Environmental Pollution 305 (2022) 119276 Available online 8 April 2022 0269-7491/© 2022 Elsevier Ltd. All rights reserved. Changes in sediment methanogenic archaea community structure and methane production potential following conversion of coastal marsh to aquaculture ponds ☆ Ping Yang a, b, c, * , Kam W. Tang d , Chuan Tong a, b, c , Derrick Y.F. Lai e , Lianzuan Wu b , Hong Yang f, g , Linhai Zhang a, b, c , Chen Tang b , Yan Hong b , Guanghui Zhao b a School of Geographical Sciences, Fujian Normal University, Fuzhou, 350007, PR China b Key Laboratory of Humid Subtropical Eco-geographical Process of Ministry of Education, Fujian Normal University, Fuzhou, 350007, PR China c Research Centre of Wetlands in Subtropical Region, Fujian Normal University, Fuzhou, 350007, PR China d Department of Biosciences, Swansea University, Swansea, SA2 8PP, UK e Department of Geography and Resource Management, The Chinese University of Hong Kong, Hong Kong, China f College of Environmental Science and Engineering, Fujian Normal University, Fuzhou, 350007, China g Department of Geography and Environmental Science, University of Reading, Reading, UK A R T I C L E INFO Keywords: Methane production Methanogenic archaea Network analysis Land-use and land coverage change (LULCC) Coastal wetlands Aquaculture systems ABSTRACT Widespread conversion of coastal wetlands into aquaculture ponds in coastal region often results in degradation of the wetland ecosystems, but its effects on sediment’s potential to produce greenhouse gases remain unclear. Using feld sampling, incubation experiments and molecular analysis, we studied the sediment CH 4 production potential and the relevant microbial communities in a brackish marsh and the nearby aquaculture ponds in the Min River Estuary in southeastern China. Sediment CH 4 production potential was higher in the summer and autumn months than in spring and winter months, and it was signifcantly correlated with sediment carbon content among all environmental variables. The mean sediment CH 4 production potential in the aquaculture ponds (20.1 ng g 1 d 1 ) was signifcantly lower than that in the marsh (45.2 ng g 1 d 1 ). While Meth- anobacterium dominated in both habitats (41–59%), the overall composition of sediment methanogenic archaea communities differed signifcantly between the two habitats (p < 0.05) and methanogenic archaea alpha di- versity was lower in the aquaculture ponds (p < 0.01). Network analysis revealed that interactions between sediment methanogenic archaea were much weaker in the ponds than in the marsh. Overall, these fndings suggest that conversion of marsh land to aquaculture ponds signifcantly altered the sediment methanogenic archaea community structure and diversity and lowered the sediment’s capacity to produce CH 4 . 1. Introduction Methane (CH 4 ) has a 45-times higher mass-specifc global warming potential than carbon dioxide (CO 2 ) over a 100-year period (Neubauer and Megonigal, 2015), and it contributes to approximately 20% of the global radiative forcing (IPCC, 2013). The average atmospheric CH 4 concentration reached 1875 ppbv in 2019 (National Oceanic and At- mospheric Administration, 2020), exceeding the pre-industrial levels by about 150%. Aquatic CH 4 is primarily produced in sediments by meth- anogenic archaea during the terminal step of organic diagenesis under anaerobic conditions (Gruca-Rokosz et al., 2020; Lai, 2009; Lofton et al., 2015; Liu et al., 2019). Land use and land cover change (LULCC) can lead to changes in hydrology, nutrient cycles, sediment properties and overall ecosystem functions (Andreetta et al., 2016; Dick and Osunkoya, 2000; Liu et al., 2021; Lai et al., 2016), and has been shown to be a major driver of anthropogenic CH 4 emissions in terrestrial and aquatic eco- systems (Chen et al., 2021; IPCC, 2013; Reay et al., 2018; Tan et al., 2020). Coastal wetlands, located at the interface between the terrestrial and marine environments, are sites of intense biological production (Chmura et al., 2003; Han et al., 2014; Doroski et al., 2019). LULCC has increasing impacts on coastal wetlands (Hao et al., 2020) and has already caused ☆ This paper has been recommended for acceptance by J¨ org Rinklebe. * Corresponding author. School of Geographical Sciences, Fujian Normal University, Fuzhou, 350007, PR China. E-mail address: yangping528@sina.cn (P. Yang). Contents lists available at ScienceDirect Environmental Pollution journal homepage: www.elsevier.com/locate/envpol https://doi.org/10.1016/j.envpol.2022.119276 Received 28 January 2022; Received in revised form 8 March 2022; Accepted 5 April 2022