Far fewer Great whites than thought


The first ever census of Great white sharks has revealed that there are far less than previously thought.

The study, which was done off the coast of California by a doctoral student from the University of California, found that there is only an estimated 219 Great white sharks (Carcharodon carcharias) cruising the waters.

Lead researcher Taylor Chapple who is now a researcher at the Max Planck Institute in Germany said: "This low number was a real surprise. It's lower than we expected, and also substantially smaller than populations of other large marine predators, such as killer whales and polar bears."

The number was reached by small boats going out to areas where great whites congregate. The researchers then lured the sharks in using a seal shaped decoy on the end of a fishing line. Photos were taken of the dorsal fins, which are unique to each shark, and from this 130 individual sharks were identified. Statistical methods were then used to estimate that there are approximately 219 adult and sub-adult sharks in the region.

Study co-author Barbara Block an international expert on sharks and Stanford University Marine Biologist is quoted: "We've found that these white sharks return to the same regions of the coast year after year. It is this fact that makes it possible to estimate their numbers. Our goal is to keep track of our ocean predators."

This population is one of only three populations of great white sharks around the world; the other two being in the waters of Australia and New Zealand and South Africa.

Great white sharks are listed as Vulnerable in the IUCN red list but this population is genetically distinct which could mean that they are extremely endangered.

Chapple added: "This estimate only represents a single point in time; further research will tell us if this number represents a healthy, viable population, or one critically in danger of collapse, or something in-between."

The team hope to repeat this study over a number of years to get a more accurate number and hope that other shark researchers around the world will follow suit: "Our methods can be readily expanded to estimate shark population abundance at other locations, and over time, to monitor the status, population trends and protection needs of these globally distributed predators."