Seaweed may not look attractive but it is used in beauty treatments

Business is booming at Irish seaweed harvesting companies, thanks, in part, to a substance called Fucoidan.

A derivative of the slimy and somewhat unattractive plant, Fucoidan is linked to skin preserving properties.

However, Martin Walsh, seaweed development officer at the Irish Fisheries Board, says Fucoidan is one of many components, and the plant is being used for a variety of purposes.

"There's a huge range of seaweeds out there," he said.

"About 36 types are being harvested around the coast for various uses, like snack products, animal feeds, gardening products and cosmetics."

The Irish seaweed industry is estimated to be worth up to 20 million euro per year, Mr Walsh told BBC News Online.

One of the drawbacks of these cosmetics in the past was that, unsurprisingly, they smelled of seaweed.

SEAWEED'S MANY USES Cosmetics Health baths Cold remedies Snacks Cheeses Gourmet cuisine Shampoos and shower gels Animal feed Fertiliser

Mr Walsh says people sometimes have to make a trade off when choosing to use such products.

"There are a lot of products coming on the market now, which have the best of both worlds - they have the natural contents as well as the pleasant smells and textures," he said.

Mr Walsh says it can be difficult to get a steady supply of certain types of seaweeds.

"There are some seaweeds that the harvesters can only get at very low tides, because of how they grow on the beach," he said.

"In the longer term, we are going to have to look at mechanisation as a way of harvesting seaweed."

Seaweed products are gaining in popularity, but Mr Walsh says there is little risk to the environment.

We are only taking a small amount of what scientists have calculated to be sustainable Martin Walsh Seaweed expert

"For example, we estimate that ascophyllum nodosum, the largest seaweed by volume harvested in Ireland, could withstand 75,000 tonnes per annum," he said.

"We are only harvesting about 15,000 tonnes a year, so we are only taking a small amount of what scientists have calculated to be sustainable."

The main season for harvesting seaweed runs from spring to late autumn.

Harvesters pick the seaweed on beaches, cutting the plants with a short-bladed knife to allow them to regrow.

"One traditional method involves cutting large bundles at low tide and roughly tying them together with net or old rope, anchored on rocks," Mr Walsh says.

"When the tide comes in, the bundle will float and the harvesters cut the ropes and bring the bundles in to be gathered onto lorries."

He says people have always believed seaweed and other marine products are good for your health.

"They have been attributed to have curative powers and other different health benefits.

"I think it's something we are going to have to look at, to put some science behind the folklore."