Unprecedented oil spill catches researchers in Peru off guard

A viscous, black wave rolled onto the beach of the seaside town of Ancón, Peru, just as Deyvis Huamán and his team arrived to assess the situation. Two days earlier, on 15 January, thousands of barrels of crude oil spilled from a refinery to the south of there. Heavy swells had slammed the coastline after the violent eruption of a volcano near Tonga, more than 10,300 kilometres away.

“We were astonished,” says Huamán, a conservation biologist with Peru’s National Service of Natural Areas Protected by the State (SERNANP) in Lima. The oil coated everything — rocks, seaweed, crabs — setting a scene unlike anything Huamán had experienced before. Although Peru is no stranger to oil spills, which have mostly occurred off its northern coast and in its Amazon jungle, this is the most damaging to pollute its marine waters, and the largest to take place near its heavily populated capital, Lima.

Scientists have joined authorities in assessing the extent of the damage and are helping to clean up the mess. According to reports, the oil slick has spread to more than 20 beaches, washing over 41 kilometres of coastline (see ‘Spill spread’). Some researchers, who were already monitoring wildlife along the coast, are dismayed by the destruction they’re seeing. Some are looking for opportunities to document and learn from the unprecedented spill, which they hope might one day spur the country to end its reliance on oil.

“Tragedies are never good,” says Héctor Aponte, a wetland researcher at the Scientific University of the South in Lima. “But sometimes they bring about change.”

A productive sea

The massive spill occurred as a tanker was pumping crude oil into a refinery — operated by the Spanish oil company Repsol — near Lima. Days afterwards, Repsol denied responsibility for the event, citing heavy waves that tossed the ship around after the powerful eruption of the volcano Hunga Tonga–Hunga Ha‘apai. Peru’s government suspended most operations at the refinery to prevent future spills, and its National Maritime Authority is investigating Repsol’s claim that the spill was due to eruption-induced swells.

According to Peru’s Agency for Environmental Assessment and Enforcement, Repsol failed to immediately contain the spill. The agency also reported that the company’s early-warning leak-detection system was not functioning properly, and that Repsol did not have the equipment and materials, nor adequately equipped and trained personnel, to mitigate a spill of such large dimensions. Repsol has responded in press statements that its commitment to the clean-up work “is absolute”, and says that, as of 14 February, the work is more than 70% complete.

Spill spread: Map showing the spread of an oil slick in the Ocean near to Lima in Peru.


No one in Peru was prepared for such a disaster, says Carmen Heck, an environmental lawyer and the policy director of the non-profit organization Oceana Peru in Lima. Peru is a fishing country “with one of the most productive seas on the planet”, she says. Learning from the situation, she adds, might help to prevent it from happening again.

On 28 January, Peru’s Ministry of the Environment announced that 11,900 barrels of oil had leaked into the sea — up from Repsol’s original estimate of about 6,000, which was later revised to 10,400 barrels. If the government’s number turns out to be accurate, the spill is the country’s largest. By comparison, a total of about 9,700 oil barrels were spilled in a series of events in Peru between 2009 and 2019, according to an estimate by the environmental news outlet Mongabay Latam.

Most previous spills were so far away from Peru’s capital that they weren’t monitored properly, says marine biologist Joanna Alfaro, director of ProDelphinus, a conservation organization based in Lima. In fact, in 2014, a group of experts on marine conservation and fisheries assessed the threats to Peru’s seas and coasts. The researchers rated the impact of oil spills as minimal. But with this incident, the picture looks different, Alfaro says. The threat has “really knocked on our doorstep”.

A dead bird lies in the oil spill off the coast of Peru.

As of 7 February, more than 190 birds had been found dead along Peru’s oil-soaked coastline.Credit: Musuk Nolte

Efforts are already in motion to understand the spread of the spill and its effect on wildlife. Researchers from the state-owned Institute of the Sea of Peru (IMARPE) have been in the field weekly to collect water samples, use drones to track the oil’s movements and document the damage to the affected ecosystems. Piero Villegas, a marine biologist at IMARPE in Lima, has helped to coordinate the efforts, which include exploring how microbial communities have responded to the spill and how food webs have been altered.

The oil has so far invaded three marine protected areas: the Ancón Reserved Zone, the Pescadores Islets and Punta Salinas. By 7 February, SERNANP had rescued 51 birds, found 193 dead and registered 953 covered in oil. The agency has also participated in rescue and clean-up.

IMARPE has started using two of its research ships: an oceanographic vessel to take samples of the ocean floor, and a hydroacoustic cruiser to survey schools of fish using sound. “We’ve had to rearrange our priorities,” Villegas says.

The damage done

Some researchers are worried about the wildlife they regularly monitor. Alfaro tracks the marine otter (Lontra felina), an endangered mammal that lives in small packs along the coast of Peru, Chile and Argentina. With some of its habitat covered in oil, many animals are expected to perish, Alfaro says. At least one family of otters has died. “It was already difficult to identify where otter colonies are,” she says.

As ocean currents carry the oil north, birds are also suffering. A rapid government census in early February showed that the slick has surrounded islands and islets where massive bird colonies breed and feed, threatening nearly 180,000 birds. This includes species that were already at risk, such as the threatened Humboldt penguin (Spheniscus humboldti).

An aerial view of the workers in white protective suits, cleaning up the large oil spill on the coastline of Peru.

The 15 January oil spill is the largest ever to occur in Peru’s marine waters.Credit: Musuk Nolte

But the damage might spread even further.

“The birds that we study are not static,” says Carlos Zavalaga, an ornithologist at the Scientific University of the South. He and his students monitor 200 seabirds, each carrying a small camera with a GPS system, to record their journeys out to sea and to quantify how they compete with commercial fisheries for food. The team has focused its research on La Libertad, a region more than 400 kilometres north of Lima and away from the oil slick. But the animals travel constantly between regions, and might drink water and eat fish that have been contaminated.

“Sooner or later, the birds of the Peruvian coast, all of them, are going to be affected because of this spill,” Zavalaga predicts.

For Heck, documenting the destruction is crucial. But even more important, she says, is that Peru consider alternative energy sources in the future, given its reliance on its fishing industry. If the country doesn’t have a proper response system, she asks, “How much sense does it make to continue promoting this type of high-risk activity in marine ecosystems?” In 2019, more than 71% of Peru’s energy came from fossil fuels, compared with about 27% from low-carbon sources, according to the Our World in Data project at the University of Oxford, UK.

But if this change comes at all, it won’t come soon enough to prevent the oil from seeping into Peru’s coastal ecosystems. “The damage is already done,” Zavalaga says.