Scientists at the University of Waikato say they have made good progress in understanding the chemical composition of the oil aboard the stricken container ship Rena.
According to the university, all of the samples collected contain similar substances to those found in diesel fuel bought from the pump.
Professor Alistair Wilkins from the university’s chemistry department examined oil from the ship’s tanks, from surface slicks and from ‘tar balls’ found on the Mt Maunganui beach.
“Oil from the Rena grounding contains polycyclic aromatic hydrocarbon compounds (PAHs), which are known to be harmful to humans and wildlife,” says Professor Wilkins.
The levels of these harmful compounds will likely determine when it is safe to eat shellfish and other marine life from the area.
“These hydrocarbon compounds are the same as those found in fuel oils from around the world but we have yet to determine how much of each compound is present in the Rena oil.”
Waikato scientists say when the oil from the ship enters the water, the smaller, lighter compounds evaporate leaving behind the lumps of tar-like substance seen washed up on the beach.
Weathering and bacterial action will eventually break-down the deposits scientists say, but it is not easy to predict how long it will take.
It is also now possible to distinguish Rena oil from local sources of oil using hydrocarbon ‘fingerprinting’ techniques.
Information gathered by University of Waikato scientists is expected to help researchers that are already studying the effects of the spill on the coastal environment.
3 News