Assessing the human and natural drivers of mangrove habitat loss in Puerto Rico

Abstract

Mangroves provide various ecosystem services that contribute to human well-being. In the last five decades, however, approximately one-third of global mangroves have disappeared due to land-use changes, water pollution, sea level rise (SLR), extreme weather events, and ineffective conservation and restoration practices. Puerto Rico's high climate variability and exposure to disturbances such as hurricanes, droughts, and urbanization make it an ideal environmental setting to explore how mangrove ecosystems respond to multiple types of disturbance in a range of biomes and climates. This study involved identifying disturbances, natural and anthropogenic, that could have impacted mangrove conditions and conducting a remote sensing analysis of mangrove cover in Puerto Rico. The estimated mangrove area after adjustment was 7,784 hectares for 2023. Furthermore, this study found Hurricane María to be the major driver of mangrove loss in Puerto Rico, with 65% of mangrove loss being associated with this disturbance. Although mangrove recovery was observed after the hurricane, as showcased by steady increases in NDVI values, the recovery was inconsistent across regions, with some areas encountering persistent stress or slow regeneration. The impacts of the 2015 Caribbean drought and the 2020 earthquakes were not as extensive and abrupt. Urbanization after Hurricane María had a more noticeable effect in areas such as Jobos Bay, where areas cleared by the hurricane were unable to recover due to illegal development. The results of this study highlight how different natural and anthropogenic drivers overlapped across regions and exacerbated mangrove loss across Puerto Rico. These findings underline the necessity of taking multiple drivers into account in the development of conservation strategies for mangroves.