Effect of Bait Type and Bait Size on Catch Efficiency in the European Hake Merluccius merluccius Longline Fishery

Manu Sistiaga,Bent Herrmann,Ivan Tatone,Lasse Rindahl

doi:10.1002/mcf2.10007

Manu Sistiaga, Bent Herrmann + Show 2 more

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https://doi.org/10.1002/mcf2.10007

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Abstract

AbstractWe investigated the effect of bait type and bait size on the catch efficiency of a demersal longline fishery targeting European Hake Merluccius merluccius in the North Sea. Automation of the labor‐intensive processes onboard fishing vessels requires finding alternatives to the traditional bait used in the fishery (i.e., whole European Pilchard Sardina pilchardus). Of the six alternative baits investigated, four resulted in significant reductions in catch efficiency ranging from 32% to 90%. Only chopped Atlantic Herring Clupea harengus was a reasonable alternative bait, with an estimated non‐significant loss of only 2.12% in European Hake catch efficiency. Our results demonstrated that choice of bait type and size can affect the catch efficiency 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 fish size when inferring the effect of bait choice on the catch efficiency of longline fisheries.

Highlights

Longlining is a widely used passive fishing method that fishing gears, such as trawls and seines, the effectiveness of is efficient and selective and can catch top-quality fish a longline depends on both the construction of the gear (Løkkeborg et al 2010)
The current study addresses the following questions: (1) “Would the catch efficiency of the Spanish longline fishery change if the bait was changed to comply with automation?”; (2) “If the catch efficiency is different, which of the different bait types would perform best compared to the currently used bait in the fishery?”; and (3) “If the catch efficiency differs among the baits, is this difference dependent on the size of European Hake?”
Catch Efficiency of Alternative Bait Types To evaluate the potential differences in catch efficiency between whole sardine and the six alternative baits tested, a comparison of the captured size distributions of European Hake, the length-dependent catch comparison, and catch ratio rates were estimated and plotted for each of the six cases (Figures 4–6)

Summary

Introduction

Longlining is a widely used passive fishing method that fishing gears, such as trawls and seines, the effectiveness of is efficient and selective and can catch top-quality fish a longline depends on both the construction of the gear (Løkkeborg et al 2010). The Spanish artisanal longline fishery as well as many other fisheries along the EU coast have traditionally used whole European Pilchard Sardina pilchardus (hereafter, sardine) as bait (Figure 1) This bait has been used effectively for generations to catch European Hake; fishermen are skeptical about using alternative baits. Atlantic Mackerel Scomber scombrus (hereafter, mackerel), and squid Loligo spp. are the most commonly used baits in the North Atlantic longline fisheries (Foster et al 2012; Santos et al 2012) Because these baits can all be used in automatic baiting machines, they are potential alternatives to whole sardine in the Spanish longline fishery. There is a need for alternative bait species with properties such as good hook holding, odor, and firmness that would make them attractive for use in longline fisheries (Løkkeborg et al 2014). Efforts to produce artificial baits based on surplus products have not yet been able to provide the necessary effectiveness in the fisheries where they have been tested (Løkkeborg 1990, 1991; Januma et al 2003)

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