Unregulated tankers sidestepping Western sanctions are posing a bigger risk to the Mediterranean region and Greece isundertaking more protective measures to safeguard its coast, the country’s shipping minister told Reuters on Tuesday.

Up to 850 oil tankers are estimated toform the so-called shadow fleet transporting oil from countries such as Iran and Venezuela as well as Russia, which has multiple restrictions on its oil exports.

The ships carrying these oil cargoes pose a massive environmental challenge, industry and analyst sources say,since they are hard to track because of their opaque ownership and use of non-Western insurance and other marine services, and they have little incentive to follow cleaner shipping standards.

“I can see some threats about the environment, in particular in areas like the Mediterranean Sea and very close to our mainland and islands,” Greece’s Christos Stylianides said on the sidelines of the Posidonia shipping week in Athens.

It posed “a big problem for the fairness” of the international oil trade, he said.

Shadow tankers have been involved in at least 50 incidents to date, including fires, engine failures, collisions, loss of steerage, and oil spills, German insurer Allianz Commercial said in a report last month.

“For us, no doubt that we are against this type of trade,” Stylianides said.

“We cannot accept this situation so close to our coast.”

Last month the Greek navy extended an advisory effectively banning ship traffic off the coast of the southeastern Peloponnese that two sources said was aimed at deterring ship-to-ship transfers of Russian oil off Greece.

“(A) ship-to-ship transfer is not prohibited. Sometimes it is necessary, it is part of the trade,” Stylianides said.

“But given this development of the grey fleet, our concerns remain about a possible accident with major environmental impact.”

Source: Reuters edited by Alexandra Hudson