Dear Editor,
For the benefit of The Australian's readership there are a number of key points to correct and clarify in your article: A tip for the CSIRO: I reckon there are more sharks, 18 April.
The central tenet of the piece is that shark research 'should be one of the easiest jobs in science.' It is not. White sharks are one of the most difficult species to study and consequently are one of the most poorly understood. Australia has the longest east-west coastline in the world, shark movements and distribution vary seasonally, and past data have been inadequate for estimating population sizes or trends.
In February CSIRO, with research partners across Australia, published results on a new genetic and statistical approach to estimate adult white shark population size and mortality around Australia. The research is world-leading and Australia is now the first country to directly estimate the abundance of its adult white shark populations. We have determined that there are two discrete populations in south-western and eastern waters, and that adult numbers have been stable since the species was protected.
We recognise the high community interest in understanding shark numbers, as well as the importance of sharks to a healthy marine ecosystem. Our ongoing research using genetic techniques will determine whether there are any trends in white shark populations over time.
Dr Tony Worby
Director
CSIRO Oceans and Atmosphere