Drowned 5,000-year-old forests reborn as thriving peat reefs and biodiversity hotspots off Mozambique

Researchers from the Bazaruto Center for Scientific Studies (BCSS) Ocean Observatory have discovered that ancient 5,000-year-old forests submerged beneath the sea off the coast of Mozambique have transformed into thriving peat reefs teeming with marine life. These submerged peat reefs, resembling tropical coral reefs in biodiversity, are now functioning as hotspots for marine biodiversity.

The BCSS Ocean Observatory, established in Mozambique in 2017, documented these submerged peat reefs in the shallow waters of the Bazaruto Archipelago. Radiocarbon dating reveals that the peat formed between 300 and 5,000 years ago, originating from coastal land plants and trees. The reefs, made of compressed, carbon-rich remains of coastal swamps and forests, now provide shelter and food for various marine species, including small fish, sharks, rays, and turtles, as well as marine invertebrates.

Despite their unique characteristics, peat reefs share many fish species and biodiversity with nearby coral reefs. Scientists are now investigating the extent of these peat reefs around the world's coastlines and their potential as blue carbon stores, which are carbon sinks that sequester carbon for long periods. However, more research is needed to determine how stable the carbon stored in these reefs is and how it might be affected by environmental changes and disturbances.