Scientists say the chances of Marovo lagoon in Solomon Islands achieving World Heritage status are diminishing because of events such as the recent widespread fish deaths.
Scientists say natural factors are the main cause of the deaths but that logging is likely to have contributed.
Marovo Lagoon, which surrounds Vangunu Island in Western Province, is the largest double barrier reef in the world and has been considered for UNESCO world heritage status.
But Simon Albert, from the University of Queensland, who was part of a team sent to investigate the fish deaths says that listing is looking fragile.
"Pre-logging 15 years ago was one of the most intact places on the planet and there's still despite the logging activities, there's still strong interest from UNESCO but as the years tick by and the resources become more and more depleted and events like this occur obviously the chances of that world heritage listing are slipping away."
Simon Albert says there's concern about the diets and incomes of those who rely on the lagoon's sea life.