Trends in mangrove canopy and cover in the Teacapan -Agua Brava Lagoon System (Marismas Nacionales), Mexico: An approach using open-access geospatial data

Abstract

Abstract Mangroves face multiple threats, including land cover and land use changes, overexploitation, and contamination, resulting in local, regional, and global impacts. Understanding these changes is essential for conserving these important coastal ecosystems. Remote sensing provides detailed and long-term data and offers an invaluable advantage in such analyses. This study focuses on the Teacapan-Agua Brava Lagoon System in Mexico, integrating a GIS with open-access geospatial data, multiple Landsat 5 satellite images, MODIS vegetation index data (MOD13Q1 v. 6.1), and thematic maps of mangrove cover from various sources to analyze change trends in mangrove canopy and cover. Using the Mangrove Vegetation Index (MVI), mangroves were effectively distinguished from other cover classes (overall accuracy = 92%, Kappa coefficient = 0.93), resulting in an estimated mangrove cover of 67,334 ha in 2005. The Enhanced Vegetation Index (EVI) time series from 2005 to 2022 revealed a generally positive trend in mangrove canopy (p < 0.0001). The principal component analysis (PCA) and hierarchical clustering identified four distinct clusters with varying EVI profiles. Of the total mangrove area, 3% was vulnerable (negative trend), 29% exhibited no significant trend, and 58% was resilient (positive trend). Data from CONABIO and Clark Labs resulted in different deforestation and reforestation trends (average annual deforestation rate of -0.87% and average annual reforestation rate of 0.49%, respectively). These findings underscore the complex and diverse trends in mangrove cover and canopy, emphasizing the need for continued research, standardized mapping, and consistent remote sensing approaches to conserve and manage mangroves and their valuable ecosystem services.