salad spinner is useful to remove excess water. Tiny shells have a liking for carrageen (as they do pepper dulse) so wash this seaweed as well as possible in a rock pool, before you leave the beach.
Storage: Deal with fresh seaweed as soon as possible. It will keep in the fridge for 3-4 days and dulse and laver freeze well but do wash fresh seaweed before storing. Sea spaghetti which is now available in a supermarket should be blanched before it is frozen. Treat this seaweed as you would pasta. Unlike pasta it will change colour when it is thrown in boiling water - from brown to green. Dulse are kelp are kitchen chameleon too.
Drying: Washed seaweeds can be dried and then ground with ease. If you are keen on this idea, invest in a food dehydrator. Dried seaweed is expensive because fresh seaweed is so full of water. The joy of dried seaweed is that the taste is concentrated; so less is more.
Commercial seaweed harvesting
Wild seaweed is increasingly being harvested commercially in Britain, both by hand and machine. Large scale commercial seaweed foragers require a licence from the Crown Estate. Exactly how, beyond artisan producer integrity, the harvesting is sustainably monitored, I'm uncertain.
Anecdotal evidence from Norway as well as from California has already linked kelp dredging with coastal erosion. Beyond the expansion in the pharmaceutical and food industries seaweed is increasingly seen as a commercially viable biofuel resource.
In a 2012 Outer Hebridean study, Juliet Brodie & Jo Wilbraham noted positively that the impact of harvesting egg wrack Ascophyllum nodosum on diversity was low. Professor Brodie however, stressed that any increase in harvesting would need to be monitored. It seems to be widely accepted that the removal of seaweed has the potential to alter the dynamics of the ecosystem.
Scottish crofters currently harvest storm cast kelp of inconsistent quality, for the seaweed industry but not on the scale that would be required for meaningful fuel production.
Do pick your own seaweed and experiment in your kitchen. If, however seaweed becomes too chic (indeed Jamie Oliver is spreading the word) we must ensure that it is harvested sustainably. In my opinion this will mean that we will need to farm seaweed.
The book: 'Seaweed in the Kitchen' by Fiona Bird is a study of the history of seaweed, harvesting and its use in a British Kitchen. It is published by Prospect Books.
The study: 'Seaweed Survey Of The Outer Hebrides - 30th July-7th August 2012' by Juliet Brodie & Jo Wilbraham is published by the Crown Estate.
Fiona Bird is the author of Kids' Kitchen (Barefoot Books 2009), The Forager's Kitchen (Cico Books 2013) and her third book is about seaweed (Prospect Books). She is married to an Island doctor and is the mother of six children (mostly boys). She loathes over-inquisitive seals.