Abstract
Growth of the offshore wind (OW) energy industry must be accelerated to meet global 2050 Net Zero Carbon commitments. The international ambitions to reach these goals include substantial upscaling of OW in the North Sea and Celtic Sea. At the European level, the ambition has been formulated for at least 60 GW offshore wind by 2030 and 300 GW offshore wind by 2050, excluding UK and Norway. The spatial study North Seas 2030 – offshore wind development (Royal HaskoningDHV, 2022) shows that the ambitions of only the member states of the EU already add up to at least 62 GW at the North Seas by 2030. This is already more than the European ambition of 60 GW offshore wind. Together with the ambition of the UK (50 GW) and Norway (4,5 GW), this brings the ambition of OW in the North Seas in 2030 up to at least 117 GW. These results show that up to 2030 and 2050, the North Seas will be changing, as a large increase of OW can be expected.
Since the construction of the first windfarms, there have been concerns about their effects on nature. The presence of offshore wind farms (OWFs) in the North Seas changes the local environment both above and below water. Impacts of OWFs appear in multiple stages of construction, operation, and decommissioning. The main impacted species groups are birds, bats, marine mammals, fish, and benthic marine organisms. In addition, significant impacts are expected on ecosystem processes through the alteration of abiotic processes like stratification and its effect on primary production. However, besides negative impacts, OWFs might also offer opportunities for nature enhancement.
To support international discussion and decision-making around the spatial aspects of future upscaling of offshore wind, a quick scan on the effects from the large upscaling of offshore wind has been commissioned by Rijkswaterstaat as delegate of the North Sea Energy Coalition (NSEC). The spatial area of this study considers the North Sea and the Celtic Sea (OSPAR regions II and III respectively). The quick scan contains the following components:
A. Cumulative effects from OW developments on species and habitats
B. Cumulative effects from OW developments on ecosystem processes
C. Opportunities from OW developments (See Report C)
This report contains the outcomes of part B from this quick scan and provides a high-level overview of published research on the effects on ecosystem processes from long-term offshore wind energy developments in the North Sea and Celtic Sea (respectively OSPAR regions II and III). These are based on the existing and designated areas for offshore wind development in 2030 as well as an outlook towards the long-term (2030-2050) plans for offshore wind energy production. The other components are described in separate reports. It should be noted that the focus of this study is on the effects on ecosystem processes during the operational phase of OW, not the construction or decomissioning phase.
This part of the quick scan focuses on the effects from large-scale OW developments on ecosystem processes in the North Sea and Celtic Sea. For this purpose, the client and NSEC partners delivered approximately 20 literature studies on the effects from OW on various ecosystem processes. A synthesis of knowledge from these studies was conducted in order to provide an overview of the main conclusions and recommendations with regards to these potential ecosystem effects from OWF. To consolidate and deepen the insights from this synthesis, two interviews plus additional email conversations were conducted with a leading subject matter expert and scientist on this topic, Dr. L.A. (Luca) van Duren of Deltares (L. A. van Duren, personal communication, 17 April 2023 and 20-04-2023). It should be noted that this literature review and interviews might not include all available knowledge on this topic and is therefore not fully comprehensive and should be considered a ‘quick scan’.