A US federal court judge is threatening to block permission granted to biotech company AquaBounty's GM salmon, fearing it may set a precedent whereby the environmental impacts of its production are not considered at other sites, the Courthouse News Service reported.

The US Food and Drug Administration (FDA) approved the company’s application to produce and sell the genetically engineered salmon in the United States in 2015, marking the first time a genetically engineered animal was approved safe for human consumption.

The decision sparked a lawsuit from the anti-GMO group Center for Food Safety and a number of environmental and trade groups representing the fishing industry, who allege potential impacts on the environment and human health.

Vincent Chhabria, US District Judge for the Northern District of California said he was concerned AquaBounty could use the FDA’s finding of “no significant impact” to expand operations without taking into account the impact on local ecosystems.

US Department of Justice (DOJ) attorneys highlighted to Chhabria that the FDA does not take into consideration environmental impacts of production when approving the safety of food and drugs.

AquaBounty plans to produce its fast growing AquAdvantage salmon eggs at its hatchery in Rollo Bay on Prince Edward Island, which would then be transported for growth at the company's Indiana land-based farming site.

Lawyers for the company claim Chhabria is asking the government to speculate on AquaBounty’s future plans, which without firm plans it is unable to do.

Environmental groups argue the FDA’s most recent environment assessment from 2015 has become outdated and does little to protect wild Atlantic salmon that could be harmed by competition for food and interbreeding.

They are demanding the judge order a more thorough environmental impact statement.

Without issuing a formal ruling, the judge indicated he was inclined to reject the assessment and order the FDA to review more closely the project’s potential environmental threats.

AquaBounty CEO Sylvia Wulf told IntraFish the company does not comment on ongoing litigation.

"AquaBounty continues to make significant progress and we are excited about the commercial launch of our product," Wulf added. "We are committed to feeding the world with our salmon farmed affordably, sustainably and safely.”