2018 MEMOIRS on the Marine Environment ENVIRONMENTAL IMPACTS SERIES OF OFFSHORE WIND FARMS IN THE BELGIAN PART OF THE NORTH SEA Edited by ASSESSING AND MANAGING Steven Degraer Robin Brabant EFFECT SPHERES OF INFLUENCE Bob Rumes Laurence Vigin SCIENTIFIC REPORTS SCIENTIFIC REPORTS MEMOIRS on the Marine Environment 2018 ENVIRONMENTAL IMPACTS OF OFFSHORE WIND FARMS IN THE BELGIAN PART OF THE NORTH SEA ASSESSING AND MANAGING EFFECT SPHERES OF INFLUENCE Edited by Steven Degraer Robin Brabant Bob Rumes Laurence Vigin Published by: Royal Belgian Institute of Natural Sciences (RBINS) Operational Directorate Natural Environment (OD Nature) Aquatic and Terrestrial Ecology (ATECO) Marine Ecology and Management (MARECO) Vautierstraat 29, 1000 Brussels, Belgium www.naturalsciences.be odnature.naturalsciences.be Revision and layout: Charlotte Gérard (RBINS) Cover illustration: Installation of wind turbine foundations in the Nobelwind wind farm © Bob Rumes (RBINS) Printed by: Peeters (Belgium) Legal deposit: D/2018/0339/5 ISBN: 978-9-0732-4242-5 Reproduction of parts of the report is possible, except for commercial purposes, provided the source is clearly acknowledged. This report should be cited as: Degraer, S., Brabant, R., Rumes, B. & Vigin, L. (eds). 2018. Environmental Impacts of Offshore Wind Farms in the Belgian Part of the North Sea: Assessing and Managing Effect Spheres of Influence. Brussels: Royal Belgian Institute of Natural Sciences, OD Natural Environment, Marine Ecology and Management, 136 p. Edited by: Steven Degraer ([email protected]) Robin Brabant ([email protected]) Bob Rumes ([email protected]) Laurence Vigin ([email protected]) This publication has been peer-reviewed Acknowledgements This research is financed by C-Power nv, Parkwind nv, Rentel nv and Norther nv, in fulfilment of the environmental monitoring programme of their environmental permits. The authors want to thank C-Power, Parkwind, Rentel and Norther for their willing cooperation. This monitoring benefited from the use of the research vessel Belgica (ship time RV Belgica was provided by BELSPO and RBINS – OD Nature), the research vessel Simon Stevin (operated by the Flanders Marine Institute) and the observation aircraft of RBINS for collecting the necessary data at sea. Table of contents Preface……………………………………………………………………………………………………..5 Executive summary……………………………………………………………………………………….7 Chapter 1. Offshore renewable energy development in the Belgian Part of the North Sea………. 13 1. Offshore renewable energy in Belgium……………………………………………………….13 2. Beyond 2020: the marine spatial plan 2020-2026…………………………………………….16 3. Grid reinforcement and the Modular Offshore Grid (MOG)…………………………………16 Chapter 2. On the effectiveness of a single big bubble curtain as mitigation measure for offshore wind farm piling sound in Belgian waters……………………………………………………………..19 1. Introduction……………………………………………………………………………………19 2. Material and methods………………………………………………………………………….20 2.1. Research strategy…………………………………………………………………………….20 2.2. Construction activities……………………………………………………………………….20 2.3. Underwater sound measurement equipment………………………………………………...20 2.4. Underwater sound measurements and post-treatment……………………………………….21 3. Results…………………………………………………………………………………………22 4. Discussion……………………………………………………………………………………..24 5. Conclusion……………………………………………………………………………………..25 Chapter 3. Soft sediment epibenthos and fish monitoring at the Belgian offshore wind farm area: situation 6 and 7 years after construction……………………………………………………………...27 1. Introduction……………………………………………………………………………………27 2. Material and methods………………………………………………………………………….28 2.1. Sampling……………………………………………………………………………..28 2.2. Data used and statistical analyses………………………………………………………30 3. Results…………………………………………………………………………………………30 3.1. Epibenthos……………………………………………………………………………30 3.2. Demersal and bentho-pelagic fish……………………………………………………...32 4. Discussion and conclusions……………………………………………………………………34 Chapter 4. Defining reference condition (T0) for the soft sediment epibenthos and demersal-benthopelagic fish in the Norther and Rentel concession zones………………………………………………………39 1. Introduction……………………………………………………………………………………39 2. Material and methods………………………………………………………………………….40 2.1. Sampling……………………………………………………………………………..40 2.2. Data used and statistical analyses………………………………………………………40 3. Results…………………………………………………………………………………………43 3.1. Community analysis of the wider offshore wind farm area…………………………………43 3.2. T0 situation in Norther and Rentel…………………………………………………………...47 4. Discussion and conclusions…………………………………………………………………...52 Chapter 5. Effects of wind turbine foundations on surrounding macrobenthic communities…… 57 1. Introduction……………………………………………………………………………………57 2. Material and methods………………………………………………………………………….59 2.1. Study area ……………………………………………………………………………59 2.2. Sample design, collection and treatment………………………………………………..59 2.3. Data Analysis…………………………………………………………………………62 3. Results………………………………………………………………………………………….63 3.1. Effects of turbine presence…………………………………………………………….63 3.2. Baseline analysis at Norther…………………………………………………………...66 4. Discussion……………………………………………………………………………………...69 4.1. Effects turbine presence on soft sediment macrobenthic communities…………………...69 4.2. Baseline analysis………………………………………………………………………72 5. Conclusion and future perspectives……………………………………………………………73 Chapter 6. A closer look at the fish fauna of artificial hard substrata of offshore renewables in Belgian waters……………………………………………………………………………………………79 1. Introduction……………………………………………………………………………………79 2. Material and methods………………………………………………………………………….80 2.1. Study site……………………………………………………………………………………80 2.2. Species list and categorisation……………………………………………………………….80 3. Results………………………………………………………………………………………….81 3.1. Species richness……………………………………………………………………………..81 4. Discussion……………………………………………………………………………………...81 4.1. Remarkable species…………………………………………………………………………..81 4.2. Fish diversity at hard substrata of offshore renewables in Belgium and beyond ………….84 5. Conclusions……………………………………………………………………………………86 Chapter 7. Lesser black-backed gull distribution in and around the Thornton Bank offshore wind farm using gps logger data……………………………………………………………………...91 1. Introduction………………………………………………………………………………………91 2. Material and methods………………………………………………………………………….92 2.1. Overall data selection………………………………………………………………………...92 2.2. Data exploration……………………………………………………………………………...94 2.3. Modelling exercises………………………………………………………………………….95 2.4. Statistics……………………………………………………………………………………...97 3. Results…………………………………………………………………………………………97 3.1. Data exploration……………………………………………………………………………...97 3.2. Modelling exercises………………………………………………………………………...103 4. Discussion……………………………………………………………………………………108 Chapter 8. Modelling the impact of pile driving on porpoise populations in the Belgian Part of the North Sea………………………………………………………………………………………………..117 1. Introduction…………………………………………………………………………………..117 2. Material and methods…………………………………………………………………………118 2.1. Study area…………………………………………………………………………………..118 2.2. Legal framework……………………………………………………………………………119 2.3. interim Population Consequences of Disturbance model (iPCOD model)………………..121 3. Results………………………………………………………………………………………..124 4. Discussion……………………………………………………………………………………125 4.1. Effect of a seasonal pile driving restriction………………………………………………..125 4.2. Effect of noise mitigation…………………………………………………………………..125 4.3. Effect of simultaneous construction………………………………………………………..125 4.4. Effect of time schedule and adverse weather………………………………………………126 4.5. Some words of caution……………………………………………………………………...126 Chapter 9. First ever detections of bats made by an acoustic recorder installed on the nacelle of offshore wind turbines in the Norh Sea………………………………………………...………….....129 1. Introduction…………………………………………………………………………………..129 2. Material and methods…………………………………………………………………………130 3. Results………………………………………………………………………………………..130 4. Discussion……………………………………………………………………………………132 PREFACE The European Directive 2001/77/EC, on the permit imposes a monitoring programme to promotion of electricity produced from re- assess the effects of the project onto the ma- newable energy sources in the internal elec- rine environment. tricity market, imposes a target figure for the Within the monitoring programme, the contribution of the production of electricity Royal Belgian Institute of Natural Sciences from renewable energy sources upon each and its partners assess the extent of the an- Member State. For Belgium, this target fig- ticipated impacts onto the marine ecosystem ure is 13% of the total energy consumption, and aim at revealing the processes behind which must be achieved by 2020. Offshore these impacts. The first objective is basically wind farms in the Belgian part of the North tackled through the baseline monitoring, fo- Sea are expected to make an important con- cusing on the a posteriori, resultant impact tribution (ca. 43%, assuming 2000 MW in- quantification, while the second monitoring stalled capacity by 2020) to achieve that objective is covered by the targeted or pro- goal. cess monitoring, focusing on the cause-ef- Within the BPNS, a zone of 238 km² fect relationships of a priori selected im- is reserved for the production of electrici- pacts. As such, the baseline monitoring deals ty from water, currents or wind. Four wind with observing rather than understanding farms are already operational. With five impacts and hence leads to area-specific