Management Adaptation to Climate Change Effect on Fisheries in Western Australia

Abstract

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Octopus as predators of abalone on a sea ranch

“…O. tetricus (= Octopus cf. O. tetricus ), the most commonly encountered octopus species in Flinders Bay and Western Australia more broadly (Caputi et al., ). The percentage of shells with boreholes is much greater than those reported by Ambrose and Nelson (), Kojima () and Smith (), who identified <10% (3.4% to 7.7%) of Haliotis spp.…”

“…During a 12‐month sampling period, 265 octopuses were encountered on the ranch, with peak numbers found in summer. Octopus tetricus is a commercially valuable, short‐lived (≤18 months), medium‐sized (<4 kg) coastal octopus species, endemic to south‐western Australia (Amor et al., ; Caputi et al., ; Hart, Leporati, Marriott & Murphy, ). In this study, data on the presence and distribution of octopus ( O. tetricus ), empty abalone shells, and counts of abalone on the artificial abalone habitats (“Abitats”), used for put and take abalone sea ranching, were examined to determine: (a) the distribution and presence of octopus across three lease sites of Abitats in the Flinders Bay sea ranching operation; (b) the distribution and counts of empty abalone shells collected across the three areas and whether the number of empty shells is related to the presence of octopus; and (c) whether evidence of predation could be observed on any of the empty abalone shells collected and how this varied with the size of shells.…”

Diet and trophic role of octopus on an abalone sea ranch

“…O . tetricus (hereafter O. tetricus ) , Gould (emend, Amor, Norman, Cameron & Strugnell, ), is a coastal merobenthic species, endemic to south‐western Australia (Caputi et al., ; Hart, Leporati, Marriott & Murphy, ). While little is known of its diet, O. tetricus is known to predate on Western rock lobster, Panulirus cygnus George (Hart et al., ) , and, like the diets of other coastal octopuses, crabs and molluscs are likely to be important contributors to the overall diet (e.g.…”

Climate change alters fish community size‐structure, requiring adaptive policy targets

“…The parallel effects of environmental and fishing pressures on community‐level size‐based indicators have been detected in many of the world's marine ecosystems beyond the North Sea, including the Bering, Southern Catalan, Irish, Adriatic and Baltic Seas, Guinea and the Eastern Scotian shelf (Blanchard et al., ). In countries such as Australia, fisheries management organizations have also recognized that climate change will pose significant challenges to the life histories of exploited populations, which will require monitoring (Caputi et al., ,b). Studies such as the present one should precede the operationalization of fish size‐based indicators, because they can support the identification of adaptive, ecologically meaningful management targets as a changing climate starts to manifest itself in wild, fished populations.…”