The potential for leakage of CO2 from a storage reservoir into the overlying marine sediments and into the water column and the impacts on benthic ecosystems are major challenges associated with Carbon Capture and Storage (CCS) in subseafloor reservoirs. A field-scale controlled CO2 release experiment was conducted in shallow, unconsolidated marine sediments. Changes were monitored of the chemical composition of the sediments and overlying water column before, during and up to 1 year after the 37-day long CO2 release from May 2012 to May 2013 in Ardmucknish Bay. Meiofaunal samples were collected and meiofauna higher taxa and the nematodes species (where possible) were identified by Plymouth Marine Laboratory. This dataset was collected under the program QICS (Quantifying and monitoring environmental impacts of geological carbon storage) which was funded by the Natural Environment Research Council (NERC), with support from the Scottish Government. The results are contained in an Excel file. QICS project website: www.bgs.ac.uk/qics/home.html. This data is currently under embargo until publication of the dataset in research article (estimated end of 2015).

The response of the benthic microbial community to a controlled sub-seabed CO2 leak was assessed using quantitative PCR measurements of benthic bacterial, archaeal and cyanobacteria/chloroplast 16S rRNA genes. Similarly, the impact of CO2 release on the abundance of benthic bacterial and archaeal ammonia amoA genes and transcripts, and also to the abundance of nitrite oxidizer (nirS) and anammox hydrazine oxidoreductase (hzo) genes and transcripts. Samples were taken from four zones (epicentre (zone 1); 25m distant (zone 2), 75m distant (zone 3) and 450m distant (zone 4)) during 6 time points (7 days before CO2 exposure, after 14 and 36 days of CO2 release, and 6, 20 and 90 days after the CO2 release had ended). Changes to the active community of microphytobenthos and bacteria were also assessed before, during and after CO2 release using Denaturing Gradient Gel Electrophoresis of cyanobacteria/chloroplast 16S rRNA. Changes to the composition of the active bacterial community was assessed first using Terminal Restriction Fragment Length Polymorphism (T-RFLP) of bacterial 16S rRNA. In depth comparisons of possible changes to the active bacterial community at zone 1 and 4 before, during and immediately after the CO2 release was performed using 16S rRNA 454 pyrosequencing. This dataset was created by Plymouth Marine Laboratory (PML) under the program QICS (Quantifying and monitoring environmental impacts of geological carbon storage) which was funded by the Natural Environment Research Council (NERC), with support from the Scottish Government. The results are contained in three text files. QICS project website: www.bgs.ac.uk/qics/home.html. Tait et al. (2015) Rapid response of the active microbial community to CO2 exposure from a controlled sub-seabed CO2 leak in Ardmucknish Bay (Oban, Scotland). IJGGC DOI: 10.1016/ijggc.2014.11.021. Watanabe et al. (2015) Ammonia oxidation activity of microorganisms in surface sediment to a controlled sub-seabed release of CO2. IJGGC DOI: 10.1016/j.ijggc.2014.11.013.

The response of the benthic microbial community to a controlled sub-seabed CO2 leak was assessed using quantitative PCR measurements of benthic bacterial, archaeal and cyanobacteria/chloroplast 16S rRNA genes. Samples were taken from four zones (epicentre; 25 m distant, 75 m distant and 450 m distant) during 6 time points (7 days before CO2 exposure, after 14 and 36 days of CO2 release, and 6, 20 and 90 days after the CO2 release had ended). Changes to the active community of microphytobenthos and bacteria were also assessed before, during and after CO2 release. Increases in the abundance of microbial 16S rRNA were detected after 14 days of CO2 release and at a distance of 25 m from the epicentre. CO2 related changes to the relative abundance of both major and minor bacterial taxa were detected: most notably an increase in the relative abundance of the Planctomycetacia after 14 days of CO2 release. Also evident was a decrease in the abundance of microbial 16S rRNA genes at the leak epicentre during the initial recovery phase: this coincided with the highest measurements of DIC within the sediment, but may be related to the release of potentially toxic metals at this time point. This is a publication in QICS Special Issue - International Journal of Greenhouse Gas Control, Karen Tait et. al. Doi:10.1016/j.ijggc.2014.11.021.

A sub-seabed release of carbon dioxide (CO2) was conducted to assess the potential impacts of leakage from sub-seabed geological CO2 Capture and Storage CCS) on benthic macrofauna. CO2 gas was released 12 m below the seabed for 37 days, causing significant disruption to sediment carbonate chemistry. Regular macrofauna samples were collected from within the area of active CO2 leakage (Zone 1) and in three additional reference areas, 25 m, 75 m and 450 m from the centre of the leakage (Zones 2, 3 and 4 respectively). Macrofaunal community structure changed significantly in all zones during the study period. However, only the changes in Zone 1 were driven by the CO2 leakage with the changes in reference zones appearing to reflect natural seasonal succession and stochastic weather events. The impacts in Zone 1 occurred rapidly (within a few days), increased in severity through the duration of the leak, and continued to worsen after the leak had stopped. Considerable macrofaunal recovery was seen 18 days after the CO2 gas injection had stopped. In summary, small short-term CCS leakage events are likely to cause highly localised impacts on macrofaunal communities and there is the potential for rapid recovery to occur, depending on the characteristics of the communities and habitats impacted. This is a publication in QICS Special Issue - International Journal of Greenhouse Gas Control, Stephen Widdicombe et. al. Doi:10.1016/j.ijggc.2015.01.003.

Available methods for measuring the impact of ocean acidification (OA) and leakage from carbon capture and storage (CCS) on marine sedimentary pH profiles are unsuitable for replicated experimental setups. To overcome this issue, a novel optical sensor application is presented, using off-the-shelf optode technology (MOPP). The application is validated using microprofiling, during a CCS leakage experiment, where the impact and recovery from a high CO2 plume was investigated in two types of natural marine sediment. MOPP offered user-friendliness, speed of data acquisition, robustness to sediment type, and large sediment depth range. This ensemble of characteristics overcomes many of the challenges found with other pH measuring methods, in OA and CCS research. The impact varied greatly between sediment types, depending on baseline pH variability and sediment permeability. Sedimentary pH profile recovery was quick, with profiles close to control conditions 24 h after the cessation of the leak. However, variability of pH within the finer sediment was still apparent 4 days into the recovery phase. Habitat characteristics need therefore to be considered, to truly disentangle high CO2 perturbation impacts on benthic systems. Impacts on natural communities depend not only on the pH gradient caused by perturbation, but also on other processes that outlive the perturbation, adding complexity to recovery. This is a publication in QICS Special Issue - International Journal of Greenhouse Gas Control, Ana M. Queirós et. al. Doi:10.1016/j.ijggc.2014.10.004.

Results of a survey undertaken in 2018 involving a range of open and closed questions intended to elicit local residents’ values they attach to the importance of coastal attributes and their perceptions of various tidal and wave energy development characteristics. Three case study sites were selected: Weston-super-Mare, Minehead, and the Taw-Torridge Estuary, South-West UK. Full details about this dataset can be found at https://doi.org/10.5285/e5190fd0-2995-42aa-aca0-80714abde768