Effect of Bait Type and Bait Size on Catch Efficiency in the European Hake Merluccius merluccius Longline Fishery
We investigated the effect of bait type and bait size on the catch ef fi ciency of a demersal longline fi shery targeting European Hake Merluccius merluccius in the North Sea. Automation of the labor-intensive processes onboard fi shing vessels requires fi nding alternatives to the traditional bait used in the fi shery (i.e., whole European Pilchard Sardina pilchardus ). Of the six alternative baits investigated, four resulted in signi fi cant reductions in catch ef fi ciency ranging from 32% to 90%. Only chopped Atlantic Herring Clupea harengus was a reasonable alternative bait, with an esti- mated non-signi fi cant loss of only 2.12% in European Hake catch ef fi ciency. Our results demonstrated that choice of bait type and size can affect the catch ef fi ciency of different sizes of European Hake. Thus, the choice of bait may also affect the size distribution of the catch. The latter highlights the importance of considering fi sh size when infer- ring the effect of bait choice on the catch ef fi ciency of longline fi sheries.