It's no secret that the commericals target sharks for food. Rec fishos also kill thousands of sharks each year. The majority of the sharks caught by commerical fishers are lower trophic level predators or scavengers, with typically shorter life cycles than tigers and great whites. These species are less susceptible to overfishing, and their removal has less impact on the food web.
Many rec fishos do keep relatively large bronze whalers, tigers etc, which they are more than entitled to (although they must be under 700mm interdorsal length in the west coast region), however, in my experience many of these guys are typically bogans with no clue/ regard for the marine environment and sustainability of our fisheries.
The issue I have with the 'shark culling' is that it's a pointless waste of money, which is unlikely to make anyone any safer. I think they've killed about 30 sharks so far if I remember correctly? That isn't going to end the world, but it is a complete and utter waste, of not only resources to catch the sharks, but of the sharks themselves which were just destroyed.
I also think the greenies and the random protesters need to settle down. I went to the latest anti-shark rally at cott, just for a look and too hear what the clowns were going on about. One so called expert in marine life claimed that without sharks there would be no oxygen. If these people did something useful with their time instead of making up bull**** propaganda, then maybe they'll be able to actually conserve our marine life.
In summary - the drumlines aren't going to end the world as the greenies are making out, but it is a bloody waste, unlikely to prevent any attacks from great whites, and there are better alternatives that the government could have used to try and prevent shark attacks.