Orcas in calfing lagoon spell peril for gray whale survival

A deadly new threat may be on the horizon for gray whales — a species already suffering from a mysterious decline in population.

For the first time in known history, orcas have been observed in the grays’ Mexican refuge: the warm, shallow lagoons of the Baja Peninsula, where the40-plusfoot leviathans go to calf, nurse and mate in peace. Until now, conservationists had considered the area a shelter from shipping, fishing gear, and killer whales — the ocean’s apex predator.

According to reports from researchers and local fishermen, Laguna San Ignacio has been visited twice this year by orcas.

One pod showed up in January and was videotaped as the orcas fatally attacked two resident bottlenosed dolphins. They may have also killed a gray whale calf, although a body was never found to confirm that.

Cindy Hansen, educator and advocacy coordinator for Orca Network, a Freeland, Washingtonbased nonprofit, said a piece of skin and blubber were found, “but there was no genetics done to be able to get a positive ID.”

Then, last week, another pod of orcas swam into the lagoon. This time, there were no gray whales — most were either in the Arctic where they traditionally spend their summers gorging on small shrimplike crustaceans that they scoop up off the ocean floor, or just starting their southward migration down the North American coastline. Gray whales usually inhabit the lagoon starting in late January and leave by mid-March or April.

It is not clear whether the two pods of orcas consisted of the same individuals. While researchers were able to photograph and identify each of the killer whales in January, a research team was not present to photograph the intrusion last week, said Steven Swartz, a primary researcher with the Laguna San Ignacio Ecosystem Science Project.

“Orcas are part of the normal fauna down there,” said Swartz, who is based in Maryland when not studying whales in Baja. “They are offshore up and down the Baja coast and in the Gulf of California, so they are not strangers to the area. What was odd is that we’ve never had any bona fide, verified real time sightings inside the gray whale breeding lagoons.”

He said that while no killer whale had ever been documented in the lagoon previously it wasn’t surprising that these social and intelligent animals would find it.

“This is the second time we know of ... ” he said. “Maybe they came in at night . ... Now whether these guys are just coming in to take a look around and then they’ll leave or come back later, we don’t know.”