NASA satellite images show that mangrove forests, which protect shorelines, support coastal ecosystems, and store large amounts of carbon along saltwater coasts, are more resilient than scientists once believed. Four decades of Landsat observations reveal that mangrove forest coverage shifted from long-term decline to expansion, with the rebound beginning in 2010.
The forests have long been shrinking as they were cleared for agriculture, logging, and urban development. The new study, published June 4 in Science, shows that the trend has largely reversed due to conservation efforts and the natural propagation of mangrove plants.
To track the extent and health of the coastal forests, researchers used Landsat images to compile a global record of mangrove extent and canopy cover from 1984 to 2023. The data showed that although mangroves declined through much of the late 20th century, gains accelerated in the past decade and have nearly offset the earlier losses.
The Landsat images reveal new mangrove forests that have formed naturally along river deltas and sediment-rich coastlines. For example, mangroves have sprouted up in northern Australia, South Asia, the Middle East, and parts of the Americas. In Southeast Asia, which was once a major center of mangrove destruction, satellite images showed signs of stabilization and recovery. In addition, mangrove forests that persevered through the era of decline have grown denser, increasing their ability to store carbon and protect coastlines.
Despite the overall rebound of mangroves, the forests still face threats from storms, erosion, pollution, and deforestation in many regions, particularly in parts of West and Central Africa. The study highlights the effectiveness of protecting existing mangroves and supporting natural recovery alongside restoration efforts.
~James Riordon
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