NorthSeaWeed: Seaweed production in the North Sea

To what extent will biofuels be part of our energy future?

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Mark
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NorthSeaWeed: Seaweed production in the North Sea

Post by Mark »

https://www.wur.nl/en/Research-Results/ ... th-Sea.htm

Seaweed is a compelling feedstock for food and chemical industries, for example as an alternative source for protein and the production of “green gas�. A condition for profitable seaweed cultivation is a year-round supply of large volumes of fresh product (100 - 1000 thousand tons), of consistent quality. It is estimated that at least 10 - 100 km2 of cultivation area is required for such production. This can only take place at sea.

At present, cultivation technology and processing technology have not yet been developed to such an extent that the large volumes can be produced. There are also still many uncertainties about the technical, economic, and ecological feasibility of large-scale cultivation in the North Sea. However, the entrepreneurs involved are optimistic. With the help of properly prioritized research, they expect to take the steps towards large-scale offshore cultivation.

Continues...
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Post by Little John »

And the marine eco-system will not be taking a hit because of this.... obviously

No such thing as a free lunch.
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Post by Mark »

Little John wrote:No such thing as a free lunch.
Totally agree, but some lunches cost more than others ?
Worth investigating/discussing all new possibilities ?
That's the point of this Forum ?
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Post by kenneal - lagger »

I think that the Japanese carry out sea weed farming for food use using hanging nets without any inputs apart from the spores to start the seaweed growing.

As long as we didn't get greedy and try to boost the natural production rate by chemical fertilization and pesticide use a stretch of sea with a steady current flowing should be able to produce a sustainable crop on suspended nets. The amount to be produced could be calculated from the flow and the nutrient density and allow for nature to take a share as well. The amount of the crop grown could be adjusted by varying the area of netting used.

I'm not sure that we should use it to produce gas to further our production of the rubbish that we now mass produce nor should it be used for home heating of our exceptionally leaky houses. It does make a good organic fertilizer though.

There could also be advantages such as the provision of nursery space for small fish and the blocking of access to trawlers which destroy the sea bed.

The sea bed in the areas most likely to be used is the property of the Crown Estate so there could be controls imposed to ensure sustainable use.
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Re: NorthSeaWeed: Seaweed production in the North Sea

Post by UndercoverElephant »

Mark wrote:https://www.wur.nl/en/Research-Results/ ... th-Sea.htm

Seaweed is a compelling feedstock for food and chemical industries, for example as an alternative source for protein and the production of “green gas�. A condition for profitable seaweed cultivation is a year-round supply of large volumes of fresh product (100 - 1000 thousand tons), of consistent quality. It is estimated that at least 10 - 100 km2 of cultivation area is required for such production. This can only take place at sea.

At present, cultivation technology and processing technology have not yet been developed to such an extent that the large volumes can be produced. There are also still many uncertainties about the technical, economic, and ecological feasibility of large-scale cultivation in the North Sea. However, the entrepreneurs involved are optimistic. With the help of properly prioritized research, they expect to take the steps towards large-scale offshore cultivation.

Continues...
Absolutely. It is a win-win. It creates new habitat for wildlife at the same time as providing a crop that requires no water and no fertiliser.
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Post by UndercoverElephant »

Little John wrote:And the marine eco-system will not be taking a hit because of this.... obviously

No such thing as a free lunch.
Actually, in this case that is exactly what it is. This actually benefits the marine ecosystem. All that is being lost to the ecosystem is open muddy/sandy sea floor, of which there is an enormous over-supply. Coastal marine habitat is limited by physical structures on which to grow. That is why rocky beaches are so vastly more biodiverse than purely sandy/muddy/pebbly beachs. The tricky part is learning how to make a particular species grow well in as particular location, and some seaweeds have very unusual lifecycles. But once you've done that, everything else is provided as an entirely free lunch: seawater contains everything the seaweed needs to grow, and the growing seaweed then provides both food and habitat for other marine life.

The only downside is people won't be able to do water sports there anymore.

NB: I have just driven back from a week away in Dorset, spent mostly looking for edible seaweeds.
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Post by adam2 »

Seaweed grows very prolifically in certain areas, and the modest harvesting of such seaweed seems unlikely to do any harm.

And seaweed can be farmed or at least encouraged to grow, thereby not depleting that which grows naturally.

As above, there could be environmental benefits from seaweed farming. The areas around offshore wind farms sound suitable as they are already off limits to trawlers and most other shipping.

A particular merit of fuel derived from seaweed is that it may be stored and used at times of high demand and low wind. A useful complement to wind and PV that must be used as produced unless expensive storage is added.
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Post by UndercoverElephant »

kenneal - lagger wrote: As long as we didn't get greedy and try to boost the natural production rate by chemical fertilization and pesticide
I very much doubt this would even work. It isn't necessary.
The amount to be produced could be calculated from the flow and the nutrient density and allow for nature to take a share as well.
This is not a problem in UK waters. Seaweed growth is not limited by nutrient availability. It's limited by available substrate to attach to in the right locations.
I'm not sure that we should use it to produce gas to further our production of the rubbish that we now mass produce nor should it be used for home heating of our exceptionally leaky houses. It does make a good organic fertilizer though.
We could also learn how to incorporate it into our diets. Many of the people who come on my courses are astonished at what a good seaweed dish tastes like.
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Post by kenneal - lagger »

Organic farming was doing quite well until after WW2, UE, when explosives manufacturers were looking for an alternative outlet for their nitrates and hit on farming as a dumping ground. That has raised food output for about 70 years but we are seeing the problems with this over production now and yeilds are coming to a plateau and reducing in many areas. As farming reduces it use of artificial fertiliser the agro chemical companies will start looking for alternatives. They are quite likely to find a way to make it work.

Seaweed growth is not limited by nutrient availability at the moment but given the human propensity for over use of everything it shouldn't be ruled out especially if seaweed becomes the new wonder fuel source!
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Post by UndercoverElephant »

kenneal - lagger wrote:
Seaweed growth is not limited by nutrient availability at the moment but given the human propensity for over use of everything it shouldn't be ruled out especially if seaweed becomes the new wonder fuel source!
It is never going to be a problem. Think how much seawater there is sloshing around the UK compared to the amount of space available for seaweeds to grow. The only nutrient-related seawater problems the UK is ever likely to have are those caused by too much nutrients. They cause algal blooms which poison shellfish and foul beaches.
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Post by UndercoverElephant »

adam2 wrote:Seaweed grows very prolifically in certain areas, and the modest harvesting of such seaweed seems unlikely to do any harm.
Unfortunately, the stuff that grows the most prolifically isn't the most useful. Wracks usually, which were historically used to improve soil and feed livestock. What ever they are planning to grow in the North Sea, it won't be those.
And seaweed can be farmed or at least encouraged to grow, thereby not depleting that which grows naturally.
Not always easy. The English woman who figured out the lifecycle of nori/laver is highly revered in Japan (they hold an annual festival in her honour): https://en.wikipedia.org/wiki/Kathleen_Mary_Drew-Baker
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Post by Little John »

UndercoverElephant wrote:
Little John wrote:And the marine eco-system will not be taking a hit because of this.... obviously

No such thing as a free lunch.
Actually, in this case that is exactly what it is. This actually benefits the marine ecosystem. All that is being lost to the ecosystem is open muddy/sandy sea floor, of which there is an enormous over-supply. Coastal marine habitat is limited by physical structures on which to grow. That is why rocky beaches are so vastly more biodiverse than purely sandy/muddy/pebbly beachs. The tricky part is learning how to make a particular species grow well in as particular location, and some seaweeds have very unusual lifecycles. But once you've done that, everything else is provided as an entirely free lunch: seawater contains everything the seaweed needs to grow, and the growing seaweed then provides both food and habitat for other marine life.

The only downside is people won't be able to do water sports there anymore.

NB: I have just driven back from a week away in Dorset, spent mostly looking for edible seaweeds.
So, if seawater, at a coastline, has sufficient nutrients in it to provide for everything the seaweed needs to grow but that seaweed will then be removed from the food chain of that coastal marine environment, the commensurate decline in the availability of those nutrients will have no effect in whatsoever on the other living systems of that coastline?
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Post by Catweazle »

When you consider the vast volume of water, and the possibility that it is close to saturated and might simply pick up more nutrients if some are removed, then I'll be surprised if a few seaweed farms cause problems.

Personally I'd rather see the seaweed harvested to improve farmland than burned for fuel.
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Post by UndercoverElephant »

Little John wrote:
UndercoverElephant wrote:
Little John wrote:And the marine eco-system will not be taking a hit because of this.... obviously

No such thing as a free lunch.
Actually, in this case that is exactly what it is. This actually benefits the marine ecosystem. All that is being lost to the ecosystem is open muddy/sandy sea floor, of which there is an enormous over-supply. Coastal marine habitat is limited by physical structures on which to grow. That is why rocky beaches are so vastly more biodiverse than purely sandy/muddy/pebbly beachs. The tricky part is learning how to make a particular species grow well in as particular location, and some seaweeds have very unusual lifecycles. But once you've done that, everything else is provided as an entirely free lunch: seawater contains everything the seaweed needs to grow, and the growing seaweed then provides both food and habitat for other marine life.

The only downside is people won't be able to do water sports there anymore.

NB: I have just driven back from a week away in Dorset, spent mostly looking for edible seaweeds.
So, if seawater, at a coastline, has sufficient nutrients in it to provide for everything the seaweed needs to grow but that seaweed will then be removed from the food chain of that coastal marine environment, the commensurate decline in the availability of those nutrients will have no effect in whatsoever on the other living systems of that coastline?
Correct, at least in north-west Europe. There are other parts of the world, mainly in the tropics, where this is not true.

The limiting factor, by far, on seaweed growth, is lack of habitat. All they need is something firm to grab hold of, that something else hasn't already claimed as theirs. There are very few free-floating seaweeds. Though there is one quite important one:https://en.wikipedia.org/wiki/Furcellaria
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Post by UndercoverElephant »

LJ

The coast of NW Europe sits on a large section of continental shelf, is swept by a strong, eddying current, frequently experiences stormy/windy weather, has some of the highest tidal ranges in the world, as well as being densely populated so the rivers discharge nutrients. It's like a food mixer for marine nutrients. Literally, the problem we are causing is too many nutritents, not insufficient. It has a name: eutrophication.

https://ec.europa.eu/environment/marine ... dex_en.htm

In order to reduce human induced eutrophication, it is necessary to reduce the nitrogen and phosphorous load to the oceans which can be done through changes in the agricultural practices, for example by restrictions in the use of fertilizers, optimizing nutrient use to crop requirements, planning of the use of fertilizers, so washout from land is minimized, establishment of more sustainable agriculture farms.
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