Investigating Behaviour and Population Dynamics of Striped Marlin (Kajikia audax) from the Southwest Pacific Ocean with Satellite Tags

Behaviour and distribution of striped marlin within the southwest Pacific Ocean were investigated using electronic tagging data collected from 2005–2008. A continuous-time correlated random-walk Kalman filter was used to integrate double-tagging data exhibiting variable error structures into movement trajectories composed of regular time-steps. This state-space trajectory integration approach improved longitude and latitude error distributions by 38.5 km and 22.2 km respectively. Using these trajectories as inputs, a behavioural classification model was developed to infer when, and where, ‘transiting’ and ‘area-restricted’ (ARB) pseudo-behavioural states occurred. ARB tended to occur at shallower depths (108±49 m) than did transiting behaviours (127±57 m). A 16 day post-release period of diminished ARB activity suggests that patterns of behaviour were affected by the capture and/or tagging events, implying that tagged animals may exhibit atypical behaviour upon release. The striped marlin in this study dove deeper and spent greater time at ≥200 m depth than those in the central and eastern Pacific Ocean. As marlin reached tropical latitudes (20–21°S) they consistently reversed directions, increased swimming speed and shifted to transiting behaviour. Reversals in the tropics also coincided with increases in swimming depth, including increased time ≥250 m. Our research provides enhanced understanding of the behavioural ecology of striped marlin. This has implications for the effectiveness of spatially explicit population models and we demonstrate the need to consider geographic variation when standardizing CPUE by depth, and provide data to inform natural and recreational fishing mortality parameters

Population-based incidence of injuries among preschoolers.

A population survey was conducted to determine the incidence of injuries among preschoolers and their risk factors. A systematic sample (15%, n = 4540) of families with at least one child aged 0-5 years in 1991 living in the Canton of Vaud (Switzerland) received a mailed questionnaire in February 1992. There were 5827 eligible children in the sample. The response rate was 67.5% after two recall mailings. Injuries were defined as those from all causes with at least one physician contact in 1991. The overall incidence was 224 injuries per 1000 children (95% CI [= confidence intervall]: 211-237); 188 per 1000 children were injured over 1 year (95% CI: 176-200, n = 746), of whom 16.5% (n = 123) had 32 injuries. Falls represented 66% of all injuries, followed by burns (8%) and poisonings (5%). The proportion of hospitalized cases was 4.8% and the population incidence of hospitalization due to injury was 10.8/1000 children. Socioeconomic factors did not influence the occurrence of injuries. CONCLUSION: The measured incidence of injuries among preschoolers is among the highest in developed countries. Practitioners could contribute more effectively to injury prevention through routine information and counselling of parents from all social backgrounds