Divers researching the types of fish in the Cook Islands believe the demise of shallow coral reefs is also affecting the health of deeper reefs.
Dr Richard Pyle, an associate zoologist at Hawai'i's Bishop Museum, is conducting research 100 metres down in a trench in Avatiu harbour where there is a rich diversity of fishlife endemic to the area.
He says that would indicate that the deep reefs have been impervious to oceanic fluctuations as a result of ice ages ocurring every 100,000 years.
But Dr Pyle says what he and his team have noticed is that as climate change warms the oceans and stops shallow reefs from being able to form, deep reefs are suffering too.
"In other words even if it's not directly impacted by the coral getting wiped out, there's far fewer fish and far less life down deep below these dead reefs. So the real concern about climate change is not only the warming of the seas which is harmful to coral fish but also all the carbon dioxide being absorbed by the ocean, which is also harmful to coral."
The Bishop Museum's Dr Richard Pyle.