The Georgia Aquarium in Atlanta is seeking federal permission to bring 18 beluga whales, captured last year off the coast of Russia, to the US at a time when pressure to end the captivity of cetaceans is at an all-time high.

In September 2013, the Georgia Aquarium sued the National Oceanic and Atmospheric Administration (NOAA) fisheries service for the right to acquire the beluga whales, which were captured in the Sea of Okhotsk and are currently under the care of a Russian team.

Lawyers for both sides argued their case on Wednesday (20 August), though a final ruling could be as far as two months away.

Aquariums have been under immense pressure in recent months following the release of the documentary Blackfish, which recounts the 2010 killing of trainer Dawn Brancheau by an Orca at SeaWorld Orlando.

As a result of protests against aquariums housing cetaceans nationwide, some have been making dramatic changes. Vancouver Aquarium was recently told it could keep its current stock of whales and dolphins in captivity,but must not breed them or promote reproduction amongst captive mammals while SeaWorld this week announced multi-million dollar expansion plans for its habitats housing killer whales. Baltimore’s National Aquarium has even considered retiring all of its dolphins to a one-of-a-kind sanctuary, keeping the animals away from the public eye.

The US government is contending that bringing the captured whales to the US violates the Marine Mammal Protection Act, depleting the known wild beluga whale population even more, while the aquarium disputes the allegations and is demanding NOAA Fisheries hand over more internal documents to show how the government made its decision.

In March 2013, Georgia Aquarium received a green light on the decision to bring in the whales, though in September later that year, the government denied the permit application.

“If they are going to change their minds, we are entitled to look at why," said aquarium attorney Daniel Diffley. "We believe the decision is arbitrary."

Georgia Aquarium also argues that acquiring the whales is crucial, “to pursue the goals of conservation, research and education.”

If the permission is granted by the courts, some of the whales would join the four beluga whales that currently reside in the aquarium, while the rest would be loaned to other approved marine sites, including SeaWorld.