Methane fluxes from tropical coastal lagoons surrounded by mangroves, Yucatan, Mexico

作者：Chuang P C; Young M B; Dale A W; Miller L G; Herrera Silveira J A; Paytan A^*

来源：Journal of Geophysical Research-Biogeosciences, 2017, 122(5): 1156-1174.

DOI：10.1002/2017JG003761

• methane flux
• coastal lagoons
• biogeochemistry
• pollution
• Yucatan Peninsula
• 0400 BIOGEOSCIENCES

Methane concentrations in the water column and emissions to the atmosphere were determined for three tropical coastal lagoons surrounded by mangrove forests on the Yucatan Peninsula, Mexico. Surface water dissolved methane was sampled at different seasons over a period of 2years in areas representing a wide range of salinities and anthropogenic impacts. The highest surface water methane concentrations (up to 8378nM) were measured in a polluted canal associated with Terminos Lagoon. In Chelem Lagoon, methane concentrations were typically lower, except in the polluted harbor area (1796nM). In the relatively pristine Celestun Lagoon, surface water methane concentrations ranged from 41 to 2551nM. Methane concentrations were negatively correlated with salinity in Celestun, while in Chelem and Terminos high methane concentrations were associated with areas of known pollution inputs, irrespective of salinity. The diffusive methane flux from surface lagoon water to the atmosphere ranged from 0.0023 to 15mmolCH(4)m(-2)d(-1). Flux chamber measurements revealed that direct methane release as ebullition was up to 3 orders of magnitude greater than measured diffusive flux. Coastal mangrove lagoons may therefore be an important natural source of methane to the atmosphere despite their relatively high salinity. Pollution inputs are likely to substantially enhance this flux. Additional statistically rigorous data collected globally are needed to better consider methane fluxes from mangrove-surrounded coastal areas in response to sea level changes and anthropogenic pollution in order to refine projections of future atmospheric methane budgets.

• 出版日期2017-5