Ah, but oil from the Niagra is not a biosecurity incursion. So Biosecurity NZ aren't responsible.
And its nothing to do with Primary Industries, so the Ministry or Primary Industries aren't interested either.
Fairly sure that NRC aren't responsible UNTIL oil leaks. Until then, the oil is the responsibility of the ship owner. Oh, and as it was sunk in an act of war, insurance wont cover it.
So someone needs to trot off and find the ships owner, and convince them to salvage the oil before its too late. But as you see, our fractionated and siloed bureaucracy wont deal with it.