Why we should grow and eat more seaweed


Seaweed is a superfood packed with nutrients

It's one of the healthiest, most versatile 'weeds' around. Asian countries have enjoyed the benefits for centuries. So where is the market for homegrown UK seaweed?

Was ever a group of aquatic plants more inaptly named? True, they're found in the sea, but the likes of kelp, dulse, laver, badderlocks, carrageen and tangle are so much more than weeds.

Seaweed, in fact, is something of an über underwater vegetable, with all the health-giving properties of any land-lubber superfood.

Already identified as a rich potential source of biomass energy, research by the Scottish Association for Marine Science has suggested that Scotland could develop its own aquaculture industry and grow seaweed as a sustainable biofuel. In 2005, Japan began piloting waterborne seaweed farms designed to absorb greenhouse gases before being harvested as biomass.

The Philippines has unveiled plans to extract ethanol from seaweed on a 100-hectare site, while earlier this year a Norwegian company patented a floating structure to cultivate seaweed on an industrial scale out to sea, calculating that just 0.05 per cent of European coastal regions could yield 75 million tonnes of seaweed a year and 3.2 billion litres of ethanol.

Seaweed can also be used as an agricultural and horticultural fertiliser, as a mineral-rich animal feed, as a bath, a shampoo, facial scrub and moisturiser...

The one thing we don't appear to do to any great extent in the UK is eat the stuff.

Eating British seaweed

But why not? With 650 edible varieties growing along the UK's 11,000 miles of coastline, it's a vast, healthy, organic and as yet untapped food resource. There's also money in it: in 2002, the seaweed industry was worth £4 billion, with world production at 11.5 million tonnes. Most of it is grown and consumed in Asia, however, with France, Europe's only commercial grower of any size, accounting for a paltry 35 tonnes.

According to Mark Turner of SeaVeg, a company that harvests and sells a range of seaweed (or 'sea vegetable') products from County Donegal in Ireland, successful commercial cultivation depends on one thing: the presence of a market. He says that while seaweed-growing has been trialled on certain UK fish farms, it hasn't been linked to demand from consumers.

As it is, what in the Orient - China, Japan and South Korea in particular - is lapped up as a luxury simply doesn't feature in the cultural and culinary history of this small corner of occidental Europe. Wales has its laver bread, of course (actor Richard Burton called it 'Welshman's caviar') and Ireland its carrageen seaweed pudding, but for all the considerable combined coastal length of the British Isles, seaweed is eaten on a disproportionately small scale.

Large-scale seaweed farming

Having established that people want to eat their produce, prospective phycological farmers will need somewhere to grow their crop. Since the seabed is the property of the Crown estates and the coastline is the responsibility of local authorities, getting permission for a large-scale seaweed farming enterprise would be one of the major obstacles. Turner says too that environmental concerns may ironically be another barrier to the promotion of this eco friendly foodstuff.

'Since it was announced that oil companies had an interest in harvesting seaweed to process for oils, the conservationist lobby has sought to have all areas of coastline protected. As a result there is more interest in prohibiting aquaculture than in promoting it. As a result the only remaining possibilities are onshore or offshore farming. For onshore farming, seawater must be pumped into tanks on land where the seaweed is grown, as is the case with organic fish. Offshore farming might be viable when offshore wind farms are constructed, as the best edible seaweeds need very oxygenated water, often found growing on rocky outcrops that cause foaming waves.'

The seaweed industry is thriving in Ireland, says Turner, partly as a result of having state support, but also because of the clean Atlantic waters that lap the Emerald Isle. Britain's coastal waters are polluted by comparison (though nothing like as badly as the waters off China, where the lion's share of global seaweed stocks are grown - nine million tonnes a year).

A toxic sponge?

Because seaweed draws its nutrients from its environment it also tends to absorb any pollution or heavy metals in the water around it. As a result, anyone who lives near a nuclear power station or industrial plant might want to consider a day trip further up the coast to collect their kelp. Routine monitoring by the Food Standards Agency from 2006 to 2009 found that radionuclides from the Sellafield facility in Cumbria were bioaccumulating in certain types of seaweed.

While the FSA has issued guidelines about the consumption of certain oily fish that can absorb dioxins and PCBs from our polluted seas, and hijiki, a seaweed used in Japanese cuisine which can contain high levels of inorganic arsenic, it has offered no official advice on the consumption of homegrown seaweeds.

A fat busting superfood

Seaweed is a good source of iodine, vital for thyroid function, although there is a danger that consuming excessive amounts can lead to thyroid disorders - in Japan, for example, where seaweed is a staple food, there is a high incidence of hypothyroidism. According to the Vegan Society, consuming more than 100g per year of most seaweeds (an iodine intake in excess of 1000 micrograms per day) carries a 'significant risk' of thyroid disorder.

The health benefits far outweigh the negatives, however. Seaweed contains more than 50 known minerals and essential trace elements, as well as high quantities of potassium, iron, magnesium, calcium, zinc and vitamins A, B, C and E. In March this year, scientists at Newcastle University even found that it can help with weight loss: alginate, the natural fibre found in sea kelp, can reduce the amount of fat the body absorbs from food by up to 75 per cent.

Given Britain's current dietary deficit - according to Government statistics, by 2025 41 per cent of us will be obese, and by 2050 more than half of us - perhaps there will soon be a market for seaweed after all.

Eifion Rees is a freelance journalist

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