Review of research and assessments on the efficacy of sea lion exclusion devices in reducing the incidental mortality of New Zealand sea lions Phocarctos hookeri in the Auckland Islands squid trawl fishery

摘要: New Zealand sea lions are incidentally killed in the Auckland Islands squid trawl fishery. Sea lion exclusion devices (SLEDs) that allow animals to escape from net have received considerable development and assessment attention. Nonetheless, there claims some could suffer head trauma when colliding with hard grid forms part of SLED this may compromise post-escape survival. We reviewed published unpublished research assessed effectiveness SLEDs reducing incidental capture (i.e. bycatch) lions, including assessments on likelihood post-SLED The available evidence shows effective bycatch nets contribute reduced rates observed mortality Efforts test efficacy shown most likely survive following their via a SLED, despite shortage verifying video due poor visibility at fishing depths. Laboratory necropsies caught been unable reliably evaluate survivability effects on-board handling carcasses, logistical necessity freezing them. Some lesions initially considered be were subsequently deemed artefacts freezing. was no clear difference between without SLEDs. Biomechanical modelling suggested it unlikely impact would cause fatal brain probability concussion result drowning probably less than 10%. As fisheries has levels driving continued decline Islands, future work better focussed alternative management areas more addressing reversing population decline.