Ancient Submerged Forests off Mozambique Thrive as New Marine Biodiversity Havens

Scientists from the Bazaruto Center for Scientific Studies (BCSS) Ocean Observatory have confirmed that forests that grew along the Mozambican coast around 5,000 years ago are now flourishing beneath the sea, forming extensive peat reefs that host a rich array of marine life.

The team mapped the submerged woodlands using underwater imaging and sediment sampling in the waters surrounding the Bazaruto Archipelago. Their surveys revealed extensive layers of preserved tree trunks and roots, now encrusted with marine organisms, indicating that the once‑terrestrial ecosystem has been transformed into a thriving underwater habitat.

These peat reefs are the result of post‑glacial sea‑level rise that inundated coastal forests, allowing the organic material to accumulate in anoxic conditions. Over millennia, the buried wood has compacted into peat, a carbon‑rich substrate that remains largely intact beneath the waves. Because peat stores carbon for long periods, the reefs represent a significant, though often overlooked, component of the coastal carbon budget.

Ecologically, the reefs act as three‑dimensional structures that attract fish, crustaceans, and a variety of invertebrates, creating biodiversity hotspots comparable to coral reefs in their capacity to support complex food webs. The presence of hard and soft substrates, combined with the steady release of organic nutrients from the peat, sustains a dynamic community of species that rely on the reefs for shelter and feeding grounds.

The discovery highlights the need to recognize submerged ancient forests as valuable marine ecosystems worthy of protection. Researchers say that further study could improve understanding of how such habitats contribute to carbon sequestration, fisheries productivity, and resilience against coastal erosion. Conservation planners are now considering how to integrate these hidden reefs into marine‑protected‑area networks, ensuring that their ecological functions are preserved for future generations.