GM Salmon's Global HQ - 1,500m high in the Panamanian Rainforest

It is hard to think of a more unlikely setting for genetic experimentation or for raising salmon: a rundown shed at a secretive location in the Panamanian rainforest miles inland and 1,500m above sea level.

But the facility, which is owned by an American company AquaBounty Technologies, stands on the verge of delivering the first genetically modified food animal - a fast-growing salmon - to supermarkets and dinner tables.

The US government this week enters the final stages of its deliberations on whether to allow commercial production of the GM fish, with a public consultation on the issue ending on Friday . Separately, a committee in Congress on Monday took up a bill that would outlaw GM salmon entirely - essentially destroying AquaBounty's commercial prospects in America. If approved, the salmon could be the first of some 30 other species of GM fish under development, including tilapia and trout. Researchers are also working to bring GM cows, chickens and pigs to market.

In Panama City, government officials are upbeat about AquaBounty's prospects of getting its fish to market. "From what we know it is very close to being approved. There have been tests for many years and the last thing we heard from the FDA is that there is a very good probability that it is going to be approved in the near future," said Giovanni Lauri, the director of the Aquatic Resources Authority of Panama, Arap.

AquaBounty must still overcome formidable opposition from supermarkets and consumer organisations, environmental groups and commercial fishermen to sell its fish, however. The prospect of introducing GM fish into the food supply has generated enormous passions, with the FDA receiving 36,000 comments on the fish so far, most of them opposing the move. But after 20 years, AquaBounty's efforts to bring GM animals to the table are getting closer to reality.

There was little outward sign of history in the making - or of the enormous controversy surrounding GM salmon at AquaBounty's remote Panamanian location on the banks of the Calderas river in the western highlands of Chiriqui province. At the premises, visitors can see a fading green industrial shed and four large above-ground pools behind a high wire fence. On the site are up to 5,000 salmon,according to Arap officials say.

The only evidence of AquaBounty's presence is a small round company decal next to the front door of the shack. Signs warn: "No pasar". The place seems deserted at first, then a guard suddenly emerges when visitors approach the wire fence.

Read the rest of this story at The Guardian.