Following the various debates on trawling it is clear that Norway has a 20 kilometer zone inside which no bottom trawling is allowed.
The details I have not been able to firmly ascertain but reading the Wikipedia article on trawling some things begin to make sense
One major effect of bottom dredging is the disturbance of sediments
The re suspension of sediments means the release of chemicals back into nature
https://www.sciencedirect.com/science/article/abs/pii/S0269749112003284 This is a report on just this.
We have nothing on the effects of continual trawling in the seaweed beds but I cannot imagine there is a major difference here – this occurs along the entire coast including bird reserves.
Could this be why it is illegal to land blue halibut from Bodæ to Lofoten, or outside of Lofoten – they are contaminated by pcbs, but nobody seems to be aware of where these chemicals come from.
Norway is a country well aware of any major marine disturbance so why is this allowed – perhaps this article may give some answers
We also found some anomalies at the last meeting on Taretråling in Trondheim – there seems to be some confusion about the rights of these trawlers
It seems even the most senior in the fiskeriedirektoratet whose job it is to regulate the activities of these boats are more interested in protecting their activities then they are in regulating them.
Seems strange that ordinary trawlers have such strict regulations whereas Seaweed trawlers have every difficulty removed, including priority over ancient rights belonging to our fishermen.
It appears many of Norway’s major institutions are governed by industrialists involved with exploiting marine resources. This is quite understandable and in fact common – however the cost in terms of health to individuals and the state and indeed the ultimate cost should their activities impact nature in the way we are all warned about would dwarf any benefit accrued to society or to the individuals concerned.