Summary
An experiment was conducted on an autoline longline vessel to derive a sink rate, and line weighting regime, that would minimise the capture of albatrosses based on knowledge of line sink rates and albatross diving abilities. Sink rates of lines deployed into propeller turbulence, which probably slowed sink rate, varied as a function of distance between line weights. Asymptotic sink rates (0.1-0.15 m/sec) were achieved with 70 m between 6.5 kg weights. Sink rates to 4 m depth were greatest with 35 m (0.44 m/sec) and 50 m (0.33 m/sec) between weights. For vessels using bird scaring lines and setting lines in propeller turbulence longline sink rates >0.3 m/sec should greatly reduce the incidental take of albatrosses. For vessels with similar gear and line setting characteristics to the experimental vessel, this sink rate should be achievable with 4 kg weights distributed every 40 m on longlines.