Characterizing activity and assessing bycatch survival of Pacific halibut with accelerometer Pop-up Satellite Archival Tags

Table 2 PSAT metric performance and activity mode frequency for hourly subset data from Port Frederick fish

% Occurrence in 120 subsampled hours	Fish PF-1	Fish PF-2	Fish PF-3
Spurious KDs	0	0.8	0
Spurious tilt	7.5	3.3	5
Under-detection by KDs	10	35.8	1.7
Under-detection by tilt	5.8	51.7	21.7
Change in depth without change in tilt	0	0.8	0
Stationary activity	29.2	37.5	36.7
Hopping activity	56.7	52.5	45
Sustained swimming activity	14.1	10	18.3

Results from hourly examination of detailed (1 Hz) acceleration and depth data from three Pacific halibut (Hippoglossus stenolepis) tagged with Pop-up Satellite Archival Tags in Port Frederick (PF), Alaska. Hourly data (n = 120 per fish) were examined from five separate 24-h periods throughout the duration of deployment. Percentage occurrence of hours with any spurious knockdowns (KD, count of abrupt changes in tilt) and %tilt (proportion of time spent active), hours where KDs or %tilt did not detect activity (under-detection), hours where change in depth occurred without tilt of PSAT, and proportion of hours classified as stationary, hopping, or sustained swimming activity modes are indicated

ISSN: 2050-3385