Ocean CO2 and pH in Shelf Sea Ecosystems 2-4 th May London (original) (raw)

Changes in surface CO2 and ocean pH in ICES shelf sea ecosystems

2008

The primary purpose of this document is to report the recommendations resulting from the ICES WORKSHOP ON THE SIGNIFICANCE OF CHANGING OCEAN CO2 AND PH IN ICES SHELF SEA ECOSYSTEMS held between 2 and 4 May 2007 in London. Some excel‐lent reports have already been published in this field, first by the Scientific Commit‐tee on Oceanic Research (SCOR; Arvidson, 2005), then by the National Oceanic and Atmospheric Administration/National Science Foundation/US Geological Survey (NOAA/NSF/USGS; ...

Reviewing the impact of increased atmospheric CO2 on oceanic pH and the marine ecosystem

Avoiding dangerous …, 2006

The world's oceans contain an enormous reservoir of carbon, greater than either the terrestrial or atmospheric systems. The fluxes between these reservoirs are relatively rapid such that the oceans have taken up around 50% of the total carbon dioxide (CO 2 ) released to the atmosphere via fossil fuel emissions and other human activities in the last 200 years. Whilst this has slowed the progress of climate change, CO 2 ultimately results in acidification of the marine environment. Ocean pH has already fallen and will continue to do so with certainty as the oceans take up more anthropogenic CO 2 . Acidification has only recently emerged as a serious issue and it has the potential to affect a wide range of marine biogeochemical and ecological processes. Based on theory and an emerging body of research, many of these effects may be non-linear and some potentially complex. Both positive and negative feedback mechanisms exist, making prediction of the consequences of changing CO 2 levels difficult. Integrating the net effect of acidification on marine processes at regional and basin scales is an outstanding challenge that must be addressed via integrated programs of experimentation and modelling. Ocean acidification is another argument, alongside that of climate change, for the mitigation of anthropogenic CO 2 emissions.

MCCIP Ecosystem Linkages Report Card 2009 CO2 and ocean acidification

2009

Evidence from experiments and observations indicate that ocean acidification is a serious threat to many marine organisms which may have implications to the food webs and ecosystems but these are difficult to predict especially as studies of potential adaptation have not been carried out. Also of less certainty are the scale and direction of impacts on biogeochemical cycling of carbon,

Marine CO2 Patterns in the Northern Salish Sea

Frontiers in Marine Science, 2019

Marine carbon dioxide (CO 2) system data has been collected from December 2014 to June 2018 in the Northern Salish Sea (NSS; British Columbia, Canada) and consisted of continuous measurements at two sites as well as spatially-and seasonally distributed discrete seawater samples. The array of CO 2 observing activities included high-resolution CO 2 partial pressure (pCO 2) and pH T (total scale) measurements made at the Hakai Institute's Quadra Island Field Station (QIFS) and from an Environment Canada weather buoy, respectively, as well as discrete seawater measurements of pCO 2 and total dissolved inorganic carbon (TCO 2) obtained during a number of field campaigns. A relationship between NSS alkalinity and salinity was developed with the discrete datasets and used with the continuous measurements to highly resolve the marine CO 2 system. Collectively, these datasets provided insights into the seasonality in this historically under-sampled region and detail the area's tendency for aragonite saturation state (arag) to be at non-corrosive levels (i.e., arag > 1) only in the upper water column during spring and summer months. This depth zone and time period of reprieve can be periodically interrupted by strong northwesterly winds that drive shortlived (∼1 week) episodes of high-pCO 2 , low-pH, and lowarag conditions throughout the region. Interannual variability in summertime conditions was evident and linked to reduced northwesterly winds and increased stratification. Anthropogenic CO 2 in NSS surface water was estimated using data from 2017 combined with the global atmospheric CO 2 forcing for the period 1765 to 2100, and projected a mean value of 49 ± 5 µmol kg −1 for 2018. The estimated trend in anthropogenic CO 2 was further used to assess the evolution of arag and pH T levels in NSS surface water, and revealed that wintertime corrosive arag conditions were likely absent pre-1900. The percent of the year spent above arag = 1 has dropped from ∼98% in 1900 to ∼60% by 2018. Over the coming decades, winter pH T and spring and summer arag are projected to decline to conditions below identified biological thresholds for select vulnerable species.

Enhanced biological carbon consumption in a high CO2 ocean

Nature, 2007

The oceans have absorbed nearly half of the fossil-fuel carbon dioxide (CO 2 ) emitted into the atmosphere since pre-industrial times 1 , causing a measurable reduction in seawater pH and carbonate saturation 2 . If CO 2 emissions continue to rise at current rates, upper-ocean pH will decrease to levels lower than have existed for tens of millions of years and, critically, at a rate of change 100 times greater than at any time over this period 3 . Recent studies have shown effects of ocean acidification on a variety of marine life forms, in particular calcifying organisms 4-6 . Consequences at the community to ecosystem level, in contrast, are largely unknown. Here we show that dissolved inorganic carbon consumption of a natural plankton community maintained in mesocosm enclosures at initial CO 2 partial pressures of 350, 700 and 1,050 matm increases with rising CO 2 . The community consumed up to 39% more dissolved inorganic carbon at increased CO 2 partial pressures compared to present levels, whereas nutrient uptake remained the same. The stoichiometry of carbon to nitrogen drawdown increased from 6.0 at low CO 2 to 8.0 at high CO 2 , thus exceeding the Redfield carbon:nitrogen ratio of 6.6 in today's ocean 7 . This excess carbon consumption was associated with higher loss of organic carbon from the upper layer of the stratified mesocosms. If applicable to the natural environment, the observed responses have implications for a variety of marine biological and biogeochemical processes, and underscore the importance of biologically driven feedbacks in the ocean to global change.