Reduction of harbour porpoise (Phocoena phocoena) bycatch by iron-oxide gillnets

Harbour porpoise bycatch was significantly lower (p<0.01) in high-denisty Iron Oxide (IO) gill nets compared to control nets. There was no significant difference in the acoustic target strength of the IO and control nets, and both nets behaved similarly in flume tank tests. The authors conclude the reduction of harbour porpoise bycatch in the IO nets was a result of the mechanical properties of the nets.
Field Studies:

Location	Fishing gear	Reduction technique	Bycatch species	Effect on bycatch species	Catch	Effect on target catch	Type
Danish North Sea	Gillnets	Metal oxide/barium sulfate nets	Large Cetaceans (maximum length > 7.5 meters)	Reduced harbour porpoise bycatch	Cod	Reduced by 30%	In the wild