Barrow Offshore Wind Farm Post Construction Monitoring Report

First Annual Report

15 January 2008

This Post Construction Monitoring Report has been prepared by Barrow Offshore Wind Ltd. as part of the environmental monitoring of Barrow Offshore Wind Farm. This report describes the first year of post-construction environmental monitoring in 2006-2007 after construction of the wind farm. The wind farm became operational in July 2006. The report is prepared to comply with the FEPA licence conditions. Technical surveys and studies are the basis of this Post Construction Monitoring Report. Full unedited copies of the environmental studies and findings can be found in the attached Appendi- ces. They are available on CD only and are attached to this report. Requests for additional copies of this report should be made to: Barrow Offshore Wind Ltd. c/o DONG Energy AC Meyers Vænge 9 DK-2450 Copenhagen SW Denmark Att. Trine H. Sørensen The report and appendices may also be downloaded from Barrow Offshore Wind Ltd.’s website: www.bowind.co.uk. No part of this publication may be reproduced without written permission from Barrow Offshore Wind Ltd. This report has been written by NIRAS Consulting Engineers and Planners A/S, based on reports and surveys produced by a wide team of consultants.

18/12-07 18/12-07 19/12-07 20/12-07 DATE ÆO. BHH HHK KURJE TRIHS NAME DATE ÆO. NAME REV. DESCRIPTION PREPARED CHECKED REVIEWED APPROVED

FLS-034378

DOC. NO.

POST CONSTRUCTION MONITORING REPORT i

TABLE OF CONTENTS

1. EXECUTIVE SUMMARY ...... 3

2. INTRODUCTION...... 5

3. ENVIRONMENTAL MONITORING SPECIFICATIONS...... 7

4. RESULTS, OFFSHORE MONITORING ...... 10 4.1 Fisheries ...... 10 4.1.1 Conditions ...... 10 4.1.2 Monitoring Methods...... 10 4.1.3 Results and conclusions...... 11 4.2 Benthic and Sediment Contaminant Survey ...... 16 4.2.1 Conditions ...... 16 4.2.2 Monitoring Methods...... 16 4.2.3 Results and Conclusions...... 18 4.3 Operational Underwater Noise ...... 21 4.3.1 Conditions ...... 21 4.3.2 Monitoring Methods...... 21 4.3.3 Results and Conclusions...... 22 4.4 Oceanography ...... 24 4.4.1 Conditions ...... 24 4.4.2 Monitoring Methods...... 24 4.4.3 Results and Conclusions...... 25 4.5 Bathymetry, Seabed Morphology and Scour ...... 26 4.5.1 Conditions ...... 26 4.5.2 Monitoring Methods...... 26 4.5.3 Results and Conclusions...... 26 4.6 Side Scan Sonar Survey and Archaeology...... 30 4.6.1 Conditions ...... 30 4.6.2 Monitoring Methods...... 31 4.6.3 Results and Conclusions...... 31 4.7 Birds ...... 37 4.7.1 Conditions ...... 37 4.7.2 Monitoring methods...... 37 4.7.3 Objective 1 ...... 41 4.7.4 Objective 2 ...... 41 4.7.5 Objective 3 ...... 45 4.7.6 Objective 4 ...... 55

5. CONCLUSIONS...... 56

6. REFERENCES...... 57

APPENDICES: APPENDIX 1: LICENCE REFERENCE 31744/07/1 – JULY 2007 APPENDIX 2: LICENCE REFERENCE 33069/07/1 – APRIL 2007 APPENDIX 3: MONITORING SPECIFICATIONS, SUBMITTED TO DEFRA IN OCTOBER 2005 APPENDIX 4: TECHNICAL MONITORING REPORTS

ii POST CONSTRUCTION MONITORING REPORT

1. EXECUTIVE SUMMARY

Barrow Offshore Wind Farm is the Environmental Impact Assess- with Amphiura preferring a finer located in the eastern Irish Sea ment. At the post construction sediment than Ophiura. near Barrow-in-Furness. The surveys no basking sharks were There are significant correlations transmission cable runs into More- detected. Concerning Thornback between the concentrations of a cambe Bay where it is connected to ray, 20 and 40 individuals were number of the metals, but not be- the National Grid transformer sta- collected at the surveys in Decem- tween metals and the grain sizes or tion in Heysham. ber 2006 and March 2007, respec- TOC. An analysis of the physical tively. They were detected both at The construction of Barrow Off- and chemical parameters and the the control site and within the wind shore Wind Farm took place be- communities present show that farm area. tween March 2005 and July 2006. grain size and TOC influence the The wind farm became operational Benthic and Sediment Contami- communities present, but no other in July 2006. nants Surveys: The grain sizes environmental variables have a across both the windfarm site and significant influence on the com- This document describes the envi- reference sites have generally munities. ronmental monitoring undertaken increased between 2004 and 2007. during the post construction phase Operational Underwater Noise: The Due to relatively consistent in 2006–2007. The environmental survey results indicate that there is changes taking place across the monitoring reported in this docu- a marginal increase in very low whole survey area, and that some ment should be seen as a con- frequency noise around individual of these changes took place, be- tinuation of the pre-construction wind turbines. This increase is fore construction of the windfarm and construction monitoring. Post- detectable to a range of approxi- began, it would appear that they construction monitoring activities mately 600m. The results from are natural fluctuations and proba- are made for a period of three measurements taken at ranges of 5 bly influenced by the general sedi- years after construction and will be m from an operational wind turbine ment movement patterns in the reported annually to the licensing indicate that the underwater noise Irish Sea. TOC levels have gener- authority, as described in the FEPA is unlikely to cause a behavioural ally decreased throughout the pe- licence. This is the first of three (avoidance) response in marine riod 2002 – 2007 across the survey post-construction monitoring re- fish and marine mammals in the area, again probably with little ports. region. influence from the construction or The environmental monitoring did operation of the windfarm. Oceanography: In all cases wakes not register major or unforeseen could be traced out to a distance of There have been changes in the environmental impacts during the at least 6–10 diameters distance benthic communities present first year of operation. The follow- downstream of each monopile (30– across the windfarm and its refer- ing paragraphs summarise the 50 m) and often a good deal fur- ence sites between the pre- and primary results from the monitoring ther, in the order of 100–200 m. post-construction surveys. Similar- programme. Bubble clouds entrained in the ity analysis shows that the sites wakes forming behind turbine mo- Fishery: Catches from inside the from 2004 as a group are more nopiles are traceable over even wind farm were compared to exter- similar to themselves than they are longer distances, as far as 200 m nal control sites. No significant to any of the sites sampled in and possibly further, although there differences were obtained between 2007. The main differences in is no evidence to suggest whether the two sites. The most abundant similarity between the groups are there is any flow structure associ- commercial species caught by otter probably the high numbers of ated with them or whether they trawl and beam trawl was dab and Ophiura present in the post- simply represent surface slicks. shrimp, respectively. Thornback ray construction survey and the more From the flow modelling under- and basking shark are electro sen- frequent occurrence of Nephtys taken prior to construction, it was sitive and thus of special interest. and high numbers of Amphiura in suggested that due to the separa- Both species have been observed the pre-construction survey. This tion of 500 m between each mono- in the vicinity of the Barrow site result reflects the recorded pile, they could be considered as during the surveys undertaken for changes in sediment grain size, independent in respect of the im-

POST CONSTRUCTION MONITORING REPORT 3

pact on the currents. On the basis For the cable route surveys it Goose passage. The aerial surveys of the wake surveys, it would ap- should be noted that the position of in the first year of post construction pear that this may still be the case the cable route centre line was monitoring showed a very similar since no obvious structures were changed between the pre- pattern, to surveys before and visible in the velocity records ex- construction and construction during construction, in the abun- tending beyond 300 m from the stages. dance and distribution of birds in nearest pile. the vicinity of Barrow Offshore An archaeological assessment was Wind Farm. The results indicate Bathymetry, Seabed Morphology made of the side scan sonar data. that the establishment of Barrow and Scour: With the exception of Only two new sites of high ar- Offshore Wind Farm did not lead to the localised areas of scour around chaeological potential have been significant changes in the occur- many of the individual turbines, identified, both of which are located rence and distribution of Common seabed levels across the whole on the cable route. These sites are Scoter, divers or other wildfowl in area are very similar to those sur- situated in areas of complex geol- the vicinity of the windfarm. veyed during the two previous ogy and may have natural origin. surveys. Scour surveys were made The exclusion zones defined in The bird surveys before, during and around 9 turbines in November earlier studies were re-identified the first year after construction of 2006 and April 2007, respectively. and have shown to be effective in the windfarm have not found bird Scours were detected around 7 protecting sites of archaeological populations of conservation con- turbines. The depths of the scours interest. No sites of high archaeo- cern significantly using the site. No were between 1 and 6 meters. In logical interest were identified collisions have been observed general, by time, the scours ex- within the navigation route area or during any of the surveys. panded horizontally, but were par- outside the exclusion zones within The findings from the Walney Is- tially infilled by natural sedimenta- the wind farm area. land study indicate that the Barrow tion processes. Faint remnants of Ornithology: In the beginning of Offshore Wind Farm do not consti- the inter-turbine cable installation 2007 a detailed post construction tute a barrier that prevents were seen around many of the bird monitoring programme was Whooper Swan or Pink-footed turbines. agreed with Natural England. Aerial Goose from passing or moving Side Scan Sonar Surveys and surveys as well as boat surveys through the site. Archaeology: Side Scan Sonar form part of the monitoring pro- Surveys were undertaken within gram. In addition, a shore based the wind farm area and along the survey from Walney Island was associated cable and navigation performed in 2007 to study routes. Whooper Swan or Pink-footed

4 POST CONSTRUCTION MONITORING REPORT

2. INTRODUCTION

The construction of Barrow Off- post-construction and will be re- cence conditions for the post con- shore Wind Farm began in March ported annually for three years to struction period: Fish, benthos, 2005, and the wind farm became the licensing authority according to operational underwater noise, operational in July 2006. The envi- the supplementary condition 9.1 of oceanography, seabed morphology ronmental post construction moni- the FEPA licence (Appendix 1). (scours etc.) and bathymetry, side toring was initiated on 1 July 2006. scan sonar surveys, including ar- As a part of the construction moni- chaeology, and ornithology. The wind farm is located in the toring a survey to monitor cable eastern Irish Sea near Barrow-in- burial was undertaken in autumn Concerning electromagnetic fields Furness. The transmission cable 2006. The survey was followed up (EMF), Barrow Offshore Wind Ltd. runs into Morecambe Bay where it by work to secure the protection has agreed that measurements will is connected to the National Grid and burial of exposed or vulnerable be undertaken at the site in spring transformer station in Heysham offshore transmission cable sec- 2008 as a part of the research (Figure 2.1). tions. This work was undertaken programme carried out by COW- from 5 May until 7 May 2007, and RIE (Collaborative Offshore Wind This document describes the envi- Centre for Environment, Fisheries farm research into the Environ- ronmental monitoring undertaken & Aquaculture Science (CEFAS) ment). A summary of these results during 2006–2007 to comply with and Marine and Fisheries Agency will be included in the second post the conditions of the Food and (MFA) have been informed about construction monitoring report Environmental Protection Act the progress of the cable protection (November 2008). (FEPA) 1985 (as amended), li- work. cence reference 31744/07/1 (Ap- Furthermore, the last of the pendix 1), latest licence is issued to The structure of this post construc- planned post construction fishery Barrow Offshore Wind Limited, July tion monitoring report is divided into surveys was undertaken in October 2007. two main sections. The first section 2007. This report has not been (chapter 3) provides an overview of finalised yet and therefore it has Furthermore Barrow Offshore Wind the environmental monitoring pro- been concluded that the result of Ltd. has received an additional gramme agreed with the authori- the last survey as well as the FEPA licence (33069/07/1). The ties. The second section (chapter analysis of the pre-construction and additional FEPA licence has been 4) describes the offshore environ- post-construction surveys will be required for cable protection work mental monitoring. presented in the second post- on the offshore transmission cable construction monitoring report in route. The licence was issued in The presentation of the monitoring November 2008. This has been April 2007 and is enclosed in Ap- results follows the same structure agreed with the Licence Authority. pendix 2. for each theme whenever possible. The presentation includes the con- The post construction environ- ditions based on the licences and mental monitoring reported in this subsequent agreements with au- document should be seen in con- thorities, the monitoring methods, tinuation of the environmental im- results and conclusions. pact statement, the preconstruction monitoring and the construction This report covers the environ- monitoring report /ref. 9, 10 and mental monitoring related to rele- 11/. Monitoring activities continue vant themes according to the li-

POST CONSTRUCTION MONITORING REPORT 5

Figure 2.1. Location of Barrow Offshore Wind Farm and export cable route to Heysham /ref. 11/.

6 POST CONSTRUCTION MONITORING REPORT

3. ENVIRONMENTAL MONITORING SPECIFICATIONS

This section provides an overview Throughout chapter 4 of this docu- Some changes in the monitoring of the environmental monitoring ment, the agreed specifications for programme have been made ac- programme agreed with the au- the different monitoring types recording to the planned schedule for thorities. quired during the construction the studies: phase are presented where rele- The licence to construct and oper- Ornithology: The boat surveys in vant. For summary purposes, Fig- ate the Barrow Offshore Wind Farm 2007 have been postponed for one ure 3.1 presents the schedule of contained a number of conditions, year. That means the three year surveys that were planned to com- many of which were environmental boat survey programme will run ply with the licence consent condi- monitoring requirements. Since the from 2008-2010 instead of 2007- tions. Table 3.1 lists the licence licence was granted, the specific 2009. The contract with the boat conditions, together with the timing monitoring activities have been surveyors has been cancelled and and any further notes. discussed and agreed continuously the work will be tendered in ad- with the authorities. The most re- The environmental monitoring vance of the first survey in May cent adjustments to the monitoring during the first year of operation of 2008. Natural England and Marine specification were contained within Barrow Offshore Wind Farm (post and Fisheries Agency have ac- the document submitted to DEFRA construction monitoring) include cepted the changed survey pro- in October 2005 (Appendix 3). A fish, benthos, operational underwa- gramme. revised programme for bird moni- ter noise, oceanography, seabed Epifauna monopile survey: The toring has been forwarded to Natu- morphology (scours etc.) and studies will be undertaken in May ral England by Barrow Offshore bathymetry, side scan sonar sur- 2008. The second post construction Wind Ltd. in February 2007, and veys, including archaeology, and monitoring report (November 2008) this has been approved by Natural ornithology. Where possible, com- will encompass these results. Natu- England in March 2007. The bird parisons between construction ral England and Marine and Fisher- monitoring programme will be pre- monitoring and post construction ies Agency have accepted the sented in details in chapter 4.7. monitoring are drawn. changed survey programme.

POST CONSTRUCTION MONITORING REPORT 7

Study Licence Pre- During Post- Notes Condition construc construc- construction No. (FEPA*) tion. tion. Com- – 1st year of Com- pleted operation. pleted Planned or completed Suspended FEPA 9.4, An alternative approach was agreed with Solids Annex 1 Licence Authority. SSC data was collected 3 during construction and was reported in the Construction Monitoring Report (November 2006) Seabed Con- FEPA 9.4, 3 3 taminants Annex 1 Archaeology FEPA Supp. For the cable route surveys it should be Cond 9.22 noted that the position of the cable route centre line was changed between the pre- construction and construction stages. 3 3 3 Therefore, localised areas of the 2005 survey may not be present, due to deviations between the proposed and as-laid cable routes. Benthos FEPA 9.4, 3 3 Annex 1 Epi-fauna, FEPA 9.4, Survey to be undertaken in May 2008. monopiles Annex 1 Results will be included in the second post- 3 construction monitoring report (November 2008). Fisheries FEPA 9.6, 3 3 Annex 1 Oceanography FEPA 9.4, 3 Annex 1 Validation of FEPA, An- numeric mod- nex 1 3 elling Noise and FEPA 9.5, Even though no noise monitoring during Vibration Annex 1 construction was required by the licence 3 3 conditions, the COWRIE research programme collected data from the installation of monopiles. Ornithology FEPA 9.8, Survey programme post-construction (boat 9.9, Annex 2 based) has been postponed to 2008. The 3 3 3 change has been accepted by Natural England. Seabed Mor- FEPA Supp. phology and Conds. 3 Scour 9.17-9.21 Pre- and post FEPA construction Supp. 3 3 bathymetry Conds. 9.24 Monitoring Marine mam- FEPA Supp. 3 mals Cond. 9.10 Electro- FEPA 9.4, Post-construction monitoring is made as a Magnetic Annex 1 part of the research programme carried out Fields 3 by COWRIE in spring 2008. Results will be included in the second post-construction monitoring report (November 2008). * FEPA: Food and Environment Protection Act. Table 3.1. Outline survey schedule for proposed studies.

8 POST CONSTRUCTION MONITORING REPORT

Task name 200 2007 2008 2009 2010 6

y y y y y y y y r g r g r g r g p p p p p p p p Se Se Se Ma Ma Ma Au Au Au Jan Feb Mar A Ma Jun Jul Au Se Oct Nov Dec Jan Feb Mar A Nov Dec Jan Feb Mar A Oct Nov Dec Jan Feb Mar A Oct Oct Nov Dec Jun Jul Jun Jul Jun Jul

Benthos and sediment contaminants

Epifaunal Monopile survey

Fisheries

Oceanography (ADCP)

Operational Underwater Noise & Vibrations

Ornithology b (boat based survey)

Ornithology (aerial surveys)

Ornithology Walney Island survey

Scour and cable survey

EMF (Intertidal)

Archaeological assessment of clearance data

Post construction bathymetry survey Figure 3.1. Schedule of environmental post construction monitoring for the Barrow Offshore Wind Farm

POST CONSTRUCTION MONITORING REPORT 9

4. RESULTS, OFFSHORE MONITORING

This section provides the results commencement of the monitor- ber 2007. The results from this from the offshore monitoring ing work. survey will be reported in the during the first year of operation second post construction moni- The monitoring requirements of Barrow Offshore Wind Farm toring report with a comparative are described in appendix 1 of (post construction monitoring). analysis of the pre and post the FEPA Licence. The follow- The environmental monitoring in construction fishery surveys. ing specification is quoted from this phase includes fish, ben- the licence: At each survey two methods thos, underwater noise, ocean- were used. Otter trawling was ography, seabed morphology The Environmental Impact As- used to survey adult commercial (scours etc.) and bathymetry, sessment observed electro species, while beam trawling side scan sonar surveys, includ- sensitive species (e.g. Thorn- was used to survey juvenile fish ing archaeology, and ornithol- back Ray, Basking Shark) in and invertebrates. Catches from ogy. Where possible, compari- Morecambe Bay and in the inside the wind farm were com- sons between pre construction vicinity of the Barrow site. In the pared to external control sites. monitoring and post construc- absence of any evidence that The demersal trawl used for the tion monitoring are drawn. electromagnetic fields do not sampling was a multipurpose pose a risk to such organisms, The presentation of the monitor- trawl with an 80mm (stretched) monitoring work is required to ing results follows the same knotted diamond cod end. determine the numbers and structure for each theme when- distribution of such species in Otter trawling ever possible. The presentation the vicinity of the Barrow Off- Sampling was undertaken over includes the conditions based shore Wind Farm (this should consecutive days; 19th-21st on the FEPA licence and sub- include the establishment of a December 2006 and 21st-22nd sequent agreements with au- baseline and the use of ade- March 2007. Figures 4.2 shows thorities, the monitoring meth- quate controls). The results the otter trawl towing tracks for ods and the results and conclu- should be presented and dis- the spring survey. Sampling is sions. cussed in combination with the undertaken inside the wind farm 4.1 Fisheries EMF-studies. area and at external control site. From the otter trawling the catch EMF measurements will be 4.1.1 Conditions rates and species distributions undertaken in spring 2008 as a The FEPA Licence (Appendix 1) are detected. Further the land- part of the research programme states in Supplementary Condi- ing size was measured, sex made by COWRIE. The results tion 9.6 that: ratios determined and the prin- from the fishery survey are cipal commercial species were Since very little is known about therefore not yet discussed in analyzed for spawning condi- the potential effect of wind combination with EMF. This will tions. farms in terms of enhancing or be presented in the second post aggregating fish populations, construction monitoring report in the Licence Holder must pro- November 2008. duce proposals for adequate Beam trawling pre-construction baseline and 4.1.2 Monitoring Methods The beam trawling was exe- st post-construction surveys of fish Titan Environmental Surveys cuted 21 December 2006 and th populations in the area of the Ltd and has undertaken the post 14 March 2007. From the wind farm. The Licence Holder construction fish surveys at the beam trawl species distribution shall, in drawing up such pro- Barrow Offshore Wind Farm. and length distribution by spe- posals, canvas the views of Two post construction surveys cies have been analyzed. local fishermen. The proposals have been undertaken in De- must be submitted to the Li- cember 2006 and March 2007, censing Authority at least one respectively /ref. 1 and 2/. The month prior to the proposed final post construction fishery survey was undertaken in Octo-

10 POST CONSTRUCTION MONITORING REPORT

4.1.3 Results and conclu- wind farm site through otter and Dragonet. The most abun- sions trawls are Dab, Lesser Spotted dant species caught in the otter Otter Trawling Dogfish, Plaice, Whiting and trawls was Dab (Limanda li- At the winter survey the otter Thornback Ray. The principle manda) comprising 71% of the trawls collected a total of 22 species caught in the control total catch (76% in the wind different species and a total sites otter trawls were the same farm area and 68.3% within the number of 2619 individuals. The as the wind farm but included control sites). principle species caught in the also Red Gurnard, Poor Cod

Figure 4.1. The Vessel 'Kiroan' /ref. 2/

POST CONSTRUCTION MONITORING REPORT 11

Figure 4.2. Otter trawl towing tracks, Spring 2007 /ref. 2/.

Figure 4.3. Percentage Distribution of species caught within the wind farm site in December 2006 /ref. 1/

12 POST CONSTRUCTION MONITORING REPORT

During the survey in March the and Bull-rout. Principal species in otter trawls was Plaice compris- otter trawls collected a total of 19 caught in control sites by otter trawl ing 43% of the total catch. Dab was different species (18 fish species were the same as the wind farm, comprising 30% of the total catch and lobster) and a total number of although significantly less Dab (36.2% in the wind farm area and 844 individuals. The principal spe- were caught (half the number 18.5% within the control sites). cies caught in the wind farm site by caught per hour at control sites Table 4.1 shows otter trawl catch otter trawl were Plaice, Dab, Lesser compared with wind farm sites). rates and total individuals caught Spotted Dogfish, Thornback Ray The most abundant species caught during the spring survey.

Species Individuals per Hour Number of Individuals Caught Common Name Scientific Name Wind Farm Control Wind Farm Control Total Plaice Pleuronectes platessa 72.1 86.2 220 145 365 Dab Limanda limanda 65.6 32.1 200 54 254 Lesser Spotted Dogfish Scyliorhinus canicula 11.8 14.9 36 25 61 Thornback Ray Raja clavata 5.9 13.1 18 22 40 Bull-Rout Myoxocephalus scorpius 7.5 4.8 23 8 31 Whiting Merlangius merlangus 4.3 8.9 13 15 28 Cod Gadus morhua 2.6 3.6 8 6 14 Lemon Sole Microstomus kitt 3.3 1.2 10 2 12 Flounder Platichthys flesus 3.0 1.2 9 2 11 Poor Cod Trisopterus minutus 1.0 2.4 3 4 7 Pogge Agonus cataphractus 1.6 0.6 5 1 6 Sole Solea solea 0.7 2.4 2 4 6 Lobster Homarus gammarus 0.7 0.0 2 0 2 Bib Trisopterus luscus 0.0 1.2 0 2 2 Grey Gurnard Eutrigla gurnardus 0.0 0.6 0 1 1 Dragonet Callionymus lyra 0.3 0.0 1 0 1 Nurse hound Scyliorhinus stellaris 0.3 0.0 1 0 1 Bass Dicentrarchus labrax 0.0 0.6 0 1 1 Topknot Zeugopterus punctatus 0.3 0.0 1 0 1

Table 4.1. Otter trawl catch rates and total individuals caught during the spring survey /ref. 2/.

POST CONSTRUCTION MONITORING REPORT 13

Figure 4.4. Otter trawl – winter survey: To the left Lesser Spotted Dogfish /ref. 1/. Thornback Ray and Basking Shark basking sharks were detected. site, and 45% has been in the wind are electro sensitive species (e.g.) Concerning Thornback Ray, 20 and farm area. EMF measurements will and has both been observed in the 40 individuals were collected at the be made in spring 2008, and the vicinity of the Barrow site during the surveys in December and March, results from the fishery survey are Environmental Impact Assessment. respectively. At both surveys 55% therefore not yet discussed in com- At the post construction surveys, no of the catch has been in the control bination with EMF .

14 POST CONSTRUCTION MONITORING REPORT

Figure 4.5. Otter trawl – spring survey: Thornback Ray /ref. 2/.

There are no significant differences caught in the wind farm site through motile and 2 sessile invertebrates) in the landing sizes within the wind beam trawls are Edible Whelk, and a total number of 1199 indi- farm area and the control site; Shrimp, Brown Shrimp, Dab, Whit- viduals. The principal species however a higher percentage of the ing, Pink Shrimp, Dover Sole and caught in the wind farm site were catch in the control area is below Sprat. The most abundant com- Dab, Brown Shrimp, Pink Shrimp, the minimum landing size. Both mercial species caught in the beam Shrimp and Spider Crab. The most inside the wind farm area and trawls was Shrimp (Crangon abundant species caught was the within the control site the majority allmanni) comprising 17% of the Brittlestar comprising 72% of total caught were female. total catch (starfish was the most individuals caught. The most abun- abundant species). Dab comprised dant commercial species was Dab, Beam Trawling 3.4% of the total individuals comprising 1.8% of the total catch. In December 2006 the beam trawls caught.During the survey in March collected a total of 25 different beam trawls collected a total of 22 species and a total number of 856 different species (9 fish species; 11 individuals. The principle species

POST CONSTRUCTION MONITORING REPORT 15

Figure 4.6. Beam Trawl – March 2007 /ref. 2/

4.2 Benthic and Sediment must be determined by diver oper- 4.2.2 Monitoring Methods Contaminant Survey ated video observations and analy- The pre-construction survey was ses with some accompanying sam- completed in the winter of Decem- 4.2.1 Conditions ple collection for verification and ber 2004. Weather conditions and The FEPA Licence (Appendix 1) identification. lack of available vessels at the end states in Supplementary Condition of 2006 and early 2007 delayed the 9.4 for benthic organisms that: Intertidal invertebrate sampling completion of the post-construction must be undertaken at lower, mid survey, and the survey was finally Sample locations for ongoing moni- and upper shore sampling stations completed in March 2007, still toring must be determined by fac- along three transects running per- considered to be within the winter tors such as precise monopile pendicular to the shore in the area period (so that seasonal differences in benthic communities should not locations, locations of cables etc. of the cable landfall. Sample locations must also take be an issue when comparing the full account of factors such as sen- Licence conditions further state that 2004 and 2007 data). sitive areas, coastal processes the post-construction surveys will modelling outputs and geophysical be conducted at the same time The following monitoring sites were surveys. Samples should be taken each year as the pre-construction established: survey was carried out and imme- to adequately cover the extent and • Five sites within the wind farm diately after the end of construction. direction of the full tidal excursion. area representing different This schedule should minimise The number and location should be habitat types and up/down drift seasonal variation in the results of negotiated with the Licensing Au- conditions thority, CEFAS and English Nature the pre- and post-construction prior to surveys. Colonisation of surveys. • Four sites within the near-field monopiles and scour protection area of the monopile founda-

16 POST CONSTRUCTION MONITORING REPORT

tions to determine scour ef- • Five sites within the tidal ex- • Four sites nearby, but remote fects, etc. cursion to the north, north- from the wind farm (controls). west, west, south-west and These should be outside the • Four sites at the eastern south of the turbine array. tidal excursion and spaced at boundary of the wind farm, reasonable distances round within the area affected by • Three sites along the cable the development area. sediment transport and depo- route sition.

Figure 4.7. Distribution of site locations /ref. 4/.

It should be noted that the 2004 is a data set stretching over five chor dredge sampling were survey locations were agreed years. used at certain sites. The follow- with the regulator and these ing analyses were made at Due to safety and the location of locations were revisited as far selected samples/sites: inter-array cables within the as possible in 2007 so that wind farm area some sampling • Benthic macro-fauna results could be easily com- sites (three in total) were relo- pared. Several of the sample cated in order to secure a 50 m • Total Organic Carbon positions specified in 2004 were exclusion zone from all cables. at locations that were sampled • Particle Size Analysis in 2002 as part of the baseline At the selected sites samples of • Trace Metal Analysis (Pb, benthic survey for the Environ- sediment were mostly taken as Cd, Zn, Cr, Cu, Ni, Al, Fe, mental Impact Assessment. For grab samples, but due to un- Hg, Ba, V and Sn) some locations, therefore, there suitable ground conditions an-

POST CONSTRUCTION MONITORING REPORT 17

• Total Petroleum Hydrocar- 4.2.3 Results and Conclu- to relatively consistent changes bon Analysis sions taking place across the whole Concerning the physical data survey area, and that some of • Gamma Spectrometry there have been changes in the these changes took place be- Analysis grain sizes across both the wind fore construction of the wind farm site and reference sites in farm began, it would appear that the period between 2002 and they are natural fluctuations, 2004 (pre-construction survey), and probably influenced by the and between 2004 and 2007 general extensive sediment (post-construction survey). Due movement in the Irish Sea.

2007 2004 2002 Station % Fines % Gravel Number % Sand (<63µm) (>2mm) Mean (µm) Mean (µm) Mean (µm) Subtidal Sites 1a 20.5 75.1 4.4 96 172 89 1b 5.8 70.9 23.3 410 125 215 1c 9.2 79.9 10.9 188 90 261 1d 7.6 88.1 4.3 127 192 129 1e 6.8 92.4 0.8 148 126 128 2a 6.8 91.5 1.1 151 165 2b 177 2c 11.3 87.8 0.9 106 224 2d 3.7 80.7 15.3 272 376 3a 135 3b 3.3 96.5 0.2 158 3c 1.4 98.2 0.4 182 3d 15.5 64.7 19.9 293 77 4a 2.5 97.2 0.3 152 146 4b 26.2 73.4 0.4 83 61 92 4c 44.6 55.4 0 39 33 26 4d 15 83.9 1.1 102 65 74 4e 8 87.2 4.8 113 70 103 5a 1.8 15.9 82.3 774 1021 5b 0.1 92.7 7.2 230 106 310 5c 2.8 97.2 0 119 103 121 6a 34.1 65.9 0 53 34 6b 61.2 38.7 0.1 28 15 6c 0 100 0 150 116 6d 47.7 52.3 0 39 54 Intertidal Sites 101 8.6 91.4 0 100 85 102 6.2 93.8 0 101 75 103 10.2 89.8 0 97 79 104 5.3 94.7 0 112 104 105 4.5 95.5 0 106 97 106 5.4 94.6 0 103 88 110 33.5 66.5 0 73 93 112 14.6 85.2 0.2 102 89 Site moved in 2007 Site sampled by anchor dredge Grain size analysis in 2002 and 2004 performed by wet sieving and hydrometry; in 2007, laser diffraction was used

Table 4.2. Comparison of grain size changes at various Barrow Offshore Wind Farm sampling sites, 2002–2007 /ref. 16/.

18 POST CONSTRUCTION MONITORING REPORT

Chemical surveys consisted of levels in the samples collected in measured in 2007 was slightly measures of Total Organic Carbon the post-construction survey were greater than that recorded from the (TOC), metals, Total Petroleum all below the upper OSPAR EAC pre-construction survey, however, Hydrocarbon (TPH) and radio- limits, though some were above the all concentrations were below chemistry. TOC levels have gener- lower EAC limits. Ranges of metal 30ppm, and therefore not of con- ally decreased throughout the pe- concentrations for which there are cern. In general, similarity compari- riod 2002 – 2007 across the survey provisional EAC limits set are gen- sons across the whole site show area, again probably with little erally similar for the Barrow pre- that there have not been consistent influence from the construction or and post-construction surveys. The changes in contaminant concentra- operation of the wind farm. Metal range of TPH concentrations tions between 2004 and 2007.

Cd Cr Cu Hg Ni Pb Zn Location mg/kg Barrow Wind farm 7.3– 5.6– 12.9– <0.1 2.1–6.6 <0.05 3.9–9.4 2007 16.7 14.2 34.5 Barrow Wind farm 0.01– 8.6– 0.02– 7.1– 25.2– 1.8–5.4 3.8–9.1 2004 0.07 17.6 0.09 17.2 44.4 Barrow Wind farm 0.02– 6.2– 1.76– 0.02– 3.5– 6.82– 30.5– 2002 0.1 25.5 7.4 0.17 11.2 20.3 55.7 OSPAR Ecotoxicological Assessment Criteria ranges 0.05– OSPAR EAC 0.1–1.0 10–100 5–50 5–50 5–50 50–500 0.5 Other Irish Sea areas Cirrus Shell Flat Array 9.2– 2.54– <0.05– 4.58– 10.8– 20.6– <1 2007 30.6 13.5 0.275 15.6 37.2 81.7 Walney and West of 0.01– 11.50– 3.74– 0.01– 6.71– 7.61– 24.3– Duddon 0.17 38.0 25.20 0.37 19.6 43.6 134.0 Ormonde Wind farm 0.008– <1.00 3–42 1.2–9.4 - 2–26 6.0–79 2004 0.22 Other British and European Sea areas Tyne 0.06 45 4 0.02 - 12 38 Humber - 99 17 - - 22 84 Wadden Sea - 84 22 0.07 - 37 103 Norwegian Coast 0.08 - 17 0.04 - 26 110 NB: all OSPAR EAC levels are provisional

Table 4.3. Trace metals concentration ranges in samples taken from Barrow Offshore Wind farm in 2007, 2004 and 2002, and a range of other European locations.

There are significant correlations generally slightly lower than, levels in the post-construction survey, and between the concentrations of a recorded from the nearby sites. the more frequent occurrence of number of the metals, but not be- Nephtys (cat worm) and high num- Benthic surveys were conducted tween metals and the grain sizes or bers of Amphiura (brittle star) in the both subtidal and intertidal. The TOC. The correlations between pre-construction survey. This result subtidal data show there have been metal concentrations is not un- reflects the recorded changes in changes in the benthic communi- usual, however it would have been sediment grain size, with Amphiura ties present across the wind farm expected that grain sizes and TOC preferring finer sediment than and its reference sites between the were significantly correlated with Ophiura. All groupings recorded pre and post-construction surveys. metal concentrations. throughout the surveys are repre- Similarity analysis shows that the sentative of the various wider Levels of gamma radiation from sites from 2004 as a group are communities which have been 137Cs had reduced between 2004 more similar to themselves than recorded from this area of the Irish and 2007 at all sites surveyed. they are to any of the sites sampled Sea /ref. 3/. Activity levels of 137Cs are fairly in 2007. The main differences in consistent throughout the study similarity between the groups is area, and are similar to, though probably the high numbers of Ophiura (large brittle star) present

POST CONSTRUCTION MONITORING REPORT 19

Figure 4.8. Sample showing benthic macro-fauna /ref. 4/.

The intertidal surveys show that were recorded in the pre- of some species in 2007 which higher numbers of species and construction work. The similarity of were not recorded frequently from higher numbers of individuals were the communities recorded in 2004 the pre-construction survey. recorded from the intertidal sites in and 2007 is low, and this is proba- the post-construction survey than bly caused by the high abundances

2007 2004

Species Total Species Total 1 Pontocrates altamarinus 755 Macoma balthica 458 2 Hydrobia ulvae 550 Bathyporeia pelagica 119 3 Nucula nitidosa 511 Hydrobia juv. 73 4 Orchomene nana 114 Corophium arenarium 52 5 Aonides oxycephala 60 Nephtys cirrosa 29

Table 4.4. Most frequently occurring species in intertidal samples, 2007 and 2004.

In general the benthic and sedi- have been impacted by the con- The fact that the results from these ment surveys show differences in struction or initial operation of the references sites show a change the physical and chemical data as wind farm, they were also present between the pre- and post- well as the biological data collected in the data from sites that were construction surveys suggests that in the pre- and post-construction expected to be outside the influ- there have been natural changes surveys. These differences were ence of the wind farm and were throughout the area in sediment not restricted to the sites that could regarded as reference locations. conditions, and that the changes at

20 POST CONSTRUCTION MONITORING REPORT

the sites within the area of possible The monitoring requirements are ground noise were obtained on 20th influence are not caused by the stated in appendix 1 to the FEPA December 2006 on a calm day construction or operation of the Licence. Paragraph 8 concerns when very few of the turbines were wind farm. noise and states: operational, with further measurements taken at a nominal distance Detailed post construction data 4.3 Operational Underwater of 1000m to 2000m from the clos- must be collected on the frequency Noise est operational wind turbine on 30th and magnitude of underwater noise January and 1st February 2007. 4.3.1 Conditions produced by the Barrow Offshore The surveys were undertaken by The FEPA Licence (Appendix 1) Wind Farm. The choice of sites for Subacoustech Ltd. The subsea states under Supplementary Condi- installing monitoring equipment operational noise measurements tions – 9.5: should reflect the different condi- undertaken at the Barrow Offshore tions such as sediment type, water The Licence Holder must make Wind Farm were part of a larger depth and pile type. This data is provision during the construction programme of work being under- required for a variety of purposes, phase of the wind-farm to install taken for the Collaborative Offshore including: facilities to enable subsea noise Wind farm research into the Envi- • In combination with the bio- and vibration from the turbines to ronment (COWRIE). The proce- logical aspects of the monitor- be assessed and monitored during dures and equipment used for the ing programme, the data the operational phase of the wind- survey were those agreed with would help to elucidate any in- farm. authorities and COWRIE as part of teractions between noise gen- the ongoing research programme. Following consultation, the above eration and the provision of condition has been changed to the new habitat and fish aggrega- During the subsea noise survey, specification below: tion effects on turbine support underwater sound recordings were structures. taken throughout the wind farm Mobile rather than fixed equipment • Determining the effects of array along two drift paths. Fur- can be used, but several surveys distance depth and back- thermore a series of recordings will be required to take account of ground sources on noise were taken at increasing range seasonal variations and fluctuating propagation. from two separate operational wind wind speeds (October, December turbines inside the wind farm (tur- th and March to coincide with the fish 4.3.2 Monitoring Methods bine C5 on 30 January 2007 and st surveys should provide sufficient The underwater noise survey at the turbine C2 on 1 February 2007) variation). Depending on the results Barrow Offshore Wind Farm was and four from operational turbines and the results from other wind undertaken on the 30th January out to approximately 2000 m follow- farms additional data may be re- 2007 and 1st February 2007, using ing orthogonal transect lines. quired. A good assessment would a hydrophone suspended in the be to correlate the met mast data water from a vessel that was float- with the noise data. ing with engines switched off. Back-

POST CONSTRUCTION MONITORING REPORT 21

Figure 4.9. Sketch of the wind farm area, and transects lines followed during the subsea operational noise survey /ref. 5/.

4.3.3 Results and Conclusions in the back of this report, and the The survey results indicate that The results for the survey were results and conclusions below are there is a marginal increase in very reported by Subacoustech in report based on a summary of all the low frequency noise around indi- no. 753R0109 dated 7 June 2007 reports/notes. vidual wind turbines. This increase /ref. 5/. The report was submitted to is detectable to a range of ap- Along the two drift paths the overall Marine and Fisheries Agency, and proximately 600m. Beyond this Sound Pressure Level in and after consulting CEFAS, Marine range, the underwater noise is around the wind farm array varied and Fisheries Agency responded consistent with that for the ap- from 112.4 to 135.3 dB re. 1 µPa on 7 September 2007 /ref. 14/. proximate ambient sea noise level (ie. RMS pressure levels from ap- Based on these comments, Suba- in the region according to Suba- proximately 1 to 20 Pa) throughout coustech prepared a clarification coustech. the measurement period. note (753R0204) /ref. 15/. All reports/notes are enclosed on the CD

22 POST CONSTRUCTION MONITORING REPORT

Figure 4.10. Spectral levels of underwater noise at increasing range from a single operational wind turbine (C5) on 30th January 2007 /ref. 5/.

The unweighted noise produced cies in the region. This provides a The mean dBht species sound from the operation of BOW is of measure of the perceived loudness. levels in and around the Barrow sufficiently low level that there is no The results from measurements Offshore Wind Farm site were likelihood of direct physical injury to taken at ranges to 5m from an found to be marginally higher than marine species in the form of lethal- operational wind turbine indicate that measured in other nearby ity, injury, nor hearing impairment (according to Subacoustech) that waters. This relatively higher noise from long term exposure. Behav- the underwater noise is unlikely to level is within the typical variation ioural response to the noise has cause a behavioural (avoidance) that would be expected in shallow been assessed by calculating the response in marine fish and marine water regions due to weather sea level of the sound above the hear- mammals in the region. state and tidal flow conditions. ing threshold (dBht) of marine spe-

POST CONSTRUCTION MONITORING REPORT 23

Figure 4.11. Frequency distribution of species perceived underwater sound level (dBht(Species)) in the waters around the Barrow offshore wind farm /ref. 5/.

4.4 Oceanography results should be compared to the strengths. It should also be shown predictions and discussed in the how the model was validated for 4.4.1 Conditions context of possible disruption to these directions. The monitoring requirements are coastal processes. If changes in 4.4.2 Monitoring Methods stated in appendix 1 to the FEPA current velocity are significantly The purpose of the survey has Licence. Paragraph 4 concerns greater than predicted, then the been to assess the extent of hydro- current and states: consequences for the sediment dynamic interference imposed by transport regime will need to be To monitor predictions made in the the 4.7m diameter monopiles in- revaluated. Environmental Impact Statement stalled within the Barrow Offshore for the Barrow Offshore Wind Farm Paragraph 9 states that: Wind Farm. of a wake effect downstream of each monopole, further investiga- All numerical model computations Surveys were carried out by Titan tion is required. within the Environmental Impact Environmental Surveys Ltd over a th Statement were completed without 13-hour period on 12 April 2007 Post construction ADCP monitoring any wind forcing. It is suggested /ref. 6/. Tidal diamond information should be undertaken taking tran- that the model be rerun with wind was fundamental in the planning of sects through the wake region. The forcing from various directions and the field campaign.

24 POST CONSTRUCTION MONITORING REPORT

95000 E 95000 85000 E 85000 E 90000 100000 E 105000 E 110000 E

6005000 N 6005000 N

SN044G

6000000 N 6000000 N SN044J

SN044Q

SN044D

5995000 N 5995000 N 95000 E 95000 85000 E 85000 E 90000 E 100000 E 105000 E 110000

Figure 4.12. Location of Tidal Diamonds (three pink diamonds SN044G, Q, and J inshore of the wind farm). The black stars show the position for each monopole within the wind farm /ref. 6/. Wake studies were made at monopole A1, B4 and D8, marked with red triangles. An Acoustic Doppler Current Pro- numerical modelling presented in cases wakes could be traced out to filer (ADCP) has been utilised to the Environmental Impact State- a distance of at least 6–10 diame- map the spatial extent, orientation ment. During the revised modelling ters distance downstream of each and geometry of the wakes along exercise, wind forcing has been monopile (30–50m) and often a transects, up to 400m from 3 repre- added as a factor in the predicted good deal further, in the order of sentative turbine towers. Transects current changes down current of 100–200m. Such distances for cover the whole wake zone. the monopiles. wake extent are reported to have been seen when detailed modelling The wake structure has been It must be borne in mind that ADCP of the wake generation process has mapped in two ways: firstly, by the is a new technology to investigate been attempted and are probably flow structure itself, i.e. detection of transient processes such as turbu- therefore not unrealistic /ref. 6/. the flow separation zone formed lent intensity and wake generation, behind each pile; and secondly, by and it is an area of active academic Bubble clouds entrained in the mapping the bubbles entrained in research; hence, analysis has been wakes forming behind turbine mo- the wake as it passes around the limited to qualitative interpretation nopiles are traceable over even pile. of the data. longer distances, as far as 200m and possibly further, although there The survey is conducted during 4.4.3 Results and Conclusions is no evidence to suggest whether maximum tidal movement during a The data collected show that the there is any flow structure associ- spring tide (anticipated to be at half wake structure can be mapped by ated with them or whether they tide). The survey vessel has trav- both the flow structure itself, i.e. simply represent surface slicks. elled at as low a speed as possible, detection of the flow separation sufficient to maintain steerage, with zone formed behind each pile, as From the flow modelling under- the ADCP sampling rate being high well as by mapping the bubbles taken prior to construction, it was enough to resolve any "wake" ef- entrained in the wake as it passes suggested that due to the separa- fects. around the pile. tion of 500m between each monopile, they could be considered as The ADCP data generated has From interpretation of the data independent of each other in re- then been used to validate the acquired, it is apparent that in all

POST CONSTRUCTION MONITORING REPORT 25

spect of the impact on the currents. The Licence Holder must ensure grid file of the same size with a On the basis of the wake surveys, it that the inter array cables are bur- much higher degree of accuracy. would appear that this may still be ied to a depth of 1.5 metres to 2 The GeoSwath system was specifi- the case since no obvious struc- metres and that the export cables, cally designed for use in shallow tures were visible in the velocity between the array and the shore, water (<150m) and under optimum records extending beyond 300m are buried to a depth as specified in conditions, enables bathymetry from the nearest pile. the annex 3 to the Licence, to coverage out to approximately 10 minimise the risk of emergence and times the water depth. 4.5 Bathymetry, Seabed reduce the potential effects of elec- Morphology and Scour tromagnetic fields. 4.5.3 Results and Conclusions Surveys were undertaken within the 4.5.1 Conditions The Monitoring Requirements wind farm area and along the asso- The FEPA Licence (Appendix 1) states for seabed morphology and ciated offshore transmission cable. states under Supplementary Condi- scour (paragraph 2) that: tions – 9.17-9.21: As a part of the monitoring pro- 4.5.2 Monitoring Methods gramme, a survey to monitor cable The Licence Holder must undertake The survey was made from a ves- burial was undertaken in autumn a bathymetric survey around a sel based at Barrow during the 2006. The survey was followed up sample of adjacent turbines (mini- survey period. The survey was by work to secure the protection mum of 4) within 3 months of com- carried out by Osiris Projects the and burial of exposed or vulnerable pletion of the construction of the 25th September to 3rd November offshore and transmission cable wind farm (or sooner if practicable) 2006 and 4th April to 13th April sections. This work was undertaken to access changes in the bathym- 2007. etry within the array. The number of from 5 May until 7 May 2007, and turbines selected for these works The primary objective of the sur- Centre for Environment, Fisheries should be sufficient so as to be veys was to map seabed morphol- & Aquaculture Science (CEFAS) representative of the different ogy, seabed features and bathym- and Marine and Fisheries Agency sediment types present at the site etry, both within the wind farm area (MFA) has been informed about the (e.g. cohesive, mobile etc.). The and along the associated cable and progress of the cable protection survey is to be undertaken immedi- navigation routes. Additional lines, work. run across the faces of the tur- ately after construction is complete Wind farm area bines, were carried out to provide and repeated at 6 monthly intervals With the exception of the eastern detailed scour assessments. for a period of 3 years. This shall corner of the development site, specifically address the need for A GeoAcoustics ‘GeoSwath’, high- much of the survey area is rela- (additional) scour protection around frequency (240 kHz) interferometric tively flat, with most of the central the turbine pylons. The Licence swath bathymetry system was section lying between -15.5mCD Holder must submit the data in form utilised to map seabed levels and and -17.0mCD. However, localised of a report to the Licensing Author- morphology. areas of scour are present around ity, including proposals for scour many of the turbines. measures. The GeoSwath is a high-resolution swath bathymetry system specifi- Seabed levels across the eastern- To ensure integrity of the wind farm cally designed for shallow water most corner of the development infrastructure and minimise hazards work. The unit utilises the phase site are more variable, ranging from to mariners this 6 monthly monitor- comparison technique (interfer- -11.5mCD, at the top of one of ing should also investigate the ometric) to provide high resolution several small seabed mound/ridge cable route to ensure that the cable XYZ data. The system has the features, to -15.0mCD moving remains buried (such monitoring capability of providing a high- westwards. The ridge/mound fea- would need to continue throughout density data set when compared to tures are randomly orientated. the lifetime of the wind farm al- a beam forming system for a given There is a slight dip of the seabed though the frequency must be water depth. A beam forming sys- towards the west across the whole reviewed in discussions with the tem must interpolate between data survey area. Licensing Authority at the end of points to achieve high-resolution With the exception of the localised the 3 year monitoring programme). grids, whereas a phase measure- areas of scour around many of the The Licensing Authority recom- ment system can average or statis- individual turbines, seabed levels mends that bathymetric surveys are tically filter many real data points across the whole area are very taken of the cable route following within each grid cell for the same similar to those surveyed during the any major storm event to ensure resolution grid. The end result is a that the cable remains buried. two previous surveys.

26 POST CONSTRUCTION MONITORING REPORT

Scour spring 2007 can be compared in the scour survey can be seen on The scour survey results from in- table 4.5. The turbines included in figure 4.13. vestigation in autumn 2006 and

A6 B8

A3 C6 B5

C3 B2 D5

Figure 4.13. The nine turbines included in the scour survey /ref. 12/.

Turbine Results of Scour Monitoring: September- Results of Scour Monitoring: April 2007 November 2006 A3 Natural seabed levels within the range from - Natural seabed levels within the from -12.00mCD to 12.25mCD to -13.75mCD. No obvious areas of -13.50mCD. No obvious areas of scour are present, scour are present and the remnants of the construc- with only minor variations in levels that can be at- tion works can be seen as a series of faint jack-up tributed to the natural movement of sediments leg depressions to the east and north west of the across the seabed. Some fill has taken place in the turbine location. These depressions appear to be remnants of the jack-up leg depressions to the east almost completely in filled, indicating the high mobil- of the turbine location. ity of the seabed sediments.

A seabed scar is also present to the SSW of the turbine location. This is believed to be a trench rem- nant from the inter-turbine cable installation.

A6 Natural seabed levels range from -16.00mCD to - Natural seabed levels range from -16.00mCD to - 16.5mCD. No obvious areas of scour are present, 16.30mCD. No obvious areas of scour are present, although seabed levels fall to below -17.0mCD to with only minor variations in levels that can be at- the SE of the turbine location, within the remnants of tributed to the natural movement of sediments

POST CONSTRUCTION MONITORING REPORT 27

Turbine Results of Scour Monitoring: September- Results of Scour Monitoring: April 2007 November 2006

an inter-turbine cable trench. across the seabed. The inter-turbine cable trench to the south east of the turbine location has been almost completely infilled by natural sedimentation processes.

B2 Natural seabed levels range from -15.0mCD to - Natural seabed levels range from -15.00mCD to - 15.8mCD. Some scouring is evident from the inter- 15.50mCD. No obvious areas of scour are present, turbine cable installation, as a series of small sea- with only minor variations in levels that can be at- bed depressions to the south east of the turbine tributed to the natural movement of sediments location. These features are up to 0.5m deeper than across the seabed. The seabed depressions related the surrounding seabed. to the inter-turbine cable installation to the south east of the turbine location has been partially infilled

by natural sedimentation processes.

B5 Natural seabed levels range from -15.50mCD to - Natural seabed levels range from -15.50mCD to - 15.75mCD. A large area of scour is developing 15.75mCD. The circular area of scour to the east of around the turbine location, with seabed levels fal- the turbine location has been completely infilled by ling below -17.25mCD, within this area. A second, natural sedimentation processes. Similarly, the data roughly circular area of scour is evident to the east indicates that the original area of scour is expanding, of the turbine location, where seabed levels fall to mainly from the north west to the south east, al- below -17.0mCD. This may be related to seabed though seabed levels within the central part of the disturbances created by the jack-up rig during the area are also becoming shallower. This may indi- installation of the turbine. cate that the main area of scour is gradually being infilled by natural processes.

B8 Natural seabed levels range from -15.65mCD to - Natural seabed levels range from -15.65mCD to - 16.00mCD. A large, circular area of scour is devel- 16.00mCD. The area of scour to the ESE of the oping around the turbine location, with seabed levels turbine location has been completely infilled by natu- falling below -18.75mCD, within this area. A second, ral sedimentation processes. Similarly, the data smaller circular area of scour is evident to the ESE indicates that the original area of scour is expanding, of the turbine location, where seabed levels fall to mainly from the east to the south, although seabed below -16.75mCD. As for turbines B5, B6 and B7, levels within the central part of the area are also this may be related to seabed disturbances created becoming shallower. This may indicate that the main by the jack-up rig during the installation of the tur- area of scour is gradually being infilled by natural bine. processes. The faint remnants of the inter-turbine cable installation can be seen to the SE of the turbine location.

C3 Natural seabed levels range from -15.65mCD to - Natural seabed levels range from -15.70mCD to - 16.00mCD, although a small seabed mound is evi- 15.90mCD. The seabed mound to the north east of dent in the extreme north eastern corner of the sur- the turbine location is still apparent, with seabed vey box, where seabed levels rise to -14.75mCD. A levels across this feature rising to approximately - large, circular area of scour is developing around the 14.5mCD. turbine location, with seabed levels falling below - The area of scour around the turbine location has 18.0mCD, within this area. been partially infilled by natural sedimentation proc- A broader area of scour is evident to the east of the esses, particularly within the original broad area of turbine location, possibly caused by seabed distur- scour to the east. However, the data also indicates bances created by the jack-up rig during the installa- that the general area of scour is expanding, although tion of the turbine. Seabed levels within this N-S seabed levels within the central part of the area are not becoming any deeper. This may indicate that

28 POST CONSTRUCTION MONITORING REPORT

Turbine Results of Scour Monitoring: September- Results of Scour Monitoring: April 2007 November 2006

orientated feature fall to -17.50mCD. the main area of scour is gradually being infilled by natural processes. The faint remnants of the inter-turbine cable installation can be seen to the N and NW of the turbine location.

C6 Natural seabed levels range from -16.25mCD to - Natural seabed levels range from -15.65mCD to - 16.55mCD, although a seabed mound is evident 16.00mCD. The seabed mound to the north of the approximately 40m to the north of the turbine posi- turbine location is still apparent, with seabed levels tion, where seabed levels rise to approximately - across this feature rising to approximately - 14.5mCD. A large, deep area of scour is developing 14.5mCD. around the turbine location and elongating to the The extended area of scour around the turbine loca- south east, with seabed levels falling below - tion has been partially infilled by natural sedimenta- 21.5mCD within this area. tion processes. However, the data also indicates The faint remnants of the inter-turbine cable installa- that the original area of scour is expanding, apart tion can be seen to the N and NW of the turbine from the south eastern quadrant, although seabed location. levels within the central part of the area are becoming shallower. This may indicate that the main area of scour is gradually being infilled by natural processes.

D2 Natural seabed levels range from -15.70mCD to - Natural seabed levels range from -15.70mCD to - 15.90mCD, although a small seabed mound is evi- 15.90mCD. The seabed mound to the north east of dent in the extreme north eastern corner of the sur- the turbine location is still apparent, with seabed vey box, where seabed levels rise to -15.0mCD. A levels across this feature rising to approximately - large, circular area of scour is developing around the 14.5mCD. turbine location, with seabed levels falling below - The extended area of scour around the turbine loca- 17.5mCD, within this area. tion has been partially infilled by natural sedimenta- A broader area of scour is evident to the E and NE tion processes, particularly within the original broad of the turbine location, possibly caused by seabed area of scour to the east and north east. However, disturbances created by the jack-up rig during the the data also indicates that the general area of scour installation of the turbine. Seabed levels within this is expanding, although seabed levels within the N-S orientated feature fall to -17.0mCD. The faint central part of the area are not becoming any remnants of the inter-turbine cable installation can deeper. This may indicate that the main area of be seen to the N and NW of the turbine location. scour is gradually being infilled by natural processes.

D5 Natural seabed levels range from -16.50mCD to - Natural seabed levels range from -15.65mCD to - 16.75mCD. A large, deep area of scour is develop- 16.00mCD. The data show that the remnants of the ing around the turbine location, with seabed levels inter turbine cable installation have now disap- falling to below -22.50mCD within this area. peared. The faint remnants of the inter-turbine cable installa- The deep area of scour around the turbine location tion can be seen to the NW of the turbine location. has been partially infilled, particularly within the central section, where seabed levels have risen from -22.50mCD to approximately -20.25mCD. However, the data also indicates that the original area of scour is more extensive, although this may indicate that the main area of scour is gradually being infilled by natural processes.

Table 4.5. Results of Scour Monitoring around selected turbines. Monitoring is made in autumn 2006 and spring 2007.

POST CONSTRUCTION MONITORING REPORT 29

In total, scour surveys was made faint remnants of the inter-turbine secure the protection and burial of around nine turbines (A3, A6, B2, cable installation have been seen. exposed or vulnerable offshore and B5, B8, C3, C6, D2 and D5). transmission cable sections was At turbine D2 a large scour pit with made from 5 May until 7 May 2007. At turbine A3 and A6, no scours the depth of approximately 2-2.5m were detected during the two sur- was observed during the survey in 4.6 Side Scan Sonar Sur- veys. November 2006. This area has by vey and Archaeology time become larger, but not deeper. During the survey in November East of the turbine a broader area 4.6.1 Conditions 2006 some scouring was evident of scour was seen in November The FEPA Licence (Appendix 1) from the inter-turbine cable installa- 2006, but this was partially infilled states under Supplementary Condi- tion at turbine B2. These features at the survey in April 2007. Faint tions – 9.24: were up to 0.5m deeper than the remnants of the inter-turbine cable surrounding seabed. These were The Licence Holder must undertake installation were seen at both sur- infilled by natural sedimentation a pre-construction bottom and side veys. processes at the survey in 2007. scan sonar survey in grid lines A large scour pit with the depth of across the area of development Around turbine B5 a scour pit with a approximately 6m was observed at (turbine array, cable route, and any depth of approximately 1.5-2.0m turbine D5. By time it has been vessel access routes from the local was detected in November 2006. At partially infilled, and the survey in service port(s) to the construction the survey in April 2007 the scour April 2007 indicate a depth of ap- site) following discussions with the has expanded horizontally, but the proximately 4m. Faint remnants of Licensing Authority as to those central part of the area has becom- the inter-turbine cable installation parts of operation for which this is ing shallower. This may indicate were noticed at the survey in No- deemed necessary. Local fisher- that the main area of scour is vember 2006, but not in April 2007. men must be invited to send repre- gradually being infilled by natural sentatives to be present during the processes. Offshore Transmission Cable survey. All obstructions found on Route At turbine B8 a large scour pit with the seabed must be plotted. A post a depth of approximately 2.5-3.0m For the cable route surveys it construction survey must be under- was detected in November 2006. A should be noted that the position of taken along the same grid lines second, smaller circular area of the cable route centre line was (within operational and safety con- scour was evident to the ESE of the changed between the pre- straints), any new obstructions turbine location, with a depth of construction and construction must be removed on developers approximately 1.0m. The smaller stages. Therefore, localised areas expense. may be related to seabed distur- of the 2005 survey may not be Concerning archaeology the FEPA bances created by the jack-up rig present, due to deviations between Licence (Appendix 1) states under during the installation of the turbine. the proposed and as-laid cable Supplementary Conditions – 9.22: At the survey in April 2007 the routes. scour around the turbine has ex- The Licence Holder shall not permit Seabed levels at the wind farm panded horizontally, but the central any development to commence as area end of the cable route initially part of the area has becoming authorised by the Licence until a rise from -13.0mCD, and the sea- shallower. The smaller scour has protocol has been submitted to the bed gradients along the first section disappeared, caused infilling by Licensing Authority which has been are generally very gentle. Moving natural processes. Scour monitor- formally agreed with an Archaeolo- further to the east, the steep west- ing details from turbine B8 in April gist representing the County Coun- ern edge of a very broad channel is 2007 is showed on figure 4.14 cil adjacent to the site of works. encountered, and the seabed levels This shall detail what action must . At both turbines C3 and C6 larger fall to below -22.0mCD. The deep- be taken to protect any archaeo- scour pit were detected around the est level on the cable route is ap- logical and shipwreck remains that turbines with depths of 2.0-2.5m proximately -30.0mCD. Inshore, were identified in the Environmental and approximately 5m, respec- seabed levels rise gently towards Statement submitted in support of tively. By time the general area of the shoreline, with ‘drying’ areas the applications for consent for the the scour pit has been expanding, (above 0.0mCD). works or any such artefacts which but the depths have not increased. Cable exposures were seen during may be discovered during the East of turbine C3 a broader area the surveys, which are likely course of progressing the devel- of scour was observed in Novem- caused by natural movement of opment. Action to be taken to pro- ber 2006, which by time has been sediment across the area. Work to tect any archaeological and ship- partially infilled. At both turbines wreck remains during Geotechnical

30 POST CONSTRUCTION MONITORING REPORT

Survey are detailed in “Jack up Comparisons of obstructions found field. These data also provide the Positioning Procedure for Avoid- through pre- and post constructions highest chance of identifying ance of Archaeological Sites and are made. Any new obstructions wooden wrecks and debris. Seabed Obstructions, Seascore” as are analysed by archaeologists. Wind farm area supplied to the department 23 The archaeological assessment The side scan sonar data indicate February 2004. was made by Wessex Archaeology. that the seabed sediments over During the assessment side scan 4.6.2 Monitoring Methods much of the eastern and north sonar data were processed using The survey was made from a ves- eastern sections of the wind farm Coda Geosurvey software. From sel based at Barrow during the area are granular till deposits com- the form, size and/or extent of the survey period. The survey was prising sands, gravels, cobbles and anomalies, each of the anomalies carried out by Osiris Projects the occasional boulders. The seabed were categorized with an archaeo- 25th September to 3rd November sediments over the remainder of logical flag; high, medium, low or 2006 and 4th April to 13th April the site are much finer grained, very low. High is used, when the 2007. The survey should has been probably comprising silty fine to anomalies clearly represent a completed in autumn 2006, but had medium sands, with frequent small wreck site or were very near to a to be postponed and finalised in ‘outcrops’ of granular till and/or previously known site. Medium is 2007 due to severe weather condi- patchy gravels. used for anomalies with no directly tions. corroborating data, but being of a From the assessment made in The primary objective of the sur- size, shape or amplitude such as to 2005, 8 exclusion zones were de- veys was to map seabed features suggest that they possible relate to fined in the wind farm area /ref. 12/. and anomalies, both within the wind archaeological sites or features. During the post construction ar- farm area and along the associated Low and very low are used for chaeological assessment the effec- cable and navigation routes. anomalies that are likely to be tiveness of the exclusion zones is natural features and of modern commented, and the presence of To map the seabed sediments and origin (e.g. moorings etc.). previously located marine sites is anomalies side scan sonar surveys confirmed. Furthermore previously were made using a GeoAcoustics Surveys were undertaken within the unrecorded sites are identified, SS941 system was used. The wind farm area and along the asso- located and characterised. /ref. 13/. system consists of a ballasted tow ciated cable and navigation routes. fish, and is capable of operating in In the wind farm area a total of 53 4.6.3 Results and Conclusions depths of up to 1000 metres. Short, side scan sonar anomalies were In general the bedrock beneath the high frequency, high intensity identified, and all 8 exclusion zones site is expected to comprise sand- sound bursts are beamed (perpen- were re-identified. The exclusion stones and mudstones of Permo- dicular to the direction of travel) zones have been effective in pro- Triassic age. These rocks are over- from transducers, which are tecting sites of potential archaeo- lain, in turn, by glacial deposits mounted either side of the fish. This logical importance. In total 17 comprising mainly stiff clays, with results in echoes, which are re- sites/anomalies were identified sands and gravels of Pleistocene turned from points on the seabed within the exclusion zones. Only age. Finally, the glacial deposits up to 100 metres abeam of each one site, within one of the exclusion are overlain in places by recent transducer. Once detected by sen- zones, was clearly identified as a deposits comprising silty or clayey sors within the transducers, these wreck site. The remaining anoma- sands, with variable gravel content. echoes are relayed to the trans- lies in the wind farm area were all These glacial deposits are also ceiver unit, via the tow cable and interpreted as being of medium or known to outcrop, close to the the signals are processed, line by low archaeological potential and existing Cumbrian shoreline. line, to produce a sonar image. therefore were not considered to be Greater amounts of energy are The geophysical data have by of significant archaeological poten- reflected by harder or denser mate- Wessex Archaeology been marked tial. Figure 4.15 shows the identi- rials, than by softer seabed types, as “good”. This label is used for fied anomalies within the wind farm resulting in images of differing data which are clear and unaffected area /ref. 13/ reflectivity or contrast. This enables by weather conditions or sea state. the geophysicist to delineate areas The dataset is suitable for the in- of differing seabed sediment types, terpretation of standing and par- including rock outcrops and iso- tially buried metal wrecks and their lated contacts/targets. character and associated debris

POST CONSTRUCTION MONITORING REPORT 31

Figure 4.14.. Scour monitoring details of turbine B8 /ref. 8/.

32 POST CONSTRUCTION MONITORING REPORT

Figure 4.15. Identified site scan sonar anomalies within wind farm area /ref. 13/.

Cable Route present, due to deviations between boulders. These deposits extend For the cable route surveys it the proposed and as-laid cable eastwards along the cable route, should be noted that the position of routes. where till deposits become pro- the cable route centre line was gressively covered by deposits of Commencing at the wind farm area changed between the pre- fine to coarse sand, with poorly end of the cable route, the seabed construction and construction defined megaripple bed forms – sediments consist of coarsely stages. Therefore, localised areas see figure 4.16. granular glacial till deposits, com- of the 2005 survey may not be prising sands, gravels, cobbles and

POST CONSTRUCTION MONITORING REPORT 33

These sandy sediments extend Later these finer grained sand Many of these boulders lie on, or eastwards, where granular glacial patches are almost totally absent, very close to the route centreline. till is once again evident, together leaving a much coarser grained, with patchy, finer grained sands. granular till deposit, with boulders.

Figure 4.16. Area of megaripples on seabed /ref. 7/

A number of sonar targets and together with several sections of targets from the survey in 2006 are cable trench remnants were seen recently exposed cable. These presented in table 4.6 /ref. 7/. along the proposed cable route,

34 POST CONSTRUCTION MONITORING REPORT

Table 4.6. Cable Route. Sonar contact listing. Survey 2006 /ref. 7/

A total of 47 side scan sonar was not re-identified, since the interpreted as being possible wreck anomalies were identified within the cable route has been moved sites due to their size and possible cable route area during the ar- slightly to the north to ensure the evidence of structure – see figure chaeological assessment in 2007 un-disturbance of this site. 4.17. However, both anomalies /ref. 13/. Two exclusion zones were were in area of complex seafloor Two new sites of high archaeologi- defined in 2005 /ref. 12/. One was sediments and may have a geo- cal potential were identified on the re-identified in the post construction logical origin. cable route during the post con- survey, and does not appear to struction survey /ref. 13/. They are have been disturbed. The other

POST CONSTRUCTION MONITORING REPORT 35

Figure 4.17. Two new sites of high archaeological potential on the cable route. They may be possible wreck sites or may have natural geological origin /ref. 13/. Navigation Route ing the course of the navigation evidence within the dredged chan- The seabed sediments along the route), with coarser grained sands, nel and also on the edges of the navigation route are generally finer gravels and occasional boulders sand banks. grained materials comprising present on the seabed at the base Numerous objects can be seen sands, or possibly silty sands. of the channel, together with irregu- along the navigation route. A total lar small patches of fine grained An approximately 100m wide of 79 anomalies were identified sands. Megaripple bed forms are in dredged channel is evident (follow- within the navigation route area. No

36 POST CONSTRUCTION MONITORING REPORT

sites of high archaeological poten- 4.7.1 Conditions vation concern, at heights that tial were identified within the navi- Monitoring will, according to the could incur a risk of collision, a gation route area. FEPA licence (Appendix 1), need to programme of collision risk fulfil the following objectives: monitoring will be imple- 4.7 Birds 1. Determine whether there is mented. change in bird use and pas- This section reports on the findings The monitoring reported here cov- sage, measured by species, of the ornithological monitoring the ers the first year of post construc- abundance and behaviour, of first year post construction. The tion monitoring for Barrow Offshore the wind farm site and the ref- monitoring programme is designed Wind Farm. to meet the objectives set out in the erence site. FEPA licence for the Barrow Off- 2. Determine whether there is a 4.7.2 Monitoring methods shore Wind Farm. barrier effect to movement of In January 2007 a meeting was birds through the site. held with Natural England to agree The findings build upon the ornitho- 3. Determine the distribution of on a detailed survey programme logical analysis and assessments wildfowl and divers in the Irish post construction /ref. 18/. The submitted in the Construction Moni- Sea, covering the Barrow site agreed programme is presented in toring Report in November 2006. and the vicinity. This will in- Table 4.7. The discussion takes into account clude movements of wildfowl the results from baseline EIA pre- to and from Walney Island and construction surveys and the re- Common Scoter. sults from the 2005-2006 environ- 4. If objectives 1 and 2 reveal mental monitoring during construc- significant use of the Barrow tion. site by populations of conser-

Survey Type Timing Comments

Boat based surveys May, 2008 All surveys cover the wind farm site, 2 km buffer July, 2008 zone and reference site. August, 2008 October, 2008

May, 2009 July, 2009 August, 2009 October, 2009

May, 2010 July, 2010 August, 2010 October, 2010

Aerial surveys January 2007 All surveys cover the NW3 survey area. February, 2007

October, 2007 February, 2008

October, 2008 February, 2009

Walney Island survey October, 2007 Scope of work agreed with Natural England.

Table 4.7. Post construction bird survey programme. The originally planned 2007 boat surveys have been postponed one year.

POST CONSTRUCTION MONITORING REPORT 37

The boat based surveys originally licence requirements and covers a The survey transects are presented planned for 2007 (May, July, Au- three year period post construction. in the figures below (Figure 4.18 gust and October) have been post- and Figure 4.19). The survey on Aerial surveys poned one year due to irregularities the 21st February did not cover the Aerial bird surveys were under- in the 2007 survey programme. complete NW3 area. The north- taken by Wildfowl and Wetland Natural England and the Marine western corner of the survey area, Trust (WWT) through a survey and Fisheries Agency have been Danger Area D406, had to be ex- programme coordinated by the informed of the delay in the survey cluded due to military activities, Department for Business Enterprise programme and have approved the therefore some of the westernmost & Regulatory Reform (BERR). The revised programme. The bird moni- survey transects were curtailed. survey area covering Barrow Off- toring programme fulfils the FEPA shore Wind Farm is named NW3.

Figure 4.18. Aerial bird survey transects 16th January 2007

38 POST CONSTRUCTION MONITORING REPORT

Figure 4.19. Aerial bird survey transects 21st February 2007

The survey transects are flown at veys. Using a clinometer, birds yond 1,000m from the flight path of 2km intervals. Information on bird were located on one of four dis- the plane were not recorded. species, numbers, distance bands tance bands covering an area from and location through the aircraft 44m to 1,000m either the side of GPS is recorded during these sur- the plane (Figure 4.20); birds be-

4.5O 10O 15O 25O 60O

76 m

D C B A 1000 m 426 m 282 m 163 m 44 m

Figure 4.20. Distance bands used for aerial survey (not to scale) /ref. 21/

POST CONSTRUCTION MONITORING REPORT 39

The aircraft flies at 76m altitude zone without bird counting are Whooper Swan off Walney Island during the surveys. This flight approximately within the 2km buffer during the autumn 2007. height cannot be maintained at the zone around the wind farm. The survey preformed by the Wal- location of Barrow Offshore Wind Distribution maps were produced ney Bird Observatory used Hilps- Farm, where pilots fly above the for each of the relevant bird species ford Point as observation site. This wind farm. Bird survey data from showing the location and relative location holds a purpose built hide the wind farm site and the areas size of the observed bird flocks. for wildfowl and seabird observa- from where the pilot leaves survey Only birds observed at 76m altitude tions. Its geographical position at height to climb above the turbines are included in the Figure 4.27 to the southernmost point on Walney are therefore not recorded. The Figure 4.32. Island, allows for uninterrupted distances at which the aircraft in- view to Barrow Offshore Wind Farm creases flight height varies be- Walney Island survey (Figure 4.21). The scope of work tween the surveys and depends on A land based survey was set up to for the study has been agreed with e.g. wind conditions. In the January gain some information on the pas- Natural England. and February 2007 surveys the sage of Pink-footed Goose and

Figure 4.21. Location of Hilpsford Point

Monitoring took place during 21 main target species had com- Continuous monitoring took place days in September-October 2007. menced. The survey periods in- between dawn and dusk each day The timing of the survey initiation cluded 24th September to 7th Octo- (c0700-1900hrs). Brief details of was triggered by anecdotal evi- ber (both days included); and 18th weather conditions, wind strength, dence from daily recording activi- October to 24th October (both days visibility and sea state were re- ties at Walney Bird Observatory included). corded every hour. High powered indicating when the migration of the

40 POST CONSTRUCTION MONITORING REPORT

telescopes were used by the bird direction, approximate distance to sponds to the footprint of the Bar- observers. the shore (Table 4.8) and approxi- row Offshore Wind Farm. If Pink- mate flight height (Table 4.9). The footed Geese and Whooper Swans The target species, agreed with distance observation bands are were observed passing at 7km to Natural England, were in order of based on the positions of existing 9.7km distance, flight pattern was importance Pink-footed Goose, buoys in the area close to Barrow registered in addition. This includes Whooper Swan and other bird Offshore Wind Farm. birds changing flight height during species. For each record the follow- the passage of the wind farm. ing data were registered; species, The approximate distance of 7km number of birds, approximate flight to 9.7km from Walney Island corre-

Distance Band Distance from shore W 0.0 km A 0 - 2.5 km B 2.5 - 4.2 km C 4.2 - 7.0 km D 7.0 – 9.7 km

Table 4.8. Approximate distances from the shore for each distance observation band

Height Band Altitude A <20 metres (less than 10m below rotor height) B 20-130 metres (10m below rotor height to 10m above rotor height) C >130 metres (more than 10m above rotors)

Table 4.9. Approximate flight height above sea level

4.7.3 Objective 1 Determine whether there is change The 2007 boat based bird survey 4.7.4 Objective 2 in bird use and passage, measured programme was postponed a year. Determine whether there is a bar- by species, abundance and behav- Boat based surveys monitor the rier effect to movement of birds iour, of the wind farm site and the use and behaviour of the birds through the site. reference site. within the wind farm footprint and at This objective leads to the following the reference site. Assessment of This objective leads to the following hypothesis: potentially significant changes in hypothesis: the occurrence of important bird 2. The establishing of Barrow 1. The establishing of Barrow species can therefore not be as- Offshore Wind farm constitutes Offshore Wind Farm leads to a barrier that prevents impor- significant changes of occur- sessed on this monitoring report; tant migrating birds from mov- rence of important bird species instead it will be addressed in the ing through the site at the wind farm site following monitoring reports.

Aerial survey data from January Bird use and abundance at Barrow and February 2007 contain some Offshore Wind Farm have been data on the abundance and bird assessed in the Construction Moni- use in the area measured by spe- toring Report from boat based cies. These results are presented observations /ref. 17/. and discussed under Objective 3.

POST CONSTRUCTION MONITORING REPORT 41

The land based survey from October and 18th October to 24th The flight distance of the birds Walney Island gained informa- October a total of 79 Whooper from Walney Island was re- tion on the passage of birds off Swans and 4,883 Pink-footed corded during the survey (Table Walney Island during the au- Geese were observed (Table 4.11). The distance of 7.0 - tumn 2007. Detailed data on the 4.10). By far the majority of the 9.7km corresponds to the dis- passage of the target species birds were flying south (86% of tance from Walney Island to Pink-footed Goose and the Whooper Swans and 97% of Barrow Offshore Wind Farm. Whooper Swan were collected. the Pink-footed Geese). Within the 21 days survey period from 24th September to 7th

Total counts Flying South Flying north and other directions Whooper Swan 79 68 (86%) 11 Pink-footed Goose 4,883 4,732 (97%) 151

Table 4.10. Counts and flight directions of Whooper Swan and Pink-footed Goose from 21 survey days at Walney Island

0 km 0 – 2.5 km 2.5 – 4.2 km 4.2 – 7.0 km 7.0 – 9.7 km Whooper Swan 40 24 5 10 0 Pink-footed Goose 1,570 1,141 1,018 578 576

Table 4.11. Bird counts according to distances from Walney Island

Whooper Swan

40 35 30 25 Numbers 20 15 10 5 0 0 0–2.5 2.5–4.2 4.2–7.0 7.0–9.7 Distance bands (km)

Figure 4.22. Whooper Swan observations within distance bands from Walney Island.

Most of the observed Whooper tern, at that time 135 out of 150 served further out than 7km and Swans (81%) were less than 2.5km Whooper Swans (90%) were pass- none were passing at distances from the coastline of Walney Island ing less than 2.5km from the coast- corresponding to the distance of (Figure 4.22). A survey in 2004 line of Walney Island /ref. 20/. None Barrow Offshore Wind Farm (Table found a very similar migration pat- of the Whooper Swans were ob- 4.11).

42 POST CONSTRUCTION MONITORING REPORT

Pink-footed Goose

1600 1400 1200 1000 Numbers 800 600 400 200 0 0 0–2.5 2.5–4.2 4.2–7.0 7.0–9.7 Distance bands (km)

Figure 4.23. Pink-footed Goose observations within distance bands from Walney Island.

The majority of the observed Pink- • “< 20m”: corresponds to the Table 4. presents the approximate footed Geese (76%) were passing area from the sea level to 10m flight heights observed for Pink- less than 4.2km from Walney Island below the rotor height of the footed Goose. The first row pre- (Figure 4.23). About half of the wind turbines at Barrow Off- sents a summary of all the observa- birds (56%) were passing less than shore Wind Farm. tions from all distance bands be- 2.5km from the coastline. Some • “20 – 130m” corresponds to tween 0 - 9.7km from Walney Is- Pink-footed Geese were passing the height between 10m below land. The last row presents the further offshore and 576 birds or the rotors to 10m above the ro- birds observed at distances from 12% were observed passing at the tors of the wind turbines at 7.0 - 9.7km, corresponding ap- same distance from Walney Island Barrow Offshore Wind Farm. proximately to the footprint of Bar- as Barrow Offshore Wind Farm • “> 130m” corresponds to the row Offshore Wind Farm (Table (Table 4.11). area above 10m from the ro- 4.12). tors of the wind turbines at • The flight height of the birds Barrow Offshore Wind Farm. were registered and divided

into three height categories:

< 20m 20 – 130m > 130m Pink-footed Goose - All observations 467 1,630 2,786 (10%) (33%) (57%) Pink-footed Goose - At distances be- 60 9 507 tween 7.0 - 9.7km from Walney Island (10.4%) (1.6%) (88.0%)

Table 4.12. Approximate flight height observed for Pink-footed Goose

Considering the flight height of between 20-130m and 10% 9.7km from Walney Island was all the observed Pink-footed flying below 20m. different from the flight heights Geese, approximately half closer to shore (Figure 4.23; The observed flight height of the (57%) were registered flying Table 4.12). Most of the Pink- Pink-footed Geese passing the above 130m height, 33% flying footed Geese changed their Barrow Offshore Wind Farm at distances between 7km to

POST CONSTRUCTION MONITORING REPORT 43

flight height when approaching wind farm and passed the wind from the groups of birds when the wind farm. farm well above the turbines. A approaching and passing above total of 503 out of 512 birds the wind farm. The observed By far the majority of the geese (98.2%) were observed to gain birds adjusted their flight height approaching at flight height flight height when approaching to safely pass the Barrow Off- above 20m gained height ap- the wind farm. In Table 4.13 the shore Wind Farm and continue proximately 2-3km before the flight behaviour is summarized their migration.

Pink-footed Goose

100 80 60 % 40 20 7.0-9.7km 0 All obs. <20 20–130 >130 Flight height (m)

Figure 4.23. Flight height of Pink-footed goose for all observations (blue columns) and at 7.0-9.7 km distance from Walney Island (orange columns).

Birds approaching the wind farm shore Wind Farm and Walney served passing birds during the at less than 20m height main- Island when passing by the 21 days survey at Walney Is- tained their flight height through wind farm. Other birds reacted land (Appendix 4). the wind farm. by increasing flight height when passing fishing boats in the The findings from this study The flight height of Pink-footed area. It is unknown if the Pink- indicate that the Barrow Off- Goose registered in a study in footed Goose also changed shore Wind Farm do not consti- 2004 /ref. 20/ is different from flight height when approaching tute a barrier that prevents the results in the 2007 study. In fishing boats in the 2004 study. Whooper Swan or Pink-footed 2004 approximately 40% of the Goose from passing or moving birds flew at less than 20m The 9 Pink-footed Geese enter- through the site. height, 50% at 20-130m height ing the wind farm at rotor height and 10% at more than 130m flew in between the first easterly height. row of turbines; all birds left the wind farm at the substation in In the 2007 study some Pink- the southern part of the site and footed Geese were observed to continued their flight south. increase flight height also in the No collisions were observed area in between Barrow Off- from the total of 16,542 ob-

44 POST CONSTRUCTION MONITORING REPORT

Date Flight pattern observations 25-09 15 birds flew in from north in normal skein formation. Approx 2-3km before wind farm they formed a tight 2007 group and gained height to fly above wind farm. 25-09 40 birds approached from north. Gained height to fly over wind farm on line and continued south 2007 26-09 13 birds flew in from north in a normal skein. About 2-3km before the wind farm they grouped into a tight 2007 flock, gained height then reformed skein to fly over the wind farm at about 200m high. 26-09 A skein of 120 birds approached from north. About 2-3km north of wind farm they grouped together and 2007 gained height then flew over the wind farm at about 150m. 27-09 Skein of 55 birds flew from north at a height of 150m but steadily gained more height to clear turbines at 2007 a height of 250m. A second skein of 160 birds shortly after flew south at a height of 300m and maintained this height as they passed over the wind farm. 27-09 40 birds flew in from the north at a height of 150m. At 2-3km before the wind farm they bunched together 2007 and climbed to 300m. They stayed bunched until they had passed the wind farm then reformed the 'V' skein when clear. Soon after a party of four birds crossed the wind farm at a height of 280m. 01-10 A flock of 60 flew from the north at rotor height. At 2-3km north of the wind farm they started to climb 2007 above rotor height and flew over the wind farm at 250m.

Table 4.13. Pink-footed Goose flight pattern when approaching Barrow Offshore Wind Farm

4.7.5 Objective 3 rence of wildfowl at the wind IV. The establishing of Barrow Determine the distribution of wild- farm site and its vicinity. Offshore Wind Farm leads to fowl and divers in the Irish Sea, II. The establishing of Barrow significant changes of move- covering the Barrow site and the Offshore Wind Farm leads to ment of Common Scoter vicinity. This will include move- significant changes of occur- across the wind farm site and rence of divers at the wind its vicinity. ments of wildfowl to and from Wal- farm site and its vicinity. ney Island and Common Scoter. Results on the relative density of birds III. The establishing of Barrow recorded in the Irish Sea within the This objective leads to the following Offshore Wind Farm leads to offshore wind farm strategic areas are four hypotheses: significant changes of move- presented in Figure 4.24 and 4.25 /ref. ment of wildfowl to and from 21/. The data are based on aerial sur- Walney Island across the wind veys during the winter 2005/2006 and I. The establishing of Barrow farm site and its vicinity. summer 2006. Offshore Wind Farm leads to significant changes of occur-

POST CONSTRUCTION MONITORING REPORT 45

Figure 4.24. Relative density of birds recorded in North West Offshore Wind Farm Strategic Area during aerial surveys, winter 2005/06 /ref. 21/

46 POST CONSTRUCTION MONITORING REPORT

Figure 4.25. Relative density of birds recorded in North West OWF Strategic Area during aerial surveys, summer 2006 /ref. 21/

The results from the two aerial the increase in survey flight height cluded in the list. When the flight winter bird surveys in the NW3 area above the wind turbines, only the height increases above the wind are presented in Table 4.14. A amount of birds observed outside turbines, the bird observations are blank field in the table means no the Barrow Offshore Wind Farm not comparable with areas flown at observations of the species. Due to and two km buffer zone are in- lower heights.

POST CONSTRUCTION MONITORING REPORT 47

January 2007 February 2007 Group Species NW3 NW3 (ex. BOW+2km) (ex. BOW+2km) Auks Auk sp. 114 240 Cormorants Cormorant/Shag 1 Divers Diver sp. 13 6 Red-throated Diver 21 Gulls Black-backed Gull sp. 6 5 Great Black-backed Gull 4 5 Common Gull 4 Grey Gull sp. (Herring or Common) 17 7 Gull sp. 17 2 Herring Gull 13 3 Large Gull sp. 2 2 Lesser Black-backed Gull 2 Little Gull 1 2 Kittiwake 25 45 Small Gull sp. 6 Seabirds Guillemot 1 Seaducks Common Scoter 56 118 Eider 27 24 Red-breasted Merganser 4 Sum 327 466 Table 4.14. Results of aerial bird surveys within the NW3 survey sector. Counts within the Barrow Offshore Wind Farm (BOW) and the 2km buffer zone have been excluded from the total counts. A blank field means no observations of the species.

The aerial surveys presented in observed distribution of individual Figure 4.26 to Figure 4.31 show the bird species in the NW3 area.

48 POST CONSTRUCTION MONITORING REPORT

Figure 4.26. Distribution of Common Scoter from two aerial surveys in January and February 2007

Figure 4.27. Distribution of Diver species from two aerial surveys in January and February 2007

POST CONSTRUCTION MONITORING REPORT 49

Figure 4.28. Distribution of Eiders from two aerial surveys in January and February 2007

Figure 4.29. Distribution of Auk species from two aerial surveys in January and February 2007

50 POST CONSTRUCTION MONITORING REPORT

Figure 4.30. Distribution of all Gulls from two aerial surveys in January and February 2007

Figure 4.31. Distribution of the Gull species from two aerial surveys in January and February 2007

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Common Scoter Island. Two birds were ob- Auks The Common Scoter is primarily served west of Lune Deep. Auk species are found more or found south of Barrow Offshore None were observed outside less regularly distributed in the Wind Farm and with a few indi- the 20m depth curve (Figure NW3 area in the January and viduals west of Duddon Sands 4.27). The distribution pattern is February 2007 surveys (Figure in the January and February comparable with the October 4.28). Similar distribution pat- 2007 observations (Figure 2005 and February 2006 sur- terns were also observed prior 4.26). This distribution pattern is veys, where most birds were to construction of Barrow Off- very similar to the distribution found in the same area west of shore Wind Farm in January observed during construction Duddon Sands /ref. 17/. and February 2005 /ref. 19/. /ref. 17/. It is also similar to Eiders Gulls distributions observed before All the eiders observed in Janu- Gulls can be observed through- the construction of Barrow Off- ary and February 2007 were out the NW3 area. They are shore Wind Farm, e.g. in Janu- registered within a few kilome- found in shallow water and as ary and February 2005 /ref. 19/. tres west of Walney Island (Fig- far offshore as the survey area The relative density of Common ure 4.28). The distribution of extends to the west (Figure 4.29 Scoter recorded from aerial Eider in the first year of opera- and Figure 4.30). This distribu- surveys in the Irish Sea from tion of Barrow Offshore Wind tion pattern is similar to earlier January to March 2006 is pre- Farm is very similar to the dis- years’ observations. The counts sented in Figure 4.32 and Fig- tribution during construction /ref. of the individual gull species are ure 4.33. 17/. The amount of birds ob- also similar to the February Divers served is also similar to the 2006 observation /ref. 17/. The majority of the 40 divers peak counts of 30 birds within observed in January and Feb- the NW3 area from the period ruary 2007 (Table 4.14) were between 2002-2005 /ref. 19/. found along the coast line west of Duddon Sands and Walney

52 POST CONSTRUCTION MONITORING REPORT

Figure 4.32. Relative density of Common Scoter recorded in North West Offshore Wind Farm Strategic Area during aerial surveys, 1 January – 12 February 2006 /ref. 21/

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Figure 4.33. Relative density of Common Scoter recorded in North West Offshore Wind Farm Strategic Area during aerial surveys, 13 February – 12 March 2006 /ref. 21/

54 POST CONSTRUCTION MONITORING REPORT

The aerial survey monitoring indi- If this hypothesis is not rejected gathered during future boat sur- cates that the establishing of Bar- then: veys. row Offshore Wind Farm does not VI. The establishing of Barrow Data from the survey from Walney lead to significant changes in the Offshore Wind Farm results in Island revealed that approximately occurrence and distribution of a number of collisions [by spe- 0.18% (9 out of 4,883) of the ob- Common Scoter, divers or other cies name] that significantly af- served passing Pink-footed Geese wildfowl in the vicinity of the wind fect the population were flying in between the wind farm. No collisions have been observed turbines at rotor height. All 9 birds 4.7.6 Objective 4 during any of the environmental passed through the wind farm and If objectives 1 and 2 reveal signifi- monitoring bird surveys. continued their flight south. None of cant use of the Barrow site by the observed Pink-footed Geese The bird surveys before, during and populations of conservation con- collided with wind turbines. No the first year after construction of cern, at heights that could incur a Wooper Swans have been ob- Barrow Offshore Wind Farm have risk of collision, a programme of served in between the wind tur- not found bird populations of con- collision risk monitoring will be bines. servation concern significantly implemented. using the site. Therefore, based on the findings of This objective leads to the following the bird monitoring so far at Barrow No boat surveys were performed in two hypotheses: Offshore Wind Farm, it is consid- 2007, therefore no flight height from ered that further collision risk V. Barrow Offshore Wind Farm this survey methodology can be analysis is not required at this are being significantly used by taken into considerations of colli- stage. This will be reviewed in the populations of conservation sion risk assessment in this report. next monitoring report based on the concern. Information on flight height will be following annual bird findings.

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5. CONCLUSIONS

Barrow Offshore Wind Farm is noise, oceanography, seabed analysis of the pre construction located in the eastern Irish Sea morphology (scours etc.) and and post construction surveys near Barrow-in-Furness. The bathymetry, side scan sonar will be presented in the second wind farm became operational surveys, including archaeology, post construction monitoring in July 2006. and ornithology. report in November 2008. All changes to the monitoring pro- This report describes the envi- Some changes in the monitoring gramme have been agreed with ronmental monitoring under- programme have been made the Licence Authority. taken during the post construc- according to the planned sched- tion phase in 2006–2007. The ule for the studies. Concerning electromagnetic environmental monitoring re- fields (EMF), Barrow Offshore Concerning ornithology, the ported in this document should Wind Ltd. has agreed that boat surveys in 2007 have been be seen as a continuation of the measurements will postponed for one year. That pre-construction and construc- means the three year boat sur- be undertaken at the site in tion monitoring. Post- vey programme will run from spring 2008 as a part of the construction monitoring activi- 2008-2010 instead of 2007- research programme carried out ties are undertaken for a period 2009. The epifauna monopile by COWRIE (Collaborative of three years after construction, survey will be undertaken in Offshore Wind farm research and will be reported annually to May 2008, and the second post into the Environment). A sum- the licensing authority, as de- construction monitoring report mary of these results will be scribed in the FEPA licence. (November 2008) will encom- included in the second post This is the first of three post- pass these results. Further- construction monitoring report construction monitoring reports. more, the last of the planned (November 2008). This report covers the environ- post construction fishery sur- In general, the surveys under- mental monitoring related to veys was undertaken in October taken during the first year of relevant themes according to 2007. This report has not been operation of the wind farm did the licence conditions for the finalised yet and therefore it has not register major or unforeseen post construction period: Fish, been concluded that the result environmental impacts. benthos, operational underwater of the last survey as well as the

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6. REFERENCES

/ref. 1/ Titan Environmental Surveys Ltd – Coastal Surveys: Barrow Offshore Wind farm Fisheries. Moni- toring Survey. Winter 2006. Sub-contractor for RSK ENSR Ltd. /ref. 2/ Titan Environmental Surveys Ltd – Coastal Surveys: Barrow Offshore Wind farm Fisheries. Moni- toring Survey Dec 04. Spawning Season March 2007. Final Report (CS0116/D2/V289(R2/V2)). Sub-contractor for RSK ENSR Ltd. /ref. 3/ Mackie A.S.Y (1990) Offshore Benthic Communities in the Irish Sea. In. The Irish Sea: An Envi- ronmental Review. Part 1. Nature Conservation. Ed. Irish Sea Study Group, pp169-218. Liverpool University Press. /ref. 4/ Titan Environmental Surveys Ltd – Coastal Surveys: Barrow Offshore Wind Farm Project. Post Construction Benthic Survey 2007. Final Report (CS0188/R1/V2). /ref. 5/ Subacoustech Report No. 753R0109: Subsea operational noise assessment at the Barrow Off- shore Wind Farm site. June 2007. /ref. 6/ Titan Environmental Surveys Ltd – Coastal Surveys: Barrow Offshore Wind Farm Turbine Wake Study. Final Report (CS0195/R1/V2). June 2007. /ref. 7/ Osiris Projects: BOWind – Barrow Offshore Wind Farm. Post construction geophysical survey. Draft report. C7007a. July 2007. /ref. 8/ Osiris Projects & RSK ENSR Groups: BOWind – Barrow Offshore Wind Farm. Scour Monitoring Geophysical Survey. Final Report. C7007b. August 2007. /ref. 9/ Barrow Offshore Wind Farm - Environmental impact statement . RSK ENSR, 2002 /ref. 10/ Barrow Offshore Wind Farm - The preconstruction monitoring. RSK ENSR, 2005. /ref. 11/ Barrow Offshore Wind Farm - The construction monitoring report. BOWind, 2006. /ref. 12/ BOWind – 2007. Note prepared by RSK concerning turbines suggested for scour surveys. RSK/He/P/P40120/03/04/02. /ref. 13/ Wessex Archaeology: Barrow Offshore Wind Farm. Post construction Monitoring. Archaeological Assessment of Geophysical Data. Ref. 67630.02. December 2007. /ref. 14/ Letter from Marine and Fisheries Agency to Barrow Offshore Wind Ltd, concerning Barrow Off- shore Wind farm - Subacoustech Report No 753R0109. Dated 7 September 2007. /ref. 15/ Note prepared by Subacoustech concerning Subsea operational noise assessment at the Barrow Offshore Wind Farm site: Response to comments from the Marine and Fisheries Agency. Report Number 753R0204. Dated 21 November 2007. /ref. 16/ Benthic and Sediment Survey: Comparative analysis of pre and post construction. Benthic and Sedimentological Data. P40120/25. November 2007. Prepared by RSK Group. /ref. 17/ BOWind. 2006. Barrow Offshore Wind Farm. Construction Monitoring Report. November 2006. /ref. 18/ BOWind. 2007. Barrow Offshore Wind Farm. Bird Monitoring Programme Post Construction. 7. February 2007. /ref. 19/ Norman, T & K. 2006. Germanis. Walney Offshore Wind farm. Ornithological Impact Assessment. RPS.

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/ref. 20/ Walney Bird Observatory. 2004. Wildfowl and seabird migration along the eastern Irish Sea flyway. A late autumn study by Walney Bird Observatory. /ref. 21/ WWT. 2006. Aerial Surveys of Waterbirds in Strategic Wind farm Areas: 2005/06. Final Report.

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