Table 2 Overview on deployment duration, recording times, number of detected vessels and exposure rate to vessels per day for each tagged individual.

From: Vessel noise exposures of harbour seals from the Wadden Sea

Animal ID

Deployment duration (days)

Total recording time (h)

Recording time on-effort (h), (Proportion of total recording time in %)

Recording time off-effort (h), (Proportion of total recording time in %)

No. of vessels on-effort

Vessel exposure rate (No. of on-effort vessels per day)

hs16_265b

10.8

124

64.5 (52.0%)

59.5 (48.0%)

17

6.3

hs16_265c

21.5

275.5

89.6 (32.5%)

185.9 (67.5%)

22

5.9

hs17_109a

15.7

172.7

60.2 (34.9%)

112.5 (65.1%)

6

2.4

hs17_109b

7.3

99.7

28.8 (28.8%)

71 (71.2%)

4

3.3

hs17_109c

9.3

113.4

49.3 (43.4%)

64.2 (56.6%)

9

4.4

hs17_109d

25.3

259

120.5 (46.5%)

138.5 (53.5%)

17

3.4

hs17_109e

26.6

294.6

95.1 (32.3%)

199.5 (67.7%)

17

4.3

hs17_283a

23.7

273.4

110.7 (40.5%)

162.7 (59.5%)

30

6.5

hs17_283b

21.6

266.4

116.7 (43.8%)

149.7 (56.2%)

11

2.3

  1. The total recording time is the effective time when underwater sound levels could be measured, i.e., excluding haul-out, surfacing and outage periods. The recording time on-effort represents the times when the ambient noise in the 2 kHz decidecade was > 6 dB below the detection threshold of 97 dB re 1µPa. The recording time off-effort represents the times when ambient noise was above 91 dB re 1µPa, i.e., noise conditions are not sufficient to reliably detect a vessel. Only vessels detected during on-effort periods are used to calculate exposure rates.