I was wondering what you meant by cultural zoo.

Now it's clearer. Such huge leaps in subject association are hard to follow. It appears that you believe island populations exercising self-determination or even the plain old claim of a right-to-existence establishes merely establishes some sort of cultural zoo unless there is an economic payoff. Presumably such zoos are only established by the indulgence of Western nations, nothing to do with the wishes of the economically valueless inhabitants themselves.
Yes, I disagree wholeheartedly.

The marine park idea is just another example of possible (actually, real) benefit of island environments that is not immediately measurable in dollars and cents.

But you're entitled to your viewpoint that there is no value in the inhabitants' cannibals' right to exist and that other considerations simply don't exist i.e. [The only benefit in trying to protect them is as some kind of cultural zoo .

Cultural (sic) zoo as one justification sounds fine to me.

Are you unaware of value of marine parks in regard to biodiversity?

Good grief, in your world do you reduce the value of everything into dollars and cents?