Norway’s snow crab – a delicacy – is off limits to fishermen from the European Union. The country’s Supreme Court ruled that they need to ask permission from Oslo.

The court rejected an appeal by a Latvian fishing firm and its Russian captain against fines imposed by a lower court for catching snow crab around the remote Svalbard Islands in 2017 with only an EU license.

“Norway is tightening its grip,” in the Arctic, said Oeystein Jensen, a researcher in international law at the independent Fridtjof Nansen Institute in Oslo.

“The court clarifies that if you are going to fish, or search for oil and gas, you need permission from the Norwegian authorities,” he told Reuters.

“For the Norwegian coastguard this is a big relief – they can arrest any ships fishing illegally in the Svalbard area,” chief public prosecutor Lars Fause told Reuters.