School of Life and Environmental Sciences, Deakin University, 221 Burwood Highway, Burwood, VIC, 3125, Australia.
Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, TAS, 7001, Australia.
Sci Rep. 2024 Nov 6;14(1):26982. doi: 10.1038/s41598-024-78643-5.
Determining the factors influencing habitat selection and hunting success in top predators is crucial for understanding how these species may respond to environmental changes. For marine top predators, such factors have been documented in pelagic foragers, with habitat use and hunting success being linked to chlorophyll-a concentrations, sea surface temperature and light conditions. In contrast, little is known about the determinants of benthic marine predators. The Australian fur seal (Arctocephalus pusillus doriferus) is a benthic-diving forager that has a breeding and foraging distribution largely restricted to Bass Strait, the shallow (max. depth 80 m) continental shelf region between the Australian mainland and Tasmania. The species forages mostly on benthic prey and represents the greatest resident marine predator biomass in south-eastern Australia. The region is also one of the world's fastest-warming marine areas and oceanographic changes are influencing shifts in prey distribution and abundance. In the present study, GPS-derived locations of benthic dives (n = 288,449) and dive behaviour metrics were used to determine seafloor habitat selection and factors influencing hunting success in 113 lactating adult females from Kanowna Island during the winters of 2006-2021. Individuals non-randomly selected foraging habitats comprised of deeper, steeper sloped, muddy-sandy areas with less gravel and highly disturbed regions (P < 0.01). Hunting success was greatest in shallower rocky reefs (< 30 m) and deep areas (> 40 m) characterised by moderate presence of gravel (25-50%) and substantial rock composition (50-75%) on the seabed. These findings suggest that habitat use and hunting success in adult female Australian fur seals could be impacted by predicted oceanographic changes, such as rising temperature, altered currents and waves which may modify seafloor characteristics and benthic communities.
确定影响顶级捕食者栖息地选择和狩猎成功率的因素对于了解这些物种如何应对环境变化至关重要。对于海洋顶级捕食者，已在远洋觅食者中记录了这些因素，其栖息地利用和狩猎成功率与叶绿素-a 浓度、海面温度和光照条件有关。相比之下，对于底栖海洋捕食者的决定因素知之甚少。澳大利亚毛皮海豹（Arctocephalus pusillus doriferus）是一种底栖潜水觅食者，其繁殖和觅食分布主要局限于巴斯海峡，这是澳大利亚大陆和塔斯马尼亚之间浅海（最大深度 80 米）大陆架区域。该物种主要以底栖猎物为食，是澳大利亚东南部最大的常驻海洋捕食者生物量代表。该地区也是世界上变暖最快的海洋地区之一，海洋变化正在影响猎物分布和丰度的变化。在本研究中，使用 GPS 生成的底栖潜水（n = 288,449）位置和潜水行为指标，确定了 2006-2021 年冬季在卡诺纳岛的 113 只哺乳期成年雌性的海底栖息地选择和影响狩猎成功率的因素。个体非随机选择的觅食栖息地包括更深、坡度更大、泥泞-沙质地区，砾石较少，高度受干扰的区域（P < 0.01）。在较浅的岩石礁（<30 米）和较深的区域（>40 米），狩猎成功率最高，这些区域的砾石（25-50%）和岩石组成（50-75%）适中。这些发现表明，海洋学变化（如温度升高、洋流和海浪改变）可能会改变海底特征和底栖群落，从而影响成年雌性澳大利亚毛皮海豹的栖息地利用和狩猎成功率。
