Barium sulphate modified fishing gear as a mitigative measure for cetacean incidental mortalities

Published source details Trippel E.A., Holy N.L. & Shepherd T.D. (2009) Barium sulphate modified fishing gear as a mitigative measure for cetacean incidental mortalities. Journal of Cetacean Research and Management, 10, 235-246.
Share Tweet Email

This study is summarised as evidence for the following.

	Action	Category
	Use acoustically reflective fishing gear materials Action Link

Use acoustically reflective fishing gear materials

A controlled study in 1998 and 2000–2001 of a pelagic area in the Bay of Fundy, Canada (Trippel et al. 2009) found that fishing nets made from an acoustically reflective material (barium sulfate) had fewer harbour porpoise Phocoena phocoena entanglements than conventional nets. Entanglement rates of harbour porpoises were lower in barium sulfate nets than in conventional nets (data reported as statistical model results). For target fish species, catch rates of haddock Melanogrammus aeglefinus were lower in barium sulphate nets than conventional nets, but catches of Atlantic cod Gadus morhua, pollock Pollachius virens and spiny dog fish Squalus acanthias were similar (see original paper for data). In July–September 1998, 2000 and 2001, gill net fishery vessels deployed a total of 590 strings of barium sulfate nets and 815 strings of conventional nets. Barium sulfate nets were made from nylon containing particles of barium sulfate (3% volume, 10% weight) and dyed pale blue. Conventional nets were transparent nylon. All nets (300 m long, 4 m deep, stretched mesh size of 15 cm) were deployed at depths of 60 m for 24 h (same study site and nets as Cox & Read 2004). Onboard observers or fishers recorded porpoise entanglements and fish catches as the nets were hauled.

(Summarised by: Anna Berthinussen)