EMODnet Seabed Habitats supports Blue carbon audit of Orkney waters (Scotland)
Marine Scotland Science (MSS) is the scientific division of the Marine Scotland Directorate, the branch of the devolved Scottish Government responsible for the marine and coastal environment. The purpose of MSS is to provide expert scientific, economic and technical advice and services on issues relating the to the marine environment, to provide evidence to support policies and regulatory activities of the Scottish Government, to perform regulatory and enforcement activities and to represent the Scottish Government at national and international meetings.
As part of the Scottish Government's objective to be world leaders in adopting evidence-based policies in the mitigation of climate change, an audit of blue carbon resources was undertaken for waters around the Orkney Islands. This was the first regional blue carbon audit in Scotland, and the overall aim was to develop more robust methods to assess blue carbon stocks associated with key habitat types. The Orkney Blue Carbon Audit was conducted using a multi-stage approach, including in situ surveys, mapping of areas of known habitats to inform habitat prediction models, determination of carbon content for specific habitats and calculation of total carbon contribution by combining these areas of habitat and their estimate carbon content. Information on the locations and extent of benthic habitats was therefore required to assess their potential for blue carbon storage.
EMODnet Seabed Habitats' EUSeaMap 2016, provided both the substrate and biozone data for the study area, from which blue carbon habitats were identified. This publicly available information allowed for time and resources to be saved compared to users having to collect their own data. Spatial data for each habitat and substrate type were extracted and categorised according to blue carbon category. The standing stock of carbon was estimated for each habitat, with estimates calculated from contributions of biological material to fixation of carbon (also termed ‘production’) and contributions of sediments to blue carbon storage. This allowed for regional-scale estimate of habitat extent, providing an estimate of blue carbon associated with habitats and surface sediments. The most important stocks of blue carbon in Orkney waters were found to be maerl beds, kelp forest and seagrass beds. New research generated for this report also provided greater details on carbon stocks in saltmarsh, brittlestar beds and bryozoan thickets.
EMODnet Seabed Habitats information and data, enabled this audit to identify the key stocks of blue carbon within Orkney waters, and has additionally identified knowledge gaps and suggestions for future research. Despite uncertainties, the general conclusions presented are robust and the audit will go on to inform the Orkney Islands Marine Region: State of the Environment Assessment. The extent to which blue carbon issues could be addressed as part of Scotland’s statutory regional marine planning process will be considered through stakeholder engagement and public consultation. Better informed management could potentially enhance the capacity of key habitats in providing a carbon sink, whilst also encouraging sustainable use of the marine environment.