Technical Note: Maximising accuracy and minimising cost of a potentiometrically regulated ocean acidification simulation system Biogeosciences DOI 10.5194/bg-12-713-2015 5 February 2015 This article describes a low-cost, easy set-up, ocean acidification simulation system that reliably mimics the effects of elevated atmospheric carbon dioxide on seawater chemistry. The accessible design of this system, along with our suggestions for the validation of pH control and characterisation of seawater chemistry, will enable researchers on a limited budget to generate high quality, repeatable data documenting the response of marine organisms to ocean acidification. Read more
Processes determining the marine alkalinity and calcium carbonate saturation state distributions Biogeosciences DOI 10.5194/bg-11-7349-2014 19 December 2014 We examine and discuss the portion of ocean alkalinity that varies in response to carbonate cycling and riverine alkalinity inputs using a new tracer, Alk*. We use this tracer to quantify the controls on marine carbonate saturation: At depth, we find carbonate cycling to be a minor control relative to organic matter cycling and pressure changes. In well-equilibrated surface water, we find carbonate cycling to be less important than temperature changes and freshwater cycling. Read more
Estimated stocks of circumpolar permafrost carbon with quantified uncertainty ranges and identified data gaps Biogeosciences DOI 10.5194/bg-11-6573-2014 1 December 2014 This study provides an updated estimate of organic carbon stored in the northern permafrost region. The study includes estimates for carbon in soils (0 to 3 m depth) and deeper sediments in river deltas and the Yedoma region. We find that field-data is still scarce from many regions. Total estimated carbon storage is ~1300 Pg with an uncertainty range of between 1100 to 1500 Pg. Around 800 Pg carbon is perennially frozen, equivalent to all carbon dioxide currently in the Earths atmosphere. Read more
Long-term trends at the Boknis Eck time series station (Baltic Sea), 1957–2013: does climate change counteract the decline in eutrophication? Biogeosciences DOI 10.5194/bg-11-6323-2014 24 November 2014 A time series of 9 oceanic parameters from the coastal time series station Boknis Eck (BE, South Western Baltic Sea) in the period of 1957-2013 is analysed with respect to seasonal cycles and longterm trends. Most striking was a paradoxical decreasing trend in oxygen with a simultaneous decline in eutrophication. Possible reasons for this paradox, e.g. processes related to warming temperatures such as increased decomposition of organic matter or altered ventilation, are discussed. Read more
Gas emissions at the continental margin west of Svalbard: mapping, sampling, and quantification Biogeosciences DOI 10.5194/bg-11-6029-2014 6 November 2014 The authors mapped, sampled, and quantified gas emissions at the continental margin west of Svalbard in late summer 2012. They found that gas emissions occurred widespread between about 80 and 415 m water depth, which indicates that hydrate dissolution might only be one of several triggers for active hydrocarbon seepage in that area. Read more
Release of hydrogen peroxide and antioxidants by the coral Stylophora pistillata to its external milieu Biogeosciences DOI 10.5194/bg-11-4587-2014 1 September 2014 This paper presents a laboratory characterisation of hydrogen peroxide (H2O2) and antioxidant activity release kinetics by intact, non-stressed Stylophora pistillata. Experimenting with bleached and non-bleached corals and different stirring speeds, the authors explored the sources and modes of H2O2 and antioxidant release. Read more
Diverse coral communities in mangrove habitats suggest a novel refuge from climate change Biogeosciences DOI 10.5194/bg-11-4321-2014 19 August 2014 This paper characterises the first natural, non-reef coral refuge from thermal stress and ocean acidification and identifies resiliency factors for mangrove–coral habitats. Read more
Ecosystem function and services provided by the deep sea Biogeosciences DOI 10.5194/bg-11-3941-2014 29 July 2014 In this manuscript we aim to provide a foundation for informed conservation and management of the deep sea by summarizing the important role of the deep sea in society. Read more
Subsurface pH and carbonate saturation state of aragonite on the Chinese side of the North Yellow Sea: seasonal variations and controls Biogeosciences DOI 10.5194/bg-11-1103-2014 26 February 2014 Based upon eight field surveys conducted between May 2011 and May 2012, we investigated seasonal variations in pH, carbonate saturation state of aragonite, and ancillary data on the Chinese side of the North Yellow Sea. Read more
Exploring local adaptation and the ocean acidification seascape – studies in the California Current Large Marine Ecosystem Biogeosciences DOI 10.5194/bg-11-1053-2014 24 February 2014 Here we present the OMEGAS strategy of co-locating sensors and oceanographic observations with biological studies on benthic marine invertebrates, specifically measurements of functional traits such as calcification-related processes and genetic variation in populations that are locally adapted to conditions in a particular region of the coast. Read more
