Search The Database

The authors assessed accurate reporting of seabird bycatch in the Greenland halibut (Reinhardtius hippoglossoides) fishery in northern Canada. The amount of bird bycatch reported by at-sea observers and carcass collections yielded different (0.5-11-fold higher) results from that of the at-sea observers database. This highlights huge discrepancies in methods which suggest that seabird bycatch data is not accurate.

The authors assessed accurate reporting of seabird bycatch in the Greenland halibut (Reinhardtius hippoglossoides) fishery in northern Canada. The amount of bird bycatch reported by at-sea observers and carcass collections yielded different (0.5-11-fold higher) results from that of the at-sea observers database. This highlights huge discrepancies in methods which suggest that seabird bycatch data is not accurate.

The study tested the effect of Lumo Leads on seabird bycatch and catch rates in the Korean tuna longline fleet. Lumo Leads (previously called "safe leads") add weight to longlines by threading the line through a channel, rather than crimping to the line. This can reduce flyback speed and improve crew safety. Lumo Leads also provide protection from exposure to lead weights, and contain optional fluorescent dye to provide an alternative to single-use glow sticks or electric lights.  Unweighted branch lines caught more than twice the number of seabirds compared to weighted branch lines, although branch weighting alone was not able to completely reduce bycatch. Adding more weight and placing weights closer to the hook increased branch weighting effectiveness as a bycatch mitigation technique. However, catch rate for albacore tuna on weighted lines was significantly lower than on unweighted lines. Catch rate also decreased as weight of the leads increased. There was no effect of branch weighting on catch rates for southern bluefin tuna or yellowfin tuna. 

Time-depth recorders paired with geolocation sensors or GPS loggers in Aotearoa, New Zealand were used to quantify the diving ecology of three Procellaria petrel species. All three species dove faster than the current best-practice longline sink rate of 0.5 meters/second, highlighting that the risk of interaction with these species is still present. There were also significant differences in diving behavior among and within species, including diurnal trends, sex-specific differences, and for black (P. parkinsoni) and Westland petrels (P. westlandica), changes in diving behavior across the breeding period. These results highlight the necessity of ensuring that bycatch mitigation methods take the strong diving capabilities of these three species into account. This includes night setting when many seabirds are less active and when dives are shallower, use of tori lines for smaller vessels, and a 20m threshold for hook-shielding or bait-setting devices (or combining these devices with bird-scaring devices and/or additional weighted branch lines to protect hooks to 20m). Furthermore, it can be beneficial for custom/target-specific bycatch mitigation methods being developed to take into account the necessary ecological context.