8. Historical Losses of Mangrove Systems in South America from Human-Induced and Natural Impacts

Mangrove forests are an intrinsic part of the coastal landscapes of tropical and subtropical South America. Although less well studied than their North American, Southeast Asian and Australian counterparts, they cover large expanses (approximately 11% of global mangrove cover) and perhaps represent a greater proportion of their respective coastline than other ecosystem types. The last century has been witness to a large but ultimately unknowable loss of mangrove forests across the continent through intensified use of coastal zones by humans. Indeed it has been estimated that more than 11% of the mangroves existing in the 1980’s have been lost or severely degraded. Additionally, while protection for mangroves in many parts of the world has increased considerably, management in South America remains complex and the lack of regular change indicators complicates status assessments at both national and international levels. This chapter presents a historical and contemporary background to losses of mangrove systems in South America with a focus on those countries that have the most up-to-date and accessible data (i.e., Brazil, Ecuador and the Guineas). The goal was to present what is known about the drivers and degree of historical loss, the current and future threats, and to document efforts at restoring degraded forests. The chapter concludes with advice on how to address important knowledge gaps and facilitate effective management to improve the conservation outcomes for South American mangrove systems.