A study on the coral reefs around American Samoa shows that sustained efforts to rebuild threatened ecosystems can be effective.
A grass-roots educational program has helped educate the local public with sessions in schools and villages on the fragile nature of their reefs.
A recent survey by geographers from Oregon State University shows the reefs are not only doing well, but some species that are thriving weren't even known in the area before.
Dawn Wright, a professor of geosciences at OSU says the scene is radically different to what it was about 20 years ago.
And she the reefs were almost wiped out in the 1990s by hurricanes, a starfish invasion, and even dynamite fishing.
She says the tuna factories have also released raw sewage into the harbour and there has been additional pollution from rubbish dumped into the ocean at beaches, and estuaries have been fouled by polluted stream runoff.
She says there are discussions about establishing other protected areas throughout American Samoa.