Fig 1.
Experimental holding tank set-up with krill control groups and trawl caught escapees to monitor escape mortality.
Table 1.
Summary of mortality inspections made for control groups.
X: no inspection made.
Fig 2.
Covered codend sampling system used to collect krill trawl escapees (A (see also Fig 1 in Krafft and Krag [24] and B).
Fig 3.
Image captured inside the cover facing the codend (located at the right side of the picture) during fishing, using underwater video, Red circles indicate krill penetrating 16 mm meshes in the codend and escapees within the cover.
The cover mesh was 7 mm supported by a 200 mm protection net.
Table 2.
Operational conditions and survival probability 60 hours (P60) after trawl arrived on deck for codend mesh escapement hauls.
Table 3.
Holding conditions during entire monitoring period 06:12:05–15:12:19 (day:hour:min).
Table 4.
Summary of mortality inspections made for experimental groups of escapees: T: terminated.
Fig 4.
Kaplan-Meier survival probability curves for individual codend escapement hauls.
Dashed lines represent 95% confidence bands. Time on x-axis is given in hours from arrival of the catch on deck.
Table 5.
Summary for linear models for effect on 60 hours survival rate.
Fig 5.
Survival probability in individual hauls 60 hours after the catch arrived on deck against different operational parameters: haul duration, sea temperature, max. fishing depth, codend catch weight, cover catch weight, seawater salinity.
The lines in the plots represent the fit of the individual single parameter models.
Fig 6.
Kaplan-Meier survival probability curves for pooled hauls: codend escapement trials (blue), control experiment (red).
Dashed lines represent 95% confidence limits. Time is given in hours from when the catch arrived on deck.
Fig 7.
Length-dependent survival probability pooled over hauls.
Circles represent experimentally observed survival probabilities. Thick solid line represents the modelled length-dependent survival rate at the end of the observation period. Dashed lines represent 95% confidence limits for the survival probability. Thin solid line shows the number of surviving krill of different sizes. Dotted line shows the number of dead krill of different sizes.
Fig 8.
Length-dependent survival probability in control groups.
Circles represent experimentally observed survival probability. Solid thick line represents the modelled length-dependent survival rate at the end of observation period. Dashed lines represent 95% confidence limits for the survival probability. Thin solid line shows the number of surviving krill of each length. Dotted line shows the number of dead krill of different sizes.