Seaweed: the next big step for Irish food and farming?

The health and food potential of the ocean’s foliage is clear, and it makes economic and environmental sense to develop our sea-farming industry

Once regarded merely as the stinking gunge one steps over on the way for a swim, seaweed these days is having a renaissance. The excitement surrounding its potential as a human superfood, a biofuel, an ocean cleanser and animal feed is reminiscent of tulip mania. This fast-growing and mineral-rich crop which sequesters carbon and purifies water is being hailed as a bountiful resource that could ultimately replace environmentally damaging crops, such as soya and corn, and offer vital chemicals for use in cosmetics, fertilisers and food production, as well as many of the key nutrients needed for human health: Vitamin B12, omega-3 fatty acids and trace minerals.

So what are the pioneering developments in seaweed production and who is spearheading them in Ireland? The most exciting development is the farming of seaweed, as opposed to harvesting the wild plants along the shore. While the Chinese and Japanese have been perfecting this over decades, the practise got a boost in international media recently with the example set by Bren Smith, a former commercial fisherman from Newfoundland, who established a system of seaweed and shellfish farming which he claims can be set up for €28,000 and provide an annual income of €64,000. His inspiring Ted Talks tale has been featured in The New Yorker and the Washington Post and on CNN.

The major innovation that Smith has pioneered is to grow long lengths of sugar kelp on ropes suspended from buoys, beneath which can hang mussels and scallops, with crates of oysters below those again, and clams growing in the mud beneath. It’s a vertical column of intensive ocean farming in which everything is in symbiosis, with the kelp eating up carbon, and the shellfish filtering and cleansing the water and creating an artificial vertical reef that shelters crabs, shrimps and scores of other marine species. He calls it 3-D vertical ocean farming.

Dulse and kelp

Lucy Watson, an aquaculture technical specialist at Bord Iascaigh Mara (BIM), says that it is not too different from "what we would term Integrated Multi-trophic Aquaculture (IMTA), where the waste from one species is used as nutrient for another, for example a salmon farm sited beside a seaweed farm. It's a concept gaining momentum in Ireland, but it has a way to go yet."


Gathering dulse and kelp was a localised, small-scale venture in Ireland until recently. The situation was similar in the United States, until Smith set up his farm in Long Island Sound, Connecticut. His traditional shellfish farms had been wiped out by storms and he wondered if he could farm kelp with shellfish in a sustainable way. There are now more than 20 ocean farms based on his model along the US eastern seaboard, and his non-profit organisation, GreenWave, is training people throughout the continent in the practise. Greenwave offer to buy 80 per cent of the crop from any new kelp farmers for five years at three times the market rate – a service they can offer because they are working with innovative chefs who pay a premium for the product.

Could this work in Ireland? The key obstacle is acquiring a foreshore license. "In the republic, the issue around licensing and sea-space has been a disaster," says Kate Burns, of the Islander Kelp company based on Rathlin Island, Co Antrim. "I was originally going to set up in Donegal, but I knew I would have to wait for seven years to get a license. I came up to Rathlin and got one in six months. Then, when you apply for your license, you need to do your environmental assessment and navigational risk assessment and there is no money or technical support to help you with that. You've got to have the cash to pay for it."

Despite the obstacles, Burns has pioneered the growth and production of high quality sugar kelp, fingered kelp and wakame in Ireland. By blanching and freezing the seaweed she is managing to develop entirely new products such as kelp that is available as noodle cut, tagliatelle cut, salad cut, minced or whole leaf. “We also do a fabulous kelp pesto with more than 60 per cent kelp to introduce people to the fact that kelp is not salty. It’s closest in flavour to oysters and is a superfood with more iron and calcium than any other vegetable, including kale and spinach. It also has protein and lots of vitamin D, because it absorbs a lot of sunlight. There’s magnesium, selenium, potassium and other trace elements in there too. Farmed seaweed is a finer, more subtle product than you can gather off the rocks, and it’s also a fat inhibitor – if you eat it, your body will not absorb fat.

“On the downside, growing it is complicated. In terms of when you seed ropes, how you seed ropes, where they are and having the boat skills. And it doesn’t grow everywhere. I tried to help a group in Donegal start a farm, but it failed. You really need strong tides. Rathlin has 23 miles of coastline and we can probably only manage a kelp farm in two miles of that, because it is too rough elsewhere; we could not hold the anchor or infrastructure in place.”

Feeding the world

While there are hurdles to overcome, all the experts agree that Ireland should be leading the way in seaweed production and not just cutting it off the rocks by the multiple-ton and sticking it in a drier for the lowest common denominator. Humans currently use 40 per cent of the earth’s landmass and three quarters of its fresh water to feed ourselves. The proponents of sea-farming claim that a network of ocean farms covering just 1 per cent of the sea could provide enough shellfish, sea vegetables and sustainably-reared fish to feed the world. By absorbing nitrogen, phosphorous and carbon dioxide, seaweeds clean the ocean, as well creating marine sanctuaries that support the development of many other wild fish and shellfish.

BIM have been researching seaweed farming at the Daithí O'Murchú Research Station on the Beara Peninsula since 2004. They have made significant advances, but it is the integrated and holistic nature of Smith's system that is attracting attention. "Currently, we are farming about 100 tonnes of brown weeds per annum here in Ireland," says Lucy Watson, "and these farms are in the main not integrated with finfish or shellfish farms."

Ann Ruddy a retired Criminologist from Leamington Spa, established Redrose Developments in Belmullet to try to address this issue. She provides training and support to local community groups to develop new products and capitalise on the commercial potential of seaweed at a local level. While glad of the positive spin that Bren Smith's 3-D Farming gets in the media, Ruddy is soberly aware of "the myriad complexities surrounding the regulation, agency and departmental layers of bureaucracy. Not least in terms of licensing."

Redrose have cooperated in the development of a new prototype for farming seaweed, "but sadly at the moment due to licence issues it cannot be trialled in Ireland. We are likely to go to sea in the North, Scotland and/or a couple of European countries." In the meantime, Redrose are supporting small local harvesters and producers through their online shop,, which sells produce from a number of sustainable, wild harvesters.

Sinead O'Brien of Mungo Murphy's Seaweed Co had hoped to farm seaweed on ropes off Connemara, "but quickly realised that it would not be feasible due to established fishing practices and licensing barriers. We now harvest seaweed and buy from local seaweed harvesters." But they also grow their own sea lettuce and dillisk in tanks on land using the nutrient-rich outflow from the Connemara Abalone farm, which was established by Sinead's mother, Cindy O'Brien, in Ros a Mhíl. At the bottom of the abalone tanks they grow sea cucumbers that feed on the seaweed detritus that falls to the bottom, thereby creating a mini ecosystem that purifies the water while producing further premium products.

O’Brien believes that “the system that we have in place can be easily scaled up and I think could be introduced around the country,” but she warns that integrated multi-trophic aquaculture systems are not always appropriate, “attaching a seaweed farm to a conventional fish farm which uses antibiotics and unnatural feed-stuff would just produce sullied seaweed. And some algae such as Sargassum are invasive in Irish waters and would be foolhardy to farm; better to keep them in check by harvesting them from the wild.”

O'Brien meanwhile faces the same challenges as everyone in the seaweed business, of introducing the Irish palate to a foodstuff that we have forgotten how to eat. Her Mungo Murphy brand aims to convey a vibrant, fun image, with quirky packaging designed by Sinead's business partner, Kevin Moore Murphy, former bassist with Dublin band Blind Yackety. The back story for their fictional Mungo Murphy character includes a life living with his one-eyed rabbit and "enjoying sneezing and watching beans sprout".

Elegant canisters

For the marine biologist, Paul O'Connor, the focus was on developing a sleek, stylish product through packaging and marketing. His brand, This is Seaweed, offers flaked dulse, carrageen, sea spaghetti and kelp in elegantly designed canisters that appeal to high-end shops. Sales are rising in Ireland and the Netherlands and he is about to establish a niche in the United Arab Emirates after a recent Bord Bia trade mission to Dubai. Regarding the attention that Smith's 3-D ocean farming is getting, O'Connor says: "It has a lot of merit and is something that could fit the Irish coastline, as long as the location is correct. Tide and wind/wave exposure will play a big factor in deciding the location. I intend setting up a seaweed farm in the west coast in the coming years. It will need a lot of investment to get it up and running and as always there are issues regarding licensing."

A husband and wife team in Dungarvan, Ria and Tom Jones, set up Sea of Vitality, to offer a seaweed product that would help to re-introduce seaweed into our daily diet. "We found that drying and grinding it to a powder allows it be incorporated completely into people's personal recipes," says Tom Jones, "so that it becomes an addition, rather than the sole focus of the dish. The goal is to avoid having the seaweed overpower the meal, but instead to have its natural glutamates and umami characteristics enrich and deepen the flavour."

The companies currently harvesting and packaging seaweed all realise that they could produce a finer, more consistent product if they were farming it, but either licensing or cost is proving a hurdle. Bren Smith in Connecticut understands their concern. “Permitting was very difficult for me too at the start, but as soon as people saw what we were doing, that we were creating jobs, with no aesthetic impact and with good ocean planning, things really took off. It’s always tough for the first movers, you’ll encounter reluctance and refusal, but the issue of our oceans and food production is just too important to let slide.”

As for the cost of establishing a seaweed farm, everyone I talked to in Ireland is dubious of the figures that Smith cites. Lucy Watson of BIM co-wrote a report on establishing a seaweed hatchery and grow-out farm in 2012, and cited costs for the hatchery (cold room, autoclave, tanks, microscope, etc) of €48,000, not including labour or electricity, and a further €30,000 for a grow-out farm of ten 100m longlines, with chains, weights, blocks and buoys, though Smith has now brought the cost of a single 100m longline down to $300 for anchors, shackles, buoys, and rope, from the €3,000 its costs in Ireland. He is making his own 500lbs anchors for $22 each. Clearly, to approach Smith’s costs we would need to create cooperatives that would share the hatchery and processing costs. He now uses one single high-tech hatchery built inside a shipping container to serve 25 different farms, and is building processing plants which farmers use on a shared basis, rather than buying all their own equipment.

With the State having recently sold our national seaweed harvesting company, Arramara, to the Canadian firm Acadian, who have now applied for seaweed harvesting rights along our coastline from Clare to Mayo, there is a real risk that we could lose control of the potential for communities to create sustainable jobs along our Atlantic coast. Clearly the challenges of establishing a viable integrated seaweed and shellfish industry are not to be underestimated, but as Bren Smith says, "the ecological, social and culinary gains are worth taking a risk on".