Great to see that somebody is noticing!
Even better seeing a member of the scientific community voicing an opinion in public!
You say that there is no scientific evidence that shark sanctuaries are effective (other people say that there is no scientific evidence for global warming). This is simply not true. If increasing numbers of sharks are a measure of effectiveness, then have a look at what happens in Fiji, for example, the Shark Reef Marine Reserve (PLoS ONE 6: e16597). There are many other examples in the peer-reviewed literature which evidence that shark sanctuaries do much more than providing hope.
And there are examples from terrestrial apex predators too.
For example, numbers of tigers in certain wildlife sanctuaries have been reported to increase (see http://green.blogs.nytimes.com/2012/12/24/scattered-tiger-populations-bu...).
I of course agree that strict monitoring and enforcement are key and often disappointing.
But by sniping against shark sanctuaries you play right into the hands of the fishing industry which has not the slightest interest in any kind of sanctuary for whatever species or group of species. At the end of the day it’s not the people who call for shark sanctuaries and have been establishing them who have to prove that they are effective. Had the fish management intelligentsia done their job and managed our fish stocks sustainably, there would be no need for conservationists to advocate sanctuaries and bans in the first place. So let the fishing industry and the traders fund the according research and let them come up with substantiated and detailed proposals via reputable third-party certifications - much like an ecological impact assessment.
It's obviously about this shit.
Juerg is this dude - yes he's a close friend but as a researcher, he never takes sides but says it like he sees it. And he's right, I totally forgot to mention the many unequivocal findings from the various MPAs!
Vinaka - much appreciated!