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I think you can safely say that this applies to seaweed trawling which is far worse because the same area (20 sq km) is trawled for a year before the next area is begun.
British Columbia urges caution on seaweed harvesting
Seaweed aquaculture in Ireland
Environmental assessment of seaweed harvesting Scotland.
Cast seaweed harvesting could damage ecosystems
Experimental canopy removal laminaria spp
Threats and knowledge gaps in ecosystem services provided by kelp forests
Deep concern over harvesting in a large area of Norway’s coast that has been plagued by sea urchin barrens
Researchers concerned about seabirds disappearing through lack of food
Deep concerns over seaweed harvesting in Bird reserves
Ecological effects of seaweed trawling on the Norwegian coast