Assessing the role of commercial aquaculture in displacing mangrove forest

Abstract

To fill a gap in the marine science literature, I calculated the amount of mangrove deforestation in tropical estuaries that is attributable to commercial aquaculture. The eight countries analyzed were Indonesia, Brazil, India, Bangladesh, China, Thailand, Vietnam, and Ecuador. Together these countries contain approximately 36% of the world's remaining mangrove forest. One precommercial aquaculture remote sensing survey and one current remote sensing survey were undertaken in the major mangrove holding estuaries in each nation. The time period of the analysis varied by country based on the first arrival of large-scale commercial aquaculture, with the majority of initial surveys occurring in the early to mid-1970s and all the current surveys occurring post-2004. The surveys classified the land cover of 110,557 randomly located estuarine point locations and examined the land-cover change over time for each of these discreet locations. Among the largest and most representative account of global mangrove to aquaculture conversion, this study revealed that mangrove forests have lost 51.9% of their aerial extent during the analysis period. Of the mangrove loss during this period, I estimate that commercial aquaculture accounted for 28% of total mangrove loss across all nations resulting in approximately 544,000 ha of mangrove forest converted to aquaculture. There were significant differences in mangrove loss and mangrove to aquaculture conversion from nation to nation and even within nations.