Year-end Sale % OFF 
Abstract
Increasing atmospheric carbon dioxide (CO2) from anthropogenic sources is acidifying marine environments resulting in potentially dramatic consequences for the physical, chemical and biological functioning of these ecosystems. If current trends continue, mean ocean pH is expected to decrease by ~0.2 units over the next ~50 years. Yet, there is also substantial temporal variability in pH and other carbon system parameters in the ocean resulting in regions that already experience change that exceeds long-term projected trends in pH. This points to short-term dynamics as an important layer of complexity on top of long-term trends. Thus, in order to predict future climate change impacts, there is a critical need to characterize the natural range and dynamics of the marine carbonate system and the mechanisms responsible for observed variability. Here, we present pH and dissolved inorganic carbon (DIC) at time intervals spanning 1 hour to >1 year from a dynamic, coastal, temperate marine system (Beaufort Inlet, Beaufort NC USA) to characterize the carbonate system at multiple time scales. Daily and seasonal variation of the carbonate system is largely driven by temperature, alkalinity and the balance between primary production and respiration, but high frequency change (hours to days) is further influenced by water mass movement (e.g. tides) and stochastic events (e.g. storms). Both annual (~0.3 units) and diurnal (~0.1 units) variability in coastal ocean acidity are similar in magnitude to 50 year projections of ocean acidity associated with increasing atmospheric CO2. The environmental variables driving these changes highlight the importance of characterizing the complete carbonate system rather than just pH. Short-term dynamics of ocean carbon parameters may already exert significant pressure on some coastal marine ecosystems with implications for ecology, biogeochemistry and evolution and this shorter term variability layers additive effects and complexity, including extreme values, on top of long-term trends in ocean acidification.
Highlights
Carbon dioxide concentrations are rising at ~3% per year in both the atmosphere and oceans
We focus on quantifying pH and associated environmental variables of a dynamic coastal estuary as part of the Pivers Island Coastal Observatory (PICO), Beaufort, NC as a representative temperate coastal environment important for recreationally and commercially important juvenile and adult marine biota and like many coastal locations, it is a site of high biological activity [24]
In mesotrophic or eutrophic coastal oceans recent observations demonstrate that some ecosystems already experience annual or daily pH and dissolved inorganic carbon (DIC) variability that vastly exceeds observed or predicted long-term changes in open ocean regions [15,16]
Summary
Carbon dioxide concentrations are rising at ~3% per year in both the atmosphere and oceans. Unmitigated, increasing pCO2 -driven acidification is expected to continue for the foreseeable future resulting in a mean ocean pH decrease of ~0.2 units over the 50 years [3]. This changing ocean pH and carbonate chemistry will affect a broad spectrum of physical and biogeochemical properties of the ocean ecosystems including transmission of sound, metals chemistry as well as the physiology, growth and reproduction of numerous organisms, especially those that deposit carbonate (e.g. corals, coccolithophorids and molluscs) and others [4,5,6,7]. Identification and quantification of explanatory variables that drive observed patterns in the marine carbonate system is critical to understanding the effects of globally increasing pCO2 on ocean ecosystems
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.
