Effects of offshore pile driving on harbour porpoise abundance in the German Bight

262 Pages·2016·11.71 MB·English

Effects of offshore pile driving on
harbour porpoise abundance in the German Bight
Assessment of Noise Effects
Final Report
Miriam J. Brandt, Anne-Cécile Dragon, Ansgar Diederichs, Alexander Schubert,
Vladislav Kosarev, Georg Nehls
Veronika Wahl, Andreas Michalik, Alexander Braasch, Claus Hinz,
Christian Ketzer, Dieter Todeskino
Marco Gauger, Martin Laczny, Werner Piper
Husum, June 2016
Prepared for Offshore Forum Windenergie
Institut für Angewandte
IBL Umweltplanung GmbH Ökosystemforschung GmbH BioConsult SH GmbH & Co. KG
Bahnhofstraße 14a Alte Dorfstraße 11 Schobüller Str. 36
26122 Oldenburg 18184 Neu Broderstorf 25813 Husum
Tel. 0441 / 50 50 17-10 Tel. 038204 / 618-0 Tel. 04841 / 66 3 29-10
Fax. 0441 / 50 50 17-11 Fax 038204 / 618-10 Fax 04841 / 66 3 29-19
[email protected] [email protected] [email protected]
www.ibl-umweltplanung.de www.ifaoe.de www.bioconsult-sh.de
Funding partners:

1. DONG Energy Wind Power A/S, Kraftværksvej 53, DK-7000 Fredericia
2. EnBW Energie Baden-Württemberg AG, Durlacher Allee 93 in 76131 Karlsruhe
3. Iberdrola Renovables Offshore Deutschland GmbH, Charlottenstraße 63 in 10117 Berlin
4. Offshore Forum Windenergie GbR, Kaiser-Wilhelm-Straße 93 in 20355 Hamburg;
5. OWP Butendiek GmbH & Co. KG, Stephanitorsbollwerk 3 in 28217 Bremen
6. PNE WIND AG, Peter-Henlein-Straße 2 - 4 in 27472 Cuxhaven
7. RWE Innogy GmbH, Gildehofstraße 1 in 45127 Essen
8. STRABAG OW EVS GmbH, Reeperbahn 1 in 20359 Hamburg
9. TenneT Offshore GmbH, Bernecker Straße 70 in 95448 Bayreuth
10. Vattenfall Europe Windkraft GmbH, Überseering 12 in 22297 Hamburg
11. wpd offshore GmbH, Stephanitorsbollwerk 3 in 28217 Bremen

Scientific partners:

12. Ocean Breeze Energy GmbH & Co. KG, Flughafenallee 11 in 28199 Bremen
13. E.ON Climate and Renewables GmbH, Brüsseler Platz 1 in 45131 Essen
14. Global Tech I Offshore Wind GmbH, Am Sandtorkai 62, Dock 4 in 20457 Hamburg;
15. Horizont II Renewable GmbH, Köpenicker Straße 154 in 10997 Berlin
16. Nordsee Offshore MEG I GmbH, Humboldtstraße 30/32 in 70771 Leinfelden-
Echterdingen
17. Offshore Windpark RIFFGAT GmbH & Co. KG, Tirpitzstraße 39 in 26122 Oldenburg;
18. Stiftung Offshore Windenergie, Oldenburger Straße 65 in 26316 Varel
19. WindMW GmbH, Schleusenstraße 12 in 27568 Bremerhaven

Further scientific partners with special agreement:

20. Trianel Windkraftwerk Borkum GmbH & Co. KG, Krefelder Straße 203 in 52070 Aachen
IBL Umweltplanung Institut für Angewandte
BioConsult SH
GmbH Ökosystemforschung
GmbH & Co KG
Bahnhofstraße 14a GmbH
Schobüller Str. 36
26122 Oldenburg Schulterblatt 120
25813 Husum
Tel.: [phone] 20537 Hamburg Tel.: [phone]
www.ibl- Tel.: [phone]
www.bioconsult-sh.de
umweltplanung.de www.ifaö.de

Lead: BioConsult SH GmbH & Co KG Dr. Georg Nehls

Editing: Hourly POD-data chapter: BioConsult SH GmbH & Co KG Dr. Miriam J. Brandt
Dr. Anne-Cécile Dragon
Ansgar Diederichs
Alexander Schubert
Vladislav Kosarev

Daily POD-data & PCoD chapters: IBL Umweltplanung GmbH Veronika Wahl
Andreas Michalik
Dr. Alexander Braasch
Dr. Claus Hinz
Christian Ketzer
Dieter Todeskino

Aerial survey chapter: IfAÖ GmbH Marco Gauger
Martin Laczny
Werner Piper

Acknowledgments:
We thank Dr. Michael Bellmann and Siegfried Gündert from itap for providing sound measure-
ments and calculations. We are also grateful for statistical advice provided by Dr. Charles Paxton
from CREEM. Furthermore, we thank Prof. Dr. John Harwood for answering questions on the in-
terim PCoD model.

Assessment of Noise Effects on Porpoises

Contents
1 SUMMARY ........................................................................................................................... 1
2 INTRODUCTION AND AIMS OF THE PROJECT ...................................................................... 4
3 DESCRIPTION OF METADATA .............................................................................................. 7
3.1 Pile driving data ................................................................................................................... 8
3.2 Noise data.......................................................................................................................... 12
3.3 Environmental data ........................................................................................................... 17
4 HOURLY POD-DATA ........................................................................................................... 18
4.1 Introduction....................................................................................................................... 18
4.2 Methods ............................................................................................................................ 18
4.3 Results ............................................................................................................................... 27
4.4 Discussion (hourly POD data) ............................................................................................ 57
5 DAILY POD-DATA ............................................................................................................... 66
5.1 Introduction....................................................................................................................... 66
5.2 Methods ............................................................................................................................ 66
5.3 Results ............................................................................................................................... 80
5.4 Discussion (daily POD-data) .............................................................................................. 99
6 AERIAL SURVEY DATA ...................................................................................................... 103
6.1 Introduction..................................................................................................................... 103
6.2 Methods .......................................................................................................................... 104
6.3 Results ............................................................................................................................. 121
6.4 Discussion (Aerial survey data) ....................................................................................... 146
7 APPLYING THE INTERIM PCOD MODEL – AN ASSESSMENT ............................................ 150
7.1 Interim PCoD model - structure and requirements ........................................................ 150
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Assessment of Noise Effects on Porpoises

7.2 Evaluation/Sensitivity of the interim PCoD model using test data (to selected
parameters) ..................................................................................................................... 156
7.3 Interim PCoD model with specifications based on results from the present project ..... 162
7.4 Conclusion and suggestion .............................................................................................. 164
8 GENERAL DISCUSSION & CONCLUSIONS ......................................................................... 169
8.1 Short-term effects of offshore piling ............................................................................... 170
8.2 Comparability of POD- and aerial survey data ................................................................ 179
8.3 Larger-scale effects of offshore piling ............................................................................. 180
9 REFERENCES .................................................................................................................... 183
A. APPENDIX ........................................................................................................................ 191
A.1 Noise-data ....................................................................................................................... 191
A.2 Hourly POD-data .............................................................................................................. 192
A.3 Daily POD-data ................................................................................................................ 205
A.4 Interim PCoD-model - general structure ......................................................................... 210
A.6 Aerial Survey data predictors .......................................................................................... 214

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List of figures
Figure 3-1 Map of the study area depicting all eight wind farms that were built between 2009 and 2013 7
Figure 3-2 Pile driving periods for the eight wind farms ............................................................................. 8
Figure 3-3 Number of piling events per month from 2010 to 2013 .......................................................... 10
Figure 3-4 Boxplots showing median and quartiles of piling duration....................................................... 11
Figure 3-5 Boxplots showing median and quartiles of time between consecutive piling .......................... 11
Figure 3-6 Measured Noise Exposure Level exceeded during 5 % of time of a piling event ...................... 14
Figure 3-7 Measured and modelled Noise Exposure Level exceeded during 5 % of time ......................... 15
Figure 3-8 Boxplot of SEL (in dB) at 750 m distance from piling with and without noise mitigation ...... 16
05
Figure 4-1 POD-positions from which data are available for this study. .................................................... 19
Figure 4-2 Data availability at single stationary POD-positions ................................................................. 20
Figure 4-3 Data availability at the 20 POD-stations ................................................................................... 21
Figure 4-4 Output from Model G1 ............................................................................................................ 32
Figure 4-5 Error bars depicting mean and 95% confidence intervals of DPH............................................ 33
Figure 4-6 Output from Model G2 ............................................................................................................. 35
Figure 4-7 Error bars depicting mean and 95% confidence intervals of DPH............................................ 36
Figure 4-8 Error bars depicting mean and 95% confidence intervals of DPH............................................ 37
Figure 4-9 Error bars depicting mean and 95% confidence intervals of DPH............................................ 37
Figure 4-10 Error bars depicting mean and 95% confidence intervals of .................................................... 38
Figure 4-11 Outputs from model G3 with and without sound mitigation .................................................. 40
Figure 4-12 Output from Model G4 ............................................................................................................ 41
Figure 4-13 Effects of HRW (from -48h to +120h) and distance to piling (in km) on DPH .......................... 44
Figure 4-14 Error bars depicting mean and 95% confidence intervals of DPH............................................ 46
Figure 4-15 Outputs from Models P4 .......................................................................................................... 49
Figure 4-16 Outputs from Models P5 and G5............................................................................................. 52
Figure 4-17 Model output from models P6_BWII ....................................................................................... 54
Figure 4-18 Ooutput from model P7 ........................................................................................................... 55
Figure 4-19 Output from model G8 ............................................................................................................. 56
Figure 4-20 Output from model G9 ............................................................................................................. 57
Figure 5-1 Piling duration and its effect on acoustic harbour porpoise detection. ................................... 68
Figure 5-2 Relation of wind speed and number of noise clicks recorded per day to average water depth
.................................................................................................................................................. 70
Figure 5-3 Detection positive ten minutes per day in relation to the total number of clicks detected. .... 71
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Figure 5-4 Monthly averages of dp10m/day ............................................................................................. 73
Figure 5-5 Visualisation of accumulation datasets. .................................................................................... 77
Figure 5-6 Subarea classification of stationary POD positions. .................................................................. 78
Figure 5-7 Extremes of spatial autocorrelation with reference to Moran’s I. ............................................ 79
Figure 5-8 Spatial autocorrelation of baseline model residuals. ............................................................... 79
Figure 5-9 Subarea specific seasonal patterns of acoustic porpoise detections. ....................................... 81
Figure 5-10 Effects of noise, SSTA and subarea on acoustic porpoise detections ........................................ 82
Figure 5-11 Subarea-specific yearly trends of acoustic porpoise detection. ................................................ 83
Figure 5-12 Acoustic harbour porpoise detections pooled by year and subarea. ........................................ 84
Figure 5-13 No sign of a critical temperature dependent behaviour of PODs. ............................................ 85
Figure 5-14 Relative effect on porpoise detections of year and piling for each subarea. ............................ 87
Figure 5-15 Piling events and data availability per year and subarea. ......................................................... 88
Figure 5-16 Season related differences in the effect of pile driving on piling day and up to two days after.
................................................................................................................................................... 90
Figure 5-17 Difference among subareas in the effect of pile driving on piling day and up to two days after.
................................................................................................................................................... 92
Figure 5-18 Porpoise detections with respect to subarea and season. ........................................................ 93
Figure 5-19 Modelled relative porpoise detections on piling days with respect to subarea and season. ... 94
Figure 5-20 Effect of consecutive days with piling. ...................................................................................... 96
Figure 5-21 Piling events and data availability per wind farm project and consecutive piling days. ........... 97
Figure 5-22 Piling events and data availability per wind farm project and piling events per day. ............... 98
Figure 5-23 Effects of up to two piling events per day. ............................................................................... 99
Figure 6-1 Location of the 13 survey areas in the German Bight between 2009 and 2013. .................... 104
Figure 6-2 Histogram showing the frequencies of density estimates from the grid cells of 6 by 6 km .... 107
Figure 6-3 The grid size of 6 by 6 km resulted in varying numbers of transect lines per grid cell ........... 107
Figure 6-4 Relative monthly coverage of survey flights in calendar years 2009 to 2013. ........................ 108
Figure 6-5 Spatial coverage and number of surveys conducted in the German Bight ............................. 110
Figure 6-6 Division into 3 subareas according to temporal coverage and overlapping surveys ............... 111
Figure 6-7 The distance (km) between piling events and cells is multi-modal ........................................ 115
Figure 6-8 Pile driving periods for wind farm projects constructed during the 2009-2013 ..................... 116
Figure 6-9 Distribution of distances between piling events and cells in kilometres................................. 117
Figure 6-10 Data reduction by excluding all grid cells from the dataset .................................................... 117
Figure 6-11 Monthly mean density estimates of harbour porpoise per .................................................... 121
Figure 6-12 Box-Whisker plots showing seasonal density estimates of flight surveys .............................. 122
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Assessment of Noise Effects on Porpoises

Figure 6-13 Density distribution of harbour porpoises in the German Bight ............................................. 124
Figure 6-14 Seasonal density distribution of harbour porpoises ............................................................... 125
Figure 6-15 Distribution patterns of harbour porpoises from model A1, A2 and A3 ................................. 128
Figure 6-16 Seasonality of porpoise densities – smooth splines of day of year per year of model A1, A2
and A3 ..................................................................................................................................... 129
Figure 6-17 Comparison of distribution data from the entire, the unaffected and affected datasets ...... 131
Figure 6-18 Model A1- partial effect of variable “day and distance” ......................................................... 131
Figure 6-19 Annually changing distribution patterns of harbour porpoises in the subarea "German Bight
NW" model A4 and A5 spring and summer pooled. ............................................................... 133
Figure 6-20 Annually changing distribution patterns of harbour porpoises in the subarea "North of
Borkum" model A6 .................................................................................................................. 134
Figure 6-21 Annually changing distribution patterns of harbour porpoises in the subarea "West of Sylt"
model A7 ................................................................................................................................. 135
Figure 6-22 Inter-annual trend in porpoise densities comparison of model A5 – A7 ................................ 137
Figure 6-23 GAM-plot illustrating the partial effect of piling_dist ............................................................ 138
Figure 6-24 Barplot of harbour porpoise densities grouped by “day and distance” ................................. 139
Figure 6-25 Spatio-temporal effect of piling activities on porpoise densities of model ST1 ..................... 142
Figure 6-26 GAM-plot illustration effect of cumulative piling events ....................................................... 144
Figure 6-27 Comparison of average seasonal acoustic porpoise detections ............................................. 145
Figure 7-1 The conceptual Population Consequences of Acoustic Disturbance (PCAD) model ............... 151
Figure 7-2 The interim Population Consequences of Disturbance (PCoD) model.................................... 152
Figure 7-3 A hypothetical relationship between the number of days of disturbance experienced by an
individual and its survival ........................................................................................................ 153
Figure 7-4 Median population decline depending on number of individuals disturbed per piling day ... 156
Figure 7-5 Days of disturbance required to affect the survival/fertility of mature, dependent or juvenile
harbour porpoises by disturbance in the interim PCoD model .............................................. 157
Figure 7-6 Median population decline depending on number of individuals experiencing PTS .............. 157
Figure 7-7 Effect of vulnerable subpopulations on median population decline depending on the number
of individuals per day experiencing disturbance .................................................................... 158
Figure 7-8 Median population decline depending on the time of piling.................................................. 160
Figure 7-9 Median population decline 1-12 years after construction...................................................... 162
Figure 7-10 Median population decline at different years modelled by the interim PCoD for the present
project ..................................................................................................................................... 163
Figure A-1 Comparison of transmission models and measured Noise Exposure Levels. ......................... 191
Figure A-2 Error bars depicting mean and 95% confidence intervals of DPH at the different hours relative
to piling ................................................................................................................................... 192
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Assessment of Noise Effects on Porpoises

Figure A-3 Error bars depicting mean and 95% confidence intervals of DPH at the different hours relative
to piling .................................................................................................................................... 193
Figure A-4 Error bars depicting mean and 95% confidence intervals of DPH at the different hours relative
to piling .................................................................................................................................... 193
Figure A-5 Error bars depicting mean and 95% confidence intervals of DPH at the different hours relative
to piling .................................................................................................................................... 196
Figure A-6 Error bars depicting mean and 95% confidence intervals of DPH at the different hours relative
to piling .................................................................................................................................... 196
Figure A-7 Error bars depicting mean and 95% confidence intervals of DPH at the different hours relative
to piling .................................................................................................................................... 196
Figure A-8 Error bars depicting mean and 95% confidence intervals of DPH at the different hours relative
to piling .................................................................................................................................... 197
Figure A-9 mean and 95% confidence intervals of DPH at distances below 5 km from MSO ................... 197
Figure A-10 Error bars depicting mean and 95% confidence intervals of DPH at the different hours relative
to piling .................................................................................................................................... 198
Figure A-11 mean and 95% confidence intervals of DPH at distances below 5 km from RG ...................... 198
Figure A-12 Output from Models P2 ........................................................................................................... 200
Figure A-13 Output from Model G6 ............................................................................................................ 201
Figure A-14 Output from models P6 .......................................................................................................... 201
Figure A-15 Model outputs from model G2 ................................................................................................ 204
Figure A-16 Relationship between water depth and number of all click .................................................... 205
Figure A-17 The degree of support among experts for different relationships linking days of disturbance to
fertility, calf survival and juvenile survival ............................................................................... 210
Figure A-18 Effect of including vulnerable subpopulations on median population decline ....................... 211
Figure A-19 Effect of the usage of vulnerable subpopulations on median population decline for two
construction sites..................................................................................................................... 211
Figure A-20 Median population decline depending on seasonal differences in affected individuals......... 212
Figure A-21 Median population decline depending on the concurrent activity of two construction sites 212
Figure A-22 Median population decline depending on continuous construction or construction with breaks
................................................................................................................................................. 213
Figure A-23 Seasonal mean density estimates for porpoises in the vicinity of “alpha ventus” ................. 215
Figure A-24 Seasonal mean density estimates for porpoises in the vicinity of “BARD” ............................ 216
Figure A-25 Seasonal mean density estimates for porpoises in the vicinity of “BWII” .............................. 217
Figure A-26 Seasonal mean density estimates for harbour porpoises in the vicinity of the wind farm DT 218
Figure A-27 Seasonal mean density estimates for porpoises in the vicinity of “GTI” ................................. 219
Figure A-28 Seasonal mean density estimates for porpoises in the vicinity of “MSO” .............................. 220
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