Why is tanking for ships forbidden at a latitude higher than 60 degrees?

What is "tanking," and how do you know it is forbidden at those latitudes? Maybe you have a source so I could read more and perhaps offer something useful in response?

I referred to the tanking of a ship in full sea. Sorry I forgot to mention that. I heard of this when I saw a documentary about Greenpeace.

Ok, I still have no idea what you mean by "tanking of a ship", and google isn't helping.

Sorry, maybe the word isn't much used in English.

 

tank

 

verb

fill the tank of a vehicle with fuel

As a guess, tanking may be fueling. If this is correct, then maybe it has something to do with fuel vapors and how they disperse (or don't) at a latitude higher than 60 degrees.

 

May have something to do with safety, and environmental concerns as well.

 

Another guess is that tanking may be purposely sinking a ship.

 

I couldn't find any reference to tanking to back up any of my guesses.