Originally Posted by Anders

I think the distinction between recreational and low level commercial/subsistence spearfishing is important in this discussion. The fishermen, and their catches, the study is based on are all fishing with all kinds of equipment, from small boats in fairly unregulated waters and mainly targeting reef species and sell their catch locally to make their livelihood. In other words, they use whatever they can to make a living. In that situation it makes sense that changes in gear can change the species you target, and seeing how spearfishing can be very effective, especially unregulated and on certain species. Also, these guys don't have access to trawlers or large scale commercial fishing gear, which would probably be more detrimental to the reefs, but are not part of the study since they're not being used.
The gear considered to have the most impact on the reef was traps and spearguns, line fishing was considered the best. My take on it is that it's easier to target "reef-cleaning" and reef beneficial fishes such as wrasses etc. with spears or traps, as opposed to line fishing, which may be more effective in targeting predators..
Also, the main idea of the study was to identify fishing regulations that would allow low level commercial/subsistence fishermen to keep fishing while at the same time provide some ease on the reefs suffering from bleaching events due to high temperature/solar radiation. The other option to protect the coral is a total fishing ban and that is far worse for the involved parties.
However, the study is not applicable to recreational and well regulated spearfishing, which in my book is a different world when it comes to impact on fish stocks or reefs.