The latest survey into the quality of the Cook Islands' main lagoon suggests it's not getting any worse but if trends continue the damage might become irreversible.
Almost all lagoon sites tested in Rarotonga failed quality standards set by the Ministry of Marine Resources.
The ministry measured the lagoon for nutrient levels, water clarity, and bacteria content and secretary of Marine Resources, Ben Ponia, says the results weren't surprising.
"The general trend is results are not getting any better. It's not to the point where we can't rehabilitate our lagoon but it is to the point where it's declining to a very poor state and we have to be concerned that if it continues in the next few years we might not be able to undo these changes."
Ben Ponia says for the first time streams were also tested and they returned poor results.
He says there are a number of sources that contribute to the high nutrient levels including agriculture, and development of the coastline.