NorthSeaWeed: Seaweed production in the North Sea

BritDownUnder · Post by **BritDownUnder** » 11 Jul 2020, 23:44

When I was on a business trip to Japan for a power station inspection the hotel I was at had seaweed for the breakfast and it tasted excellent. I hope this idea is sustainable and goes ahead. As for a feedstock I think there will be small amounts compared with biomass like wood. It would be interesting to compare the weight of biomass produced per area and see if it is greater or lesser than the area of dry land to produce a similar amount.

I think seaweed has long been used on some Scottish and Irish islands as food for sheep and fertiliser.

UndercoverElephant · Post by **UndercoverElephant** » 12 Jul 2020, 08:34

BritDownUnder wrote: I think seaweed has long been used on some Scottish and Irish islands as food for sheep and fertiliser.

Seaweeds have some specific food uses. They tend to be very rich in minerals and some vitamins, and some of them also have a decent amount of protein. What they do not have much of is digestible carbohydrates. The carbohydrates they contain are largely undigestible by mammals. However, these indigestible carbohydrates are often useful for other things, notably as gelling and thickening agents: carragheenan, agar, furcellarian.

Mark · Post by **Mark** » 12 Jul 2020, 12:03

BritDownUnder wrote:I think seaweed has long been used on some Scottish and Irish islands as food for sheep and fertiliser.

North Ronaldsay Sheep (Orkneys) are a rare breed and only eat seaweed, I think

UndercoverElephant · Post by **UndercoverElephant** » 12 Jul 2020, 14:57

Mark wrote:
BritDownUnder wrote:I think seaweed has long been used on some Scottish and Irish islands as food for sheep and fertiliser.
North Ronaldsay Sheep (Orkneys) are a rare breed and only eat seaweed, I think

I am sure they are happy to eat grass.

BritDownUnder · Post by **BritDownUnder** » 14 Jul 2020, 03:24

Interesting read about North Ronaldsay sheep. Apparently a wall was built in the 1820s around the island measuring 13 km in length that separated the kelp on the seashore from the 'nice' grass on the 'centre' of the island.
Originally the people harvested the seaweed for the minerals and maybe iodine - I think originally lye (sodium hydroxide) was made from seaweed and the wall kept the sheep away from the seaweed. Then when this market collapsed the sheep were kept on the other side of the wall on the seaward side and ate only the seaweed keeping the nice grass of the island free for cows and vegetable patches. The sheep apparently evolved to absorb copper more readily from the copper-deficient seaweed and eating normal grass will now kill them due to copper poisoning. Those island sheep are much smaller than normal sheep and I think they would make nice pets if they don't mind the heat of Australia.

There you go. The perils of harvesting seaweed is nothing new.

UndercoverElephant · Post by **UndercoverElephant** » 14 Jul 2020, 16:29

BritDownUnder wrote:Interesting read about North Ronaldsay sheep. Apparently a wall was built in the 1820s around the island measuring 13 km in length that separated the kelp on the seashore from the 'nice' grass on the 'centre' of the island.
Originally the people harvested the seaweed for the minerals and maybe iodine - I think originally lye (sodium hydroxide) was made from seaweed and the wall kept the sheep away from the seaweed. Then when this market collapsed the sheep were kept on the other side of the wall on the seaward side and ate only the seaweed keeping the nice grass of the island free for cows and vegetable patches. The sheep apparently evolved to absorb copper more readily from the copper-deficient seaweed and eating normal grass will now kill them due to copper poisoning.

Where did you read this? Seaweed contains plenty of copper. It is high in most trace elements, and very high in some.

BritDownUnder · Post by **BritDownUnder** » 18 Jul 2020, 12:38

UndercoverElephant wrote:
BritDownUnder wrote:Interesting read about North Ronaldsay sheep. Apparently a wall was built in the 1820s around the island measuring 13 km in length that separated the kelp on the seashore from the 'nice' grass on the 'centre' of the island.
Originally the people harvested the seaweed for the minerals and maybe iodine - I think originally lye (sodium hydroxide) was made from seaweed and the wall kept the sheep away from the seaweed. Then when this market collapsed the sheep were kept on the other side of the wall on the seaward side and ate only the seaweed keeping the nice grass of the island free for cows and vegetable patches. The sheep apparently evolved to absorb copper more readily from the copper-deficient seaweed and eating normal grass will now kill them due to copper poisoning.
Where did you read this? Seaweed contains plenty of copper. It is high in most trace elements, and very high in some.

You're right. According to the Wikipedia article on the sheep the seaweed contains a chemical that stops the sheep absorbing copper and the sheep have evolved to beat that.

I have read that there is even gold in seawater but in low quantities but in the whole sea there is quite a lot. Also uranium.