Murray Taryn S, Elston Chantel, Smale Malcolm J, Childs Amber-Robyn, Dicken Matthew L, Cowley Paul D
South African Institute for Aquatic Biodiversity, Makhanda, South Africa.
Port Elizabeth Museum at Bayworld, Gqeberha, South Africa.
J Fish Biol. 2025 May;106(5):1452-1466. doi: 10.1111/jfb.15781. Epub 2024 May 9.
Marine predators are vital to the healthy functioning of coastal ecosystems, but to understand their roles, it is necessary to elucidate their movement ecology, particularly in relation to one another. A decade's worth of acoustic telemetry data (2011-2020) from Algoa Bay, South Africa, was investigated to determine how two mesopredatory species (teleosts: dusky kob Argyrosomus japonicus, n = 11, and leervis Lichia amia, n = 16) and two top predatory species (sharks: ragged-tooth sharks Carcharias taurus, n = 45, and white sharks Carcharodon carcharias, n = 31) used and shared this bay ecosystem. Multi-annual seasonal fidelity to the bay was exhibited by all species, but differences in residency were observed among species. Similarly, species used space in the bay differently-the teleosts moved less and had movements restricted to the central and western inshore regions of the bay. Conversely, the sharks roamed more, but detections were concentrated in the western part of the bay for C. taurus and in the eastern part of the bay for C. carcharias. Social network analysis showed that species segregated in space and time on a fine scale. However, there was some interaction observed between C. taurus, L. amia, and A. japonicus, but to varying degrees. This is likely because of strong habitat preferences exhibited by each species and predator-prey relationships between these predatory guilds. Results highlight that the sheltered marine Algoa Bay is a resource-rich environment, supporting multiple predators with different hunting strategies albeit similar prey preferences. Finally, these species are likely afforded some protection by the current Greater Addo Elephant National Park Marine Protected Area in the bay but are vulnerable to fishing pressure when they leave this ecosystem.
海洋捕食者对于沿海生态系统的健康运转至关重要，但要了解它们的作用，有必要阐明它们的运动生态学，尤其是相互之间的关系。研究了来自南非阿尔戈阿湾长达十年（2011 - 2020年）的声学遥测数据，以确定两种中型捕食者物种（硬骨鱼：暗纹石首鱼Argyrosomus japonicus，n = 11，和六带鲹Lichia amia，n = 16）以及两种顶级捕食者物种（鲨鱼：沙虎鲨Carcharias taurus，n = 45，和大白鲨Carcharodon carcharias，n = 31）如何利用和共享这个海湾生态系统。所有物种都表现出对该海湾多年的季节性忠诚度，但不同物种之间在居留情况上存在差异。同样，不同物种在海湾中利用空间的方式也不同——硬骨鱼移动较少，活动范围局限于海湾中部和西部的近岸区域。相反，鲨鱼活动范围更广，但沙虎鲨的探测集中在海湾西部，大白鲨的探测集中在海湾东部。社会网络分析表明，物种在空间和时间上存在细微的隔离。然而，观察到沙虎鲨、六带鲹和暗纹石首鱼之间存在一定程度的相互作用，但程度各异。这可能是因为每个物种都表现出强烈的栖息地偏好以及这些捕食者群体之间的捕食者 - 猎物关系。结果表明，受庇护的阿尔戈阿湾海洋环境资源丰富，尽管猎物偏好相似，但支持多种具有不同狩猎策略的捕食者。最后，这些物种目前可能受到海湾中更大的阿多大象国家公园海洋保护区的一定保护，但当它们离开这个生态系统时，容易受到捕捞压力的影响。
