Influence of electric fishing lights on sink rates of baited hooks in Brazilian pelagic long line.

Citation
Gianuca D, Peppes FV, Sant’Ana R, Neves T (2013) Influence of electric fishing lights on sink rates of baited hooks in Brazilian pelagic long line. SBWG5 Doc 34 Doc 34:1–13
Abstract

Recently, electric fishing lights (EFL) have been adopted by the southern Brazilian pelagic longline fleet. Each EFL carries two AA batteries, and given its weight out of the water (~160g) some fishermen argue this device is a replacement for the new line weighting regime of 60g within 2m of the hook. A total of 66 repetitions during 11 sets were obtained to compare the sink rate of baited hooks with weighted swivels placed at 3.5 and 5.5m from the hook, in each case with and without EFLs. The 3.5m treatments presented the mean fastest sink rates (0.281-0.515 m/s), while 5.5m treatments presented the mean slowest sink rates (0.182-0.431 m/s). The addition of an EFL above leaded swivels tended to decrease sink rate when set with 3.5m leaders and increase sink rates with 5.5m leaders but results were not significant. These results suggest that 3.5m leader lines with ≥60g leaded swivels, with or without EFLs may achieve satisfactory sink rates while 5.5m leaders do not.