I agree with bittenbysharks that indeed tourism (thus money) might be the only way to preserve an area. The simple presence of a boats with tourist already can influences the behavior of the local people and visiting fishermen. It turned out that for example Bunaken National Park and Lembeh Strait can deal with much more dive centers and boats than we thought, or even could imagine in the early nineteens. However...there will be a tipping point when more tourism does not mean better preservation anymore. Good regulations and communication can make a big difference in when this tipping point will be reached. For divers who still want to be sure that they are the only ones within a circle of 300 kilometers: have a look at Weda Bay, East coast central Halmahera.