Several tar balls have been washed up and recovered in the area near where the MSC Baltic III boxship was grounded in Newfoundland in February.
The Canadian Coast Guard (CCG) told local media that it was almost certain the oil had come from the stranded ship, although it did not believe there was a consistent leak from its fuel tanks.
A team found the first of the tar balls, about the size of a tennis ball, during a recent search of the nearby beach on 11 April and two more were recovered the next day.
According to local media, a total of six or seven tar balls have now been found and these have been sent to a laboratory for testing.
The CCG said it suspected that the balls comprised heavy fuel that might have washed ashore during the recent stormy weather that lashed the bay where the ship was grounded. Oil has not been seen in the water anywhere else in the bay.
A remotely operated vehicle – a specialised underwater robot used for inspection and repair of ship hulls and underwater infrastructure – was used to survey the hull on April 13, and it was confirmed that there was no consistent fuel leak from the container ship.
This was despite the salvage team reporting earlier that there were multiple cracks in the hull and that there was water in the engine room and holds of the containership.
A survey of the vessel has estimated that the vessel was carrying approximately 1 600 metric tonnes of heavy fuel and marine gas oil in its tanks.
The salvage company began to pump fuel from the vessel in early March but it is a slow process due to the time required to heat and pump the fuel.
The CCG reported that 184 cubic metres of fuel had been pumped into frac tanks by early April. However, no fuel has been transferred off the vessel so far.
Eight containers of polymeric beads, which are considered dangerous goods, were initially removed from the vessel. There were about 470 containers on the ship when it ran aground on 15 February but approximately half were empties, according to MSC.
The damage to the hull of the vessel has ruled out the possibility of refloating the ship at this stage.
Harsh weather conditions continue to hamper the salvage operation.