Abstract
The world’s oceans are a major sink for atmospheric carbon dioxide (CO2). The biological carbon pump plays a vital role in the net transfer of CO2 from the atmosphere to the oceans and then to the sediments, subsequently maintaining atmospheric CO2 at significantly lower levels than would be the case if it did not exist. The efficiency of the biological pump is a function of phytoplankton physiology and community structure, which are in turn governed by the physical and chemical conditions of the ocean. However, only a few studies have focused on the importance of phytoplankton community structure to the biological pump. Because global change is expected to influence carbon and nutrient availability, temperature and light (via stratification), an improved understanding of how phytoplankton community size structure will respond in the future is required to gain insight into the biological pump and the ability of the ocean to act as a long-term sink for atmospheric CO2. This review article aims to explore the potential impacts of predicted changes in global temperature and the carbonate system on phytoplankton cell size, species and elemental composition, so as to shed light on the ability of the biological pump to sequester carbon in the future ocean.
Highlights
Marine phytoplankton perform half of all photosynthesis on Earth [1,2] and directly influence global biogeochemical cycles and the climate, yet how they will respond to future global change is unknown
The ocean is among the largest reservoirs of carbon on Earth; quantifying the efficiency of the biological carbon pump in the face of climate change is a prerequisite to predict future atmospheric CO2 concentrations
It is evident from literature reports that the strength of the biological pump will likely change in the future ocean, in response to a changing climate
Summary
Marine phytoplankton perform half of all photosynthesis on Earth [1,2] and directly influence global biogeochemical cycles and the climate, yet how they will respond to future global change is unknown. Jensen et al [39] used species distribution modelling (SDM) to predict the future global distribution of two phytoplankton species important to the biological pump: the diatom Chaetoceros diadema and the coccolithophore Emiliania huxleyi They employed environmental data described in the Intergovernmental Panel on Climate Change’s Representative Concentration Pathways scenario 8.5 (RCP 8.5), which predicts radiative forcing in the year 2100 relative to pre-industrial values. Their modelling results predicted that the total ocean area covered by C. diadema and E. huxleyi would decline by 8% and 16%, respectively, under the examined climate scenario They suggested that the predicted changes in the range and distribution of these two phytoplankton species under future ocean conditions, if realized, might result in their reduced contribution to carbon sequestration via the biological pump. We review literature to explore the effect of these concomitant changes on various parameters such as phytoplankton species and elemental composition and cell size which play important role in regulating the biological carbon pump
Sign-in/Register to view highlights & summary 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 callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
