Based on “How farming giant seaweed can feed fish and fix the climate” one would want to grow kelp at large scale even not for profit.
“The kelp draw in so much carbon dioxide that they help de-acidify the water, providing an ideal environment for shell growth.”
Low Cost Model for Valuing the Benefits
Negative_Carbon_Via_Ocean_Afforestation
Seaweed Solutions does it have solutions?
Greenwave Organization does it do anything yet?
AtSeaNova Seems active
Scotland Experimental seaweed farms