Denmark is stepping up inspections on oil tankers passing through its waters amid European efforts to counter Russia’s “shadow fleet.”

The Danish authorities will strengthen environmental checks on ships that anchor at Skaw anchorage, which is one of the largest anchorages in the Nordic region and serves as the gateway to and from the Baltic Sea.

Every year, several thousand of ships pass through the Danish waters, and a large proportion of them anchor at Skaw anchorage.

The move is a result of increased activity by older ships that transport sanctioned oil through Danish waters, among other things. These raise the risks for the marine environment, the Danish government said.

“We know that there is a lot of traffic consisting of older ships sailing through Danish waters, and they pose a particular risk to our marine environment,” said the minister for environment and gender equality, Magnus Heunicke.

“That is why we are now tightening controls with very basic environmental rules so that we can take more effective and consistent action against tankers and the Russian shadow fleet,” he added.

Denmark’s industry minister Morten Bødskov said that “We must put an end to Putin’s war machine. This also applies to the Russian shadow fleet. We are using all tools. We know from our safety checks at Skaw anchorage that among these ships there are old and worn-out ships sailing around. That is why our authorities are now intensifying controls so that we look after Denmark and Danish waters.”

The Danish Maritime Authority, in cooperation with the Environmental Protection Agency, will conduct more environmental inspections on ships to ensure compliance with environmental regulations. These measures are intended to guarantee that vessels adhere to environmental standards.

By the end of the year, Denmark will also implement measurements of sulphur content in ship fuel. The Danish government noted that information collected through these measures could be used in international cooperation against the “shadow fleet,” including compiling a list of specific vessels subject to sanctions.