A dive operator in Vanuatu says coral reefs in Port Vila harbour are regenerating after efforts to combat an invasion by crown of thorns starfish seven years ago.
The starfish eat the coral but Christina Shaw from diving company Big Blue, says following the clean up the reefs are now beginning to flourish.
But she warns people need to be vigilant about all of the reef eco-system, including protecting the fish that eat the algae that collects on the coral.
"So if too many fish are fished off the reef then the coral won't be able to seed itself back again and it then it won't grow and the fish won't be there anymore and they'll go too. So it is really important to make sure that you don't fish too much on the reefs especially after they have had a problem like crown of thorns."
Christina Shaw warns while the threat in Port Vila harbour has eased crown of thorns are now posing problems on the North Efate coast.