Impact case study database

Aberdeen’s programme of research exploring the responses of key marine mammal populations to different stages of wind farm construction and operation has led to a reduction of environmental impacts to those marine mammals, improved the economic viability of offshore renewable energy schemes, influenced industry guidelines, leading to changes in construction practices, and informed national and international decision-making.

Reducing the environmental impacts on marine mammals

Working with developers’ engineering teams and the findings from Aberdeen’s large-scale field studies [ R1]; new approaches for mitigating injury risk from piling noise were developed. These relied on routine integration of ADDs into engineering processes at BOWL, to disperse animals from near-field injury zones. Thompson led the development of risk-assessment [ S1i pp110-141; S1ii pp p89-120] that satisfied regulators that this carefully controlled use of acoustic deterrents resulted in sufficiently low residual risk of injury, and was “a key component of the approaches taken by the developers, and accepted by the RAG [regional advisory group] and the Regulator” [ S2i, S2ii], and trialed in the Moray Firth [ S3]. The existence of Aberdeen’s strategic marine mammal research programme provided the necessary framework for the required research and monitoring to be incorporated into the developer’s Project Environmental Monitoring Plan [ S4] and Prof Thompson managed the marine mammals monitoring programme (MMMP) pre- and during construction phases (2014-2021) [ S1]. Results confirmed the efficacy of the mitigation approach but highlighted additional risks from far-field disturbance [ R5]. These findings were rapidly adopted by Scottish regulators who in 2019 altered the required duration of ADD deployments during piling procedures at MOWEL [ S2; S3; S5] to reduce unintended far-field disturbance.

Improving the economic viability of offshore renewable energy schemes

The Aberdeen-based approaches for mitigating injury risk also removed an existing requirement for visual marine mammal observers on piling vessels. Due to the research “digital aerial surveys have almost completely replaced traditional methods for most population-scale surveys of marine wildlife, including marine mammals. Marine Scotland [Scottish Government] only recommends the use of this method to developers of offshore wind farms” [ S6]. Previously, significant uncertainties of engineering delays to e.g. due to poor weather preventing visual observations would extend construction schedules. This presented a key risk to the economic viability of offshore developments given the high daily cost of construction vessels. This work provided greater certainty over construction timescales and contributed to driving down project costs. Developers of the Moray windfarms saw impacts from this tighter integration of mitigation and engineering processes, resulting in “greater certainty over timescales and contributed to an estimated [ text removed for publication] reduction in construction costs” for BOWL [ S3]; and MOWEL having a “ more efficient piling campaign, a shorter programme, with a reduced predicted impact on marine mammals and estimated cost savings in excess on [ text removed for publication] [ S5] with completion of each in 10 months, in contrast to anticipated two- and three-year schedules in their respective consent applications.

Influencing industry guidelines, leading to changes in construction practices

Research evaluating monitoring approaches at Moray Firth windfarms [ S1] re-assured statutory advisors that they represent best practice, encouraging widespread use in the UK and beyond [ S2; S7; S8]. Data from the studies reduced conservatism in assumptions over cetacean displacement, and the “dose-response” curves they generated underpinned environmental assessments for the next phase of offshore wind development for UK (e.g. Hornsea 3 and Moray West) [ S5] and re-assessments for consented windfarms delayed by environmental court actions (eg. Seagreen and Inch Cape) [ S9]. JNCC refer to the research [ R2; R6] in their 2020 guidance for assessing noise disturbance in harbor porpoise SACs for England, Wales and Northern Ireland [ S10].

Informing national and international understanding through galvanizing stakeholder interactions to find solutions

The Aberdeen research has informed broader understanding of the responses of key marine mammal populations to different stages of wind farm construction and operation nationally and internationally. Approaches that Thompson developed working with MOWEL are informing their parent company Oceanwinds’ stakeholder interactions at new developments within important marine mammal habitats including the Baltic Regions, Korea and Japan, and North and South America [ S5]. In the US, Program Director for Ocean Acoustics within the government’s National Oceanic and Atmospheric Administration has applied the Aberdeen research in decision-making processing, highlighting the work as “ field-leading” and of “ central importance” [ S11].

Impacts beyond the region have been accelerated by Thompson’s involvement in steering and advisory groups. Within the UK this has included the Offshore Renewables Joint Industry Project (ORJIP) on the Efficacy of Acoustic Deterrent Devices and consultancies for other UK developers; In the EU, through Vattenfall’s DEPONS Project; in the US through activities of the Working Together to Resolve Environmental Effects of Wind Energy (WREN) Group. Cross membership of these different bodies and MFRAG led to requests from regulators for early dissemination of the initial data on the extent to which porpoises were displaced by piling noise at the BOWL development to fill a data gap identified during scoping of new consent applications. A confidential briefing paper (pre-publication data, [ R6]) was provided by Thompson for BOWL, and key developers and regulators in September 2017, allowing the data to be incorporated into consent applications at other North Sea sites prior to publication in the formal peer-review literature.

The research of Prof Thompson and his leadership of MMMP has been lauded by the Joint Nature Conservation Committee (JNCC) - the statutory adviser to UK government on nature conservation – as “ useful for not just the Moray Firth wind farms and environment, but it has been used to inform environmental impact assessments and mitigation measures for other wind farms in the UK and beyond… as an example to follow in other parts of the UK” [ S7]. NatureScot – formerly, Scottish Natural Heritage – who advise the Scottish Government attribute the research to have helped get “ to where we are now, with three commercial windfarms consented in the Moray Firth … to bring knowledge and expertise to these discussions has enabled pragmatic and proportionate conversations to continue in the search of solutions. You and your team have built strong relationships across the group comprising of regulators, advisers, developers and their consultants. This has also resulted in talks at various national and international fora (Scotmer, WREN etc.) in demonstrating the research findings and helping to formulate future offshore policy and casework guidance not just in Scottish waters, but also beyond [ S8].