ATHENS, Greece (AP) -- Greek authorities insisted Thursday they were doing everything they could to clean up the viscous, foul-smelling oil that has coated large parts of Athens' coastline following the sinking of a small oil tanker.
The Agia Zoni II tanker sank Sunday while anchored in calm seas off the coast of Salamina island, near Greece's main port of Piraeus, carrying 2,200 tons of fuel oil and 370 tons of marine gas oil. Two crew members were rescued.
"All the means available in the country" are being deployed to tackle the spill in the Saronic Gulf, Merchant Marine Minister Panagiotis Kouroumplis said Thursday.
"Things are developing very well and from day to day there is a huge improvement," he said, adding that authorities estimate the "situation will have completely changed" in 25-30 days.
Greece has requested help from the European Union and a specialized cleanup vessel has been deployed.
Critics, however, have accused the government of not acting quickly enough prevent the spill from spreading from Salamina across the coastline.
The Saronic Gulf is home to dolphins, turtles, a wide variety of fish and sea birds. Environmental and wildlife organizations have been posting instructions on social media on how residents can help any stricken wildlife they come across.
It's unclear why the ship sank. The vessel's owner, Theodoros Kountouris, said on Epsilon TV that the ship, built in 1972, had been overhauled in 2014 to make it double-hulled, which would make it safer for leaks.
Breaking down in tears, Kountouris said he had done everything in his power to try and prevent the leaking when the ship sank.
"I'm very sorry for what happened," he said.
Deputy Environment Minister Socrates Famellos said authorities think the leak had now been sealed.
"We believe that there will be no irreversible consequences to the environment," Famellos said. "I would not call it an environmental disaster. There was a serious environmental accident that is being dealt with."
Mayors of affected coastal areas were threatening to take legal action over the pollution.
Glyfada Mayor Girogos Papanikolaou said on Facebook that he planned to file a lawsuit Friday against "all responsible" — a common Greek practice when a culprit has not been identified.
"From dawn today, we have been making a superhuman effort with all means to restore the massive damage that has occurred on the Glyfada seafront," he said.
Kouroumplis said the pollution spread because heavy fuel oil can sink during cooler nights, escaping the floating booms deployed to contain the slick, before rising to the sea's surface again in the heat of the day.
Asked on Skai TV who was to blame for the oil spill, Deputy Agriculture Development Minister Giannis Tsironis said "the responsibility lies with an entire society and a global economy dependent on oil."