Triennial migration and philopatry in the critically endangered soupfin shark (Galeorhinus galeus)

Globally, one-quarter of shark and ray species is threatened with extinction due to overfishing. Effective conservation and management can facilitate population recoveries; however, these efforts depend on robust data on movement patterns and stock structure, which are lacking for many threatened species, including the Critically Endangered soupfin shark (Galeorhinus galeus), a circumglobal coastal-pelagic species. Using passive acoustic telemetry, we continuously tracked 34 mature female soupfin sharks, surgically implanted with coded acoustic transmitters, for seven years via 337 underwater acoustic receivers stationed along the west coast of North America. These sharks and an additional six were also externally fitted with spaghetti identification tags. Our tagging site was a shallow rocky reef off La Jolla (San Diego County), California, USA, where adult females were observed to aggregate every summer. Tagged soupfin sharks were highly migratory along the west coast of North A...全球范围内，四分之一的鲨鱼和鳐鱼物种因过度捕捞面临灭绝威胁。有效的保护与管理可助力种群恢复，但此类举措依赖于关于物种移动模式与种群结构的可靠数据，而包括极危（Critically Endangered）翅鲨（Galeorhinus galeus）在内的诸多受威胁物种均缺乏此类数据；翅鲨为环全球近岸远洋物种。 本研究采用被动声学遥测（passive acoustic telemetry）技术，通过部署在北美西海岸的337台水下声学接收器，对34条经手术植入编码声学发射器的成熟雌性翅鲨开展了长达7年的连续追踪。此外，这34条个体及另外6条个体还被体外安装了spaghetti识别标签（spaghetti identification tags）。本研究的标记位点位于美国加利福尼亚州圣迭戈县拉霍亚附近的浅海岩礁，观测显示成年雌性翅鲨每年夏季都会在此聚集。 被标记的翅鲨沿北美西海岸具有高度洄游性……