Abstract
Climate change presents an intensifying threat to society and biodiversity across the globe (IPBES, 2018; IPCC; 2023 UNFCC, 2023). Biodiversity loss is an equally significant threat and exacerbates climate change by deteriorating the ecosystem services that support life on Earth, e.g., biological carbon sequestration (WWF, 2020; Burns et al., 2023). To mitigate climate change and provide an alternative to pollutive, finite, fossil fuels, renewable energy development has become increasingly prevalent (IRENA, 2023; UN, 2023). The United Kingdom (UK) Government aims to install 50 GW of offshore wind energy by 2030 (DESNZ & DBT, 2023), in the context of its commitments to international climate agreements, including the 2015 Paris Agreement of limiting global warming to 1.5oC and achieving net zero by 2050 (HM Government, 2021). However, the development of renewable energy can result in adverse environmental impacts, which are identified and assessed through Environmental Impact Assessments (Gasparatos et al., 2017; Gibson et al., 2017; Nazir et al., 2020). Nonetheless, there is a growing evidence base showing that renewable energy infrastructure can also provide habitats for species and opportunities for biodiversity enhancement (Glarou et al., 2020; Cale and Churn, 2021; Lemasson et al., 2024). Understanding the interactions between biodiversity and renewable energy is crucial to enabling a renewable energy transition that mitigates climate change whilst supporting biodiversity’s recovery. In particular, the emergence of ecological compensatory measures within development consents (Ørsted, 2021) and early policy developments for Marine Net Gain (DEFRA, 2023) present the need for further research into impacts of renewable energy within the marine context.
Black-legged kittiwakes (Rissa tridactyla, henceforth referred to as kittiwakes) were first surveyed on an offshore substation of Walney 2 Offshore Wind Farm (OWF) in 2023 (Peyton-Jones and Rounce, 2023). Kittiwakes are now listed as vulnerable on the International Union of Conservation Nature Red List and the Birds of Conservation Concern Red List, due to global and UK population declines associated with widespread breeding failure (Mousley and Kershaw, 2023). This species is considered to be especially vulnerable to the impacts of wind farms (Mousley and Kershaw, 2023) due to their typical flight heights overlapping with blade swept zones of OWF turbines (Furness et al., 2013). The colony on this substation presents a unique opportunity to monitor kittiwake nesting behaviour on offshore artificial nesting sites within OWF arrays. Researching this colony could provide vital insights into kittiwake ecology and kittiwake interactions with OWF infrastructure. Such findings could help inform the effective implementation of artificial nesting structures (ANSs) as ecological compensation for renewable energy developments. This is especially relevant given Ørsted’s recent development of the first ANSs for ecological compensation (Ørsted, 2022).
In 2023, the colony on the offshore substation of Walney 2 OWF (hereafter referred to as WOW02 OSS) was studied for the first time, with a scientific report subsequently published: Kittiwake Nesting Behaviour on Walney Two Offshore Substation: Data and Recommendations (Peyton-Jones and Rounce, 2023). In 2024, a second investigation was requested by Ørsted and Natural England to build on the report from 2023, following its recommendations and developing a longer-term monitoring campaign that can provide further insights into the colonies’ breeding behaviour and its wider implications; the results of which are the subject of this report.
The 2023 report should be referred to for an introduction to kittiwake ecology, pressures on kittiwakes, offshore wind compensation opportunities and Walney Two Offshore Wind Farm and Substation. Peyton-Jones and Rounce (2023) identified the nearest land-based kittiwake colony as the St Bees colony, approximately 60km from WOW02 OSS (Figure 1).