Table 1.
Vessel and gear specifics of the four vessels used in the study.
Table 2.
Trip information and discards survival probability estimates for plaice.
Number of fish and discard survival probabilities are provided for control fish (C), test-fish sampled with dry hoppers (D), and test-fish sampled from water-filled hoppers (W).
Table 3.
Covariates and the range of their values recorded during the sea trips at haul level.
Fig 1.
Kaplan-Meier survival curves for plaice discards by hopper type (a) and by vitality class (b). In (a), curves are plotted for control fish (Control) and test-fish for two different hopper types: Conventional dry hoppers (Dry) and water-filled hoppers (Water), where both hopper types were used in a paired design. In (b), curves are plotted for test-fish of vitality classes A to D. Note that vitality class D includes fish that were dead at the start of the experiment. Drawn lines indicate mean survival percentage over time, with shaded areas indicating 95% confidence limits. Dots indicate the end of the monitoring time for individual fish that were alive at the end of the experiments.
Fig 2.
Effects of hopper type, substrate and handling time on the probability of falling in each of the vitality classes.
Dots and drawn lines indicate model estimated means, with arrows and shaded areas indicating 95% confidence limits.
Table 4.
Results from the ordinal regression analysis, testing the effects of hopper type and substrate on vitality class.
Fig 3.
Effects of fish condition (vitality class) and surface water temperature on survival probability.
Symbols indicate means, arrows indicate 95% confidence limits. Estimated effects of temperature are shown for a fish of average length (22.6 cm) and effects of fish length are shown for fish under average temperature conditions (12°C).
Table 5.
Fixed effect estimates from the final GLMM model, including standard error, z-value, and p-value.
Note that these estimates are on the logit scale.
Table 6.
Effect estimates from the GLMM model with hopper type, temperature, and fish length, including standard error, z-value, and p-value, for the eight trips where both hopper types were present.
Note that these estimates are on the logit scale.