Why are mangroves found along parts of the Rio de Janeiro coast?

Mangroves are found along parts of the coast in Rio de Janeiro because the region provides the specific tropical and subtropical conditions necessary for these salt-tolerant trees to thrive.12

These trees typically inhabit coastal areas that are protected from intense wave action, allowing their seedlings to establish in low-energy environments such as estuaries, river mouths, and muddy shorelines where freshwater and seawater mix. Because mangroves are sensitive to cold, they require regions that do not experience hard frosts, where average temperatures in the coldest months remain above 20 °C (68 °F).13

In these coastal zones, mangroves are uniquely adapted to survive in oxygen-poor, salty soils through specialized root systems, such as prop roots and pneumatophores, which facilitate gas exchange and stabilize the plants. Their presence is ecologically vital, as they act as a buffer between marine and terrestrial environments, protecting shorelines from erosion, storm surges, and flooding while providing essential nursery habitats for various marine species.32