What could you do about eco tourism?

Personally, you can pick up and properly dispose of any trash you generate during your visit, according to the guidelines of the locale you're visiting.

You can also live as lightly on the land as possible when you visit a geography.

Finally, consider your mode of travel, and choose one that makes the lightest footprint on the earth. So if you can walk or bike instead of driving, or carpool when you do drive, and limit commercial transit wherever possible, you would be doing something about eco- tourism.