Use bait throwers to reduce seabird bycatch

Overall effectiveness category Unknown effectiveness (limited evidence)
Number of studies: 1
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How is the evidence assessed?

Effectiveness

46%
Certainty

30%
Harms

0%

Calculating overall effectiveness category

Background information and definitions

The turbulence created by a boat’s wake can stop bait from sinking quickly, allowing birds more time to become hooked. Bait throwers work by throwing bait clear of the wake, so that it sinks faster. Throwers also allow fishermen to direct lines, for example aiming them to lie under streamer lines (see ‘Use streamer lines to reduce seabird bycatch on longlines’

Study locations

Key messages

A study from Australia found significantly lower seabird bycatch on longlines set with a bait thrower.

About key messages

Key messages provide a descriptive index to studies we have found that test this intervention.

Studies are not directly comparable or of equal value. When making decisions based on this evidence, you should consider factors such as study size, study design, reported metrics and relevance of the study to your situation, rather than simply counting the number of studies that support a particular interpretation.

Supporting evidence from individual studies

A comparative analysis of data from 86 longlining vessels operating around Tasmania, Australia, between April 1992 and March 1995 (Klaer & Polacheck 1998) and studying a total of 141 line sets, found that sets that using a bait thrower had significantly lower seabird bycatch rates, compared to sets without a thrower. This study is also described in ‘Set longlines at night to reduce seabird bycatch’ and ‘Thaw bait to reduce seabird bycatch’.
Study and other actions tested
Referenced paper
Klaer N. & Polacheck T. (1998) The influence of environmental factors and mitigation measures on by-catch rates of seabirds by Japanese longline fishing vessels in the Australian region. Emu, 98, 305-316.

Please cite as:

Williams, D.R., Child, M.F., Dicks, L.V., Ockendon, N., Pople, R.G., Showler, D.A., Walsh, J.C., zu Ermgassen, E.K.H.J. & Sutherland, W.J. (2020) Bird Conservation. Pages 137-281 in: W.J. Sutherland, L.V. Dicks, S.O. Petrovan & R.K. Smith (eds) What Works in Conservation 2020. Open Book Publishers, Cambridge, UK.

Where has this evidence come from?

List of journals searched by synopsis

All the journals searched for all synopses

This Action forms part of the Action Synopsis:

Bird Conservation

Related Actions

Actions	Effectiveness	Studies	Category
Use acoustic alerts on gillnets to reduce seabird bycatch Action Link	Unknown effectiveness (limited evidence)	1	Synopsis Link
Turn deck lights off during night-time setting of longlines to reduce bycatch Action Link	Unknown effectiveness (limited evidence)	1	Synopsis Link
Tow buoys behind longlining boats to reduce seabird bycatch Action Link	No evidence found (no assessment)	0	Synopsis Link