Diving is an ecologically important behaviour that provides air-breathing predators with opportunities to capture prey, but that also increases their exposure to incidental mortality (bycatch) in commercial fisheries. In this study, we characterised the diving behaviour of 26 individuals of three species, the black-browed albatross Thalassarche melanophris, grey-headed albatross T. chrysostoma and light-mantled albatross Phoebetria palpebrata, breeding at Bird Island, South Georgia. Individuals were tracked using Global Location Sensor (GLS)-immersion loggers and time-depth recorders (TDRs) and, for two species, Global Positioning System (GPS) loggers. Although the TDRs recorded 589 dives (defined in this paper as submersion > 1 m), average dive depths and durations were just 1.30–1.49 m and 2.5–3.3 s, respectively, for the three species. In addition, many individuals (22% of black-browed, 20% of grey-headed, and 57% of light-mantled albatrosses; total n = 9, 10 and 7 individuals, respectively) did not dive at all. Most dives occurred at the distal end of foraging trips and were rare during the commuting phase. No dives took place in darkness, despite long periods spent on water at night. The limited and shallow dive activity contrasts with impressions from a previous study using capillary-tube depth gauges (which are less accurate than TDRs) and has implications for the susceptibility of albatrosses to bycatch on longlines. This study provides further support for regulations requiring night setting and increased sink rates of baited hooks to help mitigate albatross bycatch.

潜水是一种生态学上重要的行为，它为呼吸掠食性动物提供了捕获猎物的机会，但同时也增加了其在商业渔业中遭受偶发性死亡（兼捕）的风险。在这项研究中，我们表征了三种物种的26个个体的潜水行为，即黑眉信天翁Thalassarche melanophris，灰头信天翁T. chrysostoma和轻型信天翁Phoebetria palpebrata，在南乔治亚州伯德岛繁殖。使用全球位置传感器（GLS）浸入式记录仪和时间深度记录仪（TDR）以及两个物种的全球定位系统（GPS）记录仪对个体进行跟踪。尽管TDR记录了589次潜水（在本文中定义为淹没> 1 m），但是这三个物种的平均潜水深度和持续时间分别仅为1.30–1.49 m和2.5–3.3 s。此外，许多人（22％的黑眉，20％的灰发和57％的轻巧信天翁；总计n 分别是9、10和7个人）完全没有潜水。大多数潜水发生在觅食旅行的末端，在通勤期间很少见。尽管晚上长时间在水上闲逛，但在黑暗中没有潜水。潜水活动有限且浅浅，与之前使用毛细管深度计（比TDR精度低）的研究印象相反，并且对信天翁延绳钓副产品的敏感性也有影响。这项研究为需要夜间设置和增加带饵钩的下沉率的法规提供了进一步的支持，以帮助减轻信天翁的兼捕。