bellicose chauvanism - the accuracy of environmental claims

I've been reading a claim that the level of unique marine life that is found off south-western Australia is greater than that on the Barrier Reef and almost anywhere in the world. I've heard a similar claim for the Port Phillip Bay. So how true it is it?

Are the people making the claim guilty of environmental hyperbole? Are we always overstating the environmental case in a form of jingoism (aka "belicose chauvanism")? Or is this like the south-west botanically - a hotspot of diversity? A special claim is extended for everything - which devalues all claims.

Do we protect places because they have a level of endemic species? Is that the same as saying they have a high level of biodiversity? Why are we protecting the Great Barrier Reef? Because it is big and beautiful, or because it has a high level of diversity?

I can't assess the validity of the claim so I'll go off and do some research.