I am extremely grateful to our friend C. Way that he opens this necessary discussion here. The ethics of excursions and fishing in threatened regions is a major topic nearly never discussed. We should contribute small pieces, nobody could treat the issue in general and comprehensively.
One very important point seems to me to be the difference between a private excursion for scientific reasons or the love of nature, its plants and animals, and excursions for commercial reasons. I think we should concentrate on the first. It does normally exclude heavy impacts on the habitats, but this could be a first statement of conduct we could possibly all agree with.