The salvage operation ensures that risks to marine life and fisheries from the wreck are minimized.
When the Manolis L went down in Notre Dame Bay, north of St. John's, she was estimated to be carrying 550 tonnes of diesel and heavy fuel oil in her bunker tanks. In early 2013, the local Canadian Coast Guard Environmental Response unit received reports of oil on the water in the vicinity of the wreck. They discovered two cracks in the hull of the ship, one 22 inches and one 12 inches long, each leaking a small quantity of oil (video below). The service used neoprene sealants and a cofferdam to temporarily contain the leaks.
Small amounts of oil have occasionally been observed on the surface over the years since, usually after storms stir up stronger undersea currents. After an advocacy campaign by a group of local residents and environmental scientists, the Canadian Coast Guard commissioned a technical assessment by Resolve Marine. In 2016, the assessors found that about 110-150 tonnes of hydrocarbons remained trapped in the wreck, about 17 percent of the total capacity of the ship’s tanks. The remaining contents likely escaped from the vessel during the sinking or seeped out over the years since. The survey found that the hull was minimally degraded by corrosion and that the ship is on stable ground.
To reach a more permanent solution, the Canadian Coast Guard selected Ardent Global to remove the remaining oil and seal the wreck's hull. The $15 million contract was awarded to Ardent in April, and the joint team finished its work last weekend. The oil is being offloaded from the chartered offshore construction vessel Tidewater Enabler for treatment and safe disposal. The amount of oil recovered has not yet been quantified.
“Before we left the wreck site we did what we call securing the wreck,” said CCG incident commander Anne Miller, speaking to media at a press conference Tuesday. “Any penetrations into the wreck were secured. There were several complete surveys done of it to ensure that any concerns were taken care of, whether it was placing seals on suspected areas and capping the protrusions.”