Human activities related to land use and land cover (LULC) conversion have been the primary factor driving changes to mangrove distribution over recent decades. In order to quantify the anthropogenic influences associated with LULC changes on mangroves in the Vietnamese Southern Coast (VSC), we investigated the variations and trends in mangrove distribution between 1988 and 2023. We used a time-series of Landsat spectral indices from Google Earth Engine and applied hot spot analysis and machine learning algorithms to analyse mangrove variations and LULC classification, respectively. Our findings revealed that over the past 36 years, approximately half of the mangrove area has been lost due to LULC conversions. The most significant losses in mangrove cover occurred during the 1998-2011 period, with a decline of 46.79% in total area (an average of 3.6% per annum). The rate of mangrove deforestation more than halved to 17.49% (1.5% per annum) in the period between from 2011 to 2023. We attribute the reduction in mangrove loss to conservation efforts and natural regeneration processes. The emerging hot spot analysis indicated that the most significant restoration of new mangrove areas occurred between 1988 and 1998, totalling 1795 ha (1.4%), while the highest rate of mangrove deforestation was observed between 1998 and 2011, amounting to 2249 ha (2.0%). The primary causes of these variations in mangrove distribution were the conversion of mangrove areas to shrimp farming (38.91%), followed by other agricultural land use (5.82%) and the expansion of impervious surfaces (3.34%). In contrast, a result of enhanced conservation efforts and natural regeneration was associated with a 17.91% of mangrove area gain in the 2011-2023 period. Despite the regeneration potential of mangroves, our study highlighted the ongoing need to manage and protect mangrove forests to facilitate their expansion in the VSC. The analytical approach adopted in this study is applicable to other coastal areas when assessing changes in mangroves and land use practices.
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http://dx.doi.org/10.1016/j.jenvman.2024.122658 | DOI Listing |
Mar Pollut Bull
January 2025
Department of Fisheries and Marine Science, Noakhali Science and Technology University, Noakhali, 3814, Bangladesh; School of Engineering and Built Environment, Griffith University, Brisbane, QLD, Australia; East Coast Environmental Research Institute, Universiti Sultan Zainal Abidin, Gong Badak Campus, 21300 Kuala Nerus, Terengganu Darul Iman, Malaysia. Electronic address:
The pervasive and escalating issue of toxic metal pollution has gathered global attention, necessitating the exploration of innovative ecological strategies like phytoremediation. This study explored the extent of potentially toxic metal contamination status and the effectiveness of three planted mangrove species (Avicennia marina, Bruguiera gymnorhiza,and Excoecaria agallocha) in phytoremediation efforts to reduce pollution level. The results indicated that the mean concentrations of elements in the sediment of the area followed a descending sequence: Fe (27,136.
View Article and Find Full Text PDFSci Total Environ
January 2025
State Key Laboratory of Marine Resource Utilization in South China Sea, School of Ecology, School of Marine Science and Engineering, Hainan University, Haikou, Hainan, China; Collaborative Innovation Center of Marine Science and Technology, Hainan University, Haikou, Hainan, China. Electronic address:
The mangrove ecosystems store a significant amount of "blue carbon" to mitigate global climate change, but also serve as hotspots for greenhouse gases (GHGs: CO, CH and NO) production. The CH and NO emissions offset mangrove carbon benefits, however, the extent of this effect remains inadequately quantified. By applying the 36 h time-series observations and mapping cruises, here we investigated the spatial and temporal distribution of GHGs and their fluxes in Dongzhaigang (DZG) bay, the largest mangrove ecosystem in China, at tidal and monthly scales.
View Article and Find Full Text PDFEffective conservation of rare species necessitates the identification of critical habitats and their specific features that influence species occurrence. This study focused on smalltooth sawfish (), a critically endangered elasmobranch, to explore how predictive spatial modeling can enhance conservation efforts. By leveraging long-term occurrence and relative abundance data from scientific gillnet surveys, along with in situ environmental data, we used boosted regression trees (BRT) to pinpoint key habitat features essential for juvenile sawfish.
View Article and Find Full Text PDFMar Pollut Bull
January 2025
State Key Laboratory of Marine Geology, Tongji University, Shanghai 200092, China.
Investigations of the spatial-temporal variations of nutrients within mangrove coastal zones are essential for assessing the environmental status of an aquatic ecosystems. However, major processes controlling nitrate cycle along the submarine groundwater discharge (SGD) pathway from the mangrove areas to adjacent tidal creek remain underexplored. A time series measurement over a 25 h tidal cycle was conducted in Qinglan Bay tidal creek (Hainan Island, China).
View Article and Find Full Text PDFJ Hazard Mater
January 2025
Department of Biology, College of Science, Shantou University, Shantou, Guangdong Province 515063, PR China. Electronic address:
Anthropogenic activities have led to serious contamination of halogenated organic pollutants (HOPs), such as PCBs, PBDEs, and HBCDs, in the mangrove wetland. Biodegradation of HOPs is generally driven by environmental microorganisms harboring dehalogenase genes. However, little is known if HOPs can affect the distributions of HOPs-degrading bacteria and dehalogenase genes in the mangrove wetlands.
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