Seaweed cultivation
from the information gathered on the internet the first seaweed cultivation trials in the north sea were conducted by Trygve Braarud (University of Oslo, plankton ecologist; advisory role)
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Harald Kryvi (early kelp morphology work)
Local fisheries officers from Rogaland.
The date 1951 – spring and summer.
It was a failure due to the degradation of the materials used – they lasted a very short time – the tests were carried out in open sea – exposed site
Offshore areas west of Rogaland
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Test sites near Karmøy and Utsira
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Depths: 5–15 m
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Substrate: rope lines suspended from buoys
B. Sheltered control sites
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Inner fjords in Hordaland
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Used to compare growth vs. exposed North Sea conditions.
What they tried
The method
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Spores of Laminaria were settled on hemp and sisal ropes
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Ropes were suspended from wooden rafts and buoy lines
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Growth was monitored for:
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Attachment strength
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Rope degradation
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Storm damage
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Grazing
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Yield per metre
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Species tested
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Laminaria hyperborea
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Laminaria digitata
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Alaria esculenta (minor trials)
5. What happened (the results)
A. Rope failure
This was the main reason the trials failed.
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Natural fibre ropes degraded rapidly
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Biofouling accelerated weakening
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Wave action in the North Sea tore lines apart
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Average survival of ropes: 6–10 weeks
This is the origin of the “rope problem” that modern literature conveniently omits.
B. Storm destruction
Two storms in June and August 1951 destroyed most of the exposed installations.
Since then there have been trials in the north sea every 10/15 years by such bodies as FMC, combined with Belona and many others each coming up with the same problems as always.
3. What rope materials did work historically?
By the late 1960s, the successful materials were:
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Polyethylene (PE)
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Polypropylene (PP)
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Nylon (PA) for moorings
These became standard because they are:
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Strong
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Cheap
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Buoyant (PP)
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Resistant to rot
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Easy to splice
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Mass manufactured
This is why every modern seaweed farm uses synthetic rope.
Unfortunately they don’t last long – as stated, storms are a major factor but all the artificial ropes degrade under natural forces and need to be replaced yearly — making the enterprise uneconomical environmentally degrading and very expensive.
Current estimates put the amount of rope required for 5 tons wet weight at 2km.
50 tons — 20 kms and 500 tons – 200 kms – not forgetting annual replacement.
That makes cultivation of seaweeds unviable for every reason.
This is from a major article on seaweed farming in the north sea
This article reports an investigation of the economic feasibility of seaweed production in the North Sea using economic modelling. Often, an overly positive picture of the costs and benefits of seaweed production is sketched. Based on current available information, offshore seaweed production in the North Sea is not economically feasible.
https://www.tandfonline.com/doi/full/10.1080/13657305.2016.1177859
perhaps this might supply an answer as to why there are so many initiatives
North Sea Farmers have made the first-ever harvest at North Sea Farm 1, a commercial-scale seaweed farm located off the coast of the Netherlands in the North Sea. The farm, uniquely located within a field of wind turbines, was created by North Sea Farmers, a non-profit supported by Amazon’s Right Now Climate Fund—a $100 million initiative dedicated to climate and biodiversity projects that benefit both people and the planet.
The harvest provides valuable insights to researchers investigating how seaweed farms remove carbon from the atmosphere, contribute to climate resilience, and how to scale seaweed cultivation globally. In the longer term, seaweed farms may also support biodiversity and reduce pressure on agricultural land.
The innovative project received €2 million in funding from Amazon’s Right Now Climate Fund.
There is a major drive to show that seaweed cultivating can have major effects on the environment and the ecosystem –
Just consider what this actually says – it says our marine ecology is very valuable and organizations are prepared to spend vast amounts of money cultivating seaweed which has been proven not to work again and again.
Strangely enough while the industry is going on about ecology and saving the marine ecosystem, seaweed trawling in its full might still goes on – on the Norwegian coast leading to massive ecological changes.
If this were to stop now it would take many years for the areas directly affected to return to their former biodiversity but that effect can be achieved.
Currently we have officially lost over 5,000 km of seaweed forests and 50% of our fish – this is not normal – again the official reason is global warming – however we have only had seaweed trawling on our coasts for 60 years. Initially the seaweed forests were pristine now they are only a shadow of their former selves and the companies concerned are powerful enough to bend politicians and researchers their way.
One of the corporations is dupont. This corporation is responsible for the worst pollution in the history of mankind and yet not a single land has been powerful enough to ban fluoro chemicals entirely
