OWFs and the Marine Environment

Transcription

1 Conference on Wind Power and Environmental Impact Stockholm Feb 2013 OWFs and the Marine Environment - lessons from the Danish Demonstration Project and elsewhere Jakob Tougaard

2 Number of turbines Installed Capacity AARHUS UNIVERSITY The Danish Demonstration Project Two large-scale OWFs (2002-3) Extensive monitoring of impact Largely UK 1 GW 100 DK Demonstration project 100 MW 10 MW Year Year

3 Idealized project cycle Results and data public domain Strategic Impact Assessment Designation of areas for OWFs Dissemination of results and data EIA for specific project Monitoring program

4 AARHUS UNIVERSITY Offshore wind farms in operation Actual effect studied in only 7 WFs: Construction/operation (3) Construction only (2) Sweden Operation only (3) 0 Country Ireland Finland Germany Sweden Belgium Netherlands 1000 Denmark 2000 United Kingdom Capacity (MW) 3000 Denmark North Sea Baltic Sea Ireland Turbines United Kingdom <10 Germany Netherlands >75 Belgium Kilometers 800 Source: 4Coffshore.com

5 OWFs are very large but open structures > 500 m > 100 m 5 Nysted, DK (DONG Energy)

6 Three Phases Construction Operation Decommisioning 6 Photos: Dong Energy, S. Tougaard

7 Construction activities Excavation/Deposition Large ships Side scan sonar Pile driving Fast boats Jack-up rigs Nothing unusual except for scale! Photos: Dong Energy, Vattenfall,Nordzeewind, KEM Offshore

8 Identified Issues Local changes to hydrography Introduction of hard substrates (foundations) Sediment spill (construction only) Habitat loss (underwater and on the surface) Electromagnetic fields Noise (underwater and in air) Collisions (in air only) Change in area use

9 Potentially affected organisms Plankton Benthos Epifauna Fish Diving birds Migrating birds Marine mammals Bats

10 Types of impact Substrate Suspended sediment Habitat loss Barrier Collisions Changes in hydrography Underwater noise Changes in use (fishery/shipping) Plankton Benthos Epifauna Fish Operation Construction and operation Birds Mammals

11 Key species: harbour porpoise Top predator Highly sensitive to underwater noise Methodological advantages Abundant (not Baltic proper) Highly vocal On annex 4 of the habitats directive The species I study

12 Possible effects on marine mammals Disturbances (Noise, reflexes, shadows etc.) Physical change to habitat Exclusion of fishery Exclusion Injury Loss of habitat Habitat gain Reduced bycatch? Net effect on population

13 Possible effects on birds Disturbances (Noise, reflexes, shadows etc.) Physical change to habitat Rotating turbines Exclusion Loss of habitat Habitat gain Collisions Net effect on population

14 Possible effects on bats Rotating turbines Collisions Net effect on population

15 Types of impact marine mammals Disturbances (Noise) Physical change to habitat Changes in use (fishery/shipping) injury Exclusion from Habitat Habitat loss Habitat gain Reduced disturbance and bycatch Net effect on population

16 Pile driving effects on porpoises Disturbances (Noise) Physical change to habitat Changes in use (fishery/shipping) Exclusion from habitat Habitat loss Habitat gain Reduced disturbance and bycatch Net effect on population Strong avoidance (>20 Km) Possible injury (TTS/PTS) Single piling largely unproblematic Cumulative effects substantial

17 Pile driving - seals Important seal breeding colony 4 km from wind farm Seals monitored by remotely operated video Negative effect of sheet piling Otherwise no effect

18 Mitigations Ramp-up procedure Use of deterring sound (seal scarer) Adresses only injury Bubble curtains Reduces radiated energy Alternative foundations

19 General effects of construction - porpoises Disturbances (Noise) Physical change to habitat Changes in use (fishery/shipping) 10% Horns Reef 1 Exclusion from habitat Habitat loss Habitat gain Reduced disturbance and bycatch 0% Net effect on population 1.0% Nysted Reduced abundance seen in 1 out of 3 wind farms studied 0% 2.0% Sprogø Likely noise from ships etc. 0% Baseline Constr.

20 Mean density (animals km -2 ) AARHUS UNIVERSITY Visual surveys - porpoises 2.5 Reference A Reference B 2.0 Reference C Impact area Baseline Construction Semi-Oper. Operation

21 Direct habitat loss Disturbances (Noise) Physical change to habitat Changes in use (fishery/shipping) Exclusion from habitat Habitat loss Habitat gain Reduced disturbance and bycatch Net effect on population Loss of sandy seabed Insignificant (<0.5% of OWF area) Weight Concrete ballast Boulders

22 Indirect Habitat Loss Avoidance Source: BSH 2010

23 PPM AARHUS UNIVERSITY Operation - porpoises 1.0% Egmond aan Zee Disturbances (Noise) Physical change to habitat Changes in use (fishery/shipping) 0% 10% Horns Reef 1 Exclusion from habitat Habitat loss Habitat gain Reduced disturbance and bycatch 0% Net effect on population 1.0% Nysted 0% 0.4% 0.3% Reference area Impact area Rødsand 2 2.0% Sprogø 0.2% 0.1% 0.0% baseline operation 0% Baseline Constr. Oper.1 Oper.2 Oper.3

24 Passive Acoustic Monitoring - porpoises Records echolocation sounds Long, continuous time series Monitoring in areas difficult to access Independent of weather Cost efficient

25 Nysted AARHUS UNIVERSITY

26 PPM AARHUS UNIVERSITY Operation - porpoises 1.0% Egmond aan Zee + Disturbances (Noise) Exclusion from habitat Habitat loss Physical change to habitat Habitat gain Changes in use (fishery/shipping) Reduced disturbance and bycatch 0% 10% Horns Reef 1 0 0% Net effect on population 1.0% (-) Nysted 0% 0.4% 0.3% 0.2% Reference area Impact area Sprogø Rødsand 2 2.0% % 0.0% baseline operation 0% Baseline Constr. Oper.1 Oper.2 Oper.3

27 Noise from operation Most likely disturbing factor Levels are low Deterrence likely low as well Fish could be different!

28 Frequency Frequency AARHUS UNIVERSITY Do seals use the wind farms? Disturbances (Noise) Physical change to habitat Changes in use (fishery/shipping) McConnell et al N Exclusion from habitat Habitat loss Habitat gain Reduced disturbance and bycatch Net effect on population 0 10 km seal: mean = m random: mean = m Harbour seals neither use, nor avoid turbines distance to nearest tower (m) distance to nearest tower (m)

29 PPM AARHUS UNIVERSITY Egmond aan Zee - porpoises Control N Wind Farm Control S Baseline Operation PPM (%) AT1 AT2 AT3 AT4 AT5 AT6 AT7 AT8 1.4% 1.2% 1.0% Reference area Impact area 0.8% 0.6% 0.4% 0.2% 0.0% baseline operation

30 Habitat gain Disturbances (Noise) Physical change to habitat Changes in use (fishery/shipping) Artificial reef on foundation Exclusion from habitat Habitat loss Habitat gain Reduced disturbance and bycatch Increased production: Increased diversity of fish Net effect on population Compensation for lost reefs in the North Sea?

31 Changes in use Disturbances (Noise) Physical change to habitat Changes in use (fishery/shipping) Exclusion from habitat Habitat loss Habitat gain Reduced disturbance and bycatch Net effect on population 1.0% 0% Egmond aan Zee Baseline Oper.1 Sheltering from trawlers and shipping Bycatch in gill-nets can go up or down

32 What does it all mean - Effect on population h Disturbances (Noise) Physical change to habitat Changes in use (fishery/shipping) Exclusion from habitat Habitat loss Habitat gain Reduced disturbance and bycatch Other factors Net effect on population

33 What is the limiting factor for porpoises? Predation Bycatch Contaminants Food Disturbance Climate change Disease/ parasites Net effect on population

34 What we usually measure Disturbance Exclusion from habitat Interruption of feeding Interruption of mating Interruption of nursing Reduced access to food Reduced energy uptake Can we conclude that: Habitat exclusion leads to reduced fitness? No habitat exclusion implies no effect? Reduced fitness (incr. mortality red. fecundity) This is the relevant measure of impact 34

35 Is impact on seals an issue? Phocine Distemper outbreak Phocine Distemper outbreak TSEG (2011)

36 Agent based model Nabe-Nielsen et al. (subm.)

37 Birds AARHUS UNIVERSITY Photo: Daníel Bergmann

38 Horns Rev, 26 March 2004 Common Scoter Legend ANTAL D Wind Turbines Depth Value Survey Track Lines m m D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D Kilometers Pedersen et al. (2005)

39 Habitat loss - divers Red-throated / Black-throated Diver Pedersen et al. (2005)

40 Habitat loss long-tailed duck Long-tailed Duck Pedersen et al. (2005)

41 Habitat loss common scoter Common Scoter Pedersen et al. (2005)

42 Habituation in common scoter? Pedersen et al. (2007)

43 Collisions radar tracks Desholm, M. (2003), J. Avian Biol. 34:

44 Avoidance Desholm & Kahlert (2005), Biology Letters 1:

45 Conclusions (at present) Epifauna Creation of artificial reefs Fish Diversity highly increased around scour protection Refuge from fishery? Marine Mammals Construction (piling) is an issue Operation likely neutral or positive NB: Baleen whales could be different! Birds In general small effects Very species and site specific!

46 Thank you for your attention Colleagues Jonas Teilmann, Rune Dietz, Jacob Carstensen, Mary S. Wisz, Susi Edren, Svend Tougaard, Henrik Skov, Peter Reijnders, Sophie Brasseur, Meike Scheidat, Bernie McConnell, Ib Krag Pedersen, Tony Fox, Mark Desholm, Johnny Kahlert, Nick Tregenza and numerous others Sponsors Danish Energy Agency, Vattenfall A/S, Dong Energy, Danish Forest and Nature Agency, Danish Research Councils