Dr. Barbara Block of Stanford University and head of TOPP (Tagging of Pacific Predators) had compiled enough preliminary tracking data to propose an amazing theory regarding white shark migratory patterns. Using various telemetry transmitters attached to sharks, Block and her team were able to determine that the great white sharks found at Isla Guadalupe and off the Central California coast appeared to migrate to an area in the mid-Pacific. They humorously nicknamed it the "White Shark Cafe."
This was heady stuff. To think that two populations of white sharks were taking the same journey to one central, albeit rather vast, location - well, this had the imaginations of many shark researchers and advocates in overdrive. What was attracting them to this area? A food source? A potential breeding ground? And if so, were the Baja sharks and the California sharks related?
One of the next steps, then, was to determine if any mutual DNA traces could be matched between the two groups. My friend, Dr. Mauricio Hoyos, at the time a young graduate student working under the guidance of Dr. Peter Klimley of UC Davis in Sacramento, California and Dr. Felipe Galvan of the marine institute, CICIMAR in La Paz, Baja, continued his work tagging and tracking the regional hunting patterns of Isla Guadalupe's white sharks, but he also began taking biopsy samples for DNA studies.
As my documentary showed, taking a biopsy sample was not always easy. It entails getting very close to a shark and poking through the shark's tough skin with a small spear outfitted with a tip that would remove a small plug of flesh. Over time, many samples were analyzed and compared with biopsy samples that were taken of white sharks in California. As a filmmaker, I was rooting for a genetic connection as I was hoping that the White Shark Cafe would prove to be some monumental white shark breeding ground. With that fact, I was contemplating a pitch for a film project to document heretofore unseen white shark breeding behavior. (Typical for an ambitious producer, I was conveniently ignoring the fact that the White Shark Cafe covers an area the size of Texas, so finding white sharks actually engaged in mating would be like finding a needle in an oceanic haystack!)
The results of the DNA studies found that there were no genetic markers, no familial connection between the two populations of white sharks. Well, there went my documentary pitch, but far more important than my self-serving interests was the fact that researchers now knew these two groups of white sharks were unique to themselves. And that made them all the more priceless. But just how many white sharks are we talking about?
At Isla Guadalupe, several research groups, including the Pfleger Institute in San Diego, had photographically cataloged many of the the island's sharks. This family album, as it were, has grown over the years and has proved to be a valuable reference guide in identifying sharks as they return year after year to Isla Guadalupe in the fall months. The current number of sharks at Isla Guadalupe is estimated to be around 100 to perhaps as many as 130 individuals.
However, there was no accurate count for the white sharks of Central California. In 2006, I interviewed Dr. Klimley for my film and he mentioned that a population study was about to get underway. Subsequent to that interview, I kept in touch with Peter and a couple of years later, he mentioned to me that one of his students, Taylor Chapple was going to begin the study but they were coming up short on cameras. I offered Pete and Taylor the use of a spare still camera and underwater video camera, and Taylor began his research in earnest.
Taylor's results were made public last year and the numbers were disconcerting. Taylor's estimated size of California's adult and juvenile white shark population combined was only 219. This was far less than anticipated by many shark advocates and it highlighted the perilous nature of the white shark in a world where sharks are either commercially hunted or caught as accidental bycatch in drift and gill nets set to catch other fish commercially sought after. With great white sharks being slow to mature and reproduce (females typically reproduce every other year and give birth to perhaps 2 or 3 pups), the loss of even one mature white shark can have a profound impact on the population's ability to sustain itself.
In Tuesday's Washington Post, environmental writer Juliet Eilperin reported that three major conservation groups involved in shark conservation have petitioned the National Oceanic and Atmospheric Administration (NOAA) to list the West Coast population of great white sharks as endangered under the Endangered Species Act.
“The new science sets off alarm bells for all of us, as no one expected the population to be so dangerously low,” said Geoff Shester, who directs Oceana’s California program. “Great white sharks are powerful allies keeping our oceans healthy, and they need us to protect them far more than we should fear them.”
Now the bureaucratic process begins, as the petition and all the research information provided will be reviewed by NOAA. Should the agency find the petition actionable, then a status review will commence. This is where an organization like the Center for Biological Diversity will sinks its teeth into the case (pardon the pun), as they are known for wielding the law and the courts to push federal environmental agencies to fulfill their legal obligations and not let issues fall through the governmental cracks.
But it is important for the U.S. to take this issue seriously, not only for the sake of the sharks but for the country's conservation image as a whole and its ability to prod and negotiate other nations to take proactive steps to preserve natural resources.
As Juliet Eilperin reported, "The petition came on the same day that a group of leading American shark and ray scientists, the International Union for Conservation of Nature Shark Specialist Group, issued a report saying 13.5 percent of shark, skate and chimaera species in North and Central America face the threat of extinction."
With the facts at hand - with other nations contemplating white shark hunts as emotional, knee jerk reactions to several unfortunate attacks - this could be a defining moment for the future of California's white sharks and for U.S. credibility as a true ocean conservation advocate.
Source: The Washington Post