Abstract
Spreading olivine powder in seawater to enhance alkalinity through weathering reactions has been proposed as a potential solution to control atmospheric CO2 concentration. Attention has usually been paid to the chemical properties of seawater after the addition of olivine within lab and modeling studies. However, both microbial acclimation and evolution in such manipulated natural environments are often overlooked, yet they are of great importance for understanding the biological consequences of whether olivine addition is a feasible approach to mitigating climate change. In this study, an olivine addition experiment was conducted to investigate variation in bacterial diversity and community composition in the surface and bottom seawater of a representative marine ranch area in the Muping, Yantai. The results show that the composition of the particle-attached microbial community was particularly affected by the application of olivine. The relative abundance of biofilm-forming microbes in particle-attached fraction increased after the addition of olivine, while no significant variation in the free-living bacterial community was observed. Our study suggests that olivine addition would reshape the bacterial community structure, especially in particle-attached microenvironments. Therefore, the risk evaluation of alkalinity enhancement should be further studied before its large-scale application as a potential ocean geoengineering plan.
Highlights
Massive fossil fuel combustion has contributed to a significant increase in atmospheric CO2 content, resulting in an increase in pCO2 from 280 to 419 ppm since the industrial revolution1, causing global warming (Lackner et al, 1995; Lal, 2008)
Little is known about the impact of mineral dissolution products on microbes in the ecosystem, which plays a vital role in ocean carbon cycling (Meysman and Montserrat, 2017; Montserrat et al, 2017)
The temperature, total alkalinity (TA), and pH in the surface layer were higher than in the bottom layer, while the salinity and dissolved silicate (DSi) were lower in the surface layer
Summary
Massive fossil fuel combustion has contributed to a significant increase in atmospheric CO2 content, resulting in an increase in pCO2 from 280 to 419 ppm since the industrial revolution, causing global warming (Lackner et al, 1995; Lal, 2008). Bacterial Response to Olivine Addition (Oelkers and Cole, 2008; Rogelj et al, 2016), and enhanced silicate weathering has been suggested as one of these solutions (Seifritz, 1990; Schuiling and Krijgsman, 2006; Hartmann et al, 2013). The removal of atmospheric CO2 could be stimulated with enhanced weathering of olivine (a type of silicate mineral) by its application to forests or oceans (Berner et al, 1983; Schuiling and Krijgsman, 2006). The ocean has absorbed one-third of the CO2 emitted by human activity (Sabine et al, 2004). Olivine added to seawater can enhance buffering capacity and absorb extra CO2 from the atmosphere. Little is known about the impact of mineral dissolution products on microbes in the ecosystem, which plays a vital role in ocean carbon cycling (Meysman and Montserrat, 2017; Montserrat et al, 2017)
Sign-in/Register to view highlights & summary 
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call