Sushi-lovers in Japan could be in for a shock if a proposed international trade ban on northern bluefin tuna goes ahead.

The United States has announced it will support the ban when it is put to a vote at the Convention on International Trade in Endangered Species (CITES) later this month.

But Japan, the biggest consumer of the fish, has indicated it may not honour the ban if it is approved.

Peter Trott, the fisheries program manager at the environment group WWF, says bluefin tuna stocks have been in steep decline across the globe for some time.

“All species are under extreme pressure from fishing activity due to the insatiable appetite and demand for the product on the Japanese market and several other Asian markets,” he said.

Brian Jeffries, the chief executive of the Australian Tuna Association, says there are three main types of bluefin tuna.

“Northern bluefin tuna or Atlantic bluefin tuna – then another type of northern bluefin which is called Pacific bluefin, which is obviously Japan and Mexico – are the major catchers,” Mr Jeffries said.

“Then there is southern bluefin, which runs around Australia towards South Africa and New Zealand.”

At the end of next week, representatives from 175 countries will attend CITES in Doha. They will be debating whether to ban all international trade in northern bluefin tuna.

“There’s no doubt a number of countries at the CITES conference follow the United States’ lead,” Mr Jeffries said.

“The US has tremendous influence in its own right as the EU will when it finally makes its decision about which way to go.”

But Mr Jeffries believes it is a decision based largely on self-interest.

“The effect on American and Canadian fishermen will be quite minor, particularly as the US government has announced that those fishermen will be allowed to continue to catch their quota,” he said.

“So the only ban we are talking about here is not being able to trade it internationally. They are certainly not talking about a ban on catching at all.”

Mr Jeffries says this means tuna caught by Americans will have to be consumed in the US.

“There’s a substantial market within the US,” he said.

“It is just at the slightly higher prices in Japan at various times of the year for specific types of fish, but that can easily be consumed in the US.”

‘Close’ vote

Mr Trott says it is difficult to know which way the vote will go in Doha.

“It’s going to be very close. There is a number of countries that are still undecided and Australia is particularly one of those countries and also New Zealand,” he said.

“We should really be, as a responsible fishing nation, leading this charge in terms of supporting the ban as well.”

Mr Trott says the ban makes economic sense for Australia.

“If you remove the Mediterranean bluefin tuna out of the market equation, then there’s a clear market opportunity there for southern bluefin tuna… to increase the market share that it currently occupies within the Japan marketplace,” he said.

“When you remove a product from the shelves, there is going to be another product that takes its place that is very similar in nature.

“Unfortunately the southern bluefin tuna fits that bill quite nicely.”

Mr Jeffries disagrees, saying it is highly likely the southern bluefin may be nominated for a similar CITES trade ban in 2013.

He says this would hurt the Australian industry more than the short-term economic benefits that would come from a ban on the northern variety.

He also believes it could encourage black market operators.

“The black market trade in this case is to export somehow to say China, and China can then process the product and it gets imported into Japan as fillets, frozen fillets where it is very difficult to identify which fish it is.”