标题：Post-release mortality of the demersal West Australian dhufish, Glaucosoma hebraicum (Richardson) following catch and release: the influence of depth of capture, venting and hook type
出版社：Government of Western Australia / Department of Fisheries
摘要：Cages were used to investigate the mortality after catch and release angling of the demersal
scalefish Glaucosoma hebraicum (Family Glaucosomatidae), a recreationally and commercially
important species in south-western Australia. The effects of capture depth, venting the swim
bladder, two types of hooks and anatomical hooking location, on mortality of G. hebraicum
were examined by simulating actual catch and release fishing by recreational anglers. Additional
factors (length of fish, duration of caging and the ability of released fish to swim) were included
in a logistic regression. Only depth (p < 0.01), duration of caging (p = 0.01) and hook location
(p = 0.01) were significant factors in predicting whether or not a fish died after release. Mortality
of G. hebraicum increased with depth of capture from 21% at 0-14 m to 86% at 45-59 m. Overall,
51% of all G. hebraicum caught in the experiment died. Most deaths (38.4%) were attributed
to barotraumas while the remainder (13.2%) was caused by damage by hooks. The high postrelease
mortality of G. hebraicum at any given depth compared to other demersal species is best
explained by their susceptibility to barotrauma. Traditional management strategies that assume
the survival of undersize or fish in excess of the bag limit that are returned to the water are not
appropriate for G. hebraicum, particularly in deeper waters. Alternative management options
must be developed to protect this slow growing, long-lived species.
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