Your inhabitants need to support a going blue island initiative not only to give your administration the crucial political mandate you require but mainly because it is the population itself that can implement many of the changes that we advocate on this site.
Inform/educate opinion leaders and community leaders of your intent and the desired outcomes and benefits in order to have them work with you.
Prepare evidence to demonstrate the financial and emotional damage done to the island by the persistent pollution of its waters. Having 'nature asset' and water pollution acquatrail cost-of-damage calculations provides a sound basis for this. (see marine positive certification).
Work with and through these leaders to disseminate the necessary behaviour-changing programmes in schools, communities, public meetings and posters, notices, newspapers, magazine, websites, radio and TV.
Lead by example, act as you say. People will heavily criticise leaders who do not behave as they say others should