Oil released from an unidentified ship along with two “natural” seepage points in the Gulf of Mexico has spread into seven protected natural areas, affecting more than 600km (373 miles), Mexican officials reported on Thursday.

The announcement comes after weeks of debate in Mexico regarding the response to the spill, which was first detected in early March off the coasts of Veracruz and Tabasco.

While authorities stated that there is no evidence of “serious environmental damage,” the marine conservation group Oceana said that local residents have reported dead sea turtles, a manatee, and multiple fish species linked to the contamination. The organisation also indicated that around 17 coral reefs have suffered damage.

According to Navy Secretary Admiral Raymundo Morales, satellite images and on-site inspections have identified three separate sources of the oil. Speaking at a press conference on Thursday, he noted that the spill remains active.

The sources include a vessel anchored near the port city of Coatzacoalcos in Veracruz, a geological formation known locally as a “chapopotera” located about 8km (5 miles) from the same port, and another natural seep in the Bay of Campeche.

‘Increased discharge of pollutants’

Morales explained that the ship believed to be involved has not yet been identified, as 13 vessels operating in the area had not undergone inspection by early March.

He added that the natural oil seeps in the Bay of Campeche are considered a significant contributor to the contamination.

“These seeps release oil continuously as part of a natural process; however, over the past month we have observed a higher volume of pollutants,” Morales stated.

In a separate event on March 17, residents of Puerto Ceiba reported an explosion near the Olmeca refinery, operated by the state-owned company Pemex, after oily water spilled onto a nearby roadway. A passing vehicle ignited, resulting in five fatalities, according to a company statement issued last week. There are growing concerns that oyster populations in the adjacent Mecoacan lagoon — and the fishing communities that depend on them — could face contamination.

Environmental groups have criticized what they describe as insufficient action by authorities in addressing the spill affecting Veracruz and Tabasco.

Greenpeace Mexico stated that the Gulf of Mexico is being treated as a “sacrifice zone for the oil industry” and urged the government to improve transparency and accelerate efforts to limit environmental harm.

The organisation emphasized that federal agencies are responsible for promptly informing the public, overseeing industrial activities, repairing environmental damage, and establishing effective measures to prevent and mitigate social and ecological risks tied to oil operations.

Mexican environmental officials have confirmed that at least six species — including sea turtles, birds, and fish — have been affected by the contamination to date.