Peterhead Fish Market had no auction for the first time in recent history yesterday.
Seafood buyers are being urged to avoid the fish market on Wednesdays in a dispute over new rules.
The town is the biggest white fish port in Europe.
The BBC says the dispute centres around Peterhead Port Authority's decision to stop buying practices which it said are anti-competitive.
It operates as a traditional shout auction, with people bidding for boxes of fish landed at the harbour.
Until recently, as part of that, the practice of so-called bid sharing was commonly used, which is when buyers sometimes bid in groups rather than individually.
Putting a stop
However Peterhead Port Authority, which runs the market, is putting a stop to this.
It said that, following complaints, it obtained legal advice which described such practices as "anti-competitive and contrary to applicable competition law".
But an industry insider said bid sharing helped buyers get hold of fish as quickly as possible, so it can be out the door and with processors as early as possible each morning.
In a letter sent in December to those who use the market, the port authority chief executive Simon Brebner said the measures "are intended to ensure therefore that in the interests of all stakeholders the sales process at the fish market is conducted in a compliant manner".
The authority insists each bidder should be acting independently and not co-operating with any other party to achieve prices at the action which may be lower than those which would otherwise be achieved in a "genuinely-competitive" market.
The move angered many buyers and they responded by boycotting the market yesterday.
Ongoing situation
The Scottish Seafood Association said the situation was ongoing and declined to comment.
The BBC understands it is seeking legal advice on the matter.
The Scottish White Fish Producers Association said it was "looking for both parties to sit down to find a workable solution to what isn't an unsurmountable difference".