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Table 1 Tracking parameters for three missions by the REMUS-100 SharkCam on basking sharks in Scotland

From: Autonomous underwater videography and tracking of basking sharks

  Mission 1 Mission 2 Mission 3
Date 11-Jul-19 14-Jul-19 16-Jul-19
Shark sex Female Female Male
Shark total length 7–8 m 6–7 m 4–5 m
Mission start 12:32 09:56 13:47
Mission end 16:42 12:05 18:23
Mission duration 250 min 129 min 276 min
AUV speed; mean (± 1 S.D.) 1.5 m s−1 (0.5) 0.9 m s−1 (0.6) 1.5 m s−1 (0.4)
Shark depth; mean (± 1 S.D.) 15.6 m (6.5) 15.3 m (12.8) 31.8 m (21.9)
Shark depth (maximum) 25.0 m 59.7 m 63.7 m
Water temperature; mean (± 1 S.D.; range) 11.3 °C (0.2; 11.1–12.0) 11.1 °C (0.7; 10.3–13.1) 11.2 °C (1.0; 9.2–12.3)
Chl-α concentration; median (IQR) 1.2 mg m3 (1.06–1.43) 0.7 mg m3 (0.46–0.83) 0.8 mg m3 (0.59–1.17)
AUV-retag tracking offsets
 Forward–aft 3 m aft 1 m aft 1 m aft
 Port–starboard 0 m 2 m port 2.5 m port
 Above–below 1 m below 1 m above 1.5 m above
Minimum AUV altitude 6 m 2 m 3 m
Minimum AUV depth 1 m 1 m 3 m
Maximum permitted AUV depth 80 m 90 m 90 m
Cumulative duration shark observed (% of mission duration) 36 min (14%) 20 min (16%) 90 min (33%)
Number of contacts events with shark 2 6 3
Horizontal visibility (% tracking duration) Mission 1 (%) Mission 2 (%) Mission 3 (%)
≤ 5 m 12
5 to 7 23
7 to 10 65 19 48
10 to 15 81 29
15 to 20 23
  1. Times given in UTC (Coordinated Universal Time). Tracking offsets are relative to the retag attached to the shark. Visibility was estimated from the video data, using the seabed, or other features visible to estimate visibility in five binned intervals