Lessons from seabird conservation in Alaskan longline fisheries

• Published in: Conservation biology 2019-08, Vol.33 (4), p.842-852
• Main Authors: Melvin, Edward F., Dietrich, Kimberly S., Suryan, Robert M., Fitzgerald, Shannon M.
• Format: Article
• Language: English
• Subjects: Animals; Aquatic birds; best practice mitigation; Best practices; bird scaring lines; Birds; Bycatch; captura accesoria de aves marinas; case history; Catch per unit effort; Conservation; Conservation of Natural Resources; Contributed Paper; Contributed Papers; Demersal fisheries; demersal longline fisheries; Fish; Fisheries; Fishery data; fishery specific solutions; Fishes; Fishing lines; Fulmarus glacialis; historia de caso; Longline fishing; líneas espanta aves; Marinas; mitigación de mejor práctica; Models, Statistical; Mortality; night setting; Observers; pesquerías demersales con palangre; puesta nocturna; Rare species; seabird bycatch; Seabirds; soluciones específicas por pesquería; Vigilance; Wildlife conservation; 减缓影响的最佳实践; 历史案例; 夜间布设钓竿; 底层延绳钓渔场; 海鸟兼捕; 渔场特异的解决方案; 鸟类警戒线
• ISSN: 0888-8892; 1523-1739
• DOI: 10.1111/cobi.13288

Although bycatch of seabirds and other long‐lived species is a critical conservation issue in world fisheries, case studies documenting significant reductions in the mortality of these low‐productivity species in a fishery are rare. We studied progress toward seabird conservation in the Alaskan longline fisheries, one of the largest and most diverse demersal fisheries. We generated annual seabird bycatch rates in 4 target fisheries and all fisheries combined from 23 years of fisheries observer data. We used 0‐inflated negative binomial models to evaluate variables influencing seabird bycatch per unit effort (BPUE) in 2 target fisheries. Following adoption of streamer lines, at first voluntarily and then mandatorily, seabird BPUE was reduced by 77–90%, preventing mortality of thousands of birds per year. Despite this, BPUE increased significantly in 2 of 4 target fisheries since streamer lines were adopted. Although night setting yielded significant reductions (74–97%) in seabird BPUE and significant increases (7–11%) in fish catch per unit effort over daytime setting, nighttime setting increased the BPUE of Northern Fulmar (Fulmarus glacialis) by 40% and nontarget fish species by 5–17%. Thus, best practices to prevent seabird mortalities in longline fisheries varied by species assemblage and fishery. Our results inform global efforts toward fisheries bycatch reduction by illustrating that successful conservation requires fishery‐specific solutions, strong industry support, constant vigilance in analysis and reporting observer data, and ongoing outreach to fleets, especially to vessels with anomalously high BPUE. Aprendizajes de la Conservación de Aves Marinas en las Pesquerías con Palangre de Alaska Melvin Resumen Aunque la captura accesoria de aves marinas y otras especies con ciclos de vida largos es un asunto de importancia para la conservación en las pesquerías a nivel global, son raros los estudios de caso que documentan las reducciones significativas de la mortalidad de estas especies de baja productividad en las pesquerías. Estudiamos el progreso hacia la conservación de aves marinas en las pesquerías con palangre en Alaska, una de las pesquerías demersales más grandes y con mayor diversidad. Generamos tasas anuales de capturas accesorias de aves marinas para cuatro pesquerías y todas las pesquerías combinadas a partir de 23 años de datos de observación de pesquerías. Usamos modelos binomiales negativos con inflación 0 para evaluar las variables que