The first study, which was published March 1 in the journal Marine Biology (Anderson et. al., 2011) shows that it is possible to positively identify the same shark year after year - even over time periods as long as 15-22 years!
Figures a and b show the fin of a single shark in 2007 and 2008;
Figure c shows a different shark in 2008 - illustrating how
distinctive the fin edge shape can be.
Because this marks the first census of this population, we have no way of knowing whether this number is typical, or if it is unusually low (or even unusually high). What it provides, however, is a baseline that can be used in the years ahead to monitor changes in the adult white shark population - which will be a key step in managing and, if needed, protecting these animals in the wild.
As one might expect, we've had a lot of media interest in the story. You can check out the latest news coverage at the GTOPP website.