Widespread dominance of methane ebullition over diffusion in freshwater aquaculture ponds

Frontiers in Water

Water

Renske J. E. Vroom¹  Sarian Kosten¹  Raquel Mendonça²  Jonas Nasário²  Icaro Barbosa²  Ive S. Muzitano³  Alexander S. Flecker⁴  Ernandes S. Oliveira Junior⁵  Nathan Barros⁵  Rafael M. Almeida⁶ 

[1] Department of Aquatic Ecology and Environmental Biology, Radboud Institute for Biological and Environmental Sciences, Radboud University, Nijmegen, Netherlands;Department of Biology, Federal University of Juiz de Fora, Juiz de Fora, Brazil;Department of Biology, Federal University of Juiz de Fora, Juiz de Fora, Brazil;Fishing Institute Foundation of the State of Rio de Janeiro, Rio de Janeiro, Brazil;Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, NY, United States;Graduate Program of Environmental Sciences, Laboratory of Ichthyology of the North Pantanal, University of the State of Mato Grosso, Cáceres, Brazil;School of Earth, Environmental, and Marine Sciences, The University of Texas Rio Grande Valley, Edinburg, TX, United States;

关键词: greenhouse gases;    fishponds;    diffusion;    tilapia;    sediment;    mitigation;    food production;    fish farming;   

DOI  :  10.3389/frwa.2023.1256799

 received in 2023-07-11, accepted in 2023-09-15,  发布年份 2023

来源: Frontiers

【 摘 要 】

An ever-increasing demand for protein-rich food sources combined with dwindling wild fish stocks has caused the aquaculture sector to boom in the last two decades. Although fishponds are potentially strong emitters of the greenhouse gas methane (CH4), little is known about the magnitude, pathways, and drivers of these emissions. We measured diffusive CH4 emissions at the margin and in the center of 52 freshwater fishponds in Brazil. In a subset of ponds (n = 31) we additionally quantified ebullitive CH4 fluxes and sampled water and sediment for biogeochemical analyses. Sediments (n = 20) were incubated to quantify potential CH4 production. Ebullitive CH4 emissions ranged between 0 and 477 mg m−2 d−1 and contributed substantially (median 85%) to total CH4 emissions, surpassing diffusive emissions in 81% of ponds. Diffusive CH4 emissions were higher in the center (median 11.4 mg CH4 m−2 d−1) than at the margin (median 6.1 mg CH4 m−2 d−1) in 90% of ponds. Sediment CH4 production ranged between 0 and 3.17 mg CH4 g C−1 d−1. We found no relation between sediment CH4 production and in situ emissions. Our findings suggest that dominance of CH4 ebullition over diffusion is widespread across aquaculture ponds. Management practices to minimize the carbon footprint of aquaculture production should focus on reducing sediment accumulation and CH4 ebullition.

【 授权许可】

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Copyright © 2023 Vroom, Kosten, Almeida, Mendonça, Muzitano, Barbosa, Nasário, Oliveira Junior, Flecker and Barros.