Trevail Alice M, Nicoll Malcolm A C, Freeman Robin, Le Corre Matthieu, Schwarz Jill, Jaeger Audrey, Bretagnolle Vincent, Calabrese Licia, Feare Chris, Lebarbenchon Camille, Norris Ken, Orlowski Sabine, Pinet Patrick, Plot Virginie, Rocamora Gerard, Shah Nirmal, Votier Stephen C
Environment and Sustainability Institute, University of Exeter, Penryn TR10 9FE, UK.
Institute of Zoology, Zoological Society of London, Regent's Park, London NW14RY, UK.
Curr Biol. 2023 Dec 4;33(23):5247-5256.e4. doi: 10.1016/j.cub.2023.10.060. Epub 2023 Nov 15.
Understanding marine predator distributions is an essential component of arresting their catastrophic declines. In temperate, polar, and upwelling seas, predictable oceanographic features can aggregate migratory predators, which benefit from site-based protection. In more oligotrophic tropical waters, however, it is unclear whether environmental conditions create similar multi-species hotspots. We track the non-breeding movements and habitat preferences of a tropical seabird assemblage (n = 348 individuals, 9 species, and 10 colonies in the western Indian Ocean), which supports globally important biodiversity. We mapped species richness from tracked populations and then predicted the same diversity measure for all known Indian Ocean colonies. Most species had large non-breeding ranges, low or variable residency patterns, and specific habitat preferences. This in turn revealed that maximum species richness covered >3.9 million km, with no focused aggregations, in stark contrast to large-scale tracking studies in all other ocean basins. High species richness was captured by existing marine protected areas (MPAs) in the region; however, most occurred in the unprotected high seas beyond national jurisdictions. Seabirds experience cumulative anthropogenic impacts and high mortality during non-breeding. Therefore, our results suggest that seabird conservation in the tropical Indian Ocean requires an ocean-wide perspective, including high seas legislation. As restoration actions improve the outlook for tropical seabirds on land and environmental change reshapes the habitats that support them at sea, appropriate marine conservation will be crucial for their long-term recovery and whole ecosystem restoration.
了解海洋捕食者的分布是阻止它们灾难性减少的重要组成部分。在温带、极地和上升流海域，可预测的海洋学特征能够聚集洄游性捕食者，这些捕食者受益于基于地点的保护。然而，在营养更为贫瘠的热带水域，尚不清楚环境条件是否会形成类似的多物种热点区域。我们追踪了一个热带海鸟群落（共348只个体，9个物种，分布于印度洋西部的10个鸟群）的非繁殖期活动和栖息地偏好，该群落拥有具有全球重要意义的生物多样性。我们绘制了追踪种群的物种丰富度图，然后预测了所有已知印度洋鸟群的相同多样性指标。大多数物种具有较大的非繁殖范围、低或可变的居留模式以及特定的栖息地偏好。这进而表明，最大物种丰富度覆盖范围超过390万平方公里，且没有集中聚集现象，这与其他所有大洋盆地的大规模追踪研究形成鲜明对比。该区域现有的海洋保护区捕获了较高的物种丰富度；然而，大多数物种丰富度出现在国家管辖范围之外的未受保护的公海区域。海鸟在非繁殖期会经历累积的人为影响和高死亡率。因此，我们的研究结果表明，热带印度洋的海鸟保护需要从全海洋角度出发，包括制定公海法规。随着恢复行动改善热带海鸟在陆地上的前景，以及环境变化重塑它们在海上的栖息地，适当的海洋保护对于它们的长期恢复和整个生态系统的恢复至关重要。
