Tresta Star

The incident

On 3 February 2022, the Mauritian registered bunker tanker Tresta Star, designed to operate in port areas, sent out a distress message while halfway between the islands of Mauritius and Reunion. The Tresta Star, used to refuel merchant vessels in Port Louis, was in difficulty due to weather conditions and propulsion issues. The tanker was swept away by cyclone Batsirai and required immediate assistance by tug. While the towing operation was being prepared, the Tresta Star shortly reported that it was unable to control its drift towards the coast of Reunion Island. It was impossible to evacuate the crew by helicopter due to the weather conditions. At the request of MRCC SOI, vessels were sent for assistance (patrol boat Osiris II, bulk carrier Stardust and bulk carrier Helena Oldendorff) but intervention was not feasible.

On the evening of 3 February, at 20:16, the Tresta Star indicated that it had dropped its starboard anchor but this did not slow the vessel which was near Tremblet beach. At 20:55, the vessel hit a black volcanic rock shoreline at “Quai de sel” in Saint-Philippe. The double hull was ripped open.

The vessel was resting on its full length at the foot of the lava rocks of the volcano Piton de la Fournaise. Its port side was exposed to the swell and its hull had several breaches, including one 3 metres long by the starboard stern. This breach caused the engine room to be flooded and fuel to be spilt into the sea. At the time of grounding, the Tresta Star was unladen but had on board approximately 8 m³ of Marine Diesel Oil (MDO), 6.31 m³ of Fuel Oil (FO) and 0.31 m³ of MDO in its cargo tanks.

On the night of 4 February, the 11 crew members were finally evacuated via a zip line set up between the ship and the shore by GRIMP (Groupe de Reconnaissance et d'Intervention en Milieu Périlleux) firefighters.

In the days following the grounding, crowds of onlookers flocked to the shore to get a glimpse of the wreck. As these people were at risk of hindering the work of experts and the upcoming clean-up operations, access by land and sea was prohibited, as were overflights by drones.

Pumps, generators, various equipment, big bags and IBCs were brought on board by helicopter. The tug Vasileios P (IMO 9651307) belonging to the Greek company Polygreen arrived on site to evacuate the materials and waste to be removed.

Pollution mitigation

Cleaning operations began on 10 February. The bunker fuel was to be pumped out, the tanks pressure washed and the equipment and debris removed. One week after the grounding, the shipowner announced that the ship would be returned home within six months. It was still the cyclone season in this part of the Indian Ocean and it was cyclone after cyclone. Cleaning operations were delayed and the vessel's condition deteriorated. The main breach opened further and pieces of the hull on the port side were swept away.

On 17 February, an oil slick 50 m wide by 2.5 km long was seen escaping from the vessel, with further leaks possible. Polygreen abandoned the cleaning operation because of a "financial disagreement". Management of cleaning operations was passed back into the hands of the Prefect for Reunion Island and DMSOI (Sea Directorate for the South Indian Ocean).

On 18 February, aerial and seaborne surveys confirmed that the oil slick had broken up.

On 19 February, shoreline response equipment was ready to be deployed, while at-sea response operations were set to be launched as soon as weather conditions settled (cyclone). Given the deterioration in the situation, the Prefect once again issued formal notice to the shipowner to take all measures to stop the pollution and repair the environmental damage caused by the pollution.

By mid-February, despite 3 formal notices issued by the Prefect of Reunion Island, concrete answers from the ship’s insurers were still lacking. The French State therefore decided to take the first steps towards complete cleaning of the vessel, mandating local companies. Among the actions undertaken, an environmental assessment of the site was deemed a priority.

On 22 February, the support and assistance vessel Champlain, deployed at the time in the north-west of Madagascar, interrupted its mission and headed to Reunion Island where it took on board pollution response equipment before being dispatched to the scene of the grounding of the Tresta Star. The Champlain was operational on site by 28 February.

On 7 March, a new oil slick more than 1 km long was spotted on the port side of the Tresta Star's hold n°3. Six local companies were contracted to reduce or eliminate the pollution risk caused by the wreck. Salvageable elements were evacuated by helicopter and the contents of the flooded holds were pumped out. The Champlain was also deployed on site to treat the oil slick by spraying dispersants and recovering the oil using a trawl.

150 m3 of oily seawater and 50 m3 of industrial waste were removed from the Tresta Star. The hull began to break up due to the action of the swell, with oil leaks escaping on several occasions.

On 11 March, 225 m3 of oily water and 11 tonnes of waste were evacuated.

On 12 March, Five Oceans Salvage (FOS), commissioned by the ship's insurer, took over from the French Government in coordinating the work of the local companies in response to the Tresta Star. Pumping operations continued in the vessel’s holds using skimmers to remove all traces of fuel. Meanwhile, some holds were undergoing final clean-up by pressure washing. 6.5 m³ of fuel mixed with water was removed. Inside the ship, operations then focused on the upper deck of the engine room and the forecastle, and 80 big bags were removed from the vessel. The pace of evacuations then began to slow down, given the reduction in the volumes to be removed and their location in more difficult access areas.

On 23 March, cleaning operations were officially completed. The Prefect of Reunion Island gave the shipowner and his insurer one month to submit a detailed plan for the removal of the wreck of the Tresta Star.

In total, the cost of cleaning and the anticipated cutting operations was expected to exceed €80 million.

Treating the wreck

Between 11 and 15 April, inspections were carried out on site and by helicopter to assess the possibility of refloating or removing the wreck.

It was estimated that wreck removal operations by sea would take 18 to 24 months and cost €12 to 17 million in the best-case scenario. Removal operations over land were expected to take 2 years and would undoubtedly generate an ecological impact. The option of removal by air was also evaluated but subsequently dismissed. Having examined these options, which proved impossible to implement, on 7 December, the Reunion Island authorities (Prefecture of Reunion Island) decided that no further action would be taken. The wreck has therefore been left to deteriorate on site.

In 2025, the wreck is still in place and continues to deteriorate.

Environmental impact

On 17 March 2022, the consultancy firm MAREX submitted an initial report investigating the ecological impact of the grounding of the Tresta Star. At the 30 subsea stations sampled between Saint-Philippe and Sainte-Rose, no direct impact was observed on the flora and fauna.

Legal proceedings

In March 2022, the Reunion Regional Council and the Reunion National Park joined forces with the municipality of Saint-Philippe to file a complaint against persons unknown for “accidental release of pollutants into the sea" and "wilful failure to respond to an incident", which led to a preliminary investigation.

In May 2024, the town of Saint-Philippe brought civil proceedings in the case of the Tresta Star grounding, claiming over €3 million in damages: monitoring costs (€266,000), damage to the site image (€2 million) and environmental damage (€1 million). Meanwhile, out-of-court negotiations, led by DMSOI and the legal affairs directorate of the French Ministry for Ecological Transition, were also underway with the insurance firm MS Amlin. The French Government was claiming €650,000 for the cleaning operations carried out. If no agreement is reached, legal action may be taken.