The great white shark is a powerful and mysterious creature that elicits a strong emotional response in humans. Love them or hate them, revere them or fear them, people can’t seem to get enough of the infamous ocean predator.
When a new juvenile great white went on display at the Monterey Bay Aquarium in September, visitors flocked from near and far to see it. And when aquarium officials announced that same shark died shortly after being released off the coast of Goleta in late October, the story made international news.
John O’Sullivan, the aquarium’s white shark research project manager, said data sampled from the 4-foot-10-inch shark’s electronic tag showed it stuck to the ocean surface for a short time after its release. It then dove down to about 54 feet, where it remained for a few days until sinking to the ocean floor.
“You always want to be careful when interpreting tag data, because we want to be as accurate as possible,” O’Sullivan said, explaining that there have been times when a tagged animal—or the tag itself—was eaten by another animal.
Researchers have yet to determine what caused the juvenile shark’s death, but O’Sullivan said they’ll be having numerous meetings to evaluate what happened.
“It’s not going to be in a finger-pointing manner, but we’re going to have to be very honest,” he said. “We didn’t begin this project thinking a shark would never die. With something like this, you have to accept responsibility that sometimes there are going to be mortalities.”
Since 2002, the aquarium and its research partners have tagged and tracked 47 juvenile great white sharks off southern California. According to researchers, the data is used to learn more about the sharks’ mating, hunting, and pupping (or birthing) patterns. This is the project’s first shark death since 2004.
Still, some conservationists have criticized the project for capturing and exhibiting the animals, claiming it’s done only for human benefit.
“This is extremely sad,” read a comment on reports of the recent shark death on underwatertimes.com, a blog dedicated to ocean life. “First they robbed this animal of a normal life by kidnapping him from his natural home so they could make money from ‘exhibiting’ him. Now, thanks to the terrible stress of captivity, he is dead. If this aquarium wants to learn more about sharks they should study them in the wild, not force them into captivity.”
O’Sullivan acknowledged the criticism, but argued that research collected through the project is used to educate commercial fishermen and the rest of the public and help preserve the sharks’ habitat.
Ten years ago, O’Sullivan said, “what you knew about [juvenile sharks] could fit in a thimble.”
New understanding of white shark territories in the Pacific Ocean, including feeding grounds off the coast of California and pup “nurseries” in Baja and Mexico, has helped create a dialogue between commercial fishermen and conservationists, he explained.
Conservation and fishery management have done a lot to protect white sharks (on top of federal mandates), he said, including a law initially created to protect sport fishing by moving commercial fishing three miles offshore. Shallow waters offshore, it turns out, is where young white sharks spend their formative years.
Sal Jorgensen, an adult-shark researcher at the aquarium, said the project has enabled scientists to learn more about the species’ genetic makeup and behavior.
“We’ve determined that there are genetically distinct and isolated populations of white sharks in the northeast Pacific [Ocean],” Jorgensen said. “There are separate populations in Mexico and the United States, just like there are separate populations in Australia and New Zealand and Japan.”
The survival rate of shark populations in general has been a major focus of conservation groups around the world, especially in light of the finning industry. Jorgensen said the white shark is well protected—so much so that its numbers could be increasing.
“Of course, with an apex predator, there are never going to be a lot because they’re feeding on the animals below them in the food chain,” he said. “But while other shark populations are decreasing, the white shark is increasing.”
It helps that the sharks’ migratory pattern coincides with elephant seal pupping. It’s scientifically proven that the elephant seal population is increasing, which could be part of why white sharks are thriving as well.
Still, no shark is completely safe from finning, which involves cutting off a shark’s valuable fin and disposing of the rest of the body.
“Once the fin is taken off the shark, it’s impossible to tell what kind of shark it is,” Jorgensen said. “But there have been forensic studies done on the genetics of the fin market, and they have found that some white shark fins get through.”
Scientists at the aquarium hope that their research and the great white exhibit will eventually help put an end to all shark finning. The aquarium recently spearheaded successful efforts to ban the sale of shark fin products in California.
The project is expected to capture and tag more sharks beginning next year.
Contact Managing Editor Amy Asman at aasman@santamariasun.com.
This article appears in Nov 17-24, 2011.