In my personal opinion tourism is helping conservation of wild life animal and species by directly and indirectly. At one side tourist spend handsome amount in traveling safari parks which facilitates to bear the expanse of wild life food. Tourist also love to feed animals with their hands which passively make a close relationship between animals and humans. In my last visit to northern area I fed a lot of monkeys with corn.monkeys love to eat corn.
Visiting safari park is not all about seeing wild life but it taught a lot of active and passive learning. Seeing is believing. People get good awareness after observing themselves. As you mentioned the case of people dived with a cage to see shark.
However with all the pros of tourism there are few cons like hydro carbon pollution due to automobiles,throwing plastic garbage etc. These issues not only damage the environment but also endanger wild life. The good thing is we can control it by giving awareness to people.so it is to raise awareness to people to make this world a better place with good ecosystem