Whales Dying in Record Numbers Near Argentina

Southern right whales are dying in record numbers along Argentina's Patagonian coast, resulting in the largest die-off of great whales that has ever been documented, according to the Wildlife Conservation Society.

Since 2005, a total of 308 dead right whales were recorded in the waters around Peninsula Valdes, which is an important calving ground for this species. Eighty-eight percent of the dead were calves less than 3 months old. That means about 28 percent of all calves in the region appear to be dying, and no one knows why.

(G. Harris/Wildlife Conservation Society)

In an attempt to solve the mystery, whale and health experts from the WCS have joined experts from other organizations at a workshop sponsored by the International Whaling Commission. The workshop runs through March 18 and is being held at Puerto Madryn in Chubut Province.

"We need to critically examine possible causes for this increase in calf mortality so we can begin to explore possible solutions," said Marcela Uhart, associate director of WCS's Global Health Program. "Finding the cause may require an expansion of monitoring activities to include the vast feeding grounds for the species."

A number of hypotheses for the whale deaths are being considered, such as biotoxins, disease, environmental factors at the nursing grounds, and potential variations in prey availability at the whales' distant feeding areas.

For those southern right whales that do reach adulthood, they can grow up to 55 feet in length and weigh up to 60 tons. Centuries of commercial whaling decimated their population, but they were on the rebound starting at about 1970, thanks to conservation efforts.

"Peninsula Valdes is one of the most important calving and nursing grounds for the species found throughout the Southern Hemisphere," said Howard Rosenbaum, director of the WCS's Ocean Giants Program and a member of the IWC's Scientific Committee.

He added, "By working with the government of Argentina, the Province of Chubut, the IWC, and our diverse team of experts and specialists, we can increase our chances of solving this mystery, the critical next step to ensuring a future for this population of southern right whales."

I invite you to watch this mesmerizing footage of southern right whales just swimming and interacting on a typical day.