Laboratory investigations into alternative baits for the channeled whelk (Busycotypus canaliculatus) fishery

Abstract

Channeled whelks (Busycotypus canaliculatus) are fished along the eastern US coast using traps typically baited with pieces of female horseshoe crabs (HSC; Limulus polyphemus). However, the use of HSC as bait, particularly females, is controversial because they are already heavily fished because their blood contains a substance that the biomedical industry uses to manufacture a test for pathogenic bacteria. Therefore, the goals of this study were to: 1) develop a cost-effective alternative bait that does not rely on HSCs and 2) determine whether whelk are more attracted to female HSC pieces than male HSC pieces. Seventeen different baits were tested in a total of 209 laboratory bait trials over a total of 5496 h. Whelk attraction to bait was measured by using time-lapse video to quantify the amount of time a whelk interacted with a bait bag containing one of the baits. While whelks were attracted to many of the alternative baits tested, those containing surf clam and green crab parts, were the most attractive. One such alternative bait composed of green crabs and clam bellies (60 GC/40 CBel Mix) resulted in greater whelk interaction than female HSC Prosoma did over a 24 hr period (mean ± SEM whelk interaction time: 60 GC/40 CBel Mix, 9.31 ± 0.52 hrs; female HSC Prosoma, 8.4 ± 4.6 hrs). We also found that male HSC pieces were as attractive to whelks as female HSC pieces, indicating that it may be possible to reduce fishing pressure on female HSCs to aid in conservation of the species. Field testing of these alternative baits is currently underway to determine whether these laboratory findings successfully translate to commercial fishing operations.