International partnership confirms a new Baja nursery area for white sharks

It’s relatively easy to spot when and where a pregnant animal gives birth on land. But in the sea, it’s a whole different story.

Over the past few decades, researchers studying the elusive great white shark have pieced together a picture of their underwater lives: The adults seasonally travel between a remote region of the Pacific Ocean—dubbed the White Shark Café—and their feeding grounds in Central California and Mexico.

But where do females give birth, and where do the offspring grow up?

Researchers in Mexico and the United States, including a team from the Aquarium, have confirmed a new nursery area for white sharks on the Pacific Coast of Baja California.

“We don’t know whether [the sharks] pup in-shore or off-shore,” explains the Aquarium’s Director of Collections John O’Sullivan. “We don’t even know whether they pup in American or Mexican waters.”

But in a paper recently published online in the journal Fisheries Research, scientists have revealed a new piece of the juvenile white shark puzzle. The study—an international collaboration between researchers at the Ensenada Center for Scientific Research and Higher Education (CICESE); Monterey Bay Aquarium; California State University, Long Beach; and other institutions—revealed that Bahia Sebastian Vizcaino, a warm lagoon on the coast of Baja California, is a nursery area for newborn white sharks.

The bay, part of a protected biosphere reserve and a prime breeding ground for gray whales, is located on the west coast of the Baja Peninsula, 500 miles south of San Diego. Continue reading International partnership confirms a new Baja nursery area for white sharks

The spooky science of shark mummies

John O’Sullivan, the Aquarium’s Director of Collections, was in Mexico on a mission. A young white shark equipped with an electronic tag had traveled over 650 nautical miles south from its release point in Monterey Bay, and the tag had popped off somewhere along the central coast of Baja California. The tag contained a complete data set documenting the shark’s movements and physiology since its release, and John aimed to recover it.

Instead his guide, a local fisherman, led John to a shark graveyard.

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Location of shark dump site in Baja California, Mexico.

A grisly grimace

Sometimes, commercial and sport fishermen accidentally ensnare juvenile white sharks off the coasts of California and Mexico. But locals in some communities consider it bad luck to discard the unmarketable parts, such as the heads, back into the ocean. Instead, they deposit these shark parts at dump sites in the Mexican desert.

In central Baja, just north of Guerrero Negro, John and a team of local Mexicans encountered hundreds of shark heads, in various stages of decay. Some were fresh; others were rotting. Some had skin that was dry and well-preserved—in other words, mummified—in this arid location.

Many of us would turn away from that gruesome sight. But John and his colleagues looked into the mouths of the shark-head mummies and saw an opportunity.

Continue reading The spooky science of shark mummies

Collaboration for conservation in Baja California

In the coastal habitats of Baja California, life thrives on the edge of desert sands and sapphire seas. Our newest special exhibition, ¡Viva Baja! Life on the Edge, opened on March 19, featuring the incredible creatures and habitats of this narrow Mexican peninsula.

But we’re not just exhibiting the splendors of Baja’s rugged 800-mile coastline. We’re also taking a lead role, working with colleagues here and in Mexico, to safeguard it.

Close ties with Mexican researchers

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A male azure parrotfish hangs with tangs, sturgeons and a golden grouper off Cabo Pulmo. Photo by @underwaterpat

The Aquarium works with several universities in Baja—including El Centro Interdisciplinario de Ciencias Marinas (CICIMAR) and Centro de Investigación Científica y de Educación Superior de Ensenada (CICESE)—to study key marine species, such as white sharks and and mahi-mahi (also known as dorado).

“There’s been this growth in how we approach other countries and also meet our needs as an aquarium,” says John O’Sullivan, the Aquarium’s director of collections

We’ve been tagging juvenile white sharks in Southern California since 2002, documenting seasonal migrations of these young fish between coastal waters in the United States and those on Baja’s Pacific coast.

Continue reading Collaboration for conservation in Baja California