Which baits for attracting black seabream (Spondyliosoma cantharus) in fish traps?

The pressure that fishing exerts on marine ecosystems is of increasing concern worldwide. When deployed in compliance with appropriate technical regulations, the use of passive baited gear such as traps is a selective and low-impact fishing technique that can contribute to the sustainable exploitation of marine resources. In the case of traps or lines, the choice of bait might further increase the selectivity of the gear, particularly when the decision is based on the feeding preferences of the target species. In the present study, we investigate the effectiveness of different types of bait in attracting black seabream (Spondyliosoma cantharus), a commercially valuable fish with healthy populations in the Bay of Biscay (France). Specifically, we deployed a baited underwater video camera devoid of trap gear to identify the preferred bait among 10 options selected based on a review of the literature and interviews with recreational and professional fishermen. Because the performance (attractiveness) of a bait might vary depending on how it is assessed, we calculated and compared three indicators to describe the behavior of black seabream in relation to each bait: the number of fish per hour that exhibited Interest or Baited behaviors, with the latter being characterized by an attempt to eat the bait; the amount of time these fish spent in the vicinity of the bait (referred to as time of residence); and the probability that a fish that entered the view of the camera would exhibit Baited behavior (referred to as Baited probability). Cockles were associated with the longest time of residence of Baited fish and presented the highest Baited probability. Lugworm presented the highest time of residence for Interested fish, but the lowest Baited probability. More generally, all baits except an artificial lure demonstrated an ability to attract black seabream, but this tended to decrease with soaking time. The complementarity of the indicators used is discussed, as well as the application of our results to the development of passive baited gear such as fish traps targeting black seabream.