The Group Fishermen and Friends of the Sea claims land at Invaders Bay is being bulldozed, without official clearance.
The group says more than two hectares have already been destroyed, with the latest activity coming despite assurances from the Planning Minister.
FFOS says it wrote to the Minister in August highlighting the need for a supplemental Environmental Impact Assessment for Invaders Bay.
It says the Minister responded in September, acknowledging the critical importance of the system and assuring that any proposed development would consider the impact on coastal mangrove ecosystems.
Today, FFOS alleges no EIA was done, since this would have mandated public consultation to consider the concerns about Woodbrook flooding, public access to the sea, recreational space, ecosystem integrity, wetlands policy, fishery considerations, and other factors.
The group is now calling for action by the relevant authorities to stop environmental destruction in the area.