Southern Right Whale Deaths Hit Record Pace in Argentina

Southern right whale deaths are piling up along Argentina's Patagonian coast, and scientists now say this could be the worst season ever recorded. According to El País, researchers have been tracking an unusual die-off of calves and adults since July at Península Valdés, a protected sanctuary in Chubut province.

A Record Year Nobody Wanted

Every year, more than one thousand southern right whales swim up from the cold waters near Antarctica to the sheltered gulfs of Península Valdés. They breed, nurse their calves and put on a show for tourists by breaching and slapping their tails close to shore between May and December.

A few dead whales wash up in a normal year. This year is different. Neither scientists nor local authorities will release an official death toll until the season ends, but unofficial estimates put the number at more than three hundred, per El País and MercoPress.

For context, the monitoring program run by the Whale Conservation Institute since two thousand three recorded its worst calf year in two thousand twelve, with one hundred thirteen dead calves. The most adult strandings came in two thousand twenty-two, when twenty-eight adults were found dead. Researchers expect this year to beat both marks.

What Is Killing the Calves?

For the babies, the leading suspect is a bacterium called Erysipelothrix rhusiopathiae, which causes erysipelas. Lab tests on animals that died this year came back positive, according to Live Science, which also reported the calf toll has already passed the previous annual record.

Mariano Coscarella, a researcher at the Marine Mammal Laboratory, explained that the germ lives on the whale's skin and can slip in through wounds, such as gull pecks, or through food. Scientists do not yet know which route it took this time, but he said it proved highly pathogenic for calves.

Young animals are hit harder because their immune systems are less developed. Specialist Víctor Fratto noted that the disease has been seen before, including a calf death identified in this same area in two thousand sixteen and cetacean cases in the Netherlands, the United Kingdom and California.

The Adult Mystery and the Red Tide Theory

The adults are a different puzzle. Researchers say the cause is still under investigation, but they suspect a harmful algal bloom, also called red tide, which makes toxins that can kill whales and other marine life under certain conditions. A similar bloom was behind the two thousand twenty-two spike.

Necropsies and sampling are running under a health monitoring program led by veterinarian Marcela Uhart of UC Davis. Provincial officials say water and shellfish sampling in both Nuevo and San José gulfs will follow in stages. Her team has said the calf events are unusual based on twenty-three years of data, as reported by the Associated Press.

Is Climate Change in the Mix?

Here is where it gets heavy for anyone who follows the climate emergency. Scientists looked into whether industrial changes or a new factory nearby could be responsible and, according to Coscarella, found no direct evidence that human activity caused the deaths.

He added a careful warning, though. That does not mean climate change or El Niño have not altered ocean conditions in ways that let the bacterium spread. In other words, the link is plausible but unproven, and nobody is claiming a smoking gun yet.

What Happens to the Population?

The numbers behind the story are mixed. The population visiting the sanctuary grew from roughly five hundred whales in the late nineties to a record of two thousand one hundred ten in two thousand twenty-five. This year's aerial census counted one thousand three hundred seventy-five whales, including four hundred nine calves.

The Whale Conservation Institute urged patience. These whales are long-lived and mostly reach reproductive maturity around age nine, so the impact of a die-off at one site cannot be judged from isolated figures. It has to be studied over wide stretches of time and space.

The species nearly vanished a century ago because of commercial whaling. Today it is an Argentine National Natural Monument and draws tens of thousands of visitors a year, which is why this story hits both the science world and local communities that depend on whale tourism.

Cleanup is its own challenge. Under the Coastal Wildlife Network protocol, carcasses in remote areas are left alone, while those on busy beaches are removed quickly with heavy machinery and buried, since a single whale can weigh about fifty tons.

The season runs until late November, so the final tally of southern right whale deaths is still ahead. Until then, expect more necropsy results, more theories and a lot of scientists watching the water. If red tide or a bacterial outbreak is tied to warming seas, this die-off could become a warning shot for other whale nurseries around the world.