Monterey Bay Aquarium tags, releases fifth white shark

November 4th, 2009 • Related • Filed Under

The Californian

A young female white shark placed on exhibit at the Monterey Bay Aquarium in late August was returned to the wild today, marking the fifth time the aquarium has successfully exhibited and released a great white shark.

Aquarium staff released the shark in offshore waters near the southern tip of Monterey Bay shortly after sunrise.

In 50 years of attempts worldwide, the Monterey Bay Aquarium remains the only institution to keep a great white shark on exhibit for more than 16 days, to get the animals to take food consistently from staff and to document the sharks’ successful return to the ocean.

Prior to her release, the shark was fitted with two electronic tracking tags. One will deliver real-time data on her location to researchers; a second will collect and store information documenting her travels, the depths she dives to and the water temperatures she favors for about six months, before it pops free and delivers those data to scientists via satellite.

The timing of her release was prompted by several recent observations of aggressive behavior toward other sharks in the million-gallon Outer Bay exhibit.

Data from tracking tags on four previous sharks kept at the aquarium for up to six-and-a-half months have documented their successful release. Two sharks traveled to the southern tip of Baja California and beyond within 90 days, and a third with a 30-day tracking tag headed to waters near Santa Barbara. The fourth shark, tagged and released near Santa Barbara after 11 days in Monterey, was caught and released in good health just a few days later by a commercial fisherman in Santa Barbara.

During her 69 days on exhibit, the most recent shark grew from a length of 5-foot, 3-inches and just under 80 pounds to a length at release of 5-feet-5 inches and a weight of 100 pounds. During her stay she fed exclusively on mackerel offered by aquarium staff, eating up to three percent of her body weight each day, Hamilton said.

She had not yet reached a size where human safety or animal welfare concerns were a factor in the decision to release her, Hamilton said. Rather, the change in her behavior prompted the decision, he said.

Over Halloween weekend, she received a superficial bite wound, was observed chasing scalloped hammerhead sharks in the exhibit, and bit and injured a Galapagos shark, Hamilton said.