[sfrechtling]

Some countries like New Zealand and Australian have these - called Marine Reserves and limit commercial activities. They normally are in areas of great diversity (Milford Sounds) or international importance (great barrier reef).

[marcus_holmes]

or, like here in Perth, just off the coast of a major city.

There's a lot of local controversy because people believe that sharks living in the protected reserves are a danger to the people swimming off the city's beaches.

But politically this sort of conservation is very fragile. It's fine as long as no-one with any power wants to do anything profitable in the protected areas. But previous governments have caved in easily under commercial pressure.