Description: From the foreword: This report, CBD Technical Series No. 75, “An updated synthesis of the impacts of ocean acidification on marine biodiversity”, represents an enormous scientific effort by researchers and experts from around the world to synthe- size the best available and most up-to-date information on the impacts of changing ocean pH on the health of the world’s oceans. Among other findings, the report notes that ocean acidifica- tion has increased by around 26% since pre-industrial times and that, based on historical evidence, recovery from such changes in ocean pH can take many thousands of years. The report outlines how ocean acidification impacts the physi- ology, sensory systems and behavior of marine organisms, and undermines ecosystem health. It, furthermore, shows that impacts due to ocean acidification are already under- way in some areas and that future projected impacts could have drastic irreversible impacts on marine ecosystems. Despite the growing body of information on ocean acidifica- tion, the report points out key knowledge gaps and, in light of the many complex interactions related to ocean chemis- try, stresses the difficulty of assessing how future changes to ocean pH will affect marine ecosystems, food webs and ecosystems, and the goods and services they provide. This report, which presents complex scientific information on ocean acidification in a clear and understandable way, provides an important reference point for scientists, policy- makers and anyone else interested in understanding how ocean acidification affects our oceans and the vital services they provide. As the need for urgent action to address ocean acidification becomes ever more pressing, collaboration among governments and organizations in enhancing and sharing knowledge through efforts such as this report will become increasingly important.

Description: Here we present a new, pan-Atlantic compilation and analysis of data on Calanus finmarchicus abundance, demography, dormancy, egg production and mortality in relation to basin-scale patterns of temperature, phytoplankton biomass, circulation and other environmental characteristics in the context of understanding factors determining the distribution and abundance of C. finmarchicus across its North Atlantic habitat. A number of themes emerge: (1) the south-to-north transport of plankton in the northeast Atlantic contrasts with north-to-south transport in the western North Atlantic, which has implications for understanding population responses of C. finmarchicus to climate forcing, (2) recruitment to the youngest copepodite stages occurs during or just after the phytoplankton bloom in the east whereas it occurs after the bloom at many western sites, with up to 3.5 months difference in recruitment timing, (3) the deep basin and gyre of the southern Norwegian Sea is the centre of production and overwintering of C. finmarchicus, upon which the surrounding waters depend, whereas, in the Labrador/Irminger Seas production mainly occurs along the margins, such that the deep basins serve as collection areas and refugia for the overwintering populations, rather than as centres of production, (4) the western North Atlantic marginal seas have an important role in sustaining high C. finmarchicus abundance on the nearby coastal shelves, (5) differences in mean temperature and chlorophyll concentration between the western and eastern North Atlantic are reflected in regional differences in female body size and egg production, (6) regional differences in functional responses of egg production rate may reflect genetic differences between western and eastern populations, (7) dormancy duration is generally shorter in the deep waters adjacent to the lower latitude western North Atlantic shelves than in the east, (8) there are differences in stage-specific daily mortality rates between eastern and western shelves and basins, but the survival trajectories for cohort development from CI to CV are similar, and (9) early life stage survival is much lower in regions where C. finmarchicus is found with its congeners, C. glacialis and/or C. hyperboreus. This compilation and analysis provides new knowledge for evaluation and parameterisation of population models of C. finmarchicus and their responses to climate change in the North Atlantic. The strengths and weaknesses of modeling approaches, including a statistical approach based on ecological niche theory and a dynamical approach based on knowledge of spatial population dynamics and life history, are discussed, as well as needs for further research.

Description: The sensitivity of copepods to ocean acidification (OA) and warming may increase with time, however, studies 〉10 days and on synergistic effects are rare. We therefore incubated late copepodites and females of two dominant Arctic species, Calanus glacialis and C. hyperboreus, at 0 °C at 390 and 3000 µatm pCO2 for several months in fall/winter 2010. Respiration rates, body mass and mortality in both species and life stages did not change with pCO2. To detect synergistic effects, in 2011 C. hyperboreus females were kept at different pCO2 and temperatures (0, 5, 10 °C). Incubation at 10 °C induced sublethal stress, which might have overruled effects of pCO2. At 5 °C and 3000 µatm, body carbon was significantly lowest indicating a synergistic effect. The copepods, thus, can tolerate pCO2 predicted for a future ocean, but in combination with increasing temperatures they could be sensitive to OA.