Offshore wind energy - sectoral marine plan: seabird tagging feasibility

How to undertake a seabird tagging study for species and colonies potentially impacted by the sectoral marine plan for offshore wind energy


The offshore wind industry is set to play a crucial role in Scotland’s economy as part of efforts to generate 50% of Scotland’s energy from renewable sources by 2030 and to reach Net Zero by 2045. This means that, as we emerge from the COVID-19 pandemic, the industry is likely to play a central role in a green economic recovery.

At present, there are six offshore wind farms in Scottish waters, including the world’s first floating offshore wind project. A further five are either under construction or have been consented. Building on this success, the recently announced ScotWind Leasing Round aims to deliver additional energy from offshore wind. The Sectoral Marine Plan for Offshore Wind Energy (SMP) published in October 2020 set out the spatial Plan Options for a new round of offshore wind seabed leasing, known as ScotWind and managed by Crown Estate Scotland (CES). The SMP assessed the impact of up to 10GW of new development (Figure 1). In January 2022, CES announced that Option Agreements will be offered to 17 projects with a total stated capacity ambition of up to 25GW (Figure 1). Subsequently, three further projects, with a capacity in excess of 2GW were announced following the completion of a clearing round and 13 projects have been announced following the outcome of the Innovation and Targeted Oil and Gas (InTOG) Leasing Round. Whilst offshore wind energy offers the potential to mitigate the negative impacts of climate change by reducing reliance on fossil fuels, concerns remain over the potential for negative environmental impacts, particularly in relation to birds (Bradbury et al., 2014; Furness et al., 2013; Garthe & Hüppop, 2004). The key effects associated with offshore wind are believed to be collision with turbines, displacement, and barrier effects (Cook et al., 2018; Dierschke et al., 2016; Masden et al., 2012; Mendel et al., 2019; Thaxter et al., 2018). Prior to consent for a development being granted, the potential for these impacts to negatively affect populations, particularly those of designated features of protected sites, must be considered as part of the Environmental Impact Assessment (EIA) and Habitats Regulations Appraisal (HRA) processes.

The Strategic Assessment for the Scottish Governments’ SMP for Offshore Wind Energy (comprising Strategic Environmental Assessment (SEA), Habitats Regulations Appraisal (HRA) and a socio-economic impact assessment (SEIA)), assessed the option areas based on a 10GW scenario, highlighting the potential for negative effects in relation to the Plan Options (POs, Figure 1). The HRA highlighted potential cumulative ornithological impacts as a key constraint to the future delivery of offshore wind in Scottish waters. As indicated above, the ScotWind and INTOG Leasing rounds have option agreements for approximately 30GW, i.e a substantially greater amount of potential development than was assessed. In five of the POs (E3, NE2, NE3, NE4 and NE6), which include ScotWind leases option agreements with a combined capacity of up to 4.5 GW, it was determined that further empirical evidence was required before it can be concluded that the risk to seabird populations can be reduced or is at an acceptable level. An additional two sites (E1 and E2) were identified as needing strategic regional surveys and assessments to address uncertainties about the potential cumulative impacts on seabirds, particularly in the non-breeding season.

The SMP Roadmap of Actions[2] highlighted that collecting seabird tracking data offers a valuable opportunity to provide the empirical evidence to assess whether the risk to seabird populations from these developments can be reduced to an acceptable level, and to reduce uncertainties about potential cumulative impacts. In addition to establishing connectivity between seabird populations in Special Protection Areas (SPAs) and these POs, the data can be used to investigate seabird activity budgets and patterns in flight height, speed, and avoidance of existing offshore wind farms (Cleasby et al., 2015; Johnston et al., 2021; Masden et al., 2021; Ross-Smith et al., 2016). By collecting data from species from SPAs where there is likely to be connectivity with ScotWind POs, we will have greater power to investigate spatial and temporal patterns in these parameters, and better understand how they may be influenced by weather conditions. This will allow us to better quantify these parameters and consequently, reduce uncertainty surrounding assessments of key impacts, particularly collision risk mortality.

Figure 1 Plan Options identified as part of the Sectoral Marine Plan for Offshore Energy in October 2020 (black hatched shading) and subsequent ScotWind Lease Agreement Offers (blue solid shading) as of February 2022. Also shown are SPAs for which the Plan Strategic Assessment highlights the potential for negative impacts in relation to the plan options (orange), and including those for which the Habitats Regulations Appraisal concluded that it was not possible to conclude that there would be no adverse effects on site integrity resulting from development within POs (red) without the application of mitigation approach highlighted above (i.e. no development in E3, NE2, NE3, NE4 and NE6 until evidence can be produced to demonstrate the risks to seabirds are reduced, or are at an acceptable level).

At present, there are a number of ongoing seabird tagging studies during both the breeding and non-breeding seasons, often associated with post-consent monitoring programmes. These include studies in the Firth of Forth, Fowlsheugh and St Abb’s Head. However, the collection of tracking data of relevance to many of the ScotWind Option Agreements is likely to require work in additional SPAs, particularly further north along North Sea coasts (Figure 1, Table 1). Whilst puffin was not considered for inclusion in this feasibility study, discussion about the practicalities of working on the species, particularly in relation to tag effects which are a known concern for this species, is included in the report as it co-occurs with the other auk species at several sites of interest. There may be a number of constraints to further work including the challenges of working at unfamiliar sites and the availability of suitably trained and qualified staff. Consequently, there is a need for a strategic overview of this work to ensure an optimal allocation of effort, and a careful consideration about at which sites and for which species tagging work is feasible. This report provides an overview of the feasibility of planning a strategic tagging programme in advance of any implementation and the necessary steps prior to a breeding season when tagging will occur. To achieve this, the report aims to:

  • Produce a summary timeline detailing the key tasks for a tracking project from inception to delivery;
  • Produce recommended protocols for tagging covering tag types, capture and attachment methodologies;
  • Identify sites where additional tagging work is both feasible and necessary through consultation with local researchers, ringers and fieldworkers and site visits.
Table 1 SPAs and species for which additional tracking requirements were identified as part of the ScotWind Roadmap of Actions, highlighted cells (the last seven columns) indicate colonies at which a site visit is likely to be required in order to assess the feasibility of tagging one or more species.
St Abbs Head to Fast Castle Forth Islands Fowlsheugh Buchan Ness to Collieston Coast Troup, Pennan and Lion’s Heads East Caithness Cliffs North Caithness Cliffs Copinsay Fair Isle
Great Black-backed Gull
Herring Gull



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