New Zealand's oldest fishing club wants marlin to be dropped from restaurant menus to help protect declining stocks of the fish.
The Bay of Islands Swordfish Club has called for a nationwide boycott of the commercial sale of marlin.
One famous Northland restaurant has already swung behind the move - but a supplier says that even if successful a boycott will have no effect on marlin stocks.
Club president Trevor Woolston said members backed the boycott for fear of depleted stocks being further ravaged by commercial fishing.
In 1988 the club was instrumental in a memorandum of understanding under which commercial fishing companies agreed not to catch marlin in New Zealand waters.
But marlin caught outside New Zealand waters can still be sold here.
Mr Woolston said that because marlin were migratory fish it mattered little where they were caught.
"They come and go through certain currents, and those are the currents where the long-liners are fishing."
The International Game Fishing Association has lobbied the United States Government to ban the commercial sale of marlin. The Billfish Conservation Act recently passed Congress with a large majority and came after a similar boycotting campaign in the US.
Mr Woolston said US politicians recognised that the economic benefits of game fishing far outweighed selling marlin commercially.
"We would like the Government to look at what is the better commercial activity here. We are better to be promoted as one of the greatest marlin fisheries in the world."
Russell's Duke of Marlborough Hotel had already backed the boycott.
Yesterday Solander Gourmet Seafood was selling whole loin of blue or striped marlin at $49.90 for 2kg.
Company director Paul Hufflett said the marlin came from Fiji, but were an accidental bycatch of longline fishing operations.
However, Mr Woolston, whose club members return more than 50 per cent of all fish caught to the sea, said other companies were killing large numbers of marlin.
"We recently heard a report of a boat unloading a whole lot of striped marlin ... about three months ago.
"The amount of fish that they unloaded would have pretty much been half the fish that we tagged [for a preservation programme] for the whole season."
Q&A: Marlin fishing
Why the calls for a boycott?
The Bay of Islands Swordfish Club says marlin stocks in the Pacific are being further depleted by commercial fishing, and will eventually disappear if nothing is done. The club believes it makes economic sense to do everything possible to protect the fish - and therefore the tourism that comes from game fishing in New Zealand waters.
Isn't the commercial fishing of marlin in New Zealand waters banned?
A memorandum of understanding means marlin cannot be caught commercially in New Zealand waters. However, marlin caught by New Zealand vessels operating outside our waters can be sold here.
How widespread is the sale of marlin in New Zealand?
Club president Trevor Woolston says the trade is relatively minor, but has been increasing in recent years. He wants the Government to ban it, but in the meantime advocates a boycott.
What do the sellers say?
Solander Gourmet Seafood, one company to sell marlin here, says the small quantities are an accidental bycatch of longline tuna fishing in Fiji. Because the fish are caught accidentally, a boycott or ban would not lessen how many were caught.