Table 1 Accelerometer-derived metrics of activity and/or behaviour for marine animals, including the targeted activity or behavior, equipment used, and example study or studies using the metric
Metric | Identification | Target activity | Equipment | Frequency/timespan | Species | Ref |
|---|---|---|---|---|---|---|
Calculated before data transmission (no device retrieval needed) | ||||||
PrCA (prey catch attempt) | Per-second change in acceleration greater than a (running average + threshold) value | Dive-foraging attempts via rapid head and body movements | Relay satellite tag | One dive sampled and summarized every 2.25 h at 16 Hz for up to 338 days | Wedell (Leptonychotes weddellii)41 and southern elephant seals (Mirounga leonine)31 | |
KD (knockdown event) | Abrupt switch of PSAT from vertical to horizontal | Beginning of a swimming bout, mortality | PSAT | 2-h summary of 1-Hz data/60Â days | Pacific halibut (Hippoglossus stenolepis) | |
Tilt (g) | Degree of PSAT tilt, from vertical to horizontal via z-axis | Swimming behavior (sustained or saltatory), mortality | PSAT | 2-h summary of 1-Hz data/60Â days | Pacific halibut (Hippoglossus stenolepis) | |
ATS (activity time-series) | Per-second instances of mobility exceeding a dynamic high activity threshold | Relative high activity | PSAT | 75-s and 1-h summaries of 1-Hz data/30Â days | Sandbar sharks (Carcharhinus plumbeus) | [This study] |
G | Vectorized acceleration along x, y, and z-axes | Diurnal activity | PSAT | 3-min summaries of 1.5625-Hz data | Pacific sailfish (Istiophorus platypterus) | [34] |
Calculated before device retrieval | ||||||
Burst acceleration events | Exceeds manually defined acceleration threshold | Escape behaviors | Accelerometer logger | 500 Hz/18–45 h | Red seabream (Pagrus major) and yellowtail kingfish (Seriola lalandi) | [45] |
Calculated after device retrieval | ||||||
Prey engulfment | Differential of acceleration > 1000 m/s | Feeding (raptorial and suction) | Accelerometer logger | 200 and 333 Hz/timespan NA | Harbor seal (Phoca vitulina) | [19] |
ODBA (overall dynamic body acceleration) | (Absolute acceleration along x, y, and z-axes) – (static acceleration due to gravity) | Energy expenditure (as acceleration around a center of mass) | Accelerometer logger | Moderate-to-high frequency (> 10 Hz) | NA | [46] |