There have been a couple of international agreements (at the UNbiodiversityconvention last year, for example, when governments agreed there should be no geo-engineering schemes that damage nature).
Fiji wants 30% of its waters protected and European nations including the UK are slowly imposing their own marine protected zones, prompted by the UNConvention on Biodiversity (CBD) which was initiated at Rio.
Some 18, 000 participants representing 193 State Parties to the UNConvention on Biological Diversity and their partners attended the Nagoya Biodiversity Summit in Japan this October to agree a global deal to protect biodiversity.