Novel approaches to line-weighting in New Zealand’s inshore surface-longline fishery

Globally, there is ongoing research into new measures to reduce seabird bycatch in surface-longline fisheries. Improved safety is a key component of the development of some of these measures. In this project, we trialled four devices intended to reduce the risk of seabird bycatch in surface-longline fisheries. These devices were (i) safe leads, weighing 60 g and comprising two lead pellets secured with O-rings around a rubber core, through which the monofilament snood passes, (ii) luminous plastic-covered “lumo” leads, weighing 40 g (iii) lumo leads weighing 60 g, respectively comprising a partly or fully lead-filled tapered plastic cylinder which attaches to longline snoods via a screw cap, and (iv) hook pods, which completely enclose longline hooks during setting until the fishing depth is reached. Safe leads and lumo leads are designed to move on snoods when monofilament stretches, and tension is suddenly released. This situation can arise during longline hauling, and the movement of the weights is designed to reduce the potentially dangerous recoil resulting in a weight flying back towards the vessel. Hook pods also move on the snood, though less readily than the other weight types.