I'm bringing this up because catch and release, frustratingly, does not seem to be a common practice among certain folk here. Way too often do I see people keeping fish that are too small. 3 inch queenfish also keep for what?! I'm not saying that everybody keeps everything but I do still notice it happening often.
In other countries where I've fished there are no requirements for a license, but you are required to follow size regulations. For example, in New Zeland the minimum size required to keep a snapper is 30cm, with a daily bag limit of 7 per person. Regulations like this should be easily enforceable since there aren't many places to fish nowadays with the government closing off so many shorelines...
I've fished in Singapore for many years and the decline is noticable. 10 years ago you could very easily take home a decent fish or two. Nowadays, more often than not you go home with nothing. If we could make fishing more sustainable I'm all for it, even if it means more rules to follow. Our waters are already under too much pressure.