ChAOS will quantify the effect of changing sea ice cover on organic matter quality, benthic biodiversity, biological transformations of carbon and nutrient pools, and resulting ecosystem function at the Arctic Ocean seafloor. We will achieve this by determining the amount, source, and bioavailability of organic matter (OM) and associated nutrients exported to the Arctic seafloor; its consumption, transformation, and cycling through the benthic food chain; and its eventual burial or recycling back into the water column. We will study these coupled biological and biogeochemical processes by combining (i) a detailed study of representative Arctic shelf sea habitats that intersect the ice edge, with (ii) broad-scale in situ validation studies and shipboard experiments, (iii) manipulative laboratory experiments that will identify causal relationships and mechanisms, (iv) analyses of highly spatially and temporally resolved data obtained by the Canadian, Norwegian and German Arctic programmes to establish generality, and (v) we will integrate new understanding of controls and effects on biodiversity, biogeochemical pathways and nutrient cycles into modelling approaches to explore how changes in Arctic sea ice alter ecosystems at regional scales. We will focus on parts of the Arctic Ocean where drastic changes in sea ice cover are the main environmental control, e.g., the Barents Sea. Common fieldwork campaigns will form the core of our research activity. Although our preferred focal region is a N-S transect along 30 degree East in the Barents Sea where ice expansion and retreat are well known and safely accessible, we will also use additional cruises to locations that share similar sediment and water conditions in Norway, retrieving key species for extended laboratory experiments that consider future environmental forcing. Importantly, the design of our campaign is not site specific, allowing our approach to be applied in other areas that share similar regional characteristics. This flexibility maximizes the scope for coordinated activities between all programme consortia (pelagic or benthic) should other areas of the Arctic shelf be preferable once all responses to the Announcement of Opportunity have been evaluated. In support of our field campaign, and informed by the analysis of field samples and data obtained by our international partners (in Norway, Canada, USA, Italy, Poland and Germany), we will conduct a range of well-constrained laboratory experiments, exposing incubated natural sediment to environmental conditions that are most likely to vary in response to the changing sea ice cover, and analysing the response of biology and biogeochemistry to these induced changes in present versus future environments (e.g., ocean acidification, warming). We will use existing complementary data sets provided by international project partners to achieve a wider spatial and temporal coverage of different parts of the Arctic Ocean. The unique combination of expertise (microbiologists, geochemists, ecologists, modellers) and facilities across eight leading UK research institutions will allow us to make new links between the quantity and quality of exported OM as a food source for benthic ecosystems, the response of the biodiversity and ecosystem functioning across the full spectrum of benthic organisms, and the effects on the partitioning of carbon and nutrients between recycled and buried pools. To link the benthic sub-system to the Arctic Ocean as a whole, we will establish close links with complementary projects studying biogeochemical processes in the water column, benthic environment (and their interactions) and across the land-ocean transition. This will provide the combined data sets and process understanding, as well as novel, numerically efficient upscaling tools, required to develop predictive models (e.g., MEDUSA) that allow for a quantitative inclusion seafloor into environmental predictions of the changing Arctic Ocean.

Corrosion of metals affects multiple industries and poses major risks to the environment and human safety, and is estimated to cause economic losses in excess of £2.5 trillion worldwide (around 6% of global GDP). Microbiologically-influenced corrosion (MIC) is believed to play a major role in this, but precise estimates are prevented by our limited understanding of MIC-related processes. In the oil and gas sector biocorrosion is usually linked to the problem of "souring" caused by sulfate-reducing bacteria (SRB) that produce corrosive hydrogen sulfide in subsurface reservoirs and topsides facilities. To combat souring, reservoir engineers have begun turning to nitrate injection as a green biotechnology whereby sulfide removal can be catalysed by diverse sulfide-oxidising nitrate-reducing bacteria (soNRB). However, this promising technology is threatened by reports that soNRB could enhance localized corrosion through incomplete oxidation of sulfide to corrosive sulfur intermediates. It is likely that soNRB are corrosive under certain circumstances; end products of soNRB metabolism vary depending prevailing levels of sulfide (i.e., from the SRB-catalyzed reservoir souring) and nitrate (i.e., the engineering "nitrate dose" introduced to combat souring). Furthermore soNRB corrosion will depend on the specific physiological features of the particular strains present, which vary from field to field, but usually include members of the Epsilonproteobacteria - the most frequently detected bacterial phylum in 16S rRNA genomic surveys of medium temperature oil fields. A new era of biological knowledge is dawning with the advent of inexpensive, high throughput nucleic acid sequencing technologies that can now be applied to microbial genomics. New high throughput sequencing platforms are allowing unprecedented levels of interrogation of microbial communities at the DNA (genomic) and RNA (transcriptomic) levels. Engineering biology aims to harness the power of this biological "-omics" revolution by bringing these powerful tools to bear on industrial problems like biocorrosion. This project will combine genomics and transcriptomics with process measurements of soNRB metabolism and real time corrosion monitoring via linear polarization resistance. By measuring all of these variables in experimental oil field microcosms, and scaling-up to pan-industry oil field screening, a predictive understanding of corrosion linked to nitrogen and sulfur biotransformations will emerge, putting new diagnostic genomics assays in the hands of petroleum engineers. The oil industry needs green technologies like nitrate injection. This research will develop new approaches that will safeguard this promising technology by allowing nitrate-associated biocorrosion potential to be assessed in advance. This will enhance nitrate injection's ongoing successful application to be based on informed risk assessments.

This project will shed light on a key stage in the evolution of life on Earth. The advent onto land of limbed vertebrates (tetrapods) was an event that shaped the future evolution of the planet, including the appearance of humans. The process began about 360 million years ago, during the late Palaeozoic, in the early part of the Carboniferous Period. Within the 20 million years that followed, limbed vertebrates evolved from their essentially aquatic and fish-like Devonian predecessors into fully terrestrial forms, radiating into a wide range of body forms that occupied diverse habitats and ecological niches. We know this because we have an adequate fossil record of the earliest limbed vertebrates from the Late Devonian, contrasting with the terrestrial forms that lived significantly later in the Early Carboniferous, about 340 million years ago. It is also clear that a mass extinction event occurred at the end of the Devonian, following which life on land and in fresh water habitats had to be re-established. Unfortunately, the formative 20 million years from the end of Devonian times has remained almost unrepresented for fossil tetrapods and their arthropod contemporaries. Thus, we know little about how tetrapods evolved adaptations for life on land, the environments in which they did so, and the timing or sequence of these events. The evolutionary relationships among these early tetrapods and how they relate to modern forms are also unclear and controversial as a result of this lack of fossil information. The entire fossil hiatus has been called 'Romer's Gap' after the American palaeontologist who first recognized it. Now, for the first time anywhere in the world, several fossil localities representing this period have been discovered in south-eastern Scotland. They have already provided a wealth of new fossils of tetrapods, fish, invertebrates and plants, and our team is the first to have the opportunity to study this material and the environmental, depositional, and climatic context in which this momentous episode took place. We have a number of major aims. The existing fossil material will form a baseline for this study, but the project will augment this by further excavating the richest of the sites so far found and subjecting it to a detailed archaeological-style analysis. We will collect from other recently recognized sites and explore for further sites with relevant potential. The fossil material will be described and analysed using a range of modern techniques to answer many questions related to the evolution of the animals and plants. Not only that, using stratigraphical, sedimentological, palynological, geochemical and isotopic data, we will establish the conditions of deposition that preserved the fossils, the environments in which the organisms lived and died, and the precise times at which they did so. We will drill a borehole that will core through the entire geological formation in which these fossils have been found. Using this, we will integrate data from our fossil sites using the signals provided by the sedimentary record to build a detailed time line showing in which horizons the fossils were found, the age of each occurrence and their sequential relationship. We will compare and correlate our data with that from contemporaneous deposits in Nova Scotia, the only other locality with information sufficiently rich to be meaningful. Our data will allow us to infer changes to the environment and the evolutionary trajectories of the animals and plants during the deposition of this formation, covering the 20 million years following the end-Devonian mass extinction. Comparison with similar data for the Late Devonian will allow us to chart the changes around the time of the mass extinction, to infer its causes and consequences, and obtain a detailed record of exactly how changes to the environment correlated with changes to the fauna and flora.