Tigerman
Contributor
Ive seen reefs teaming with fish one day, almost dead the next couple of days and teaming with fish again the following week....
1) A healthy reef should be teaming with fish. If it isn't it is not healthy. By spear fishing on an unhealthy reef you have much bigger effect in further damaging that reef especially as spear fishing tends to take the bigger predators. You can destroy the top of the food chain by spear fishing an unhealthy reef. This will cause there to be an even more unhealthy balance in herbivores vs predators, in algal infestations, coral death, etc. The relationship is well understood these days. If you kill the predators you'll kill the reef.
...
Not all fish are stationary to the reef or the same spot on the reef.
I do however have to agree that taking out the "wrong" fish in some cases can cause serious issues with the reefs eco-system. Taking the one grouper thats running his protection racet on the glassfish for example is pretty much certain to make that glassfish population disappear as the other groupers will eat them all.