The Northern Ireland Biodiversity Group, which was set up to monitor the delivery of measures to protect species and habitats across the province, has called for an urgent review of guidance to halt biodiversity loss.
It claimed that there is no evidence on the effectiveness of the main method of protecting biodiversity through the planning system - introducing sites of local nature conservation importance (SLNCIs).
There are ten times more SLNCIs than there were a decade ago, according to the group's second report on the delivery of the biodiversity strategy. But only 137 of the 889 total have been formally adopted in area plans.
The group, chaired by Bob Brown, said there is a need for guidance on the monitoring of the impact of SLNCIs and on the measures that are needed to protect the sites from development.
"We have action plans, commitments and delivery groups, but the real test is whether any of these are actually making a difference," maintained Brown. "There are often no meaningful data to demonstrate success or failure."