By Emilio Godoy
One year after the British Petroleum (BP) oil spill in the Gulf of Mexico, the worst accidental offshore oil spill in history, the search for damages in Mexican territory remains inconclusive, while scientists continue gathering and testing samples.
Between Apr. 20 and Jul. 15, 2010, almost five million barrels of oil were released into the Gulf from a BP well in the United States’ exclusive economic zone, according to figures from the U.S. federal authorities. It was the worst accident of this kind in the history of the oil industry. And of those five million barrels, only 800,000 were captured through containment efforts. (Each barrel of oil is equivalent to 159 litres.)
While the damages are still visible in the waters and on the coasts of the United States, “we have not observed direct evidence of high levels of oil or oil wastes, and there have been no reports of oil from the spill reaching Mexican waters,” said Sharon Herzka, a marine ecology specialist at the Centre for Scientific Research and Higher Education at Ensenada (CICESE), based in the northwestern Mexican state of Baja California, on the Pacific Ocean.
This is “probably due to the fact that the closest point between the well and Mexican waters is around 400 kilometres,” she told Tierramérica.
Herzka is the coordinator of research into the effects of the spill being undertaken jointly by a number of institutions, including the Autonomous University of Baja California (UABC) and the Mexican Petroleum Institute and National Institute of Ecology, both government agencies.
During the first phase of research, carried out Nov. 6 to 22, a team on board the XIXIMI-1 research vessel collected more than 1,000 water samples and hundreds of sediment samples at depths between 1,000 and 3,500 metres.
The second phase involves the chemical and biological analysis of the samples and definition of the characteristics of the water, such as salinity and temperature, in the central area of the Gulf. The results will be ready in June.
But Herzka noted that “in the coming years there could be indirect negative effects,” such as impacts on the reproduction of “mammals, sea turtles and species of large fish that sustain major fishing industries.”
The Gulf of Mexico, an arm of the Atlantic Ocean covering 1.55 million square kilometres, contains significant offshore oil deposits shared among the countries that surround it: the United States to the north and northeast, Mexico to the west and south, and Cuba to the east.
Oil operations compete with fishing industries that are vital for many coastal populations and are dependent on the Gulf’s rich biodiversity.
The second worst offshore oil spill in history also took place in the Gulf of Mexico, when an explosion on the Mexican oil rig Ixtoc released 3.3 million barrels of oil in 1979.
“The Gulf has a high natural capacity for the degradation of hydrocarbons. This means that, apparently, much of the oil that was in the water and that wasn’t captured near the well or didn’t evaporate has been broken down,” said Herzka.
On Apr. 20, 2010 the Deepwater Horizon drilling rig, which BP was leasing from the Swiss company Transocean, was hit by an explosion off the coast of the southeastern U.S. state of Louisiana and sunk two days later.
“We are carrying out an alert on migratory species, like Kemp’s ridley sea turtles, bluefin tuna and pelicans, which have been affected and come to the coasts of Veracruz and the Yucatán,” Alejandro Olivera, the coordinator of Greenpeace Mexico’s oceans and coasts campaign, told Tierramérica.
Olivera took part in a Greenpeace expedition in which 32 experts toured the area contaminated by the spill in October and November. The results of their research will be released in the coming weeks.
In the section of the Gulf that falls within U.S. jurisdiction, the research team identified a strip of water several kilometres in size with a low concentration of oxygen, which is a symptom of contamination and could also appear off Tamaulipas, the closest Mexican state, said Olivera.
In addition to its coastal mangroves, which play an important biological role and act as barriers against hurricanes and the erosion of its beaches, Tamaulipas is the leading producer of brown shrimp (Farfantepenaeus aztecus), with an output of 10,784 tons annually.
“In the medium to long term, the spill could affect the reproduction of yellowfin and bluefin tuna,” UABC researcher Rafael Solana told Tierramérica.
The yellowfin tuna (Thunnus albacares) and bluefin tuna (Thunnus thynnus) are overfished in the Mexican waters of the Pacific Ocean and Gulf of Mexico. Annual production in the latter is estimated at around 1,000 tons by the International Commission for the Conservation of Atlantic Tunas.
Between September and November 2010, the state governments of Tamaulipas, Veracruz and Quintana Roo filed two lawsuits in U.S. courts against BP, Transocean and other companies for possible damages to the marine environment, coasts and estuaries.
These suits were incorporated into multidistrict litigation MDL-2179, filed in a Louisiana court, along with hundreds of other consolidated cases with thousands of claimants, including cases involving 11 deaths and personal, environmental and economic damages. The trial is currently expected to begin in February 2012.
Something that particularly troubles scientists are the balls of oil deposited on the sea floor. These balls were formed after toxic chemical substances were sprayed on the spill to disperse the oil floating on the water. Some species could ingest these balls, introducing the toxins into the food chain. BP has acknowledged spraying 6.8 million litres of the chemical dispersant Corexit.
“Chemical pollutants seriously affect the physiology of fish species, which has direct repercussions on the reproductive cycle. This will be reflected in fishing yields, economic terms and conservation of these resources,” said Solana.
The Mexican government is providing support for the research conducted by CICESE and has been monitoring the country’s territorial waters in the Gulf, although it has yet to find traces of oil. The government has also activated the National Contingency Plan for Oil and Hazardous Substances Spills, drafted in the 1990s.
“Specialists estimate that it might even take decades for the real consequences of the spill to be determined,” stated the last Mexican government report, published online last Aug. 5.
Determining the environmental impact of the BP spill is crucial given the eagerness of the countries that border the Gulf to explore its oil reserves.
Mexico and the United States agreed in 2000, through the Treaty on the Delimitation of the Continental Shelf in the Western Gulf of Mexico Beyond 200 Nautical Miles, to impose a 10-year moratorium on offshore oil drilling within this area, while negotiating an exploration and drilling agreement.
The moratorium expired in January of this year, but in 2010 the two governments agreed to extend it until 2014.
Given the evidence of how quickly the United States has been moving in granting deepwater drilling concessions, the Mexican state-owned oil company Petróleos Mexicanos (PEMEX) is working to catch up.
The National Hydrocarbons Commission, established in 2008, has issued regulations on the use of technology, environmental protection, industrial security and the contracting of insurance against accidents like the Deepwater Horizon disaster.