Electronic Supplementary Material - Short-term disturbance by a commercial

2-D seismic survey does not lead to long-term displacement of harbour

porpoises

Methodology. Seismic Survey Characteristics

Seismic surveys were conducted from MV Sea Surveyor, using a six air-gun phased

array, operated by Gardline Geosurvey. Marine Mammal Observers (MMO) onboard

the vessel conducted visual and passive acoustic surveys of the area around the

ship prior to the start of shooting to ensure that no marine mammals were within

500m of the guns. A soft start procedure was then initiated in which the volume of

the discharge was gradually increased to its full operating volume of 470 cu inches

over a 20 minute period. The shot point interval was approximately 5-6 seconds

during survey lines. During each line turn, the volume of the gun discharge was

reduced to 60 cu inches and the shot point interval increased to 4 minutes for

approximately 30 minutes. A soft start was again initiated once the MMO had

confirmed that the area was free of marine mammals.

Survey effort was maintained 24 hrs a day throughout the 10 day survey. A time line

of the vessel’s activity is provided in Table S1, and an animation of the vessel track

is provided in the electronic supplementary video file “MorayFirthSeismic.mp4”. In

this video the vessel track is shown in black when in transit, in red when the air-guns

are at full power and in grey during line turns.

Noise Recording Equipment

The frequency characteristics of a recording system is limited by the component with

the narrowest and/or most variable frequency response. Here, the overall system

behaviour with respect to frequency was dominated by three main components: the

RESON TC-4032 hydrophone, the National Instruments NI USB-6251 analogue to

digital convertor and the RESON VP2000 conditioning amplifier. This hydrophone

has a flat response between 10 Hz and 80 kHz (http://www.teledyne-

reson.com/products/hydrophones/tc-4032/) and was further calibrated between 250

Hz and 250 KHz by the UK National Physical Laboratory in accordance with UKAS.

The analogue to digital convertor has a specified flat frequency response to over 200

KHz (http://sine.ni.com/ds/app/doc/p/id/ds-21/lang/en#detailedspecs-section) and

was tested prior to this study by the manufacturer. Measurement standards and

instruments used for that calibration are traceable to NIST and/or other International

Measurement Institutes (NMI's) that are signatories of the International Committee of

Weights and Measures (CIPM) Mutual Recognition Agreement (MRA). The

conditioning amplifier was tested by a third party in accordance with ISO/IEC 17025.

Operating characteristics and calibration records for these devices are included in

Annex I.

With reference to these calibration records, the hydrophone was the device for which

the greatest degree of uncertainty is specified: ±1.2dB with 95% certainty. The

sampling rate of the analogue to digital convertor was deliberately curtailed to

sample frequencies no greater than 250 kHz. All devices have calibration information

up to this frequency with uncertainty less than ±1.2dB. Therefore the overall system

calibration indicates that measurements between 250 Hz and 250 kHz were within

±1.2dB with 95% certainty.

Aerial surveys

Digital aerial surveys were conducted in 2011 to determine how the relative

distribution of porpoises changed in relation to distance from the seismic survey

vessel. The timing of surveys made before and during the seismic survey period is

provided in Table S 2,and both flight lines and detections of porpoises are shown in

Figure S 2.

Identification of harbour porpoises from the video was carried out by experienced

analysts at WWT Consulting Ltd., who had extensive experience of both visual and

digital aerial survey work in UK waters. Harbour porpoises were identified on the

basis of their small and compact body size (approx 1.3-1.9m for adults); a blunt head

that lacked the beak of the other small cetaceans likely to be encountered in the

Moray Firth (i.e. Bottlenose dolphin, Tursiops truncatus, Risso’s Dolphin, Grampus

griseus , White-beaked Dolphin, Lagenorhynchus albirostris and Short-beaked

common dolphin, Delphinus delphis [1]; and their dark back with paler undersides

that lacked the distinct body patterns of other small delphinids such as Short-beaked

common dolphin. In practice, harbour porpoises in this study area were most likely to

be confused with seals, meaning that observations of the compact horizontal fluke

were a key criteria when assigning detections as “definite” and “probable” harbour

porpoises. Example images are presented in Figure S 3.

Visual Aerial Surveys were carried out between 16th August and 27th September

2010 to provide baseline data on the absolute density of harbor porpoises in each of

our 25 x 25 km study blocks.

Surveys were made using a Partenavia P68 aircraft, on days with sea state ≤ 3,

minimum visibility of 1000m and a cloud base above 200m to allow surveys to be

conducted at a height of 183m. Within each study block, parallel north/south transect

lines spaced at 4 km were flown at a speed of 100 knots. An offset of 1 km was

used and the starting position was selected randomly so that during the course of the

whole survey period, the blocks were covered at 1 km spacing (Figure S 4). Surveys

were made over each block on 9 days, representing 2934 km of effort.

Two observers made observations out of different sides of the aeroplane. Time,

species, number of animals and the declination angle to the sighting were recorded.

The horizontal distance from the trackline to the sighting was later calculated from

the declination angle and used with the aircraft GPS track to calculate the position of

each animal seen. Environmental variables were recorded by a third observer and

included Beaufort sea state and glare intensity. A subjective measure of sighting

conditions was recorded as four levels; poor, moderate, good and excellent. All data

collected under poor sighting conditions were removed prior to analysis.

We used standard procedures available in the program Distance (Thomas et al.

2009) to calculate density and abundance from these data. Given the much larger

dataset available from the SCANS-II aerial surveys of the North Sea in 2005, we

used their value of 0.45 for g(0) for harbour porpoises sighted under good conditions

[2]. Although our dataset included some periods with moderate sighting conditions,

95 out of 111 (>85%) of survey lines were flown in good sighting conditions. A

hazard rate detection function was used incorporating those environmental

covariates that may have affected detection. Four covariates were tested; observer

identity, sea state, sighting conditions and glare intensity. These were added using a

forward stepwise selection procedure based on AIC. Observer identity was the only

covariate retained in the detection function. Data from the whole survey period were

pooled to calculate a single detection function for porpoises that was then applied to

data collected within each of the survey blocks to provide estimates of density in

those sub-areas.

References:

1. Reid J.B., Evans P.G.H., Northridge S.P. 2003 Atlas of Cetacean distribution

in north-west European waters. Peterborough, UK, Joint Nature Conservation

Committee; 76 p.

2. Hammond P., Macleod K., Berggren P., Borchers D., Burtc L., Cañadas A.,

Desportese G., Donovan D., Gilles A., Gillespie D., et al. 2013 Cetacean abundance

and distribution in European Atlantic shelf waters to inform conservation and

management. Biological Conservation 164, 107-122.

Figure S1. Map showing locations (solid dots) at which calibrated noise

measurements of seismic air gun noise were made between 1st and 5th September

2011. Seismic survey lines for those portions of the overall survey programme being

carried out during this period are shown in blue.

a)

b)

Figure S2. High definition video survey effort (grey lines) and sightings (red dots)

within each 5 x 5 km analysis block a) before the seismic survey and b) during the

seismic survey. The blue dot on each map indicates the mean position of the seismic

vessel during high definition video surveys carried out between 2nd-5th September.

Actual seismic survey lines are shown in blue in part b.

a) Definite harbour porpoise

b) Probable harbour porpoise

c) Possible harbour porpoise

Figure S 3. Example images taken from the hi-definition video collected during 2011

digital aerial surveys, illustrating the confidence categories used for the identification

of harbour porpoises.

Figure S 4. Flight tracks used during the visual aerial surveys that were used in

2010 to provide baseline estimates of the absolute abundance of harbour porpoises

in the two 25 x 25 km study blocks.

Table S1. Detailed time line of the activity of the seismic survey vessel. A full GPS

trail for the vessel’s movements during this period is provided in the DRYAD archive

that included data from this publication.

Event Start Event End Event

Duration

(hrs:

Mins)

Event Date Time Date Time

30/08/2011 18:30 31/08/2011 07:02 Vessel transiting to Block 17/4b from Montrose Harbour.

31/08/2011 07:02 01/09/2011 15:14 Vessel on site deploying and balancing equipment

01/09/2011 15:15 01/09/2011 15:38 00:23 Soft start (aborted).

01/09/2011 17:08 01/09/2011 17:23 00:15 Soft start (aborted).

01/09/2011 22:04 01/09/2011 22:07 00:03 Soft start (aborted).

01/09/2011 22:11 01/09/2011 22:30 00:19 Soft start (aborted).

01/09/2011 22:33 01/09/2011 22:57 00:24 Soft start (aborted).

01/09/2011 22:57 02/09/2011 01:57 03:00 Vessel running test lines

02/09/2011 01:58 02/09/2011 03:14 01:16 Soft start started.

02/09/2011 03:14 02/09/2011 03:23 00:09 Start of Line (SOL) 1. Hdg 146°. Line aborted

02/09/2011 03:23 02/09/2011 04:55 01:32 Line turning to restart line.

02/09/2011 04:55 02/09/2011 04:56 00:01 MMO confirmed area cetacean free.

02/09/2011 04:56 02/09/2011 05:24 00:28 Soft start started.

02/09/2011 05:24 02/09/2011 06:41 01:17 SOL line 1A. Hdg 146°. Km run 7.0.

02/09/2011 06:41 02/09/2011 07:01 00:20 Line turning on 60 cu in source power and a 4 min shot

interval.

02/09/2011 07:01 02/09/2011 07:02 00:01 MMO confirmed area cetacean free.

02/09/2011 07:02 02/09/2011 07:31 00:29 Soft start started.

02/09/2011 07:31 02/09/2011 08:48 01:17 SOL line 4. Hdg 326°. Km run 7.0.

02/09/2011 08:48 02/09/2011 09:14 00:26 Line turning on 60 cu in source power and a 4 min shot

interval.

02/09/2011 09:14 02/09/2011 09:15 00:01 MMO confirmed area cetacean free.

02/09/2011 09:15 02/09/2011 09:44 00:29 Soft start started.

02/09/2011 09:44 02/09/2011 11:00 01:16 SOL line 2. Hdg 146°. Km run 7.0.

02/09/2011 11:00 02/09/2011 11:33 00:33 Line turning on 60 cu in source power and a 4 min shot

interval.

02/09/2011 11:33 02/09/2011 11:34 00:01 MMO confirmed area cetacean free.

02/09/2011 11:34 02/09/2011 12:06 00:32 Soft start started.

02/09/2011 12:06 02/09/2011 13:23 01:17 SOL line 14. Hdg 216°. Km run 7.0.

02/09/2011 13:23 02/09/2011 13:59 00:36 Line turning on 60 cu in source power and a 4 min shot

interval.

02/09/2011 13:59 02/09/2011 14:00 00:01 MMO confirmed area cetacean free.

02/09/2011 14:00 02/09/2011 14:31 00:31 Soft start started.

02/09/2011 14:31 02/09/2011 15:48 01:17 SOL line 3. Hdg 146°. Km run 7.0.

02/09/2011 15:48 02/09/2011 16:26 00:38 Line turning on 60 cu in source power and a 4 min shot

interval.

02/09/2011 16:26 02/09/2011 16:27 00:01 MMO confirmed area cetacean free.

02/09/2011 16:27 02/09/2011 16:59 00:32 Soft start started.

02/09/2011 16:59 02/09/2011 17:49 00:50 SOL line 15. Hdg 326°. Line aborted.

02/09/2011 17:49 02/09/2011 18:17 00:28 Line turning on 60 cu in source power and a 4 min shot

interval.

02/09/2011 18:17 02/09/2011 18:18 00:01 MMO confirmed area cetacean free.

02/09/2011 18:18 02/09/2011 18:42 00:24 Soft start started.

02/09/2011 18:42 02/09/2011 20:28 01:46 Vessel conducting test fixes .

02/09/2011 20:28 02/09/2011 20:29 00:01 MMO confirmed area cetacean free.

02/09/2011 20:29 02/09/2011 20:56 00:27 Soft start started.

02/09/2011 20:56 02/09/2011 22:12 01:16 SOL line 27. Hdg 146°. Km run 7.0.

02/09/2011 22:12 02/09/2011 22:33 00:21 Line turning on 60 cu in source power and a 4 min shot

interval.

02/09/2011 22:33 02/09/2011 22:34 00:01 MMO confirmed area cetacean free.

02/09/2011 22:34 02/09/2011 23:06 00:32 Soft start started.

02/09/2011 23:06 03/09/2011 00:24 01:18 SOL line 30. Hdg 326°. Km run 7.0

03/09/2011 00:24 03/09/2011 00:44 00:20 Line turning on 60 cu in source power and a 4 min shot

interval.

03/09/2011 00:44 03/09/2011 00:45 00:01 MMO confirmed area cetacean free.

03/09/2011 00:45 03/09/2011 01:19 00:34 Soft start started.

03/09/2011 01:19 03/09/2011 02:36 01:17 SOL line 26. Hdg 146°. Km run 7.0.

03/09/2011 02:36 03/09/2011 02:54 00:18 Line turning on 60 cu in source power and a 4 min shot

interval.

03/09/2011 02:54 03/09/2011 02:55 00:01 MMO confirmed area cetacean free.

03/09/2011 02:55 03/09/2011 03:30 00:35 Soft start started.

03/09/2011 03:30 03/09/2011 04:47 01:17 SOL line 32. Hdg 326°. Km run 7.0.

03/09/2011 04:47 03/09/2011 05:07 00:20 Line turning on 60 cu in source power and a 4 min shot

interval.

03/09/2011 05:07 03/09/2011 05:08 00:01 MMO confirmed area cetacean free.

03/09/2011 05:08 03/09/2011 05:41 00:33 Soft start started.

03/09/2011 05:41 03/09/2011 06:57 01:16 SOL line 29. Hdg 146°. Km run 7.0.

03/09/2011 06:57 03/09/2011 07:13 00:16 Line turning on 60 cu in source power and a 4 min shot

interval.

03/09/2011 07:13 03/09/2011 07:14 00:01 MMO confirmed area cetacean free.

03/09/2011 07:14 03/09/2011 07:48 00:34 Soft start started.

03/09/2011 07:48 03/09/2011 09:04 01:16 SOL line 34. Hdg 326°. Km run 7.0.

03/09/2011 09:04 03/09/2011 10:12 01:08 Line turning to re-run line 1. Source array stopped.

03/09/2011 10:12 03/09/2011 10:13 00:01 MMO confirmed area cetacean free.

03/09/2011 10:13 03/09/2011 10:48 00:35 Soft start started.

03/09/2011 10:48 03/09/2011 12:04 01:16 SOL line 1B. Hdg 146°. Km run 7.0.

03/09/2011 12:04 03/09/2011 12:23 00:19 Line turning on 60 cu in source power and a 4 min shot

interval.

03/09/2011 12:23 03/09/2011 12:24 00:01 MMO confirmed area cetacean free.

03/09/2011 12:24 03/09/2011 12:57 00:33 Soft start started.

03/09/2011 12:57 03/09/2011 14:15 01:18 SOL line 4A. Hdg 326°. Km run 7.0.

03/09/2011 14:15 03/09/2011 14:32 00:17 Line turning on 60 cu in source power and a 4 min shot

interval.

03/09/2011 14:32 03/09/2011 14:33 00:01 MMO confirmed area cetacean free.

03/09/2011 14:33 03/09/2011 15:06 00:33 Soft start started.

03/09/2011 15:06 03/09/2011 16:22 01:16 SOL line 2A. Hdg 146°. Km run 7.0.

03/09/2011 16:22 03/09/2011 16:56 00:34 Line turning on 60 cu in source power and a 4 min shot

interval.

03/09/2011 16:56 03/09/2011 16:57 00:01 MMO confirmed area cetacean free.

03/09/2011 16:57 03/09/2011 17:27 00:30 Soft start started.

03/09/2011 17:27 03/09/2011 18:44 01:17 SOL line 14A. Hdg 326°. Km run 7.0.

03/09/2011 18:44 03/09/2011 19:13 00:29 Line turning on 60 cu in source power and a 4 min shot

interval.

03/09/2011 19:13 03/09/2011 19:14 00:01 MMO confirmed area cetacean free.

03/09/2011 19:14 03/09/2011 19:47 00:33 Soft start started.

03/09/2011 19:47 03/09/2011 21:04 01:17 SOL line 3A. Hdg 146°. Km run 7.0.

03/09/2011 21:04 03/09/2011 21:41 00:37 Line turning on 60 cu in source power and a 4 min shot

interval.

03/09/2011 21:41 03/09/2011 21:42 00:01 MMO confirmed area cetacean free.

03/09/2011 21:42 03/09/2011 22:12 00:30 Soft start started.

03/09/2011 22:12 03/09/2011 23:28 01:16 SOL line 15A. Hdg 326°. Km run 7.0.

03/09/2011 23:28 03/09/2011 23:58 00:30 Line turning on 60 cu in source power and a 4 min shot

interval.

03/09/2011 23:58 03/09/2011 23:59 00:01 MMO confirmed area cetacean free.

03/09/2011 23:59 04/09/2011 00:31 00:32 Soft start started.

04/09/2011 00:31 04/09/2011 01:49 01:18 SOL line 5. Hdg 146°. Km run 7.0.

04/09/2011 01:49 04/09/2011 02:20 00:31 Line turning on 60 cu in source power and a 4 min shot

interval.

04/09/2011 02:20 04/09/2011 02:21 00:01 MMO confirmed area cetacean free.

04/09/2011 02:21 04/09/2011 02:54 00:33 Soft start started.

04/09/2011 02:54 04/09/2011 04:11 01:17 SOL line 16. Hdg 326°. Km run 7.0.

04/09/2011 04:11 04/09/2011 04:40 00:29 Line turning on 60 cu in source power and a 4 min shot

interval.

04/09/2011 04:40 04/09/2011 04:41 00:01 MMO confirmed area cetacean free.

04/09/2011 04:41 04/09/2011 05:12 00:31 Soft start started.

04/09/2011 05:12 04/09/2011 06:28 01:16 SOL line 6. Hdg 146°. Km run 7.0.

04/09/2011 06:28 04/09/2011 06:56 00:28 Line turning on 60 cu in source power and a 4 min shot

interval.

04/09/2011 06:56 04/09/2011 06:57 00:01 MMO confirmed area cetacean free.

04/09/2011 06:57 04/09/2011 07:30 00:33 Soft start started.

04/09/2011 07:30 04/09/2011 08:46 01:16 SOL line 17. Hdg 326°. Km run 7.0.

04/09/2011 08:46 04/09/2011 09:16 00:30 Line turning on 60 cu in source power and a 4 min shot

interval.

04/09/2011 09:16 04/09/2011 09:17 00:01 MMO confirmed area cetacean free.

04/09/2011 09:17 04/09/2011 09:47 00:30 Soft start started.

04/09/2011 09:47 04/09/2011 10:46 00:59 SOL line 7. Hdg 146°. Km run 5.3.

04/09/2011 10:46 04/09/2011 11:38 00:52 Line turning on 60 cu in source power and a 4 min shot

interval.

04/09/2011 11:38 04/09/2011 11:39 00:01 MMO confirmed area cetacean free.

04/09/2011 11:39 04/09/2011 12:55 01:16 Soft start started.

04/09/2011 12:55 04/09/2011 13:29 00:34 SOL line 18. Hdg 326°. Km run 7.0.

04/09/2011 13:29 04/09/2011 13:58 00:29 Line turning on 60 cu in source power and a 4 min shot

interval.

04/09/2011 13:58 04/09/2011 13:59 00:01 MMO confirmed area cetacean free.

04/09/2011 13:59 04/09/2011 14:33 00:34 Soft start started.

04/09/2011 14:33 04/09/2011 15:18 00:45 SOL line 8. Hdg 146°. Km run 4.5.

04/09/2011 15:18 04/09/2011 16:22 01:04 Line turning on 60 cu in source power and a 4 min shot

interval.

04/09/2011 16:22 04/09/2011 16:23 00:01 MMO confirmed area cetacean free.

04/09/2011 16:23 04/09/2011 16:57 00:34 Soft start started.

04/09/2011 16:57 04/09/2011 18:14 01:17 SOL line 19. Hdg 326°. Km run 7.0.

04/09/2011 18:14 04/09/2011 18:43 00:29 Line turning on 60 cu in source power and a 4 min shot

interval.

04/09/2011 18:43 04/09/2011 18:44 00:01 MMO confirmed area cetacean free.

04/09/2011 18:44 04/09/2011 19:17 00:33 Soft start started.

04/09/2011 19:17 04/09/2011 20:06 00:49 SOL line 9. Hdg 146°. Km run 5.2.

04/09/2011 20:06 04/09/2011 21:03 00:57 Line turning on 60 cu in source power and a 4 min shot

interval.

04/09/2011 21:03 04/09/2011 21:04 00:01 MMO confirmed area cetacean free.

04/09/2011 21:04 04/09/2011 21:39 00:35 Soft start started.

04/09/2011 21:39 04/09/2011 22:56 01:17 SOL line 20. Hdg 326°. Km run 7.0.

04/09/2011 22:56 04/09/2011 23:26 00:30 Line turning on 60 cu in source power and a 4 min shot

interval.

04/09/2011 23:26 04/09/2011 23:27 00:01 MMO confirmed area cetacean free.

04/09/2011 23:27 05/09/2011 00:01 00:34 Soft start started.

05/09/2011 00:01 05/09/2011 00:52 00:51 SOL line 10. Hdg 146°. Km run 5.1.

05/09/2011 00:52 05/09/2011 01:52 01:00 Line turning on 60 cu in source power and a 4 min shot

interval.

05/09/2011 01:52 05/09/2011 01:53 00:01 MMO confirmed area cetacean free.

05/09/2011 01:53 05/09/2011 02:26 00:33 Soft start started.

05/09/2011 02:26 05/09/2011 03:43 01:17 SOL line 31. Hdg 326°. Km run 7.0.

05/09/2011 03:43 05/09/2011 04:29 00:46 Line turning on 60 cu in source power and a 4 min shot

interval.

05/09/2011 04:29 05/09/2011 04:30 00:01 MMO confirmed area cetacean free.

05/09/2011 04:30 05/09/2011 05:02 00:32 Soft start started.

05/09/2011 05:02 05/09/2011 05:55 00:53 SOL line 11. Hdg 146°. Km run 5.3.

05/09/2011 05:55 05/09/2011 06:46 00:51 Line turning on 60 cu in source power and a 4 min shot

interval.

05/09/2011 06:46 05/09/2011 06:47 00:01 MMO confirmed area cetacean free.

05/09/2011 06:47 05/09/2011 07:20 00:33 Soft start started.

05/09/2011 07:20 05/09/2011 08:37 01:17 SOL line 28. Hdg 326°. Km run 7.0.

05/09/2011 08:37 05/09/2011 09:17 00:40 Line turning on 60 cu in source power and a 4 min shot

interval.

05/09/2011 09:17 05/09/2011 09:18 00:01 MMO confirmed area cetacean free.

05/09/2011 09:18 05/09/2011 09:51 00:33 Soft start started.

05/09/2011 09:51 05/09/2011 11:08 01:17 SOL line 12. Hdg 146°. Km run7.0.

05/09/2011 11:08 05/09/2011 11:40 00:32 Line turning on 60 cu in source power and a 4 min shot

interval.

05/09/2011 11:40 05/09/2011 11:41 00:01 MMO confirmed area cetacean free.

05/09/2011 11:41 05/09/2011 12:15 00:34 Soft start started.

05/09/2011 12:15 05/09/2011 13:32 01:17 SOL line 23. Hdg 326°. Km run 7.0.

05/09/2011 13:32 05/09/2011 14:02 00:30 Line turning on 60 cu in source power and a 4 min shot

interval.

05/09/2011 14:02 05/09/2011 14:03 00:01 MMO confirmed area cetacean free.

05/09/2011 14:03 05/09/2011 14:38 00:35 Soft start started.

05/09/2011 14:38 05/09/2011 15:54 01:16 SOL line 13. Hdg 146°. Km run 7.0.

05/09/2011 15:54 05/09/2011 16:25 00:31 Line turning on 60 cu in source power and a 4 min shot

interval.

05/09/2011 16:25 05/09/2011 16:26 00:01 MMO confirmed area cetacean free.

05/09/2011 16:26 05/09/2011 16:59 00:33 Soft start started.

05/09/2011 16:59 05/09/2011 17:44 00:45 SOL line 25. Hdg 326° Line stopped due to compressor

failure.

05/09/2011 17:44 05/09/2011 18:55 01:11 Turning to resume line at fix 460.

05/09/2011 18:55 05/09/2011 18:56 00:01 MMO confirmed area cetacean free.

05/09/2011 18:56 05/09/2011 19:31 00:35 Soft start started.

05/09/2011 19:31 05/09/2011 20:13 00:42 SOL line 25A. Hdg 326°. Km run 7.0.

05/09/2011 20:13 05/09/2011 20:33 00:20 Line turning on 60 cu in source power and a 4 min shot

interval.

05/09/2011 20:33 05/09/2011 20:34 00:01 MMO confirmed area cetacean free.

05/09/2011 20:34 05/09/2011 21:05 00:31 Soft start started.

05/09/2011 21:05 05/09/2011 22:23 01:18 SOL line 21. Hdg 146°. Km run 7.0.

05/09/2011 22:23 05/09/2011 22:59 00:36 Line turning on 60 cu in source power and a 4 min shot

interval.

05/09/2011 22:59 05/09/2011 23:00 00:01 MMO confirmed area cetacean free.

05/09/2011 23:00 05/09/2011 23:34 00:34 Soft start started.

05/09/2011 23:34 06/09/2011 00:51 01:17 SOL line 33. Hdg 326°. Km run 7.0.

06/09/2011 00:51 06/09/2011 01:24 00:33 Line turning on 60 cu in source power and a 4 min shot

interval.

06/09/2011 01:24 06/09/2011 01:25 00:01 MMO confirmed area cetacean free.

06/09/2011 01:25 06/09/2011 02:00 00:35 Soft start started.

06/09/2011 02:00 06/09/2011 03:18 01:18 SOL line 22. Hdg 146°. Km run 7.0.

06/09/2011 03:18 06/09/2011 03:52 00:34 Line turning on 60 cu in source power and a 4 min shot

interval.

06/09/2011 03:52 06/09/2011 03:53 00:01 MMO confirmed area cetacean free.

06/09/2011 03:53 06/09/2011 04:24 00:31 Soft start started.

06/09/2011 04:24 06/09/2011 05:41 01:17 SOL line 34A. Hdg 326°. Km run 7.0.

06/09/2011 05:41 06/09/2011 06:12 00:31 Line turning on 60 cu in source power and a 4 min shot

interval.

06/09/2011 06:12 06/09/2011 06:13 00:01 MMO confirmed area cetacean free.

06/09/2011 06:13 06/09/2011 06:45 00:32 Soft start started.

06/09/2011 06:45 06/09/2011 08:03 01:18 SOL line 24. Hdg 146°. Km run 7.0.

06/09/2011 08:03 06/09/2011 08:40 00:37 Line turning on 60 cu in source power and a 4 min shot

interval.

06/09/2011 08:40 06/09/2011 08:41 00:01 MMO confirmed area cetacean free.

06/09/2011 08:41 06/09/2011 09:14 00:33 Soft start started.

06/09/2011 09:14 06/09/2011 10:32 01:18 SOL line 39. Hdg 326°. Km run 7.0.

06/09/2011 10:32 06/09/2011 10:53 00:21 Line turning on 60 cu in source power and a 4 min shot

interval.

06/09/2011 10:53 06/09/2011 10:54 00:01 MMO confirmed area cetacean free.

06/09/2011 10:54 06/09/2011 11:25 00:31 Soft start started.

06/09/2011 11:25 06/09/2011 12:43 01:18 SOL line 35. Hdg 146°. Km run 7.0.

06/09/2011 12:43 06/09/2011 13:09 00:26 Line turning on 60 cu in source power and a 4 min shot

interval.

06/09/2011 13:09 06/09/2011 13:10 00:01 MMO confirmed area cetacean free.

06/09/2011 13:10 06/09/2011 13:42 00:32 Soft start started.

06/09/2011 13:42 06/09/2011 15:01 01:19 SOL line 42. Hdg 326°. Km run 7.0.

06/09/2011 15:01 06/09/2011 15:23 00:22 Line turning on 60 cu in source power and a 4 min shot

interval.

06/09/2011 15:23 06/09/2011 15:24 00:01 MMO confirmed area cetacean free.

06/09/2011 15:24 06/09/2011 15:57 00:33 Soft start started.

06/09/2011 15:57 06/09/2011 17:14 01:17 SOL line 36. Hdg 146°. Km run 7.0.

06/09/2011 17:14 06/09/2011 17:40 00:26 Line turning on 60 cu in source power and a 4 min shot

interval.

06/09/2011 17:40 06/09/2011 17:41 00:01 MMO confirmed area cetacean free.

06/09/2011 17:41 06/09/2011 18:14 00:33 Soft start started.

06/09/2011 18:14 06/09/2011 19:31 01:17 SOL line 44. Hdg 326°. Km run 7.0.

06/09/2011 19:31 06/09/2011 19:52 00:21 Line turning on 60 cu in source power and a 4 min shot

interval.

06/09/2011 19:52 06/09/2011 19:53 00:01 MMO confirmed area cetacean free.

06/09/2011 19:53 06/09/2011 20:28 00:35 Soft start started.

06/09/2011 20:28 06/09/2011 21:45 01:17 SOL line 37. Hdg 146°. Km run 7.0.

06/09/2011 21:45 06/09/2011 22:20 00:35 Line turning on 60 cu in source power and a 4 min shot

interval.

06/09/2011 22:20 06/09/2011 22:21 00:01 MMO confirmed area cetacean free.

06/09/2011 22:21 06/09/2011 22:52 00:31 Soft start started.

06/09/2011 22:52 07/09/2011 00:08 01:16 SOL line 46. Hdg 326°Km run.7.0.

07/09/2011 00:08 07/09/2011 00:36 00:28 Line turning on 60 cu in source power and a 4 min shot

interval.

07/09/2011 00:36 07/09/2011 00:37 00:01 MMO confirmed area cetacean free.

07/09/2011 00:37 07/09/2011 01:06 00:29 Soft start started.

07/09/2011 01:06 07/09/2011 02:21 01:15 SOL line 38. Hdg 146°. Km run. 7.0.

07/09/2011 02:21 07/09/2011 02:51 00:30 Line turning on 60 cu in source power and a 4 min shot

interval.

07/09/2011 02:51 07/09/2011 02:52 00:01 MMO confirmed area cetacean free.

07/09/2011 02:52 07/09/2011 03:25 00:33 Soft start started.

07/09/2011 03:25 07/09/2011 04:42 01:17 SOL line 48. Hdg 326°. Km run 7.0.

07/09/2011 04:42 07/09/2011 05:09 00:27 Line turning on 60 cu in source power and a 4 min shot

interval.

07/09/2011 05:09 07/09/2011 05:10 00:01 MMO confirmed area cetacean free.

07/09/2011 05:10 07/09/2011 05:40 00:30 Soft start started.

07/09/2011 05:40 07/09/2011 06:57 01:17 SOL line 41. Hdg 146°. Km run 7.0.

07/09/2011 06:57 07/09/2011 07:20 00:23 Line turning on 60 cu in source power and a 4 min shot

interval.

07/09/2011 07:20 07/09/2011 07:21 00:01 MMO confirmed area cetacean free.

07/09/2011 07:21 07/09/2011 07:53 00:32 Soft start started.

07/09/2011 07:53 07/09/2011 09:06 01:13 SOL line 47. Hdg 326°. Km run 7.0.

07/09/2011 09:06 07/09/2011 09:30 00:24 Line turning on 60 cu in source power and a 4 min shot

interval.

07/09/2011 09:30 07/09/2011 09:31 00:01 MMO confirmed area cetacean free.

07/09/2011 09:31 07/09/2011 10:02 00:31 Soft start started.

07/09/2011 10:02 07/09/2011 11:19 01:17 SOL line 40. Hdg 146°. Km run 7.0.

07/09/2011 11:19 07/09/2011 11:50 00:31 Line turning on 60 cu in source power and a 4 min shot

interval.

07/09/2011 11:50 07/09/2011 11:51 00:01 MMO confirmed area cetacean free.

07/09/2011 11:51 07/09/2011 12:23 00:32 Soft start started.

07/09/2011 12:23 07/09/2011 13:40 01:17 SOL line 49. Hdg 326°. Km run 5.7.

07/09/2011 13:40 07/09/2011 14:13 00:33 Line turning on 60 cu in source power and a 4 min shot

interval.

07/09/2011 14:13 07/09/2011 14:14 00:01 MMO confirmed area cetacean free.

07/09/2011 14:14 07/09/2011 14:47 00:33 Soft start started.

07/09/2011 14:47 07/09/2011 16:04 01:17 SOL line 38A. Hdg 146°. Km run 7.0.

07/09/2011 16:04 07/09/2011 16:43 00:39 Line turning on 60 cu in source power and a 4 min shot

interval.

07/09/2011 16:43 07/09/2011 16:44 00:01 MMO confirmed area cetacean free.

07/09/2011 16:44 07/09/2011 17:16 00:32 Soft start started.

07/09/2011 17:16 07/09/2011 18:32 01:16 SOL line 51. Hdg 326°. Km run 7.0.

07/09/2011 18:32 07/09/2011 19:59 01:27 Source array stopped.

07/09/2011 19:59 07/09/2011 20:00 00:01 MMO confirmed area cetacean free.

07/09/2011 20:00 07/09/2011 20:31 00:31 Soft start started.

07/09/2011 20:31 07/09/2011 20:44 00:13 SOL line 49_Infil. Hdg 326°. Km run 1.3.

07/09/2011 20:44 07/09/2011 21:09 00:25 Line turning on 60 cu in source power and a 4 min shot

interval.

07/09/2011 21:09 07/09/2011 21:10 00:01 MMO confirmed area cetacean free.

07/09/2011 21:10 07/09/2011 21:43 00:33 Soft start started.

07/09/2011 21:43 07/09/2011 23:00 01:17 SOL line 43. Hdg 146°. Km run 7.0.

07/09/2011 23:00 07/09/2011 23:33 00:33 Line turning on 60 cu in source power and a 4 min shot

interval.

07/09/2011 23:33 07/09/2011 23:34 00:01 MMO confirmed area cetacean free.

07/09/2011 23:34 08/09/2011 00:07 00:33 Soft start started.

08/09/2011 00:07 08/09/2011 01:22 01:15 SOL line 53. Hdg 326°. Km run 7.0.

08/09/2011 01:22 08/09/2011 01:50 00:28 Line turning on 60 cu in source power and a 4 min shot

interval.

08/09/2011 01:50 08/09/2011 01:51 00:01 MMO confirmed area cetacean free.

08/09/2011 01:51 08/09/2011 02:22 00:31 Soft start started.

08/09/2011 02:22 08/09/2011 03:39 01:17 SOL line 45. Hdg 146°. Km run 7.0.

08/09/2011 03:39 08/09/2011 04:10 00:31 Line turning on 60 cu in source power and a 4 min shot

interval.

08/09/2011 04:10 08/09/2011 04:36 00:26 MMO confirmed area cetacean free.

08/09/2011 04:36 08/09/2011 04:42 00:06 Soft start started.

08/09/2011 04:42 08/09/2011 05:59 01:17 SOL line 55. Hdg 326°. Km run 7.0.

08/09/2011 05:59 08/09/2011 06:22 00:23 Line turning on 60 cu in source power and a 4 min shot

interval.

08/09/2011 06:22 08/09/2011 06:23 00:01 MMO confirmed area cetacean free.

08/09/2011 06:23 08/09/2011 06:53 00:30 Soft start started.

08/09/2011 06:53 08/09/2011 08:11 01:18 SOL line 50. Hdg 146°. Km run 7.0.

08/09/2011 08:11 08/09/2011 08:30 00:19 Line turning on 60 cu in source power and a 4 min shot

interval.

08/09/2011 08:30 08/09/2011 08:31 00:01 MMO confirmed area cetacean free.

08/09/2011 08:31 08/09/2011 09:04 00:33 Soft start started.

08/09/2011 09:04 08/09/2011 10:21 01:17 SOL line 54. Hdg 326°. Km run 7.0.

08/09/2011 10:21 08/09/2011 10:45 00:24 Line turning. No source array energised.

08/09/2011 10:45 08/09/2011 10:46 00:01 MMO confirmed area cetacean free.

08/09/2011 10:46 08/09/2011 11:19 00:33 Soft start started.

08/09/2011 11:19 08/09/2011 13:10 01:51 SOL line 46A. Hdg 146°Line aborted.

08/09/2011 13:10 08/09/2011 13:11 00:01 MMO confirmed area cetacean free.

08/09/2011 13:11 08/09/2011 13:43 00:32 Soft start started.

08/09/2011 13:43 08/09/2011 15:00 01:17 SOL line 46A. Hdg 146°. Km run 7.0.

08/09/2011 15:00 08/09/2011 15:24 00:24 Line turning. No source array energised.

08/09/2011 15:24 08/09/2011 15:25 00:01 MMO confirmed area cetacean free.

08/09/2011 15:25 08/09/2011 15:50 00:25 Soft start started.

08/09/2011 15:50 08/09/2011 17:14 01:24 SOL line 52. Hdg 326°. Km run 7.0.

08/09/2011 17:14 08/09/2011 19:05 01:51 Line turning. No source array energised.

08/09/2011 19:05 08/09/2011 19:06 00:01 MMO confirmed area cetacean free.

08/09/2011 19:06 08/09/2011 19:36 00:30 Soft start started.

08/09/2011 19:36 08/09/2011 21:53 02:17 SOL line 56. Hdg 236°. Km run 15.0.

08/09/2011 21:53 08/09/2011 22:33 00:40 Line turning. No source array energised.

08/09/2011 22:33 08/09/2011 22:34 00:01 MMO confirmed area cetacean free.

08/09/2011 22:34 08/09/2011 23:05 00:31 Soft start started.

08/09/2011 23:05 09/09/2011 01:21 02:16 SOL line 60. Hdg 056°. Km run 15.0.

09/09/2011 01:21 09/09/2011 01:50 00:29 Line turning. No source array energised.

09/09/2011 01:50 09/09/2011 01:51 00:01 MMO confirmed area cetacean free.

09/09/2011 01:51 09/09/2011 02:25 00:34 Soft start started.

09/09/2011 02:25 09/09/2011 04:41 02:16 SOL line 57. Hdg 236°. Km run 15.0.

09/09/2011 04:41 09/09/2011 05:17 00:36 Line turning. No source array energised.

09/09/2011 05:17 09/09/2011 05:18 00:01 MMO confirmed area cetacean free.

09/09/2011 05:18 09/09/2011 05:50 00:32 Soft start started.

09/09/2011 05:50 09/09/2011 08:05 02:15 SOL line 61. Hdg 056°. Km run 15.0.

09/09/2011 08:05 09/09/2011 08:45 00:40 Line turning on 60 cu in source power and a 4 min shot

interval.

09/09/2011 08:45 09/09/2011 08:46 00:01 MMO confirmed area cetacean free.

09/09/2011 08:46 09/09/2011 09:09 00:23 Soft start started.

09/09/2011 09:09 09/09/2011 11:26 02:17 SOL line 58. Hdg 236°. Km run 15.0.

09/09/2011 11:26 09/09/2011 12:08 00:42 Line turning on 60 cu in source power and a 4 min shot

interval.

09/09/2011 12:08 09/09/2011 12:09 00:01 MMO confirmed area cetacean free.

09/09/2011 12:09 09/09/2011 12:40 00:31 Soft start started.

09/09/2011 12:40 09/09/2011 14:50 02:10 SOL line 62. Hdg 056°. Km run 15.0.

09/09/2011 14:50 09/09/2011 15:35 00:45 Line turning on 60 cu in source power and a 4 min shot

interval.

09/09/2011 15:35 09/09/2011 15:36 00:01 MMO confirmed area cetacean free.

09/09/2011 15:36 09/09/2011 16:06 00:30 Soft start started.

09/09/2011 16:06 09/09/2011 18:22 02:16 SOL line 59. Hdg 236°. Km run 15.0.

09/09/2011 18:22 09/09/2011 20:20 01:58 Block 17/4b survey complete; Source array recovered;

Transit to Helmsdale survey area.

09/09/2011 20:20 09/09/2011 21:42 01:22 Source array deployed & test line conducted at SOL 14.

09/09/2011 21:42 09/09/2011 21:43 00:01 MMO confirmed area cetacean free.

09/09/2011 21:43 09/09/2011 22:15 00:32 Soft start started.

09/09/2011 22:15 10/09/2011 00:16 02:01 SOL line 14. Hdg 281.3°. Km run 13.0.

10/09/2011 00:16 10/09/2011 00:43 00:27 Line turning on 60 cu in source power and a 4 min shot

interval.

10/09/2011 00:43 10/09/2011 00:44 00:01 MMO confirmed area cetacean free.

10/09/2011 00:44 10/09/2011 01:16 00:32 Soft start started.

10/09/2011 01:16 10/09/2011 03:23 02:07 SOL line 9. Hdg 101.6°. Km run 13.6.

10/09/2011 03:23 10/09/2011 03:52 00:29 Line turning on 60 cu in source power and a 4 min shot

interval.

10/09/2011 03:52 10/09/2011 03:53 00:01 MMO confirmed area cetacean free.

10/09/2011 03:53 10/09/2011 04:26 00:33 Soft start started.

10/09/2011 04:26 10/09/2011 06:27 02:01 SOL line 11. Hdg 281.3°. Km run 13.2.

10/09/2011 06:27 10/09/2011 07:10 00:43 Line turning on 60 cu in source power and a 4 min shot

interval.

10/09/2011 07:10 10/09/2011 07:11 00:01 MMO confirmed area cetacean free.

10/09/2011 07:11 10/09/2011 07:45 00:34 Soft start started.

10/09/2011 07:45 10/09/2011 09:56 02:11 SOL line 7. Hdg 101.6°. Km run 14.1.

10/09/2011 09:56 10/09/2011 10:31 00:35 Line turning on 60 cu in source power and a 4 min shot

interval.

10/09/2011 10:31 10/09/2011 10:32 00:01 MMO confirmed area cetacean free.

10/09/2011 10:32 10/09/2011 11:04 00:32 Soft start started.

10/09/2011 11:04 10/09/2011 13:10 02:06 SOL line 10. Hdg 281.3°. Km run 13.4.

10/09/2011 13:10 10/09/2011 14:02 00:52 Line turning on 60 cu in source power and a 4 min shot

interval.

10/09/2011 14:02 10/09/2011 14:03 00:01 MMO confirmed area cetacean free.

10/09/2011 14:03 10/09/2011 14:34 00:31 Soft start started.

10/09/2011 14:34 10/09/2011 16:48 02:14 SOL line 5. Hdg 101.6°. Km run 14.6.

10/09/2011 16:48 10/09/2011 17:22 00:34 Line turning on 60 cu in source power and a 4 min shot

interval.

10/09/2011 17:22 10/09/2011 17:23 00:01 MMO confirmed area cetacean free.

10/09/2011 17:23 10/09/2011 17:55 00:32 Soft start started.

10/09/2011 17:55 10/09/2011 20:03 02:08 SOL line 8. Hdg 282°. Km run 13.8.

10/09/2011 20:03 10/09/2011 20:37 00:34 Line turning on 60 cu in source power and a 4 min shot

interval.

10/09/2011 20:37 10/09/2011 20:38 00:01 MMO confirmed area cetacean free.

10/09/2011 20:38 10/09/2011 21:06 00:28 Soft start started.

10/09/2011 21:06 10/09/2011 23:54 02:48 SOL line 3. Hdg 102.6°. Km run 15.3.

10/09/2011 23:54 10/09/2011 23:57 00:03 Line turning on 60 cu in source power and a 4 min shot

interval.

10/09/2011 23:57 10/09/2011 23:58 00:01 MMO confirmed area cetacean free.

10/09/2011 23:58 11/09/2011 00:32 00:34 Soft start started.

11/09/2011 00:32 11/09/2011 02:44 02:12 SOL line 6. Hdg 282°. Km run 14.3.

11/09/2011 02:44 11/09/2011 03:03 00:19 Line turning on 60 cu in source power and a 4 min shot

interval.

11/09/2011 03:03 11/09/2011 03:04 00:01 MMO confirmed area cetacean free.

11/09/2011 03:04 11/09/2011 03:39 00:35 Soft start started.

11/09/2011 03:39 11/09/2011 06:01 02:22 SOL line 2. Hdg 102.3°. Km run 15.7.

11/09/2011 06:01 11/09/2011 06:27 00:26 Line turning on 60 cu in source power and a 4 min shot

interval.

11/09/2011 06:27 11/09/2011 06:28 00:01 MMO confirmed area cetacean free.

11/09/2011 06:28 11/09/2011 06:59 00:31 Soft start started.

11/09/2011 06:59 11/09/2011 09:14 02:15 SOL line 4. Hdg 282.4°. Km run 15.0.

11/09/2011 09:14 11/09/2011 09:29 00:15 Line turning on 60 cu in source power and a 4 min shot

interval.

11/09/2011 09:29 11/09/2011 09:30 00:01 MMO confirmed area cetacean free.

11/09/2011 09:30 11/09/2011 10:03 00:33 Soft start started.

11/09/2011 10:03 11/09/2011 12:25 02:22 SOL line 1. Hdg 102°. Km run 16.1.

11/09/2011 12:25 11/09/2011 14:21 01:56 Line turning on 60 cu in source power and a 4 min shot

interval.

11/09/2011 14:21 11/09/2011 14:22 00:01 MMO confirmed area cetacean free.

11/09/2011 14:22 11/09/2011 14:53 00:31 Soft start started.

11/09/2011 14:53 11/09/2011 16:46 01:53 SOL line 13. Hdg 024.7°. Km run 12.0.

11/09/2011 16:46 11/09/2011 18:00 01:14 Line turning on 60 cu in source power and a 4 min shot

interval.

11/09/2011 18:00 11/09/2011 18:01 00:01 MMO confirmed area cetacean free.

11/09/2011 18:01 11/09/2011 18:32 00:31 Soft start started.

11/09/2011 18:32 11/09/2011 20:20 01:48 SOL line 12. Hdg 196°. Km run 11.4.

11/09/2011 20:20 12/09/2011 12:40 Helmsdale survey complete; Source array recovered; Transit

to Inverness via Buckie.

Table S 2. Timing of aerial digital surveys made before and during the seismic

surveys.

Date No. of

Transects

Start

Time

(BST)

End

Time

(BST)

Vessel Activity

6th

August 2011 10 09:50 15:35 Before seismic

22nd

August 2011 10 12:45 18:18 Before seismic

31st August 2011 6 16:01 19:16 Before seismic

2nd

September 2011 4 11:24 13:49 During seismic

3rd

September 2011 4 15:24 17:31 During seismic

4th

September 2011 8 12:17 15:52 During seismic

5th

September 2011 10 10:24 15:41 During seismic

Annex I. Calibration documents for the recording equipment used to estimate

received noise levels at different distances from the seismic survey vessel.

a) Hydrophone

b) Conditioning Amplifier

c) Analogue to digital converter

Full specifications are available from the manufacturer’s data sheet at:

http://sine.ni.com/ds/app/doc/p/id/ds-21/lang/en#detailedspecs-section