Good topic, crew. The only known ecotourism promoter in the area is John Gray. He does the boat tours in Krabi, around James Bond Island and into the caves. I just happened to see an episode of Globe Trekker yesterday where part of the trip was in Phuket.
John Gray had said that there ar wars with gunfights in that area between tour operators and that one of his guys was shot three times. What the Thai loperators do is hire guides who work for free and they rely on tips. One thing that they tell them to do is to break stalactites off from the caves and sell them to the tourists as souvenirs. The "tour operator mafia" will also block other operators from going into the caves unless they pay a bribe.
This was in the pre-tsunami days, but I haven;t heard anything different now. On the boat trips to Phi Phi, the operators tell the guests to throw their cigarette butts into the water. There's a tread on Thai Visa talking about volunteering to clean up garbage on the beaches of Phuket. A few people replied saying that if the police see westerners doing this, it could create big problems.
The mafia is big in Phuket and the TAT seems to be blind to any crimes against nature or people. There are a couple of NGO's that I found by accident on the net that preserve the coral and marine life, and there's one for the sea turtles too.
It's inaccurate to say that all Thais are like that, because I personally know alot of Thais who are proactive in these issues. They 're just too few people for to big a job.