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Providing evidence to improve practice

Action: Use high-visibility mesh on gillnets to reduce seabird bycatch Bird Conservation

Key messages

Read our guidance on Key messages before continuing

  • A repeated, randomised and controlled trial in the USA found that having gillnets made partially from high-visibility mesh was effective in reducing seabird bycatch.
  • Having a greater percentage (25% vs. 10%) of the net made from high-visibility mesh was more effective, but also reduced catch of the target species.


Supporting evidence from individual studies


A repeated, randomised and controlled trial in a drift gillnet fishery in North Puget Sound, Washington, USA, in July- August 1996 (Melvin et al. 1999), found that nets fitted with highly visible mesh in the top 25% caught significantly fewer common guillemots (common murres) Uria aalge and rhinoceros auklets Cerorhinca monocerata than control nets (guillemots: 0.37 vs. 0.6 entanglements/net; auklets: approximately 0.05 vs. 0.2 entanglements/net). Nets fitted with highly visible mesh in the top 10% caught significantly fewer guillemots than controls (0.32 vs. 0.6 entanglements/net), but there was no significant change in the number of auklets caught. Nets with 25% high visibility mesh also caught significantly fewer sockeye salmon Oncorhynchus nerka, the target species, compared to controls (10 vs. 36 entanglements/net). A total of eight boats and 482 net sets were studied.


Referenced papers

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. (2019) Bird Conservation. Pages 141-290 in: W.J. Sutherland, L.V. Dicks, N. Ockendon, S.O. Petrovan & R.K. Smith (eds) What Works in Conservation 2019. Open Book Publishers, Cambridge, UK.